Ophthalmology

Pupil

Neuro-ophthalmology Question of the Week: Aberrant Regeneration of the 3rd Nerve

Question:

Which of the following are correct?

1. The pupil may be the only sign of aberrant regeneration of the third nerve.
2. The upper lid may be the only sign of aberrant regeneration of the third nerve.

3. Both, the pupil and the upper lid are always involved in a case of aberrant regeneration of the third nerve.

4. In a case of aberrant regeneration of third nerve, the pupil of the affected eye may constrict on attempted elevation, and/or depression and or adduction.
5. In a case of aberrant regeneration of third nerve, the upper lid of the affected eye may elevate on attempted infraduction, adduction and/or accommodation.
6. In a case of aberrant regeneration of third nerve, anisocoria may increase on attempted accommodation.

Case 642


__________________________________________________


Correct Answers: All are correct, except 3. The the pupil and the upper lid are both always involved in a case of aberrant regeneration of the third nerve.


Explanation:

1


Case 642

Image: Aberrant Regeneration of Third Nerve

There is elevation of the left eyelid on right gaze, down gaze.


The key clinical finding of aberrant regeneration of the third nerve is over action of one of the muscle it innervates with attempts to perform one of the functions of the third cranial nerve (elevation, depression,  adduction, convergence or accommodation).

Typical positive findings include:

1. the pupil of the affected eye constricts on attempted elevation, depression, or adduction of the eye,

2. the eyelid of the affected eye elevates on attempted depression, adduction, convergence or accommodation.


In a review of “39 cases and looked for any signs of aberrant regeneration in either the pupil, the lid or motility. In about 78% of cases, he found some aberrant regeneration of the pupil. The pupil got smaller on adduction in some cases, or smaller on infraductions or supraductions or smaller with a combination.

The lid was involved in about 77% of cases, and motility in about 33%. These cases overlapped — 56% involved both the pupil and lid, and 25% involved the pupil, lid and motility.”1  


Pearls for examination & diagnosis of 3rd nerve aberrant regeneration1

Dr. Kardon looks at one organ at a time — pupil, lid or globe. Dr. Kardon looks first at the patient’s pupil in every direction of gaze and in combination. Some of the signs are subtle.

“The most common way to miss it is to try to look for everything (lid, eye movement, pupil) at once,” he said. “You’ll miss it every time because your attention is too spread out.”

Also, the amount of misdirection or regeneration is always proportional to the loss of function. Misdirection of the iris sphincter should reveal a proportional loss of the normal light reflex.

The misdirection is often segmental. Slit lamp exams will show that segments of the pupil are contracting with different eye movements. The entire pupil may not move at once.

The pupil may be the only sign of misdirection syndrome. In 20% of patients, Dr. Kardon saw that motility recovered completely and lid re-innervation was normal. The pupil was the only sign.

Finally, re-innervation of the iris sphincter may come not just from the extraocular muscle nerves, but also from accommodative nerves.

As a result of these observations, Dr. Kardon follows several rules for diagnosing oculomotor nerve aberrant regeneration:

  • Observe the pupils in bright and dim light for anisocoria.

  • Put the normal iris sphincter innervation to rest by observing the pupils in dim light.

  • Constriction of the pupil in a certain gaze position should be reproducible and repeatable for every observation.

  • Look for an abnormal near constriction of the pupil. Sometimes misdirected accommodative fibers are the culprit.

  • Segmental iris contraction on gaze or accommodation may be overlooked without slit lamp magnification.

  • Adie’s pupil may be the most common example of a misdirection syndrome of the iris sphincter.



References:
1. Warning signs reveal aberrant nerve regeneration. Pupil dysfunctions and misdirection syndromes show when nerve endings re-innervated incorrectly. Kardon RH . Ocular Surgery News U.S. Edition, June 15, 2000.
2. CASE 64: Third nerve palsy with aberrant regeneration. CyberSight http://www.cybersight.org/bins/volume_page.asp?cid=1-2161-2379-2435-2504

 

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Neuro-ophthalmology Question of the Week: Guillain-Barré Syndrome Findings

Figure 1. Contrast-enhanced 3-D MRI in Miller Fisher syndrome
A and B show a Gd-enhancement of the right abducens nerve (arrows), and D shows the enhancing right oculomotor nerve (arrow). The intensity of the right abducens nerve (A) is markedly decreased after symptomatic improvement (C).1


Question:

Which of the following are features of the Guillain-Barré syndrome?

1. Progressive, fairly symmetric muscle weakness
2. Absent or depressed deep tendon reflexes
3. The weakness varies from mild difficulty with walking to nearly complete paralysis of all extremity, facial, respiratory, and bulbar muscles.
4. Severe respiratory muscle weakness necessitating ventilatory support develops in 10 to 30 percent.
5. Oculomotor weakness occurs in about 15 percent of patients.
6. Paresthesias in the hands and feet accompany the weakness in more than 80 percent of patients.
7. Dysautonomia occurs in 70 percent of patients.
8. The typical presentation of the Miller Fisher syndrome ( a variant of Guillain-Barré syndrome) includes ophthalmoplegia with ataxia and areflexia.
9. Antibodies against GQ1b (a ganglioside component of nerve) are present in 85 to 90 percent of patients with Miller Fisher syndrome.
10. Light-near dissociation is frequently seen in the Miller Fisher syndrome.

_________________________________________________________________


Figure 1. On the 3rd day of hospitalization, both pupils were dilated and ocular motor examination revealed bilateral complete limitation of abduction and supraduction and mild limitation of adduction.2


Correct Answers: all are correct


Explanation:

CLINICAL FEATURES — The cardinal clinical features of Guillain-Barré syndrome (GBS) are progressive, fairly symmetric muscle weakness accompanied by absent or depressed deep tendon reflexes. Patients usually present a few days to a week after onset of symptoms. The weakness can vary from mild difficulty with walking to nearly complete paralysis of all extremity, facial, respiratory, and bulbar muscles.


Studies from the United States and Europe, reflecting primarily patients with acute inflammatory demyelinating polyneuropathy (AIDP), show that GBS is associated with the following clinical features [3]:

● Although the weakness usually starts in the legs, it begins in the arms or facial muscles in about 10 percent of patients.

● Severe respiratory muscle weakness necessitating ventilatory support develops in 10 to 30 percent [4].

● Facial weakness occurs in more than 50 percent and oropharyngeal weakness eventually occurs in 50 percent.

● Oculomotor weakness occurs in about 15 percent of patients.

● Paresthesias in the hands and feet accompany the weakness in more than 80 percent of patients, but sensory abnormalities on examination are frequently mild.

● Pain, typically located in the back and extremities, can be a presenting feature and is reported during the acute phase by 66 percent of patients with all forms of GBS [5,6].

● Dysautonomia occurs in 70 percent of patients and manifests as symptoms that include tachycardia (the most common), urinary retention, hypertension alternating with hypotension, orthostatic hypotension, bradycardia, other arrhythmias, ileus, and loss of sweating. Severe autonomic dysfunction is important to recognize since this is occasionally associated with sudden death [7].


Unusual features of GBS include papilledema, facial myokymia, hearing loss, meningeal signs, vocal cord paralysis, mental status changes [8], and the syndrome of inappropriate antidiuretic hormone secretion [9-12]. In addition, posterior reversible encephalopathy syndrome, also known as reversible posterior leukoencephalopathy syndrome (see "Reversible posterior leukoencephalopathy syndrome"), has been associated with GBS in adults and children, likely related to acute hypertension from dysautonomia [13-15].


GBS usually progresses over a period of about two weeks. By four weeks after the initial symptoms, 90 percent of GBS patients have reached the nadir of the disease. Disease progression for more than eight weeks is consistent with the diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).


Miller Fisher syndrome — The typical presentation of MFS is that of ophthalmoplegia with ataxia and areflexia [18,34]. About one-quarter of patients who present with MFS will develop some extremity weakness, clearly linking this disorder to GBS. Incomplete forms include acute ophthalmoplegia without ataxia, and acute ataxic neuropathy without ophthalmoplegia [1,35].


Antibodies against GQ1b (a ganglioside component of nerve) are present in 85 to 90 percent of patients with MFS [36,37]. The GQ1b antibody is strongly associated with involvement of oculomotor nerves and is also found in most patients with prominent oculomotor weakness and GBS.


Clinical neurophysiology studies in patients with MFS reveal reduced or absent sensory responses without slowing of sensory conduction velocities [38]. When there is associated weakness, the motor nerve conduction abnormalities of acute inflammatory demyelinating polyneuropathy may be present.3


Approximately 50% of patients with Fisher's syndrome show involvement of the pupillomotor fibers and present with mydriasis and light-near dissociation and can be supersensitive to cholinergic agents. However, it is uncertain whether this phenomenon is induced by an aberrant reinnervation mechanism as in tonic pupil, or is based on other mechanisms such as those associated with tectal pupils.4


References:

1. Cranial nerve enhancement on three-dimensional MRI in Miller Fisher syndrome. U. Nagaoka, MD, et al. Neurology. 1996: 47: 6. 1601-1602
2. A Case of Anti-GQ1b-Positive Atypical Miller Fisher Syndrome With Pupil Involvement. Ahn JH and Lee SG. Korean Ophthalmol Soc. 2009 Apr;50(4):645-648

3. UpToDate. Clinical features and diagnosis of Guillain-Barré syndrome in adults. Vriesendorp FJ. Literature review current through: July 2015.
4. Mydriasis with light-near dissociation in Fisher's Syndrome. Nitta T1, Kase M, Shinmei Y, Yoshida K, Chin S, Ohno S. Jpn J Ophthalmol. 2007 May-Jun;51(3):224-7.



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Neuro-ophthalmology Question of the Week: 3rd Nerve Palsy

                            Left 3rd Nerve Palsy 8

Question:

Which of the following are correct?

1. The side with a 3rd nerve palsy will have a larger pupil.
2. Anisocoria with a 3rd nerve palsy will be greater in dim light than in bright light.
3. Examination of the pupillary responses to light cannot help detect an optic neuropathy in an eye with a 3rd nerve palsy with complete pupillary dilation.
4. A 3rd nerve palsy with any extraocular motility involvement (complete or partial) with pupillary involvement requires an emergent evaluation to rule-out aneurysm.
5. The presence or absence of pain in a patient is not helpful in establishing the cause of a 3rd nerve palsy.
6. Signs of aberrant regeneration are unlikely in ischemic lesions and suggest the presence of a compressive lesion, including aneurysm.

__________________________________________________


Correct Answers:  

1. The side with a 3rd nerve palsy will have a larger pupil.
4. A 3rd nerve palsy with any extraocular motility involvement (complete or partial) with pupillary involvement requires an emergent evaluation to rule-out aneurysm.
5. The presence or absence of pain in a patient is not helpful in establishing the cause of a 3rd nerve palsy.
6. Signs of aberrant regeneration are unlikely in ischemic lesions and suggest the presence of a compressive lesion, including aneurysm.



Explanation:

1. Parasympathetic innervation leads to pupillary constriction. A circular muscle called the sphincter pupillae accomplishes this task. The fibers of the sphincter pupillae encompass the pupil. The pathway of pupillary constriction begins at the Edinger-Westphal nucleus near the oculomotor nerve nucleus. The fibers enter the orbit with CNIII nerve fibers and ultimately synapse at the ciliary ganglion.1

2. Causes of anisocoria range from benign (normal) to life-threatening conditions. Clinically, it is important to establish whether anisocoria is more apparent in dim or bright light:

  • Anisocoria which is greater in dim light suggests Horner's syndrome or mechanical anisocoria. In Horner's syndrome sympathetic fibers have a defect, therefore the pupil of the involved eye will not dilate in darkness.

  • Anisocoria which is greater in bright light suggests Adie tonic pupil, pharmacologic dilation, Oculomotor nerve palsy, or damaged iris.2

Distinguishing pupillary involvement caused by third cranial nerve lesions from ocular sympathetic palsy (Horner or Claude Bernard syndrome) or physiological anisocoria requires detailed examination of pupil size in dim and in bright, ambient light.

  * With sphincter weakness due to parasympathetic involvement in third cranial nerve lesions, the involved pupil is larger than the fellow pupil.

  * The size difference between the 2 pupils (anisocoria) is greater in bright light (when the sphincter is called upon to act most strongly) and less in dim light (when the sympathetically innervated dilator fibers are the dominant contributors to pupil size). The reverse is true for ocular sympathetic lesions, the pathological pupil is the smaller one and the difference (anisocoria) is greater in dim light than in bright light. The anisocoria remains the same in dim and bright light in simple central anisocoria, also called physiological anisocoria3.

