Oculomotor Disorders

Question 1

Clinical presentation of CNIII palsy?

3

Answer 1

1. Sudden onset of binocular horizontal, vertical, or oblique diplopia
2. Ptosis or a droopy eyelid
3. 25% are idiopathic

Question 2

What is a major complication of congenital CNIII palsy?

Answer 2

amblyopia

Question 3

Why might pt with congenital CNIII palsy not complain of double vision?

Answer 3

because they have suppressed vision in the affected eye

Question 4

What would you find on the eye exam for CNIII palsy?

Answer 4

1. partial or complete ptosis
2. dilated, and poorly or nonreactive pupil
3. Deficits in adduction, elevation and depression (EOMs)

Question 5

What is considered a complete impairment of CN III?

2

Answer 5

1. Impairment in the majority of the functions in the muscles of the eye that are controlled by cranial nerve III
2. ptosis

Question 6

Complete III nerve palsies are associated most commonly with what kind of eye movement?
2

Answer 6

large-angle exotropia and hypotropia (down and out) and Ptosis.

Question 7

How can we rule out if compressive lesion is affecting CNIII?

Answer 7

It will almost always involve the pupil

Question 8

Ischemic palsy is different from a tumor how?

Answer 8

Will usually not involved the pupil

Question 9

If complete impairment of CNIII with pupil affected what do we do?

Answer 9

tumor= MRI

Question 10

If complete impairment without affected pupil what do we do?

Answer 10

watch for 3 months

Question 11

If incomplete impairment of CNIII what do we do?

Answer 11

MRI

Question 12

Hallmark of Complete CN 3 Palsy??

Answer 12

Ptosis with down and out movement

Question 13

What else should be in the diff with CN3 symtpoms?

4

Answer 13

1. Vasculopathic
   - HTN
   - Diabetes
2. Tumor
3. Congenital
4. Aneurysm

Question 14

What is our goal in treating CNIII palsy?

Answer 14

goal is to maximize visual function, including ocular alignment

Question 15

Why is CN IV so prone to injury from blunt head trauma or compression (ICP, brain tumors, swelling)?

Answer 15

Its long course coming from the back of the head

Question 16

Clinical presentation of CN IV?

3

Answer 16

1. vertical diplopia/ tortional diplopia
2. objects in primary position or in downward gaze will be double
3. PATIENT MAY TILT HEAD TO SIDE TO BE ABLE TO SEE BETTER

Question 17

If a patient is experiencing CNIV palsy which side will their head be tilting?

Answer 17

head tilting to the side opposite the paralyzed muscle

Question 18

Where will the eye be pointing in cranial nerve IV palsy?

Answer 18

nasal upshoot

ability to rotate downward is weak because of superior oblique muslce

Question 19

IN CNIV palsy where is deviation the greatest?

Answer 19

when gaze is directed toward the weak muscle = greater hypertropia

Question 20

Hallmark signs of CN4 palsy?

2

Answer 20

head tilt and nasal upshoot

Question 21

What else should be in the differential for CN IV palsy?

4

Answer 21

Acquired  (40%)
1. Vasculopathic (13%)
-HTN
-Diabetes
2. Tumor (10%) (2.8%)
3. Trauma (54%)
Congenital  (60%)

Question 22

If imaging is normal in a suspected CNIV nerve palsy what should the next step be?

Answer 22

Lumbar puncture may be warranted in patients who have normal imaging studies but are suspected of having subarachnoid space lesions.

Question 23

What disease often affects the 6th cranial nerve?

Answer 23

diabetes

Question 24

Clinical presentation of CNVI palsy?

Answer 24

horizontal diplopia that worsens with gaze with gaze laterally
-strabismus present right away with gaze to lateral side but could later present in straight forward gaze

Question 25

Where will the affected eye be deviated in CNVI palsy?

Answer 25

primary position is esotropia (crossed eyed/buried eye)

Question 26

Hall mark sign of CN VI palsy?

Answer 26

buried eye?

Question 27

In all cranial palsies where is the eye’s primary position/deviation?

Answer 27

Away from the movement of the eye

moves eye downward then eye will stay up

Question 28

In all cranial nerve palsies where is the deviation the worst?

Answer 28

When the gaze is toward the injured muscle

Question 29

What else should be in the Diff for CNVI?

3 plus some subcategories

Answer 29

1. Vasculopathic
   - -HTN
   - -Diabetes
2. Tumor
3. Elevated cranial pressure
   - -Temporal arteritis
   - -Pseudotumor cerebri

Question 30

If it persists for more beyond 6-12 months what do we do?

In what cases should imaging be done immediately?

Answer 30

Neuroimaging to exclude neoplasm

focal signs or papilledema are present

Question 31

What are some treatments that could be used for CNVI palsy?

4

Answer 31

1. alternate patching,
2. prism therapy,
3. strabismus surgery, and
4. botulinum toxin.

Question 32

Hallmarks for each palsy?

Answer 32

“Down and out” = CN 3 Palsy
“Nasal upshoot” = CN 4 Palsy
“Cross eyed” = CN 6 Palsy