Thread by @theneurolander

Nystagmus series – Part III
(downbeat nystagmus)

"definers of modern neuro-ophthalmology"

William Fletcher Hoyt and Frank Burton Walsh

#MedTwitter #neurotwitter #EndNeurophobia #tweetorials

1/

Pathophysiology

“vestibulocerebellum pathway lesion”

- craniocervical junction lesion
- central vestibular imbalance

10.1016/j.jocn.2012.03.017 via: Journal of Clinical Neuroscience

2/

Associated symptoms

cerebellar symptoms
- decomposition of movement

Cerebellum Part I&II


3/

Fixation in central vestibular nystagmus

“poorly suppressed by fixation of a visual target”

- abnormal smooth-pursuit system

4/

Making downbeat nystagmus more noticeable

Alexander’s law
- looking down and laterally

Bedside maneuvers
- change head position
- vigorous head-shaking
- hyperventilation
- mastoid vibration



5/

Obs

a) often, downbeat nystagmus is associated w/ horizontal gaze-evoked nystagmus
b) slow-phase without specific waveform
c) convergence does not specific change nystagmus features
d) downbeat nystagmus greatest on up gaze; vertical gaze-holding impair
e) rarely disjunctive

6/

Downbeat nystagmus - features

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

7/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Moran CORE

8/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Moran CORE

9/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Moran CORE

10/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Neuron Bundle

11/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Raed Behbehani

12/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Scott Sanders

13/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Neurology Made Interesting

14/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Raed Behbehani

15/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Raed Behbehani

16/

Downbeat nystagmus

i) evoked by looking down and laterally
ii) no suppress by visual fixation
iii) vestibulocerebellar involvement

via: Raed Behbehani

17/

Nystagmus general description

"Nystagmus – Moving eyes!!!"