3. Optic neuropathy and complete internal 3rd nerve palsy in the same eye and the swinging flashlight test

Swinging Flashlight test

“The test is positive when the pupil into which the light is shined dilates instead of constricts. If the pupil of the involved eye is non-reactive or non-functional, then observe the fellow, normal eye for a reverse afferent defect (dilation when the light is on the non-reactive eyem and constriction when the light is shined on the reactive eye). A reverse afferent pupillary defect results from a poor consensual pupillary response.”9

In the case of a patient with both optic neuropathy and a 3rd nerve palsy with complete pupillary dilation affecting the same eye, a “reverse” afferent pupillary defect will be found with the swinging flashlight test .
4. Complete internal dysfunction (pupil-involved) third nerve palsy (complete internal & partial external) should be assumed to be due to aneurysmal compression until proven otherwise. Patients should undergo MRI and MRA (or CTA); however, even if the noninvasive study is negative, a catheter angiogram should be strongly considered to exclude aneurysm.
Other patterns of isolated third nerve deficits include incomplete external dysfunction with no pupil involvement (eg, divisional palsy) and incomplete or complete external dysfunction with partial internal dysfunction (relative pupil-sparing). These patients should undergo a contrast-enhanced brain MRI to exclude a mass lesion, with an MRA or CTA to look for an aneurysm or other mass lesion.
A neurologically isolated third nerve palsy with a normal pupillary sphincter and completely palsied extraocular muscles (complete external dysfunction) is almost never caused by an aneurysm.4
5. The presence or absence of head or periorbital pain in a patient is not helpful in establishing the cause of a 3rd nerve palsy. Although most 3rd nerve palsies caused by aneurysms present with pain, many vasculopathic palsies also produce pain, that in some cases, may be intense. In older adults, vasculitis (eg. giant cell arteritis) must also be considered.5
6. The key clinical finding of aberrant regeneration of the third nerve is over action of one of the muscle it innervates with attempts to perform one of the functions of the third cranial nerve (elevation, depression,  adduction, convergence or accommodation).

Typical positive findings include:

1. the pupil of the affected eye constricts on attempted elevation, depression, or adduction of the eye,

2. the eyelid of the affected eye elevates on attempted depression, adduction, convergence or accommodation.


In a review of “39 cases and looked for any signs of aberrant regeneration in either the pupil, the lid or motility. In about 78% of cases, he found some aberrant regeneration of the pupil. The pupil got smaller on adduction in some cases, or smaller on infraductions or supraductions or smaller with a combination.

The lid was involved in about 77% of cases, and motility in about 33%. These cases overlapped — 56% involved both the pupil and lid, and 25% involved the pupil, lid and motility.”6  

6

Case 647

Image: Aberrant Regeneration of Third Nerve

There is elevation of the left eyelid on right gaze, down gaze.


References:

1. Pupillary Responses. Stanford Medicine 25: An initiative to revive the culture of bedside medicine.

http://stanfordmedicine25.stanford.edu/the25/pupillary.html

2. Anisocoria. Wikipedia https://en.wikipedia.org/wiki/Anisocoria#Interpretation
3. Oculomotor Nerve. E NEUROSURGERY  http://www.eneurosurgery.com/oculomotornerve.html
4. Third cranial nerve (oculomotor nerve) palsy in adults. Lee AG. UpToDate 2015. http://www.uptodate.com/contents/third-cranial-nerve-oculomotor-nerve-palsy-in-adults
5. Pupil-sparing third nerve palsy. Neuro-ophthalmology BCSC 2006-2006. AA0 p.230
6. Warning signs reveal aberrant nerve regeneration. Pupil dysfunctions and misdirection syndromes show when nerve endings re-innervated incorrectly. Kardon RH . Ocular Surgery News U.S. Edition, June 15, 2000.
7. CASE 64: Third nerve palsy with aberrant regeneration. CyberSight http://www.cybersight.org/bins/volume_page.asp?cid=1-2161-2379-2435-2504
8. Fixation of the Eyeball to the Periosteum Over the Posterior Lacrimal Crest in Inveterate Exotropia. Seol BR et. al . J Korean Ophthalmol Soc. 2014 Mar;55(3):408-415.  http://synapse.koreamed.org/DOIx.php?id=10.3341/jkos.2014.55.3.408&vmode=PUBREADER
9. Essentials of Ophthalmology. Neil J. Friedman & Peter K. Kaise. Elsevier Health Sciences: 2007 p. 53.




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Neuro-ophthalmology Question of the Week: Indications for Emergent Evaluation of Isolated 3rd Nerve Palsy

                            Left 3rd Nerve Palsy1

Axial T2 image and 3 D TOF Non contrast MR Angiography of Brain shows a left side Pcom Aneurysm presenting with left side isolated 3rd CN Palsy2


Question: Which of the following include indications for emergent evaluation of a patient with an isolated 3rd nerve palsy to rule-out aneurysm?
1. Third nerve palsy with a normal pupillary sphincter and completely palsied extraocular muscles.
2. Third nerve palsy with complete internal dysfunction (pupil-involved) and complete external dysfunction.
3. Third nerve palsy with complete internal dysfunction (pupil-involved) and incomplete external dysfunction.
4. Isolated third nerve deficits with incomplete external dysfunction with no pupil involvement (eg, divisional palsy).
5. Incomplete or complete external dysfunction with partial internal dysfunction (relative pupil-sparing).

_____________________________________________


Correct Answers:

2. Third nerve palsy with complete internal dysfunction (pupil-involved) and complete external dysfunction.
3. Third nerve palsy with complete internal dysfunction (pupil-involved) and incomplete external dysfunction.

4. Isolated third nerve deficits with incomplete external dysfunction with no pupil involvement (eg, divisional palsy).
5. Incomplete or complete external dysfunction with partial internal dysfunction (relative pupil-sparing).


Explanation:

Complete external dysfunction with normal internal function (pupil-sparing complete third nerve palsy)3 A neurologically isolated third nerve palsy with a normal pupillary sphincter and completely palsied extraocular muscles (complete external dysfunction) is almost never caused by an aneurysm. A single case has been reported due to a basilar artery aneurysm, but this is exceptional [17].

In older adults, this presentation is most commonly caused by ischemic injury [12,39]. Observation alone is an appropriate diagnostic option for older patients with vascular risk factors (hypertension, diabetes) [39]. However, contrast-enhanced brain MRI and MRA should be strongly considered in patients without vascular risk factors whose deficits progress or do not improve by 6 to 12 weeks of follow-up or in those with signs of aberrant regeneration [13]. In some hospitals, combined examination with CT and CTA may be superior to MRA for aneurysm evaluation. However, MRI is superior to CT for imaging the cavernous sinus, posterior fossa, and meninges and is the preferred imaging study for third nerve palsy.

Older patients (>55 years) should be evaluated for signs or symptoms of giant cell arteritis (headache, jaw or tongue claudication, polymyalgia rheumatica, visual loss) [40,41]. These patients may require serum erythrocyte sedimentation rate and C reactive protein, steroid treatment, and temporal artery biopsy. (See "Clinical manifestations of giant cell (temporal) arteritis".)

If a third nerve palsy persists in a patient with normal imaging studies, a lumbar puncture (LP) should be considered, especially if historical or examination features suggest an infectious, inflammatory, or neoplastic process affecting the meninges.


Third nerve palsy with complete internal dysfunction (pupil-involved) and complete or incomplete external dysfunction3Complete internal dysfunction (pupil-involved) third nerve palsy should be assumed to be due to aneurysmal compression until proven otherwise. Patients should undergo MRI and MRA (or CTA); however, even if the noninvasive study is negative, a catheter angiogram should be strongly considered to exclude aneurysm.

Once aneurysm and other mass lesions have been excluded, an evaluation for giant cell arteritis should be undertaken in older patients; and an LP should be considered for persistent or progressing deficits when the cause remains unclear.


Other patterns of isolated third nerve deficits3Other patterns of isolated third nerve deficits include incomplete external dysfunction with no pupil involvement (eg, divisional palsy) and incomplete or complete external dysfunction with partial internal dysfunction (relative pupil-sparing). These patients should undergo a contrast-enhanced brain MRI to exclude a mass lesion, with an MRA or CTA to look for an aneurysm or other mass lesion. If negative, catheter angiography should be considered to further investigate the presence of an aneurysm or the less likely possibility of a posterior draining carotid-cavernous sinus fistula [2]. In this intermediate risk category, individual and institution-specific assessments of risks and benefits determine the choice of testing.

As discussed above, an evaluation for giant cell arteritis should be undertaken in older patients, and an LP should be considered for persistent or progressing deficits when the cause remains unclear after neuroimaging.


Isolated third nerve palsy with signs of aberrant regeneration3Signs of aberrant regeneration are unlikely in ischemic lesions and suggest the presence of a compressive lesion, including aneurysm (see 'Subarachnoid space' above). Contrast-enhanced brain MRI with MRA (or CTA) is the procedure of choice for these patients.


Partial or complete internal sphincter dysfunction in isolation without extraocular muscle paresis or ptosis (no external dysfunction) is at the lowest risk for aneurysm.4 An isolated dilated pupil in an ambulatory patient in the absence of any other signs of TNP (e.g., ophthalmoplegia or ptosis) is extremely unlikely to be caused by an aneurysm (class III–IV, level B). The etiology for an isolated dilated pupil is usually related to sphincter abnormality (e.g., trauma or surgery), tonic pupil syndrome (e.g., Adie’s syndrome), or pharmacologic dilation. Although there is no class I–II evidence, there is consensus from class III–IV evidence that these patients do not require any neuroimaging. In addition, ordering a conventional angiogram in this setting is not indicated and exposes the patient to unnecessary risk from the procedure (level B).


References:

1. Fixation of the Eyeball to the Periosteum Over the Posterior Lacrimal Crest in Inveterate Exotropia. Seol BR et. al . J Korean Ophthalmol Soc. 2014 Mar;55(3):408-415.  http://synapse.koreamed.org/DOIx.php?id=10.3341/jkos.2014.55.3.408&vmode=PUBREADER
2. Aneurysmal 3rd CN palsy. Dr. Balaji Anvekar’s Neuroradiology Cases. Neuroradiology Unit, S P Institute of Neurosciences,Solapur,Maharashtra, India.

http://www.neuroradiologycases.com/2012/07/aneurysmal-3rd-cn-palsy.html

3. Third cranial nerve (oculomotor nerve) palsy in adults. Lee AG. UpToDate 2015. http://www.uptodate.com/contents/third-cranial-nerve-oculomotor-nerve-palsy-in-adults
4.  The evaluation of isolated third nerve palsy revisited: an update on the evolving role of magnetic resonance, computed tomography, and catheter angiography. Lee AG, Hayman LA, Brazis PW. T Surv Ophthalmol. 2002;47:137-157.


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Neuro-ophthalmology Question of the Week: Dilated pupil constricts to pilocarpine 0.125%

Question:

A 35-year-old woman is evaluated for a 2-week history of photophobia and awareness that her right pupil is larger than the left. Examination shows absent right pupillary response to light stimulation of either eye. There is no diplopia and no evidence of extraocular muscle palsy. Upon local instillation of 0.125% pilocarpine, the larger pupil becomes smaller than the contralateral pupil.

http://www.neurology.org/content/79/11/e97.full?sid=edd94f48-3045-4340-a102-c00b7fd13480


Which of the following is the most likely location of the lesion?

1. ciliary ganglion

2. Edinger-Westphal nucleus

3. oculomotor nerve

4. optic chiasm

5. pretectal nucleus

______________________________________________________

Correct Answer:

1. ciliary ganglion


Explanation:

This patient has a right Adie tonic pupil. The affected pupil is dilated and poorly reactive to light. Within the first 1 or 2 weeks of its denervation, the iris sphincter will become supersensitive to cholinergic agents such as pilocarpine diluted to a concentration of 0.125% or less. Following 1 drop placed in each eye, a positive response to dilute pilocarpine is either (1) the larger pupil constricts 0.5 mm more than the normal pupil or (2) the larger pupil becomes the smaller pupil. In the absence of associated ptosis or ocular motility deficits, a positive dilute pilocarpine test indicates postganglionic parasympathetic denervation of the iris. In this case, the denervation is likely etiologic, hence a diagnosis of Adie pupil. An isolated unilateral mydriasis as the sole manifestation of an oculomotor nerve palsy is exceedingly rare.


For more information, refer to page 1011 of the CONTINUUM article “Diagnostic Approach to Pupillary Abnormalities.”


Reference:

1. Question and and explanation are from Continuum Lifelong Learning in Neurology  

August 2014 - Volume 20 - Issue 4, Neuro-ophthalmology

Available at Lane Medical Library - SuNet UserID & Password Required


2. Simulation of Adie Pupil http://www.mrcophth.com/eyeclipartchua/pupils.html


3. Teaching Video NeuroImages: Acute Adie syndrome, Benjamin R. Wakerley, et. al, Neurology September 11, 2012 vol. 79 no. 11 e97 http://www.neurology.org/content/79/11/e97.full?sid=edd94f48-3045-4340-a102-c00b7fd13480

Video available for download:  http://www.neurology.org/content/79/11/e97/suppl/DC1


4. Adie Tonic Pupil - American Academy of Ophthalmology OneNetwork

http://one.aao.org/bcscsnippetdetail.aspx?id=1af235eb-71a5-497f-8fac-308c9ea3a0eb

Diagnostic features of tonic pupils include sluggish, segmental pupillary responses to light and better response to near effort followed by slow redilation. A tonic pupil is caused by postganglionic parasympathetic pupillomotor damage. Seventy percent of patients are female. Tonic pupils are unilateral in 80% of cases, although the second pupil may later become involved (4% per year). Holmes-Adie syndrome includes other features, notably diminished deep tendon reflexes and orthostatic hypotension.

