Neuro-Ophthalmology 4

Question 0

Periodic alternating nystagmus? Associated with what conditions?

Answer 0

Horizontal jerk my status that changes direction every few minutes

#Craniocervical junction abnormalities
# MS
#anticonvulsant toxicity

Question 1

Physiologic types of nystagmus?

Answer 1

Optokinetic – normal response to continuously moving object

Vestibulo-ocular – by rotations of the subjects head or caloric test

Endpoint nystagmus – few beats of nystagmus in eccentric gaze

Congenital – remains throughout life

Question 2

Downbeat nystagmus? Associated with what conditions?

Answer 2

Present in primary physician

#Craniocervical junction disorders (Chiari malformation)
#Spinocerebellar degeneration
#MS
#Familial ataxia
#Drugs

Question 3

Upbeating nystagmus – location of the lesion? Associated with what conditions?

Answer 3

Lesions of the anterior cerebellar vermis and lower brainstem

#Wernecke's encephalopathy
#Drug intoxication

Question 4

Seesaw nystagmus? Associated with what conditions?

Answer 4

One eye elevates and intorts while other eye depresses and extorts

#Third ventricle tumors
#Bitemporel hemianopsia
#Brainstem vascular disease

Question 5

Gaze-Evoked nystagmus? Associated with what conditions?

Answer 5

Similar to pinpoint nystagmus but with greater amplitude and occurs in a less eccentric position of the eyes

#drug intoxication (most common)
#Cerebellar disease
#Brainstem or hemisphere pathology

Question 6

Rebound nystagmus? Associated with what conditions?

Answer 6

Cerebellar or posterior fossa lesions

Transient rapid horizontal jerk when eyes are moving to or from eccentric position

Question 7

Vestibular nystagmus? Associated with what conditions?

Answer 7

Usually horizontal with rotatory component

#Peripheral inner ear disorders
#Meniere's disease
#Vascular disorder
#Drug toxicity

Question 8

Peripheral versus Central nystagmus:

1. Direction?
2. Is it horizontal without vertical component?
3. Vertical nystagmus?
4. Effect of visual fixation?

Answer 8

1. Unidirectional away from lesion versus unidirectional or bidirectional
2. Uncommon versus common
3. Never versus sometimes
4. Fixation inhibits nystagmus versus no effect

Question 9

Peripheral versus Central nystagmus:

1. Tinnitus or deafness present?
2. Romberg’s sign present?
3. Vertigo?
4. Deletion

Answer 9

1. Often versus rarely
2. Toward the slow phase versus variable
3. Severe versus mild
4. Short and recurrent versus chronic

Question 10

Peripheral versus Central nystagmus:

Causes?

Answer 10

Vascular disorders in both

#Trauma
#Toxicity
#Vestibular neuronitis
#Ménière's disease 

Versus

#Demyelination
#Neoplastic/paraneoplastic disorders