Classification and features of nystagmus

1. Big picture

Nystagmus is one of the most important bedside signs in patients with vertigo, dizziness, diplopia, brainstem symptoms, cerebellar signs, or vestibular disease. In the final exam, the examiner usually wants you to do three things:

1. Describe the nystagmus correctly Direction, plane, trigger, suppression by fixation, and associated signs.

2. Decide whether it is peripheral or central This is the most important clinical distinction.

3. Localize the lesion Peripheral vestibular apparatus / vestibular nerve versus brainstem, cerebellum, or ocular motor pathways.

The dangerous exam trap is this: vertical, direction-changing, fixation-resistant nystagmus is central until proven otherwise, especially if associated with ataxia, diplopia, dysarthria, dysphagia, weakness, sensory signs, or skew deviation.