In the initial stages, a tonic pupil is dilated and poorly reactive. The examiner at the slit lamp can usually distinguish segments of sphincter paralysis and contraction. The iris crypts stream toward the area of normal sphincter function, bunching up along the pupillary border in areas of normal function and thinning in the areas of paralysis (Fig 10-5). After a few weeks, a tonic pupil constricts to near effort with a slow, tonic movement and redilates just as slowly, whereas a normal pupil redilates promptly (Fig 10-6). This may account for symptomatic complaints of difficulty refocusing for distance.

The denervated iris sphincter is supersensitive to topical parasympathomimetic solutions. Pilocarpine drops (0.1%) can be used to demonstrate this, as the normal pupil will constrict slightly, if at all. (This strength of pilocarpine can be obtained by diluting commercial 1% solution with sterile saline for injection.) After 60 minutes, the pupils are reexamined, and if Adie is present, the affected pupil (dilated pupil) will constrict more than the normal pupil (Fig 10-7). About 80% of patients with a tonic pupil show cholinergic denervation supersensitivity.

Patients with tonic pupils may have accommodative symptoms or photophobia, but just as often they have no symptoms and report that anisocoria was first noticed by a friend or relative. Accommodative symptoms are difficult to treat. Fortunately, they usually resolve spontaneously within a few months of onset. When photophobia from a dilated pupil is a problem, topical dilute pilocarpine (0.1%) may be helpful. With time (months to years), an Adie tonic pupil gets smaller. Histopathologic examination of the ciliary ganglion in patients with Adie tonic pupil has shown a reduction in the number of ganglion cells.

Systemic conditions associated with tonic pupils only rarely include varicella-zoster, giant cell arteritis, syphilis, and orbital trauma. Bilateral tonic pupils may be seen in patients with diabetes, alcoholism, syphilis, cancer-associated dysautonomia, and amyloidosis.

Kardon RH , CorbettJJ, ThompsonHS. Segmental denervation and reinnervation of the iris sphincter as shown by infrared videographic transillumination.Ophthalmology.1998;105(2):313–321. Thompson HS . Segmental palsy of the iris sphincter in Adie’s syndrome.Arch Ophthalmol.1978;96(9):1615–1620.


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Neuro-ophthalmology Question of the Week: OS with 3rd nerve palsy & no intorsion on attempted abduction

Question:

http://www.oftalmo.com/seo/archivos/maquetas/C/292340FB-46F9-98E9-D28D-00002366E6BC/f10-1.jpg A 45-year-old man with diabetes mellitus is evaluated for abrupt-onset headache and double vision. Examination shows left ptosis and lateral and downward deviation of the left eye with impaired elevation, depression, and adduction. The left pupil is dilated and its constriction to light is impaired. When the left eye is abducted, attempts to look down fail to elicit intorsion of the globe. Which of the following is the most likely diagnosis?

1. anterior midbrain infarction

2. cavernous sinus aneurysm

3. expanding posterior communicating artery aneurysm

4. ischemic oculomotor neuropathy

5. posterior midbrain syndrome
______________________________________________________

Correct Answer:

2.cavernous sinus aneurysm


Explanation: This patient has a complete left third nerve palsy (left ptosis with impaired elevation, depression, and adduction of the left eye; the left pupil is dilated and poorly reactive to light). The patient also has a left fourth nerve palsy, consistent with a lesion in the left cavernous sinus. When a complete third nerve palsy results in paralysis of the medial rectus, it is difficult to test for ipsilateral superior oblique weakness since it acts in the vertical plane during adduction. To test its function, the practitioner may instead bring the eye into the abducted position and ask the patient to then look down, which should result in intorsion of the globe if the superior oblique is functional. Identifying a concomitant trochlear nerve palsy alongside an oculomotor nerve palsy is crucial, in that it is unlikely to be the result of the common and relatively benign microvascular etiology and suggests a localization either at the orbital apex or within the cavernous sinus. Also, the impaired pupillary constriction to light indicates involvement of preganglionic parasympathetic axons travelling along the superficial portion of the oculomotor nerve, which is consistent with an extrinsic compression rather than an ischemic lesion affecting the central portion of the nerve.


http://www.mrcprevisionnotes.co.uk/2012_01_01_archive.html


References:

Question and and explanation are from Continuum Lifelong Learning in Neurology  

August 2014 - Volume 20 - Issue 4, Neuro-ophthalmology

Available at Lane Medical Library - SuNet UserID & Password Required


More than 600 additional neuro-ophthalmology questions are freely available at http://EyeQuiz.com.  

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Adult Horner’s syndrome: a combined clinical, pharmacological, and imaging algorithm

Adult Horner's syndrome: a combined clinical, pharmacological, and imaging algorithm. 
Davagnanam I, Fraser CL, Miszkiel  K, Daniel CS, Plant GT. Eye 2013;27(3):291-8. 

Article http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3597883/

The diagnosis of Horner's syndrome (HS) can be difficult, as patients rarely present with the classic triad of ptosis, miosis, and anhydrosis. Frequently, there are no associated symptoms to help determine or localise the underlying pathology. The onset of anisocoria may also be uncertain, with many cases referred after incidental discovery on routine optometric assessment. Although the textbooks discuss the use of cocaine, apraclonidine, and hydroxyamphetamine to diagnose and localise HS, in addition to reported false positive and negative results, these pharmacological agents are rarely available during acute assessment or in general ophthalmic departments. Typically, a week is required between using cocaine or apraclonidine for diagnosis and localisation of HS with hydroxyamphetamine, leaving the clinician with the decision of which investigations to request and with what urgency. Modern imaging modalities have advanced significantly and become more readily available since many of the established management algorithms were written. We thus propose a practical and safe combined clinical and radiological diagnostic protocol for HS that can be applied in most clinical settings.

Neuro-ophthalmology Question of the Week: Episodic Anisocoria

http://www.neurology.org/content/79/9/949.full.pdf+html?ct


Question:

Which condition is demonstrated in the above photos of episodic anisocoria?

1. Horner syndrome

2. Adie’s pupil

3. Tadpole pupil

4. Traumatic pupillary sphincter muscle tear

__________________________________________________


Correct Answer:

3. Tadpole pupil


Reference:

1. Tadpole pupil. Aki Kawasaki and Cedric Mayer, Neurology 2012;79;949

http://www.neurology.org/content/79/9/949.full.pdf+html?ct

A young woman has recurrent episodes of unilateral mydriasis lasting several minutes. The left pupil becomes large and deformed, described as “egg-shaped” (figure). Examination, including pharmacologic pupil tests, revealed no ophthalmologic or neurologic abnormalities. Cranio-orbital MRI was normal. Diagnosis of tadpole pupil was confirmed by self-taken photographs using a cellular phone.

Spontaneous segmental spasm of the iris dilator can cause pupillary distortion that resembles the shape of a tadpole.

Occasional patients with tadpole pupil have underlying Horner syndrome; otherwise, the syndrome is benign and self-limited. 1,2

Cellular phone “telemedecine” was particularly helpful in diagnosing this form of episodic mydriasis.

1. Thompson HS, Zackon DH, Czarnecki JS. Tadpole-shaped pupils caused by segmental spasm of the iris dilator muscle. Am J

Ophthalmol 1983;96:467– 477.

2. Balaggan KS, Hugkulstone CE, Bremner FD. Episodic segmental iris dilator muscle spasm: the tadpole-shaped pupil. Arch Ophthalmol 2003;121:744 –745.


2. Anisocoria. Sam Tapsell http://youtu.be/jgVJyEOXVvM 5 minute video


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Neuro-ophthalmology Question of the Week: Optic Tract Signs

The right optic tract is hyperintense on the FLAIR axial MRI

Am J Ophthalmol 2007;143:772-80.

Which of the following findings are compatible with an optic tract lesion?

1. Contralateral visual field defect

2. Ipsilateral visual field defect

3. Incongruous homonymous hemianopia

4. Congruent homonymous hemianopia

5. Complete homonymous hemianopia

6. Relative afferent pupillary defect on the side ipsilateral to the lesion

7. Relative afferent pupillary defect on the side contralateral to the lesion

8. Optic atrophy

________________________________________________________


Correct Answers:

1. Contralateral visual field defect

3. Incongruous homonymous hemianopia

4. Congruent homonymous hemianopia

5. Complete homonymous hemianopia

7. Relative afferent pupillary defect on the side contralateral to the lesion

8. Optic atrophy


References:

1. Pearls & Oy-sters: Optic tract syndrome, Rodriguez AR & Reddy K.

Neurology 75:e86-7:2010. Divisions of Ophthalmology and Neuro-Surgery, Department of Surgery, McMaster University, Hamilton, Canada.


PEARLS

• The optic tract syndrome is characterized by a contralateral, incongruous homonymous hemianopia, contralateral relative afferent pupillary defect (RAPD), and optic atrophy due to retrograde axonal degeneration.

• Optic disc pallor often results in a pattern of bowtie atrophy of the eye with temporal field

loss and atrophy of the upper and lower poles of the disc of the eye with nasal field loss.

• Visual acuity and color vision are usually normal unless there is bilateral involvement or extension to the chiasm or optic nerve.

OY-STERS

• Homonymous hemianopia is typically incongruous in optic tract lesions although this concept only applies if the defect is incomplete. Complete homonymous hemianopia is of no localizing value.

• Behr’s pupil (larger pupil on the side opposite to the lesion) and pupillary hemiakinesia (Wernicke sign) are historical signs that are not helpful in the clinical setting


Behr’s pupil: Behr's pupil sign reported with lesions of the optic tract is an anisocoria with the larger pupil in the contralateral eye. It has been largely discredited. Neuro-ophthalmology, Glaser JS, 1990 JB Lippincott Company


Wernicke sign:  In hemianopia, a reaction due to damage of the optic tract, consisting in loss of pupillary constriction when the light is directed to the blind side of the retina; pupillary constriction is maintained when light stimulates the normal side. This sign cannot be seen with a bright light because of intraocular scatter onto the seeing half of the retina.http://www.medilexicon.com/medicaldictionary.php?s=Wernicke+reaction


2. Visual fields in neuro-ophthalmology. Kedar S, Ghate D, Corbett JJ. Indian J Ophthalmol [serial online] 2011 [cited 2013 Dec 5];59:103-9. Available from: http://www.ijo.in/text.asp?2011/59/2/103/77013

Retrochiasmal disorders

Retrochiasmal disorders produce varied patterns of homonymous hemianopia, depending on the site of the lesion. Before the advent of modern neuroimaging, these patterns were used to localize a lesion in the visual pathway. However, a recent study has shown that the visual field defects may not be as specific to a given location as was previously believed. [55] Lesions anywhere along the retrochiasmal pathway can produce virtually any type of homonymous visual field deficit, except a unilateral loss of the temporal crescent and homonymous sectoranopia that are produced exclusively by anterior occipital and geniculate lesions, respectively. Contrary to existing and persistent belief, almost 50% of lesions involving the optic tracts produce congruent homonymous hemianopia even though they have a reputation for being notoriously incongruous. [56]Congruent homonymous hemianopias are produced by posterior pathway lesions and the chance that a congruent homonymous hemianopia is produced by a lesion involving the occipital lobe was estimated to be 56%.

Optic tract lesion - Homonymous hemianopia (50% congruent and 50% incongruent)

3. Congruency in homonymous hemianopia. Kedar S, Zhang X, Lynn MJ, Newman NJ, Biousse V. . Am J Ophthalmol 2007;143:772-80.

FIGURE 6. Congruent homonymous hemianopia (HH) from optic tract lesion. (Left) Goldmann visual fields showing a congruent right homonymous superior quadrantic visual field defect associated with a right homonymous scotomatous defect secondary to a left optic tract lesion (Right, arrow) after a posterior GPi pallidotomy for Parkinson disease. (Reprinted with permission from Biousse V, Newman NJ, Carroll C, et al. Visual fields in patients with posterior GPi pallidotomy. Neurology 1998;50:258–265).



FIGURE 7. Congruent homonymous hemianopia (HH) from a demyelinating optic tract lesion in a patient subsequently diagnosed with multiple sclerosis. (Left) 24-2 SITA-fast Humphrey visual field test (grayscale and pattern deviation) showing a congruent left incomplete HH secondary to a right optic tract lesion (Right). The right optic tract is hyperintense on the FLAIR axial MRI (Right).


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Neuro-ophthalmology Question of the Week: Aberrant Regeneration of the 3rd Nerve

http://www.revophth.com/CMSImagesContent/2012/3/RP-Plastics-Fig4.jpg

Question: Which of the following potential causes of a 3rd nerve paresis would be very unlikely to cause aberrant regeneration (oculomotor synkinesis)?

1. Aneurysm

2. Tumor

3. Diabetes

4. Trauma

5. Vasculopathic Ischemia
_______________________________________________________

Correct Answers:

Which of the following potential causes of a 3rd nerve paresis would be very unlikely to cause aberrant regeneration (oculomotor synkinesis)?

