Pupil Testing

What would an afferent pupillary defect NOT have?

anisocoria

Damage to the preganglionic sympathetic fibers going to the eye can occur where?

anywhere from T1/2--> superior cervical ganglion

Damage to the postganglionic sympathetic fibers going to the eye can occur where?

superior cervical ganglion --> effector

Damage to the central sympathetic fiber going to the eye can occur where?

hypothalamus --> T1/2

Damage to the central parasympathetic fibers going to the eye can occur where?

hypothalamus --> EW nucleus

Damage to the preganglionic parasympathetic fibers going to the eye can occur where?

EW nucleus --> ciliary ganglion

Damage to the postganglionic parasympathetic fibers going to the eye can occur where?

ciliary ganglion --> effector

What is Wallenberg syndrome?

damage to the lateral aspect of the medulla

What is a common cause of Wallenberg syndrome?

blockage of the PICA

What can Wallenberg Syndrome (lateral medulla damage) affect? What does this cause?

1. central ipsilesional horners

2. Spinothalamic tract (control loss of pain and temp)

3. descending spinal trigeminal tract (causes pain head + neck)

4. Inferior cerebellar peduncle damage (cerebellar ataxia)

5. Inferior vestibular nuclei damage (jerk nystagmus)

6. CN IX, X nuclei damage (dysphagia, dysarthria)

7. caudal tractus solitarius (ipsilesional loss of taste)

What is spared in Wallenberg syndrome? Why?

motor tracts

DCML

they are more ventral

What is a common symptom/presentation with horners due to Wallenberg syndrome?

hemifacial flushing

What is margin reflex distance 1?

measurement from pupillary reflex to center of upper lid

What margin reflex distance is decreased horners?

MRD 1

What is margin reflex distance 2?

measurement from pupillary reflex to center of lower lid

Why can MRD2 be increased in horners?

loss of tone of orbicularis oculi

Sympathetic innervation to iris pathway

1. T1-T2

2. Superior cervical ganglion

3. Internal Carotid

4. Ophthalmic branch (V1)

5. Nasociliary Nerve

6. long ciliary nerve

7. iris dilator muscle

Parasympathetic innervation to iris pathway

1. EW nucleus

2. CN III

3. inferior division of CN III

4. IO division of CN III

5. ciliary ganglion

6. short ciliary nerves

7. iris sphincter

If you have a sympathetic lesion when is anisocoria worse?

in dim light

If you have a parasympathetic lesion when anisocoria worse?

in bright light

When in anisocoria is the light response normal?

if sympathetic lesion (both sphincters still working)

If a patient has anisocoria and the direct light response is abnormal, what kind of lesion is it? What eye is abnormal?

parasympathetic

mydriatic eye is abnormal

What can cause anisocoria that has abnormal light response?

trauma

CN III palsy (internal or complete)

Adies

Rx

If a patients anisocoria has abnormal light response, no history of trauma, no ptosis/diplopia, and no vermiform movement, what must you assume/do?

assume aneurysm or tumor causing internal ophthalmoplegia and order a scan

What is Adies pupil?

idiopathic inflammation of ciliary ganglion

What can Adies pupil affect?

sphincter

ciliary muscle (not as affected)

Adies pupil affects which fiber?

postganglionic parasympathetic

What effect does dilute pilocarpine have on Adies pupil? why?

miosis

denervation hypersensitivity

What is Adie's Syndrome? What does it cause

non-progressive systemic condition of autonomic system

causing Adies pupil and poor/absent tendon reflexes

Direct and consensual light response should be?

equal

What is the main driver of the pupil?

ipRGCs

The 10% of fibers that do not go to the LGN go where?

brachium of superior colliculus into pretectal nucleus in mesencephalon

Path of pupillary fibers if diffuse light shone in one eye

1. RGCs

2. Brachium of superior colliculus

3. R+L Pretectal nucleus

4. R+L Edinger westphal

Light in one eye goes where?

to both pretectal nucleus + both EWs

What is the decussation of R + L pretectal nucleus called?

posterior commissure

Path of pupillary fibers if direct line shown only to right eye temporal side?

1. temporal RGCs

2. ipsilateral (right) optic tract

3. right pretectal

4. both EW

Nasal fibers project to which pretectal? How about temporal fibers?

nasal projects to contralateral pretectal nucleus

temporal to ipsilateral

What does relative afferent pupillary defect (RAPD) look like?

direct response of pupil isn't as large as the consensual response of pupil

What is an example of something that causes RAPD?

optic neuritis (unilateral)

What is another name for RAPD?

Marcus Gunn pupil

Anisocoria is caused by what kind of problem?

EFFERENT

fibers for pupillary light response come in from?

dorsal region of mesencephalon to EW

fibers for near pupillary response comes from?

ventral tegmentum of mesencephalon to EW

What can cause a posterior commissure lesion?

tabes dorsalis

MS

pineloma

What kind of pupillary response is lost with a posterior commissure lesion? What response is spared?

lose light response

still have near response

What is light-near dissociation?

light pupillary response is diminished but near pupillary response is spared

What causes light-near dissociation?

posterior commissure lesion/disease

What does light-near dissociation mean is spared/working?

EW

CN III

iris

all okay and working