The neurootological examination of dizzy patients

We do have many dizzy patients to work up in the ER. Nowadays with the HINTS or INFARCT scheme, life has become much easier if you have to distinguish between vestibular neuritis and central vertigo (stroke and migraine mostly) in an acute vestibular syndrome. But if they are only dizzy, you have to invest more work. In today’s session we concentrated on the neurophysiology of extraocular eye movements, the various categories and how to examine them.
From a physiological viewpoint you have to distinguish the following EOM categories:
  • Voluntary and involuntary (e.g. the correcting saccade of a nystagmus) saccades
  • VOR movements
  • Smooth pursuit
  • Optokinetic reflex
Here are the basic exam steps for a dizzy patient:
  • Spontaneous nystagmus (using Frenzel glasses or the penlight cover test)
  • Gaze directions: check gaze in all 9 directions at about 30-45° for diplopia and bulbar misalignment
  • Check for gaze evoked nystagmus in the same step
  • Head shaking nystagmus (quickly oscillate move the head between left 45° to right 45° with about 2 cycles per second)
  • Vergence movements (move the fixated pen from 60 to 10cm before the nose)
  • Saccadic eye movements: preferably use diagonal saccades between two pens
  • Smooth pursuit: estimate the speed at which the patient can still keep up with a moving pen, horizontally and vertically, compare sides
  • Horizontal VOR: use the head thrust maneuver (Halmagyi)
  • VOR cancellation: the easiest is to have the patient follow your finger with his head rather than the eyes, can also use a rotating chair
  • Dynamic visual acuity: have the patient read some text while moving his head rhythmically between left and right
  • Positional nystagmus: Dix-Hallpike, head roll test and head hanging test
  • Tragus test: occlude the ear and press on the tragus
  • Romberg’s and Unterberger’s test
  • Complete neuro examination including testing for extremity ataxia
I never use the drum roll because it does not properly test the optokinetic reflex (which is a non-foveal process).
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