3. Diabetes & 5. Vasculopathic Ischemia


References:

1. Neuro-ophthalmology Minute - Third Nerve Misdirection. Thomas J. Walsh, MD. Orbis Telemedicine

http://telemedicine.orbis.org/bins/volume_page.asp?cid=1-600-13-2191

“This was first described by Walsh and Ford. It occurs infrequently after a 3rd nerve paresis that returns to normal. It is frequently seen after trauma, less often with an aneurysm and NEVER after diabetes.

The sign appears that as the 3rd nerve recovers there was a mixing of fibers as has been described with 7th nerve misdirection. In third nerve misdirection this is not the case. The current causation theory is ephaptic transmission. The nerve loses its myelin covering and there is cross talk between different 3rd nerve fibers. This explains why there are cases where there is disappearance of misdirection after a period of time.

The signs of misdirection are as follows:

1) Pseudo Argyll Robertson Pupil Sign: The pupil reacts to near but not light. However, the near reflex is not accommodation but contraction of the medial rectus. The same pupil reaction occurs with a distance gaze movement of the medial rectus and not on contraction for convergence.

2) Lid Gaze Dyskinesis Sign: Normally as we look from one gaze right or left to the other, the lid stays in the same relative position over the cornea. However, there develops a relationship between the medial rectus and the levator. Instead of staying in the same relative position to the cornea it becomes elevated on adduction. This is best seen by doing the gaze movement in the down position.

3) Pseudo Von Graefe Sign: When a normal functioning eye looks up and down the levator adjusts the lid accordingly and stays in the same relative position to the pupil. In the misdirection phenomenon as the eye looks down the levator retracts. It is not the same as thyroid disease ophthalmopathy. If one does the movement quickly, the lid doesn’t just hang up but jumps up slightly due to abnormal misdirection innervation.

The sign is most important when considering diabetic versus one of the other diagnoses since this phenomenon has never been reported with diabetes.”


2. Big red flags in neuro-ophthalmology. Ling BS. et; al. Canadian Journal of Ophthalmology. 2013:48:1:3 -7

Figure 7. Aberrant regeneration of the third cranial nerve. Patient sustains a left eye adduction when attempting to look up.


The most common clinical findings of aberrant regeneration are eyelid retraction with adduction, elevation, or depression (pseudo–von Graefe sign); abnormal extraocular muscle firing (e.g., adduction with elevation); or pupillary miosis with elevation, adduction, or depression (Fig. 7). Thus, the red flag of interest to ophthalmologists that should prompt neuroimaging is the development of aberrant regeneration in a patient with an improving presumed vasculopathic (e.g., diabetic) third nerve palsy. In such a case, a compressive lesion (e.g., aneurysm or tumor) often in the cavernous sinus should be suspected.


3. Video - Aberrant Regeneration 3rd Nerve - Kathleen B. Digre, MD, Professor of Neurology and Ophthalmology, Director of Neuro-Ophthalmology, John A. Moran Eye Center, University of Utah School of Medicine http://content.lib.utah.edu/cdm/singleitem/collection/EHSL-Moran-Neuro-opth/id/80/rec/18    

At the link above, click on the icon circled in blue to stream the video.


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Neuro-ophthalmology Question of the Week: Anisocoria #12 Horner syndrome & Heterochromia Iridis

commons.wikimedia.org HeterochromicBorderCollieCross.JPG

Question:

Which of the following are correct?

1. A heterochromia iridis-associated acquired Horner syndrome is usually due to a lesion of the postganglionic neuron (third order).

2. Heterochromia iridis-associated acquired Horner syndrome only occurs in children?

3. In a patient with isolated heterochromia iridis-associated Horner syndrome, the lighter eye is the one with the oculosympathetic paresis.

4. When both Waardenburg and congenital Horner syndromes occur in the same individual the darker iris is the one with the oculosympathetic paresis.

___________________________________________________


Correct Answers: 1, 3, & 4

1. A heterochromia iridis-associated acquired Horner syndrome is usually due to a lesion of the postganglionic neuron (third order).

3. In a patient with isolated heterochromia iridis-associated Horner syndrome, the lighter eye is the one with the oculosympathetic paresis

4. When both Waardenburg and congenital Horner syndromes occur in the same

individual the darker iris is the one with the oculosympathetic paresis.


References: (Emphasis added)


1. Don't it make my blue eyes brown: heterochromia and other abnormalities of the iris. Eye:2012:26:1:29-50. Rennie IG

Although less common, it would appear that cases of acquired Horner’s syndrome in childhood and adult life may occasionally also give rise to iris heterochromia. Laties [28] reported a case of a 29-year-old female who had developed Horner’s syndrome, with associated heterochromia, following the removal of a neurolemmoma when aged 14. Diesenhouse et al subsequently reported two cases of Horner’s syndrome following sympathectomy, which were associated with the development of iris hypo-pigmentation. A number of reports in the literature have also indicated the development of iris heterochromia in children who develop Horner’s syndrome as a result of either a cervical ganglioneuroma, 30 neurolemmoma, or neuroblastoma. [32,33 & 31] Again, it is interesting to note that in all cases of heterochromia-associated acquired Horner’s syndrome, the causal lesion was postganglionic in origin. 29  


2. Acquired heterochromia with Horner syndrome in two adults. Ophthalmology. 1992;99(12):1815-7. Diesenhouse MC, Palay DA, Newman NJ, To K, Albert DM.

BACKGROUND: Heterochromia iridis, asymmetry of iris pigmentation, has been well described with congenital Horner syndrome. Acquired heterochromia associated with lesions in the ocular sympathetic pathways in adulthood, however, is rare.

METHODS: Two cases are reported in which sympathectomy in adults resulted in ipsilateral Horner syndrome with heterochromia. In each case, pharmacologic testing with cocaine and hydroxyamphetamine was performed.

RESULTS: In both cases, sympathectomy occurred at the level of the second order neuron, but hydroxyamphetamine testing suggested at least partial third order neuron involvement.

CONCLUSION: Acquired heterochromia can occur in adults. The partial response to hydroxyamphetamine in the two cases presented may reflect trans-synaptic degeneration of the postganglionic neuron. A reduction in trophic influences on iris melanocytes may have contributed to the observed heterochromia.


3. When the darker eye has the smaller pupil. J AAPOS. 2003 Jun;7(3):215-6. Wallis DH, Granet DB, Levi L.


Waardenburg and congenital Horner syndromes are both recognized causes of congenital hypochromic iris heterochromia. Each has been linked to disruptions in the pathway of tyrosinase induction, thus leading to a deficiency in melanin production of the iris. These syndromes must be considered in the differential diagnosis of a patient presenting with heterochromia iridis. We present the case of a 20-month old boy afflicted with both congenital Horner syndrome and Waardenburg syndrome, type II. In contrast to the more common presentation of congenital Horner syndrome, the affected iris in this case was the darker of the two because of the effects of the concomitant Waardenburg syndrome on the contralateral iris pigmentation. We are unaware of any other cases presenting with both Horner and Waardenburg syndromes and believe that this case serves as an excellent opportunity to briefly review the pathophysiology involved with these disorders.


4. Autonomic innervation of the pupil and Horner's syndrome  Suraj Rajan commons.wikimedia.org

Diagram: Scheme showing sympathetic and parasympathetic innervation of the pupil and sites of lesion in a Horner's syndrome.

1. sympathetic fibers arise from the hypothalamus

2. stellate ganglion

3. synapse at the superior cervical ganglion

4. sympathetic plexus around internal carotid artery

5. oculomotor nerve (Cranial nerve 3) fibers synapse at the ciliary ganglion (blue)

6. short ciliary nerves from ciliary ganglion carrying parasympathetic supply to sphincter pupillae (green)

7. trigeminal fibers (Cranial nerve 5) relay in ciliary ganglion and carry sympathetic supply (yellow)

8. long ciliary nerves (from the ophthalmic branch of CN 5) carrying sympathetic supply to the dilator pupillae

9. dilator pupillae muscles of the pupil

Near the stellate ganglion, the sympathetic fibers go around the subclavian artery (shown along with the carotid vessels). This is a site of lesion especially due to its proximity to the apex of the lung (eg. Pancoast's tumor).

The superior division of oculomotor nerve is shown supplying the Superior rectus and levator palpebrae superioris.


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Neuro-ophthalmology Question of the Week: Anisocoria #11 Horner Syndrome in Children

MRI showing a heterogeneously enhancing soft tissue lesion involving the root of neck

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2636023/figure/F2/


Question: 

Which of the following are correct? 

1. Heterochromia iridis in a child with Horner syndrome rules out neuroblastoma as a cause. 

2. The most common cause of congential Horner syndrome is a neuroblastoma.

3. Cervical neuroblastoma, a disease primarily of infants, has a favorable prognosis. 

4. Cervical masses due to neuroblastoma, when felt, are commonly mistaken for infectious adenitis in children. 

5. Cervical neuroblastoma in children almost always causes Horner syndrome.

_______________________________________________________________

Correct Answers:

3. Cervical neuroblastoma, a disease primarily of infants, has a favorable prognosis.

4. Cervical masses due to neuroblastoma, when felt, are commonly mistaken for infectious adenitis in children.


References: (emphasis added)

Horner’s syndrome in children

Patients with an oculosympathetic paresis occurring in the perinatal period or early childhood may develop a lighter colored iris on the affected side. Horner’s syndrome present at birth is usually idiopathic, less often it may be associated with a brachial plexus injury from birth trauma, and rarely can be caused by intrauterine diseases such as neuroblastoma [40]. Congenital Horner’s syndrome has been reported to occur with internal carotid hypoplasia [41] or agenesis [42] and ectopic cervical thymus [43]. Harlequin sign (contralateral hemifacial flushing and ipsilateral hypohidrosis) is a striking presentation that may be seen in infants with an oculosympathetic paresis [44].

An acquired oculosympathetic paresis in childhood suggests a neuroblastoma involving the sympathetic chain or some other mediastinal malignancy until proven otherwise. Mahoney et al. [45] performed a retrospective review identifying 56 children with Horner’s syndrome. In 23%, a neoplasm was identified as the underlying cause. The authors suggest that any child presenting with an oculosympathetic paresis without an obvious surgical or traumatic cause requires a complete physical examination for a mass lesion, as well as an MRI of brain, neck, and chest (with and without contrast), and urinary catecholamine testing [45]. In addition to neuroblastoma [46], sympathetic chain paragangliomas [47,48] and ganglioneuromas [49] have also been described. Non-neoplastic causes of acquired pediatric Horner’s syndrome in the recent literature include pneumothorax [50] and thoracic empyema [51].


Pediatric Horner syndrome: etiologies and roles of imaging and urine studies to detect neuroblastoma and other responsible mass lesions. Am J Ophthalmol 2006, 142: 651–659. Mahoney NR, Liu GT, Menacker SJ, et al.

This paper is a retrospective review of pediatric Horner’s syndrome. It discovered malignancies in 23% of 56 pediatric patients with Horner’s syndrome.

CONCLUSIONS: We confirm that Horner syndrome in a child of any age without a surgical history requires a complete examination to exclude a mass lesion.

In such patients, we recommend brain, neck, and chest magnetic resonance imaging (MRI) with and without contrast as well as urinary catecholamine metabolite testing. However, imaging is more sensitive than urine testing in this setting.


Cervical neuroblastoma in eleven infants--a tumor with favorable prognosis. Clinical and radiologic (US, CT, MRI) findings. Pediatric radiology. 1993:23:4:253-257. Abramson sJ, et al.

Cervical neuroblastoma, a disease primarily of infants, has a favorable prognosis. Eleven patients are reported. Clinical presentations (other than mass) included stridor and swallowing problems. Masses when felt were commonly mistaken for infectious adenitis. Imaging studies (US, CT, MRI) showed solid masses with vascular displacement and narrowing; intraspinal extension was absent though extension into the adjacent sites of mediastinum and skull occurred. Horner syndrome was seen in five patients with accompanying heterochromia iridis in one. Five tumors had calcification. A high index of suspicion will lead to biopsy and less delay in diagnosis once a mass is felt or imaged.


Congenital or acquired Horner's? Indian J Ophthalmol. 200:5(5):399-400. Toprani K, Shetty S, Vijayalakshmi P. Source for the MRI showing a heterogeneously enhancing soft tissue lesion involving the root of neck at the top of the page.


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Neuro-ophthalmology Question of the Week: Anisocoria #10 Pseudo-Horner Syndrome

Autonomic innervation of the pupil and Horner's syndrome  Suraj Rajan commons.wikimedia.org

Numbered labels are found in references below.

Question:

Which of the following may reveal that the cause of anisocoria is not Horner syndrome?

1. Slit-lamp exam

2. The degree of anisocoria remains relatively constant in bright and dim illumination.

3. Repeat examinations of the patient on different days.

4. The absence of miosis on attempted near vision.

5. The failure of the pupil to constrict to light but does constrict with attempted near vision.

____________________________________


Correct Answers:

1. Slit-lamp exam

2. The degree of anisocoria remains relatively constant in bright and dim illumination.

3. Repeat examinations of the patient on different days.



References: (emphasis added)

1. Horner's syndrome, Pseudo-Horner's syndrome, and simple anisocoria. Curr Neurol Neurosci Rep. 2007 Sep;7(5):397-406. Martin TJ.


