10 Nystagmus

Question 1

Nystagmus

How to determine direction? exception?

Answer 1

Fast phase (exception: Pendular=Equal speed in both eyes)

Question 2

Nystagmus

How to Categorize?

Answer 2

Direction + Physiological/pathological

Question 3

Nystagmus

Sub type by direction

Answer 3

Horizontal (most common, both), Vertical (always central, ominous), Rotatory/Torsional , Mixed

Question 4

Nystagmus

Name 3 physiological?

Answer 4

Physiological: End point nystagmus (extreme gaze), Optokinetic nystagmus (train windows), Vestibulo-ocular Reflex (head rotation causes compensatory eye movements)

Question 5

Nystagmus

Categorize Pathological?

Answer 5

Peripheral (Vestibular): Unidirectional, horizontal, inhibited by visual fixation, Vertigo, tinnitus, hearing loss
Central: Brainstem or Cerebellar, horizontal or Vertical/often bilateral changing direction, Not suppressed by fixation, Ataxia Diplopia
Causes: Cerebellar stroke, tumor, MS, Wernicke, Chiary malformation, Drugs anticonvulsant alcohol

Question 6

Nystagmus

Investigation

Answer 6

Brain MRI (central), Audiometry(hearing), B12, ENG or VNG , Skew test, HINTS test

Question 7

Nystagmus

Management

Answer 7

Remove underlying cause, Prochlorperazine, meclizine, vestibular rehabilitation

Question 8

Nystagmus

What is oscillopsia and what causes it?

Answer 8

Oscillopsia: Illusion that visual environment is moving (Vestibulo ocular reflex damaged)
Bilateral vestibular loss due to Gentamicin, Meningitis, Bilateral vestibular neuritis, Cerebellum ( Follucus nodulus )

Question 9

Nystagmus

Seesaw nystagmus, explain and cause?

Answer 9

one eye up and in, other down and out): Suprasellar mass: Optic chiasma, craniopharyngioma, pituitary tumors, bitemporal field defect + midbrain

Question 10

Nystagmus

Convergence retraction nystagmus

Answer 10

Both eyes move medially when trying to look up. Midbrain (parinaud syndrome)

Question 11

Nystagmus

Upbeating

Answer 11

All 3 parts of brain stem + Cerebellum

Question 12

Down beating

Answer 12

cannot read, can read coffee shop menus, betters when they hold it above their head
Cerebellar stroke, tumor, MS, Wernicke, Chiari malformation, Drugs anticonvulsant alcohol

Question 13

Pendular

Answer 13

MS (INO side of the lesion fail to adduct, contralateral eye gets horizontal nystagmus)

Question 14

Brun’s

Answer 14

CP angle mass like vestibular schwannoma/acoustic neuroma, nerve 5.7.8, coarse low frequency nystagmus when looking towards the lesion (peripheral) + Fine high frequency fast looking away from lesion (Central)