Neuro-Ophthalmology 3

Question 0

CN III inervates?

Answer 0

#Superior rectus
#Medial rectus
#Inferior rectus
#Levator palpebrae
#Pupillary constrictor
#Inferior oblique muscle

Question 1

1. Strabismus
2. Comitant
3. Incomitant
4. Phoria
5. Tropia

Answer 1

1. Misalignment of the eyes
2. Misalignment in all directions of gaze (ophthalmologic problem)
3. Degree of misalignment varies with direction of gaze (logic problem)
4. Misalignment of the eyes when binocular vision is absent
5. Misalignment of the eyes when both eyes are open

Question 2

Defects if third nerve contains a lesion at:

1. Nucleus of CN III
2. Subarachnoid space
3. Tentorial edge compression

Answer 2

1. Bilateral ptosis and weakness of contralateral superior rectus; failure of eye elevation
2. Meningismus, constitutional symptoms
3. LOC, hemiparesis

Question 3

CN4 – innervates? Function? Lesion produces? Clinical sighs?

Answer 3

Superior oblique; intorts and depresses adducted eye

Diplopia worse when eye is adducted and looking down (when reading or going downstairs)

Patients compensates with contralateral head tilt

Question 4

Nerve palsy that can be a non-localizing sign of increased ICP?

Answer 4

CN6

Question 5

Destruction of the abducens nucleus in the brainstem leads to?

Answer 5

Complete ipsilateral conjugate gaze palsy (because of simultaneous damage to the interneurons connected to the contralateral third nerve)

Question 6

Signs of right intranuclear ophthalmoplegia?

Answer 6

#Inability to adduct right eye
#nystagmus of abducting left eye

Question 7

Bilateral internuclear opthalmoplegia can be seen in?

Answer 7

#Wernecke encephalopathy
#Botulism
#myasthenia gravis 
#Brainstem strokes
#Demyelination

Question 8

One and a half syndrome occurs as a consequence of a lesion involving?

Answer 8

Paramedian Pontine reticular formation (PPRF), six nerve nucleus, and adjacent ipsilateral MLF

Question 9

Virtual eye movements are controlled by? Located where?

Structure?

Answer 9

Rostral interstitial nucleus of the MLF; pretectal midbrain; CN 3 nucleus

Question 10

Parinaud syndrome - symptoms?Typical cause?

Answer 10

#Upgaze disturbance
#Conversions-retraction nystagmus
#Light-near dissociation

Pineal tumor compressing dorsal midbrain

Question 11

Skew deviation is generally caused by? Lesion is often located on which side?

Answer 11

Brainstem or cerebellar lesion; hypotrophic (lower) eye is the side with the lesion

Question 12

Cover test and interpretation?

Answer 12

1. Ask patient to fixate on target
2. Cover one eye and watch the other guy
   #Exotropia if eye moves nasally
   #Esotropia eye moves temporally

Question 13

Phorias do not cause diplopia because?

Answer 13

Eyes are aligned when both are open simultaneously

Question 14

Parks three-step test?

Answer 14

Detects a fourth nerve palsy

1. Hypertropia of the paretic eye
2. Hypertropia increases when patient looks to opposite side
3. Hypertropia increases when patient tilts head to the same side

Question 15

Doll’s eye test also known as?

Answer 15

Oculocephalic maneuver

Question 16

Saccade? Voluntary saccades originate from? Inability to produce saccades is called?

Answer 16

Rapid eye movements to redirect the eyes to a new object

Frontal eye field and superior colliculus contralateral to the direction of gaze

Oculomotor apraxia

Question 17

Types of abnormal saccades?

Answer 17

1. Hypermetric – overshoots object
2. Hypometric – undershoots object
3. Unwanted – square wave jerks, ocular flutter, opsoclonus

Question 18

Controls pursuing moving objects with eyes?

Answer 18

Hemispheric (occipitoparietotemporal Junction) and ipsilateral

Question 19

Vestibulo-ocular reflex?

Answer 19

Coordinate eye movements with head movement

Question 20

Diseases that can slow down pursuit?

Answer 20

#Parkinson's
#Progressive supranuclear palsy
#drugs
#Aging
#Deep parietal lobe lesions