“Pseudo-Horner’s Syndrome and Simple Anisocoria


Essential anisocoria Essential or physiologic anisocoria is a difference in pupillary size (generally less than 0.5 mm) that may be present in normal individuals. A pupil difference of 0.4 mm is easily noticeable, and 15% to 30% of the normal population may have at least this amount of anisocoria at any given time. In essential anisocoria, the pupillary inequality changes day to day and may even switch sides. This condition can usually be distinguished from pathologic states, as the degree of anisocoria remains relatively constant in light and dark.


Causes of anisocoria In addition to Horner’s syndrome, a miotic pupil can be the result of iridocyclitis, current or previous chronic use of miotic (glaucoma) eyedrops, Argyll Robertson pupil, old Adie’s pupil, and iris atrophy. It may be that the opposite, larger pupil is abnormal from trauma, pharmacologic agents, previous surgery, acute glaucoma, or other causes. Neovascularization of the iris and posterior synechia can cause a “stiff” pupil that can be larger or smaller that a normal pupil. Iris malformations and iris atrophy from any cause can also affect the size and function of the pupil [69]. Ophthalmologists may be in a position to avert an extensive neurologic evaluation by identifying iris structural abnormalities as the cause of anisocoria [This is facilitated by the slit-lamp examination.-TDC]O

Causes of ptosis/pseudoptosis

An idiopathic difference in palpebral fissure can be found in about 9% of normal individuals. Many disorders, other than Horner’s syndrome, can result in ptosis, including mechanical (from upper eyelid tumors, infiltration, edema, blepharochalasis), myogenic (myasthenia, chronic progressive external ophthalmoplegia), levator dehiscence (aging, trauma, inflammation, contact lens wear), and neurogenic (oculomotor nerve palsy) causes. Pseudoptosis can result from overhanging upper eyelid skin (dermatochalasis), relative enophthalmos (Duane’s syndrome, phthisis bulbi, microphthalmos, silent sinus syndrome [70]), overaction of eyelid protractors (blepharospasm, recovered facial nerve palsy), or eyelid retraction in the fellow eye (thyroid eye disease) [69].

Conclusions

Since it was first recognized, Horner’s syndrome has been a frequent subject in the scientific literature. The recent case reports and series presented in this review should encourage the clinician to appreciate the diversity of disease process and anatomic location when evaluating patients with an oculosympathetic paresis. The experience to date regarding the diagnostic use of apraclonidine is quite positive, but the matter is not entirely settled. However, there is sufficient information to permit an informed clinician to use apraclonidine in the evaluation of patients with a suspected Horner’s syndrome (Fig. 2), especially in those cases when testing with cocaine is simply not an option. It is important to understand that all ocular pharmacologic tests should carry less weight than the clinical examination and the clinician’s suspicion. It is important for the clinician to understand the pharmacology of apraclonidine and other diagnostic agents, and thus understand their limitations and shortcomings. We are convinced that apraclonidine will remain an important tool in the diagnosis of Horner’s syndrome; however, future studies with greater numbers of subjects will tell us whether apraclonidine will unseat cocaine as the gold standard in the pharmacologic diagnosis of Horner’s syndrome.


2. Autonomic innervation of the pupil and Horner's syndrome  Suraj Rajan commons.wikimedia.org


Diagram: Scheme showing sympathetic and parasympathetic innervation of the pupil and sites of lesion in a Horner's syndrome.

1. sympathetic fibers arise from the hypothalamus

2. stellate ganglion

3. synapse at the superior cervical ganglion

4. sympathetic plexus around internal carotid artery

5. oculomotor nerve (Cranial nerve 3) fibers synapse at the ciliary ganglion (blue)

6. short ciliary nerves from ciliary ganglion carrying parasympathetic supply to sphincter pupillae (green)

7. trigeminal fibers (Cranial nerve 5) relay in ciliary ganglion and carry sympathetic supply (yellow)

8. long ciliary nerves (from the ophthalmic branch of CN 5) carrying sympathetic supply to the dilator pupillae

9. dilator pupillae muscles of the pupil

Near the stellate ganglion, the sympathetic fibers go around the subclavian artery (shown along with the carotid vessels). This is a site of lesion especially due to its proximity to the apex of the lung (eg. Pancoast's tumor).

The superior division of oculomotor nerve is shown supplying the Superior rectus and levator palpebrae superioris.


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Neuro-ophthalmology Question of the Week: The Dilated Pupil

           Pupil blown by a puffer

http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(04)16352-6/fulltext

Question: Which of the following may cause a pupil to be dilated?

1. local contamination by antihistamines

2. tropane alkaloids from plants

3. nebulized bronchodilators

4. Herpes zoster

5. Herpes simplex


_________________________________________________________

Correct Answer: all are correct


Reference:

A diagnostic challenge: dilated pupil.

Curr Opin Ophthalmol. 2013 Nov;24(6):550-557. Caglayan HZ, Colpak IA, Kansu T.

FIGURE 1. Schematic diagram of the parasympathetic and sympathetic pathways that innervate the iris muscles.


FIGURE 2. Flow diagram summarizing the stepwise diagnostic approach to dilated pupils.



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Neuro-ophthalmology Question of the Week: Anisocoria #9 Pharmacology Horner Syndrome

Question:

1. Match the effect of the following agents to its effect on the pupils in Horner Syndrome?


Cocaine

Hydroxyamphetamine

Apraclonidine

A. Dilates the normal pupil more than the abnormal pupil. B. Dilates the normal pupil less than the abnormal pupil. C. Dilates the normal pupil and may dilate the abnormal pupil. D. May dilate the normal pupil and dilates the abnormal pupil. E. Fails to dilate the normal pupil and dilates the abnormal pupil. F. Dilates the normal pupil and fails to dilate the abnormal pupil.


2. Match the pharmacologic agent used to test Horner syndrome to the correct statement on mechanism of action. Cocaine Hydroxyamphetamine Apraclonidine

A. Acts by forcing the release of norepinephrine into the synaptic cleft at the neuromuscular junction which dilates the pupil if norepinephrine is present. 

B. Eyes with an oculosympathetic paresis have upregulated postsynaptic receptors which results in a supersensitivity to the pharmacologic agent dilating the pupil. 

C. Blocks the normal reuptake of norepinephrine, allowing norepinephrine to accumulate in the synaptic cleft which dilates the pupil if norepinephrine is present.


________________________________________________________

Correct Answers:

Question 1.

Cocaine - A. Dilates the normal pupil more than the abnormal pupil.

Hydroxyamphetamine - C. Dilates the normal pupil and may dilate the abnormal pupil.

Apraclonidine - E. Fails to dilate the normal pupil and dilates the abnormal pupil.


Question 2.

Cocaine - C. Blocks the normal reuptake of norepinephrine, allowing norepinephrine to accumulate in the synaptic cleft which dilates the pupil if norepinephrine is present.

Hydroxyamphetamine - A. Acts by forcing the release of norepinephrine into the synaptic cleft at the neuromuscular junction which dilates the pupil if norepinephrine is present.

Apraclonidine - B. Eyes with an oculosympathetic paresis have upregulated postsynaptic receptors which results in a supersensitivity to the pharmacologic agent dilating the pupil.


Reference:

Horner's syndrome, Pseudo-Horner's syndrome, and simple anisocoria.

Martin TJ. Curr Neurol Neurosci Rep. 2007 Sep;7(5):397-406.

                                           Figure 1.

Cocaine Norepinephrine is the neurotransmitter at the neuromuscular junction of the sympathetic third-order neuron and the iris dilator muscle (Fig. 1). In the normal state there is a continuous release of norepinephrine from the presynaptic terminal due to baseline sympathetic tone. The neurotransmitter is continuously degraded by reuptake at the presynaptic nerve terminal. Topical cocaine blocks the reuptake of norepinephrine, causing an accumulation of the neurotransmitter in the synaptic cleft, which produces dilation of a normal pupil. If sympathetic tone is lacking and there is little or no baseline release of norepinephrine into the cleft, then cocaine is an ineffective dilator. Thus topical cocaine can be used to detect a deficiency of sympathetic tone caused by a defect at any point in the sympathetic chain. The test is therefore “positive” for Horner’s syndrome if the affected eye fails to dilate as well as the normal eye dilates, resulting in at least 1 mm of anisocoria within 45 minutes after instillation [52]. If both pupils dilate equally well then an oculosympathetic paresis is unlikely. However, cocaine will also fail to dilate pupils that are otherwise incapable of dilating, such as an atrophic iris, or an iris with posterior synechiae or iris neovascularization. Thus, there are potential false-positive situations inherent in this test, especially if a slit-lamp examination of the iris is not performed. A mild reversal of the ptosis may be noted with cocaine drops, but this finding is usually subtle and not clinically useful.


Hydroxyamphetamine Hydroxyamphetamine hydrobromide 1% (previously available as Paredrine; Smith Kline & French, Philadelphia, PA) acts by forcing the release of norepinephrine into the synaptic cleft at the neuromuscular junction, independent of any neural signal (Fig. 1). This causes dilation of the pupil as long as the third-order neuron is intact. Prompt dilation occurs in a normal eye but also in an eye with a preganglionic Horner’s syndrome. Failure to dilate suggests that the presynaptic bulb has degenerated secondary to a lesion of the third-order neuron. A false-negative test can occur if the test is performed too soon after a third-order neuron insult, before atrophy of the presynaptic bulb has occurred. The test is generally considered accurate after the symptoms have been present for 2 to 3 weeks [53]. Like cocaine testing, a drop is placed in both eyes, with the unaffected eye serving as a control (Table 1).

In congenital Horner’s syndrome, preganglionic lesions may produce orthograde transsynaptic failure of the postganglionic oculosympathetic neuron. The hydroxyamphetamine test may therefore fail to dilate such a pupil, falsely localizing a lesion as postganglionic. The hydroxyamphetamine test may therefore be misleading in infants with Horner’s discovered during the first year of life [54,55].


Apraclonidine Apraclonidine (Iopidine; Alcon, Fort Worth, TX) is a direct alpha-adrenergic receptor agonist that lowers intraocular pressure by reducing aqueous production. It is commercially available as an eye drop for the treatment of glaucoma, and is approved as a treatment and prophylaxis for elevated intraocular pressure following argon laser trabeculoplasty. This agent primarily acts on post-junctional alpha-2 receptors in the (aqueous-secreting) ciliary body, decreasing aqueous production and hence lowering intraocular pressure. Apraclonidine also has a weak alpha-1 effect, which can be seen as conjunctival blanching from vasoconstriction of conjunctival vessels when placed topically. In normal eyes, apraclonidine has no appreciable effect on pupil size. However, Morales et al. [57] reported that 1% apraclonidine dilated the pupil in eyes with unilateral Horner’s syndrome. Patients with Horner’s syndrome were chosen for this glaucoma study because apraclonidine’s effect on intraocular pressure could be assessed without the potentially confounding systemic effect of oculosympathetic tone. The study showed that apraclonidine successfully lowered the pressure in both affected and normal eyes, and they concluded that the drug’s effect was indeed at the post-junctional alpha-2 receptors of the ciliary body, and any systemic effect (via oculosympathetic efferents) on intraocular pressure was negligible. Pupillary size was initially of secondary interest. However, the study showed that apraclonidine reliably dilated the Horner’s pupil but had no significant effect on the normal pupil. In fact, apraclonidine reversed the anisocoria in all six patients with Horner’s syndrome in this study (four were postganglionic, two were preganglionic). They proposed that the upregulation of post-junctional alpha-1 receptors in denervated sympathetic pupillary dilator muscles produced a pharmacologic supersensitivity in affected eyes (Fig. 1 inset). In normal eyes, any small degree of alpha-1 activity that might tend to dilate the pupil would be offset by apraclonidine’s presynaptic alpha-2 activity, which tends to downregulate the production and release of norepinephrine. In eyes with Horner’s syndrome, the activity becomes clinically visible with upregulation from denervation hypersensitivity, and loss of sympathetic tone negates the effect of further inhibition from alpha-2 activity. This study was the first to suggest that apraclonidine may indeed have clinical diagnostic value for Horner’s syndrome [57].

Cocaine requires a normal control eye to demonstrate greater dilation than the affected pupil to produce a “positive” test. The active effect of apraclonidine suggests that apraclonidine could possibly be used to test for oculosympathetic paresis in a patient with suspected bilateral Horner’s syndrome.

Apraclonidine did reverse the ptosis in the majority of patients with Horner’s syndrome, but it also elevated the eyelids in 45% of normal eyes. Thus, reversal of ptosis with apraclonidine is not useful in diagnosis but may be a consideration for symptomatic relief in patients with Horner’s syndrome [63,66].


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Neuro-ophthalmology Questions of the Week: Anisocoria #8 Horner Syndrome - Hydroxyamphetamine

Questions:


1. A positive Hydroxyamphetamine pharmacologic test for Horner Syndrome indicates a problem in which neuron of the sympathetic chain?


a. 1st order neuron (preganglionic)

b. 2nd order neuron (preganglionic)

c. 3rd order neuron (postganglionic)

2. How reliable is the Hydroxyamphetamine pharmacologic test for Horner Syndrome?

a. sensitivity of 100% and specificity of 100%

b. sensitivity of 93% and specificity of 83%

c. sensitivity of 83% and specificity of 73%

d. sensitivity of 73% and specificity of 63


____________________________________________________________

Answers:

1. c. 3rd neuron (postganglionic)

2. b. sensitivity of 93% and specificity of 83%


Reference:

1. http://eyewiki.aao.org/Horner's_syndrome#Pathophysiology

The pupil is innervated by sympathetic and parasympathetic fibers. Pupillary dilation is mediated by a three- neuron sympathetic pathway that originates in the hypothalamus.

