62,63,69,71

Question 1

The brainstem neurons

responsible for conjugate horizontal saccadic eye movements are located in the

Answer 1

paramedian pontine reticular formation (PPRF) and abducens nucleus

Question 2

if one wants to look left, what happens in eyes?

Answer 2

left abducens abducts left eye

left abducents crosses to contralateral lower pons and goes up right MLF to activate right oculomotor nucleus

Question 3

A right internuclear ophthalmoplegia affects what

Answer 3

the disprupted right MLF (seen when looking left- right eye cant adduct)

and left eye has nystagmus on abduction- unclear etiology

Question 4

4 types of MS

Answer 4

relapsing-remitting,
progressive-relapsing,
secondary progressive,
primary progressive MS.

Question 5

which type of MS is most common at presentation?

Answer 5

relapsing-remitting

Question 6

Mitoxantrone, is what type of medicine used for what, and limited by what side effect?

Answer 6

chemo drug

used for MS

limited by cardiotoxicity

Question 7

Relapsing-remitting MS time presentation

Answer 7

Neurologic dysfunction increases over days or weeks, then plateaus,
then resolves over days or weeks.

return to baseline

Question 8

exotropia

Answer 8

lateral deviation

Question 9

hypotropia

Answer 9

downward deviation

Question 10

anisocoria

Answer 10

pupillary asymmetry

Question 11

what should you think with: ptosis, exotropia, hypotropia, aniscoria of one eye?

Answer 11

third nerve palsy

Question 12

The superior and inferior recti muscles are best evaluated with the eye

Answer 12

abducted

Question 13

The oblique muscles are best evaluated with the eye

Answer 13

adducted

Question 14

what helps with eye opening vs closing

Answer 14

opening- CN 3- levator palpebrae superioris

closing- CN 7 - orbicularis oculi

Question 15

locations of potential lesions to cause CN 3 palsy

Answer 15

midbrain (nucleus or fascicular portion),

subarachnoid space

cavernous sinus,

superior orbital fissure,

the orbit.

Question 16

third nerve palsy associated with a small pupil (Horner’s syndrome) due to oculosympathetic compromise virtually localizes the lesion to the

Answer 16

cavernous sinus.

Question 17

Aberrant regeneration of the third nerve common causes

Answer 17

by intracavernous aneurysms, following aneurysm surgery, or trauma.

Question 18

Signs of aberrant regeneration of the third cranial nerve include the following:

Answer 18

retraction and elevation of the lid on downward gaze

elevation of the lid on attempted adduction

retraction on attempted vertical eye movements;

adduction on attempted elevation or depression;

lack of pupillary reactivity to light, but adequate response when the medial rectus muscle,
inferior rectus muscle, or elevators of the eye are activated (pseudo-Argyll Robertson pupil);

delayed onset abduction defect;

lagophthalmos.

Question 19

The abducens nucleus is located in the

Answer 19

dorsal lower portion of the pons.

Question 20

The abducens nerve exits the brainstem via ___________ and courses through the ______ and enters via the ____

Answer 20

exits ventrally at the level of the horizontal sulcus between the pons and medulla

courses anterolaterally passing over the petrous apex to enter the lateral wall of the cavernous sinus.

enters the superior orbital fissure

Question 21

potential causes of abducens palsy

Answer 21

ischemic and hemorrhagic disorders; aneurysms or other vascular anomalies;

demyelinating, neoplastic, metabolic, traumatic, inflammatory/infectious disorders; hydrocephalus; raised ICP; or CSF hypotension.

Question 22

the most common etiologic factor of a sixth nerve palsy in older adults is

Answer 22

microvascular occlusion of the abducens nerve, also known as a vasculopathic sixth nerve palsy.

Question 23

Most vasculopathic sixth nerve palsies recover over a period of

Answer 23

3 to 6 months.