Torsional Jerk Nystagmus

Presented here are 3 patients with torsional jerk nystagmus. The first patient presented with vertigo and experienced oscillopsia due to her torsional nystagmus. Pure or predominantly torsional nystagmus is highly suggestive of a central process. Her nystagmus was unidirectional and followed Alexander's law (torsional nystagmus that beat towards the left ear, more robust in left gaze, minimal in right gaze), and this can be seen with peripheral or central vestibular disorders. Her MRI was unremarkable, and symptoms/signs had resolved completely at follow-up 2 months later. There were peripheral (e.g., + head impulse test to the right) and central signs (e.g., right facial numbness, predominantly torsional nystagmus), but a specific etiology has not yet been identified. ; The second patient experienced oscillopsia in left gaze due to her gaze-evoked torsional nystagmus, and this was the presenting sign of MS. The third patient had a years-long history of imbalance and oscillopsia, and had a variety of ocular motor abnormalities that localized to the posterior fossa in addition to gait and limb ataxia suggestive of a neurodegenerative process (e.g., spinocerebellar ataxia). Extensive nutritional/inflammatory/autoimmune work-up was unrevealing and genetic testing was deferred.