The first order (central) neuron descends caudally from the hypothalamus to the first synapse in the cervical spinal cord (C8-T2 level-also called the ciliospinal center of Budge). The descending sympathetic tract is in close proximity to other tracts and nuclei in the brainstem.

The second order (preganglionic) neuron destined for the head and neck exits the spinal cord and travels in the cervical sympathetic chain through the brachial plexus, over the pulmonary apex and synapses in the superior cervical ganglion. The superior cervical ganglion is located near the angle of the mandible and the bifurcation of the common carotid artery.

The third order (postganglionic) neuron for the orbit enters the cranium within the adventitia of the internal carotid artery into the cavernous sinus. Here the oculosympathetic fibers exit the internal carotid artery in close proximity to the trigeminal ganglion and the sixth cranial nerve and join the 1st division of the trigeminal nerve to enter the orbit. The fibers (long ciliary nerve) innervate the dilator muscles of the iris and the Müller’s muscle in the upper and lower lid.

The vasomotor and sudomotor fibers to the face exit the superior cervical ganglion and ascend in the external carotid artery.

Pupillary constriction is produced by parasympathetic (cholinergic) fibers that travel with the third cranial (oculomotor) nerve.”

http://www.pacificu.edu/optometry/ce/courses/19433/pupilanompg1.cfm


2. Hydroxyamphetamine mydriasis in Horner’s syndrome. Cremer SA, Thompson S, Digree KB, et al. Am J Ophthalmol 1990;110:71–6.

Using 1% Hydroxyamphetamine 1 drop to each eye, the eyes wiped, and a second drop administered about 20-40 seconds later, the mean probability that a patient with a 1.5-mm difference in dilation has a postganglionic lesion in the oculosympathetic pathway was 96% while a difference of 1.0-mm had a mean probability of 85.5%. In this study 5 of 30 patients with postganglionic lesions had a difference in dilation of less than 1.0.mm.

When the lesion was judged to be preganglioinic or central (nonpostganglionic) the difference in dilation was negative or zero 83% of the time (specificity = 83%).


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Neuro-ophthalmology Questions of the Week: Anisocoria #7 Horner Syndrome - Apraclonidine

Reference 1.


Questions:

1. How reliable is the Apraclonidine pharmacologic test for Horner Syndrome?

a. less reliable than cocaine

b. at least as reliable as cocaine

c. more reliable than cocaine


2. In children up to what age may Apraclonidine cause lethargy, bradycardia, or a reduced respiratory rate for up to 2 hours?

a. 3 months

b. 6 months

c. 1 year

d. 2 years


Correct Answers:

Question 1. b. at least as reliable as cocaine

Question 2. b. 6 months

References: (emphasis added)

1. The sensitivity and specificity of 0.5% apraclonidine in the diagnosis of oculosympathetic paresis. F Koc, S Kavuncu, T Kansu, G Acaroglu, E Firat. Br J Ophthalmol 2005;89:1442–1444.

Aims: To evaluate the sensitivity and specificity of 0.5% apraclonidine test in the diagnosis of oculosympathetic paresis (OSP).

Method: Apraclonidine (0.5%) was administered to 31 eyes, nine with a diagnosis of Horner syndrome (HS), 22 with bilateral OSP caused by diabetes, and to 54 control eyes. All were confirmed with the cocaine test. The effects on pupil diameter and upper eyelid level were observed 1 hour later.

Results: Apraclonidine caused a mean dilation of 2.04 mm (range 1–4.5) (p<0.001) in the pupils with OSP and it caused pupillary constriction in the control eyes with a mean change of -0.14 mm (range 0.5-1) (p<0.05). It caused reversal of anisocoria in all HS cases. Its effects on both pupil diameters and upper lid levels differed significantly between the groups (p<0.001). The mean elevation in the upper lid was 1.75 mm (range 1–4) in the OSP group (p<0.001) and 0.61 mm (range 0–3) in the control group (p<0.001).

Conclusion: The effect of the apraclonidine (0.5%) test on the pupil diameter was diagnostic for OSP and had at least the same sensitivity and specificity as the cocaine test for the diagnosis of OSP.


2.  Adverse effects of apraclonidine used in the diagnosis of Horner syndrome in infants. Watts S, et al. Journal of AAPOS 2007:11(3):282-283

The reported adverse effects included in this report suggest that apraclonidine should be used with caution or not at all, in infants under the age of 6 months. Though a reduced concentration of apraclonidine (0.5%) is also effective in the diagnosis of Horner syndrome,8 it is the immaturity of the blood-brain barrier in young infants that permits central nervous system depression suggesting that patients may still be at risk.9 If apraclonidine must be used in infants younger than 6 months of age, the patient should be observed for a period of at least 2 hours after instillation of the drops, with admission to a pediatric ward prompted by lethargy, bradycardia, or a reduced respiratory rate.”


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Neuro-ophthalmology Question of the Week: Anisocoria #6 Horner Syndrome Cocaine Test Continued

Fig. 5.3. Right Horner's syndrome http://www.clicktocurecancer.info/optic-nerve/id.html

Question:

Which of the following are correct?

1. A positive cocaine test (a mydriatic response to cocaine that is at least 1.0 mm less than in the unaffected eye) only occurs with Horner syndrome.

2. A negative cocaine test (a mydriatic response to cocaine that is NOT at least 1.0 mm less than in the unaffected eye) rules-out Horner Syndrome.

3. The magnitude of the response to cocaine is related to the site of the lesion in he sympathetic system. 

4. The cocaine test for Horner syndrome affects a urine test for cocaine for up to 2 hours.

_________________________________

Correct Answer:

1. A positive cocaine test (a mydriatic response to cocaine that is at least 1.0 mm less than in the unaffected eye) only occurs with Horner syndrome.

References: (emphasis added)

1. The diagnosis of Horner’s syndrome:  use and limitations of the cocaine test. Van der Wiel HL, Van Gijn J.  J Neurol Sci.  1986;74:311-316

We prospectively studied the value of the cocaine test in the diagnosis of Horner's  syndrome, by performing the test in 20 control subjects and in 20 patients with a  provisional diagnosis of Horner's syndrome. Photographic testing of the darkness reflex of the pupil was used as an independent criterion of oculosympathetic dysfunction, and  confirmed the diagnosis in 12 of the 20 patients. A mydriatic response to cocaine that was at least 1.0 mm less than in the unaffected eye occurred only with Horner's  syndrome (7 patients). On the other hand, if the difference is smaller than 1.0 mm the  chance that the patient does not have Horner's syndrome is only around 60%There  was no relationship between the magnitude of the response to cocaine and the site of  the lesion in the sympathetic system.

...if a difference between the two eyes of 1.0 mm or more is considered to be evidence of Horner's syndrome, the predictive value of an abnormal test result is 100 % (7/7; 95 % confidence interval 59-100%), that of a normal test result 62 % (8/13; 95 % confidence interval 32-86 %).

2. Duration of positive urine for cocaine metabolite after ophthalmic administration: implications for testing patients with suspected Horner syndrome using ophthalmic cocaine. Jacobson DM, Berg R, Grinstead GF, Kruse JR. Am J Ophthalmol. 2001 Jun;131(6):742-7.

Patients should be informed that their urine may test positive for cocaine, if assayed according to US federal guidelines and using the protocol employed in this study, up to 2 days after undergoing testing for Horner syndrome.

 

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Neuro-ophthalmology Questions of the Week: Anisocoria #5 Horner Syndrome & the Cocaine Test

Fig. 5.3. Right Horner's syndrome http://www.clicktocurecancer.info/optic-nerve/id.html


Questions:

1. What is the approximate mean odds ratio for the Cocaine pharmacologic test for Horner syndrome assuming a postcocaine anisocoria of at least 0.8mm?

a.       10:1

b.     100:1

c.   1,000:1

d. 10,000:1


2. Which of the following races may not dilate well with topical cocaine?

a. Asians

b. African Americans

c. Caucasians

d. Native Americans


______________________________________________________________________


Correct Answers:

1. d. 10,000:1 (Reference 1)

2. b. African Americans (References 2 & 3)


References:

1. Critical evaluation of the cocaine test in the diagnosis of Horner's syndrome - Kardon et al, - Arch Ophthalmol. 1990;108:384-387

We evaluated the effectiveness of the cocaine test for diagnosing Horner's syndrome. The test was administered to 119 patients with a diagnosis of Horner's syndrome and to 50 normal subjects. We compared the cocaine-induced anisocoria in the two groups by measuring photographs of the pupils. We found the cocaine test to be highly effective in separating normal subjects from patients with Horner's syndrome. The chances of having Horner's syndrome increased with the amount of cocaine-induced anisocoria. Through the use of logistic regression analysis, we determined the odds ratio of having Horner's syndrome compared with not having it for each 0.1-mm increment of anisocoria measured after cocaine administration. A postcocaine anisocoria value of 0.8 mm gave a mean odds ratio of approximately 1050:1 that Horner's syndrome was present (lower 95% confidence limit ° 37:1). (emphasis added) We found that simply measuring the postcocaine anisocoria provided a better prediction of Horner's syndrome than taking the trouble to calculate the net change in anisocoria. Odds ratios should help the clinician decide if the result of a cocaine test is indicative of Horner's syndrome.


2. The cocaine test in normal patients.  Friedman JR, Whiting DW, Kosmorsky GS, Burde RM. Am J Ophthalmol. 1984;98:808-81

Of 24 normal patients 20 had less than 0.5 mm of asymmetry in response to two drops of 10% topical cocaine five minutes apart. “The development of anisocoria of more than 0.5 mm is necessary for the diagnosis of Horner’s syndrome to be made using cocaine.” Individual variation between the two normal eyes, “although minimal, does exist in white patients. No such conclusion could be drawn for black patients because of their overall lack of response to the application of topical cocaine routinely used. The cocaine test may not be appropriate for use in black patients to diagnose Horner’s syndrome.” (emphasis added)


3. The Diagnosis of Horner's Syndrome Use and Limitations of the Cocaine Test. H.L. Van der Wiel and J. Van Gijn. Journal of the Neurological Sciences, 1986, 73:311-316 311

In the only two black control subjects (with dark brown irises), the pupils dilated

by only 0.3 mm or less, which was confirmed on repeated testing.” (emphasis added)




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Neuro-ophthalmology Question of the Week: Anisocoria #4 Horner Syndrome Dilation Lag in Darkness

http://content.lib.utah.edu/cdm/singleitem/collection/EHSL-Moran-Neuro-opth/id/120/rec/2
Left-sided dilation lag in a 29-year-old man with Horner's syndrome caused by a posterior mediastinal ganglioneuroma. Note that the degree of anisocoria is greater after 5 seconds in darkness (top) compared with findings after 15 seconds in darkness (bottom).

Question:

How often is a dilation lag present in a patient with Horner Syndrome on the initial determination?

a. 100%

b.    85%

c.    70%

d.    50%

_____________________________________________________________

Correct Answer:

b. 85%


Reference:

Pupillary dilation lag is intermittently present in patients with a stable oculosympathetic defect (Horner syndrome).

Crippa SV, Borruat FX, Kawasaki A. Am J Ophthalmol. 2007; 143(4):712-5

PURPOSE: To examine the repeatability of detecting pupillary dilation lag in patients with Horner syndrome.

DESIGN: Retrospective interventional study.

METHODS: Setting: Single referral institution. Patient population: Fifteen patients with unilateral Horner syndrome and 16 subjects with physiologic anisocoria. Intervention procedure: Each subject underwent four pupillometric recordings in darkness. The asymmetry of pupillodilation between the two eyes was calculated as the change in anisocoria between five seconds and 15 seconds in darkness. Pupillary dilation lag was considered present if the asymmetry measured > or =0.4 mm. Main outcome measure: Asymmetry of pupillodilation over four determinations.

RESULTS: All subjects demonstrated fluctuations in the calculated asymmetry of pupillodilation. Eight patients(53%) with Horner syndrome demonstrated dilation lag on the first determination; 13 patients (87%) eventually demonstrated it during four determinations.

