Macrosaccadic oscillations in cerebellar ataxia

This patient presented with years of progressive imbalance, and had clear neurologic (e.g., cerebellar limb and gait ataxia) and ocular motor (e.g. downbeat and gaze-evoked nystagmus in lateral gaze, impaired smooth pursuit, saccadic hypermetria) manifestations of cerebellar dysfunction. There were frequent spontaneous back-to-back oscillations with an intersaccadic interval that straddled (overshot) fixation which were consistent with macrosaccadic oscillations, which are commonly associated with cerebellar disease and saccadic hypermetria. In fact, these oscillations can be thought of as an extreme form of saccadic hypermetria. Although the largest amplitude oscillations were not captured during this video, they are still larger than what would be expected with square wave jerks (typically <3 degrees/second), were symptomatic, and oscillated around the desired eye position.