CONCLUSIONS: Pupillary dilation lag is intermittently present in most patients with Horner syndrome. Repeated observations improve the detection rate of dilation lag, a confirmatory sign of an oculosympathetic deficit. Its absence does not rule out Horner syndrome. (emphasis added)


AAO Eye Net - Video Horner Syndrome Dilation Lag http://www.aao.org/publications/eyenet/201206/


Sam Tapsell How to Examine Horner's Syndrome  http://www.youtube.com/watch?v=JBVGh0gyyYc


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Neuro-ophthalmology Question of the Week: Anisocoria #3 - Adult Horner Syndrome - Value of Imaging


Questions:

1. When the etiology of a case of Horner syndrome is NOT known at the time of presentation, and clinical information permits a targeted imaging evaluation, how often is an etiology discovered?

a. In about 90%

b. In about 60%

c. In about 30%

d. In about 10%


2.  What are the two most common causes of Horner syndrome when the cause is NOT known at the time of presentation and clinical information permits a reasonably inferred targeted imaging evaluation?

a. Apical lung malignancy

b. Carotid artery dissection

c. Cavernous sinus lesion

d. Thyroid malignancy


3. How often is the cause of a case of Horner syndrome discovered when it is NOT known at the time of presentation and clinical information is insufficient to allow a reasonably inferred  targeted imaging evaluation?

a. In about 80%

b. In about 60%

c. In about 30%

d. In about 10%


_______________________________________________


Correct Answer(s):

1. b. In about 60%

2. b. Carotid artery dissection & c. Cavernous sinus lesion

3. d. In about 10%


Reference: Diagnostic Value of Imaging Horner Syndrome in Adults

Almog et al: J Neuro-Ophthalmol 2010; 30: 7-11

Background: The yield of imaging in Horner syndrome has been explored only in children. This study evaluates the yield of imaging in adults.

Methods: This was a retrospective cohort study of 52 patients with Horner syndrome examined in 2 neuroophthalmology hospital clinics. Patients were divided into 3 groups according to the ability to determine the etiology at the time of the first neuro-ophthalmology consultation: group I, etiology of Horner syndrome known at the initial neuro-ophthalmologic examination; group II, etiology of Horner syndrome not known at the initial neuro-ophthalmologic examination, but sufficient information obtained to allow targeted imaging; and group III, etiology of Horner syndrome not known at the initial neuro-ophthalmologic examination, and sufficient information not obtained to allow targeted imaging. The yield of investigation and the frequency of the different etiologies were evaluated.

Results: In 32 (62%) patients, the etiology was already known at the initial neuro-ophthalmologic examination (group I). The most prevalent etiology was surgical trauma. In 11 (21%) patients, a targeted imaging workup was possible, revealing an etiology in 7 patients (group II). Carotid dissection and cavernous sinus mass were the most common etiologies. In 9 (17%) patients, a nontargeted imaging evaluation was necessary, revealing an etiology in only 1 patient, who had a previously undetected thyroid malignancy (group III).

Conclusions: The etiology of Horner syndrome is usually known at the time of initial presentation to a neuroophthalmologist. When the etiology is not known and clinical information permits a targeted imaging evaluation, an etiology can usually be determined, most commonly a cervical carotid artery dissection or a cavernous sinus mass. When the etiology is not known and clinical information is insufficient to allow a targeted imaging evaluation, an etiology is rarely discovered. Even so, nontargeted imaging is warranted because life-threatening lesions, such as thyroid malignancies, may rarely be detected.  (emphasis added)


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Neuro-ophthalmology Question of the Week: Non-physiologic Anisocoria 2


From: Kellogg Eye Center University of Michigan

Question:

A patient presents with 1 mm of anisocoria with the left pupil being larger. Your examination of the pupils reveals: 1. each pupil reacted briskly to light, 2. the swinging flashlight test was normal, 3. the anisocoria was greater in a very dim room, and 4. at 15 seconds after dimming the room lights the right eye has not completed its dilation.

Which of the following possibilities should be considered?

1. Adie's pupil

2. Horner's syndrome

3. Chemical blockade

4. Iris sphincter damage

____________________________________________


Correct Answer:

2. Horner's syndrome


References:


1. Anisocoria http://www.kellogg.umich.edu/theeyeshaveit/symptoms/anisocoria.html

“What causes it?

Anisocoria, or a difference in the diameter of the pupils in dim illumination, may be physiologic if the difference is less than 1 mm and both pupils react briskly and equally to light. Otherwise it may be pathologic.

There are four possible causes:

  • Parasympathetic innervation failure causes a relatively dilated pupil that reacts sluggishly to direct light.

The major concern, as with ptosis, is a third cranial nerve palsy, especially one caused by an aneurysm. However, anisocoria is never caused by a third nerve palsy unless there are other signs of a third cranial nerve palsy—ptosis, reduced ocular movements, or ocular misalignment.

A common cause of isolated anisocoria is a viral infection of the ciliary ganglion (Adie's syndrome), an orbital structure that receives the parasympathetic component of the third cranial nerve.

  • Horner's syndrome causes anisocoria in which the affected pupil is smaller, but both pupils react briskly to light. Ptosis is usually present but is always mild (2 mm or less).

For more information on Horner's syndrome see Ptosis in this section.

  • Chemical blockade. If parasympatholytic (atropine-like) chemicals come in contact with the conjunctiva by accidental (or deliberate!) instillation, they will deactivate the iris sphincter muscle and cause (often very wide) pupil dilation.

This occurs most commonly among hospital personnel and those exposed to atropine-containing plants.

  • Iris sphincter damage. Inflammation and trauma to the iris sphincter are other causes of anisocoria. The pupil is usually irregular in shape and magnified examination shows evidence of muscle damage.

What to do?

If you suspect third cranial nerve palsy, refer immediately for brain imaging. Other suspected diagnoses can wait, but anisocoria must always be evaluated unless you are convinced it is physiologic.”


2. Horner Syndrome Video http://youtu.be/JBVGh0gyyYc - Dr. Sam Stapsell


3. Neurology Update Blog - Anisocoria - Dr Holland -  Monmouth Neuroscience Institute http://mmcneuro.wordpress.com/2013/02/26/anisocoria-unequal-pupils/


4. UpToDate - Approach to the patient with anisocoria figure 1


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Neuro-ophthalmology Question of the Week: Non-physiologic Anisocoria 1

www.nanosweb.org

Question:

A patient presents with anisocoria. Your examination of the pupils reveals that the right pupil reacted briskly to light, whereas the larger left pupil was very sluggishly reactive.

Which of the following possibilities should be considered?

1. Adie's pupil

2. 3rd nerve palsy

3. Chemical blockade 

4. Iris sphincter damage

____________________________________________________________


Correct Answers: all are correct.


References:

1. http://www.kellogg.umich.edu/theeyeshaveit/symptoms/anisocoria.html

Anisocoria, or a difference in the diameter of the pupils in dim illumination, may be physiologic if the difference is less than 1 mm and both pupils react briskly and equally to light. Otherwise it may be pathologic.

There are four possible causes:

  • Parasympathetic innervation failure causes a relatively dilated pupil that reacts sluggishly to direct light.

  • The major concern, as with ptosis, is a third cranial nerve palsy, especially one caused by an aneurysm. However, anisocoria is never caused by a third nerve palsy unless there are other signs of a third cranial nerve palsy—ptosis, reduced ocular movements, or ocular misalignment.

  • A common cause of isolated anisocoria is a viral infection of the ciliary ganglion (Adie's syndrome), an orbital structure that receives the parasympathetic component of the third cranial nerve.

  • Horner's syndrome causes anisocoria in which the affected pupil is smaller, but both pupils react briskly to light. Ptosis is usually present but is always mild (2 mm or less).

  • For more information on Horner's syndrome see Ptosis in this section.

  • Chemical blockade. If parasympatholytic (atropine-like) chemicals come in contact with the conjunctiva by accidental (or deliberate!) instillation, they will deactivate the iris sphincter muscle and cause (often very wide) pupil dilation.

  • This occurs most commonly among hospital personnel and those exposed to atropine-containing plants.

  • Iris sphincter damage. Inflammation and trauma to the iris sphincter are other causes of anisocoria. The pupil is usually irregular in shape and magnified examination shows evidence of muscle damage.

What to do?

If you suspect third cranial nerve palsy, refer immediately for brain imaging. Other suspected diagnoses can wait, but anisocoria must always be evaluated unless you are convinced it is physiologic.”


2. Neurology Update Blog - Anisocoria - Dr Holland -  Monmouth Neuroscience Institute http://mmcneuro.wordpress.com/2013/02/26/anisocoria-unequal-pupils/

3. Success in MRCOphth - Animated Clip Art Anisocoria http://www.mrcophth.com/eyeclipartchua/pupils.html

4. A Five Minute Anisocoria Video Lecture - Dr. Sam Stapsell http://www.youtube.com/watch?v=jgVJyEOXVvM


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Neuro-ophthalmology Question of the Week: Physiologic Anisocoria

http://www.kellogg.umich.edu/theeyeshaveit/symptoms/anisocoria.html


Question 1:

Which of the following are correct for physiologic anisocoria of 0.4 mm?

1. It is present in about 5% of the population at any given time.

2. It is present in about 10% of the population at any given time.

3. It is present in about 15% of the population at any given time.

4. It is present in about 20% of the population at any given time.


Question 2:

Which of the following are correct for physiologic anisocoria of 0.4 mm?

1. It is present all the time in about 1% individuals.

2. It is present all the time in about 3% individuals.

3. It is present all the time in about 7% individuals

4. It is present all the time in about 10% individuals


Question 3:

Which of the following are required for anisocoria to be physiologic?

1. Both pupils must react briskly to light

2. The swinging flashlight test must be normal (no relative afferent pupillary defect.)

3. There must be no dilation lag 5-15 seconds after room illumination is reduced to near darkness.

4. The patient must not be aware of the anisocoria.

__________________________________________________________


Questions with correct answers:


Question 1:

Which of the following are correct for physiologic anisocoria of 0.4 mm?

1. It is present in about 5% of the population at any given time.

2. It is present in about 10% of the population at any given time.

3. It is present in about 15% of the population at any given time.

4. It is present in about 20% of the population at any given time.


Correct Answer:

4. It is present in about 20% of the population at any given time.


Question 2:

Which of the following are correct for physiologic anisocoria of 0.4 mm?

1. It is present all the time in about 1% individuals.

2. It is present all the time in about 3% individuals.

3. It is present all the time in about 7% individuals

4. It is present all the time in about 10% individuals


Correct Answer:

2. It is present all the time in about 3% individuals.


Question 3:

Which of the following are required for anisocoria to be physiologic?

1. Both pupils must react briskly to light

2. The swinging flashlight test must be normal (no r relative afferent pupillary defect).

3. There must be no dilation lag 5-15 seconds after room illumination is reduced to near darkness.

4. The patient must not be aware of the anisocoria.

Correct Answers:

1, 2. and 3 are correct.


References:

1. The prevalence of simple anisocoria. Lam BL, Thompson HS, Corbett JJ. Am J Ophthalmol. 1987;104(1):69.

“We photographed the pupils of 128 normal subjects in dim light, morning and afternoon, for five consecutive days. Fifty-two of the subjects (41%) had an anisocoria of 0.4 mm or more at one time or another during these five days, but only four (3%) had unequal pupils of 0.4 mm or more in all ten photography sessions. At any given examination, a fairly constant 19% (24 of 128) of the subjects showed this amount of anisocoria. These numbers shifted dramatically when anisocoria was defined as a pupillary inequality of greater than, or less than, 0.4 mm. The prevalence of anisocoria did not vary with the time of day, from day to day, or from week to week, nor was it influenced by the sex, age, or iris color of the subject.”

2. Anisocoria http://www.kellogg.umich.edu/theeyeshaveit/symptoms/anisocoria.html


3. How to Examine the Normal Pupils - Dr. Sam Stapsell http://youtu.be/E2XzBaOOX8g


4.
Case 4.7 - Dr. Sam Stapsell http://www.youtube.com/watch?v=kzqgB2mPmGg&feature=c4-overview&list=UU7K3GgfCdrrvLRi3MiQOV4Q


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Please send feedback, questions and corrections to tcooper@stanford.edu.  


Neuro-ophthalmology Question of the Week: Aberrant Regeneration of the Third Nerve

Question:

Which of the following are correct for aberrant regeneration of the third nerve.

1. It is likely to be due to microvascular ischemia to the third nerve.

2. It is likely to be due to compression of the third nerve.

3. It is likely to be due to trauma to the third nerve.

4. It is likely to follow a third nerve palsy from multiple sclerosis.


photo

Image: Aberrant Regeneration of Third Nerve

____________________________________________________________

Correct Answers:

2. It is likely to follow compression of the third nerve.

3. It is likely to follow trauma to the third nerve.


Reference:

Aberrant regeneration of the third nerve follows trauma or occurs with compression of the third nerve. The branches of the third nerve originally destined for one muscle aberrantly regenerate to innervate a different muscle, including the pupillary sphincter and ciliary muscles. Aberrant regeneration is not seen after nerve palsies from a microvascular occlusive etiology or multiple sclerosis.  It occurs with traumatic and compressive lesions such as tumors, aneurysms and is an indication for neuro-imaging. Neuro-Ophthalmology Illustrated. Biousse V & Newman NJ. 2009


The key clinical finding of aberrant regeneration of the third nerve is over action of one of the muscle it innervates with attempts to perform one of the functions of the third cranial nerve (elevation, depression,  adduction, convergence or accommodation).

Typical positive findings include:

1. the pupil of the affected eye constricts on attempted elevation, depression, or adduction of the eye,

2. the eyelid of the affected eye elevates on attempted depression, adduction, convergence or accommodation.


In a review of “39 cases and looked for any signs of aberrant regeneration in either the pupil, the lid or motility. In about 78% of cases, he found some aberrant regeneration of the pupil. The pupil got smaller on adduction in some cases, or smaller on infraductions or supraductions or smaller with a combination.

The lid was involved in about 77% of cases, and motility in about 33%. These cases overlapped —56% involved both the pupil and lid, and 25% involved the pupil, lid and motility.” http://www.healio.com/news/print/ocular-surgery-news-europe-asia-edition/%7BE04F6128-3694-47DF-908F-32CDE0D37706%7D/Warning-signs-reveal-aberrant-nerve-regeneration


photo

Image: Aberrant Regeneration of Third Nerve

The left pupil is smaller than the right with the eyes in primary position.

On right gaze the left pupil constricts.

Fibers to the left medial rectus muscle have aberrantly regenerated and innervated the left pupillary sphincter muscle. http://www.healio.com/news/print/ocular-surgery-news-europe-asia-edition/%7BE04F6128-3694-47DF-908F-32CDE0D37706%7D/Warning-signs-reveal-aberrant-nerve-regeneration


Case 64

Image: Aberrant Regeneration of Third Nerve

There is elevation of the left eyelid on right gaze, down gaze. http://telemedicine.orbis.org/bins/volume_page.asp?cid=1-2161-2379-2435-2504



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Please send feedback, questions and corrections to tcooper@stanford.edu.  


Neuro-ophthalmology Question of the Week: Horner Syndrome & 4th Nerve Palsy

Question

What is the location of a lesion causing a Horner syndrome in the right eye and a 4th cranial nerve palsy in the left eye?



1. Midbrain

2. Pons

3. Medulla

4. Cavernous sinus

_______________________________________________________


Correct Answer:

1. Midbrain on the right


Reference: Contralateral trochlear nerve paresis and ipsilateral Horner's syndrome. Guy J, Day AL, Mickle JP, Schatz NJ.Am J Ophthalmol. 1989 Jan 15;107(1):73-6. Source: Department of Opthalmology, University of Florida, College of Medicine, Gainesville 32610.

Abstract

Two patients had paresis of the trochlear nerve contralateral to the site of lesions in the brainstem. Both patients had ipsilateral blepharoptosis and miosis suggesting oculosympathetic paresis from involvement of the descending sympathetic tract, adjacent to the fourth cranial nerve nucleus and its fascicles, in the caudal mesencephalon. Cerebral angiography documented an arteriovenous malformation of the brainstem in Case 1. Magnetic resonance imaging disclosed a lesion of high signal intensity on T2-weighted images involving the dorsal mesencephalon in Case 2. Involvement of the superior cerebellar peduncle produced ipsilateral dysmetria and ataxia. Lesions involving the fourth cranial nerve nucleus or its fascicles, before decussation in the superior medullary velum, and adjacent sympathetic fibers may produce an ipsilateral Horner's syndrome and contralateral superior oblique muscle paresis.



http://what-when-how.com/neuroscience/brainstem-iii-the-midbrain-organization-of-the-central-nervous-system-part-1/



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Please send feedback, questions and corrections to tcooper@stanford.edu.  

Neuro-ophthalmology Question of the Week: Pupils in Patients with Coma

Question:

Which of the following are correct for patients who present to the emergency department with a Glasgow coma scale of 7 or less?

1. The cause of coma in a patient with anisocoria is more likely to be due to metabolic than a structural cause.

2. Coma is due to a metabolic cause in over 80% of cases.

3. The absence of the light reflex is a more sensitive indicator of structural causes of coma than anisocoria but is less specific.

4. The Glasgow coma scale ranges from 3 to 15 and is based on eye opening, verbal response and motor response.

_____________________________________________________________

Correct Answer(s):

3. The absence of the light reflex is a more sensitive indicator of structural causes of coma than anisocoria but is less specific.

4. The Glasgow coma scale ranges from 3 to 15 and is based on eye opening, verbal response and motor response


References:

Pupillary evaluation for differential diagnosis of coma. , Postgrad Med J 2003;79:49-51

Objectives: To determine the usefulness of bedside evaluation of pupils in determining the aetiology of coma by adopting a probabilistic approach.

Patients and methods: One hundred and fifteen consecutive patients presenting with coma were enrolled in this prospective cohort during the 12 month study period in the emergency room of a community teaching hospital. Patients underwent structured clinical examinations and laboratory and imaging tests. Assignment of aetiology of coma was based on strict adherence to predetermined criteria and achieved by consensus of the two physician investigators. One year follow up was obtained in all patients.

Results: Aetiology of coma was determined in 98% of the patients. It was metabolic in 69 patients (60%) and structural in 46 patients (40%). Metabolic causes included drug overdose, acute alcohol intoxication, hypoglycaemia, sepsis, and pneumonia. Structural causes included intracerebral haemorrhage, subarachnoid haemorrhage, cerebral infarction, subdural haematoma, and epidural haematoma. Multivariate logistic regression analysis showed light reflex loss (likelihood ratio for positive test result 3.59) and anisocoria (likelihood ratio for positive test result 9.0) as independent predictors

of structural origin.

Conclusions: In this prospective study of patients presenting to the emergency room of a community based teaching hospital with coma, in about 60% the coma is of metabolic origins and in about 40% of structural origins. Light reflex loss and anisocoria suggest a structural aetiology.  


Glasgow Coma Scale  http://en.wikipedia.org/wiki/Glasgow_Coma_Scale

http://www.braininjuryhawaii.com/wp-content/uploads/2011/03/Glasgow_Coma_Scale_Chart.gif


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Please send feedback, questions and corrections to tcooper@stanford.edu.  

Neuro-ophthalmology Question of the Week: Pupil Light Reflex Anatomy

Question:

Which of the following structures are NOT involved in the pupil light reflex?

1. Retina

2. Chiasm

3. Optic tracts

4. Lateral geniculate nucleus

5. Optic radiations

6. Occipital lobes

7. Pretectal nuclei of dorsal midbrain

8. Edinger-Westphal nuclei

9. Third cranial nerve

10. Ciliary ganglion

11. Short ciliary nerves

Animation that illustrates the pupillary light...

 
(Photo credit: Wikipedia)



Enhanced by Zemanta
______________________________________________

Correct Answers: 4. Lateral geniculate nucleus, 5. Optic radiations, & 6. Occipital lobes


Reference: Neuro-Ophthalmology Illustrated. Biousse V & Newman NJ, Theime Medical Publishers 2009 272

“Pupillary constriction to light is mediated via parasympathetic (cholinergic) nerve fibers that travel along the third cranial nerve. When light is shone into one eye, both pupils constrict symmetrically (direct and consensual response to light). Light information from retinal ganglion cells travels through the optic nerve, chiasm, (where the nasal fibers decussate), and optic tracts to reach the pretectal nuclei of the dorsal midbrain.

Afferent pupillary fibers leave the optic tract before the lateral geniculate nucleus via the brachium of the superior colliculus to reach the pretectal nuclei (explaining why lesions of the geniculate nucleus, the optic radiations or the visual cortex do not affect pupillary size or pupillary reactivity, and why lesions of the brachium of the superior colliculus can cause a relative afferent pupillary defect without visual loss).

Both pretectal nuclei receive input from both eyes, and each sends axons to both Edinger-Westphal nuclei (connections are bilateral but predominantly from the contralateral nucleus). Parasympathetic fibers of pupillary constriction leave the Edinger-Westphal nucleus and travel along the ipsilateral third cranial nerve to the ipsilateral ciliary ganglion within the orbit.”

The postganglionic parasympathetic fibers from the ciliary ganglion travel in the short ciliary nerve to “innervate the ciliary muscle (for lens accommodation) and the pupillary sphincter muscle (for pupil construction) in a proportion of 30:1.”  


Interactive Animated Light Reflex

http://www.tedmontgomery.com/the_eye/reflex.html



Wikipedia

“The long ciliary nerves, two or three in number, are given off from the nasociliary, as it crosses the optic nerve.

They accompany the short ciliary nerves from the ciliary ganglion, pierce the posterior part of the sclera, and running forward between it and the choroid, are distributed to the iris and cornea.

The long ciliary nerves provide sensory innervation to the eyeball, including the cornea. In addition, they contain sympathetic fibers from the superior cervical ganglion to the dilator pupillæ muscle. The sympathetic fibers to the dilator pupillae muscle mainly travel in the nasociliary nerve but there are also sympathetic fibers in the short ciliary nerves that pass through the ciliary ganglion without forming synapses.”


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Please send feedback, questions and corrections to tcooper@stanford.edu.  

Neuro-ophthalmology Question of the Week: Third Nerve Palsy

Question (multiple choice):

When examining the extraocular motility of a patient who is recovering from a presumed vasculopathic third nerve palsy, it is noted that the left upper lid elevates with adduction and downgaze. Which of the following should be considered as likely potential causes?

Image 20-19:http://telemedicine.orbis.org/bins/content_page.asp?cid=735-2858-4397-2804-3110-3023-3024-3054

1. Vasculopathic third nerve palsy in a diabetic patient

2. Vasculopathic third nerve palsy in a patient with hypertension and hyperlipidemia

3. Third nerve palsy from aneurysm

4. Third nerve palsy from tumor

________________________________________________________________

Correct Answer(s): 3 & 4


Reference: Big red flags in neuro-ophthalmology. Ling et al. Can J Oph:48:1:3-7

Red flag 4: Aberrant Regeneration of the Third Cranial Nerve Is Not Due to Ischemia

When a peripheral nerve like the third cranial nerve is damaged from compression or trauma, the nerve will attempt to regenerate. The regenerative process may result in partial or complete recovery of third nerve function, but sometimes the regeneration process is aberrant and fibers destined for the originally innervated muscle might regenerate aberrantly to another muscle. Aberrant regeneration of cranial nerve III most commonly results from trauma, aneurysms, and tumors, and is not a feature of ischemic (e.g., diabetic) vasculopathic cranial neuropathy. If aberrant regeneration presents in the setting of a presumed vasculopathic third nerve palsy, then additional neuroimaging is imperative to evaluate for a compressive

lesion (e.g., aneurysm or tumor). The recommended neuroimaging to evaluate an aneurysmal cause for an acute third nerve palsy believed to be aneurysmal in origin is typically CT angiography, but for chronic, compressive causative factors of a third nerve palsy with aberrant regeneration, MRI/magnetic resonance angiography with contrast is recommended. The most common clinical findings of aberrant regeneration are eyelid retraction with adduction, elevation, or depression (pseudo–von Graefe sign); abnormal extraocular muscle firing (e.g., adduction with elevation); or pupillary miosis with elevation, adduction, or depression

(Fig. 7)10. Thus, the red flag of interest to ophthalmologists that should prompt neuroimaging is the development of aberrant regeneration in a patient with an improving presumed vasculopathic (e.g., diabetic) third nerve palsy. In such a case, a compressive lesion (e.g. aneurysm or tumor) often in the cavernous sinus should be suspected.


Fig. 5 — Axial magnetic resonance image, T1 weighted, without fat suppression, showing bilateral enlarged superior ophthalmic veins in carotid cavernous fistula with arterialized flow signal in the veins at the arrows.


Fig. 6 — Catheter angiography illustrates both anterior and posterior drainage in a carotid cavernous fistula.


Fig. 7 — Aberrant regeneration of the third cranial nerve. Patient sustains a left eye adduction when attempting to look up.



Aberrant regeneration of iris sphincter by misdirected medial rectus nerve fibers OS.

SOURCE: RANDY H. KARDON, MD, PHD MONT TREMBLANT, Canada

http://www.healio.com/news/print/ocular-surgery-news-europe-asia-edition/%7BE04F6128-3694-47DF-908F-32CDE0D37706%7D/Warning-signs-reveal-aberrant-nerve-regeneration


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Please send feedback, questions and corrections to tcooper@stanford.edu.

Neuro-ophthalmology Question of the Week: Optic Tract Syndrome

Question: Which of the following statements about the optic tract syndrome are correct?
1. The visual field defect is an incongruous homonymous hemianopia that is on the same side as the lesion,.
2. A relative afferent pupillary defect is likely to be present on the side that is opposite to the lesion.
3. Visual acuity is usually normal.
4. Color vision is usually normal.
____________________________________________________________

Correct answers: 2, 3, & 4

Reference: Pearls & Oy-sters: Optic tract syndrome, Rodriguez AR & Reddy K.
Neurology 75:e86-7:2010. Divisions of Ophthalmology and Neuro-Surgery, Department of Surgery, McMaster University, Hamilton, Canada.

PEARLS

• The optic tract syndrome is characterized by a contralateral, incongruous homonymous hemianopia, contralateral relative afferent pupillary defect (RAPD), and optic atrophy due to retrograde axonal degeneration.

• Optic disc pallor often results in a pattern of bowtie atrophy of the eye with temporal field

loss and atrophy of the upper and lower poles of the disc of the eye with nasal field loss.

• Visual acuity and color vision are usually normal unless there is bilateral involvement or extension to the chiasm or optic nerve.

OY-STERS

• Homonymous hemianopia is typically incongruous in optic tract lesions although this concept only applies if the defect is incomplete. Complete homonymous hemianopia is of no localizing value.

• Behr’s pupil (larger pupil on the side opposite to the lesion) and pupillary hemiakinesia (Wernicke sign) are historical signs that are not helpful in the clinical

setting.


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Please send feedback, questions and corrections to tcooper@stanford.edu.


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