A 59-year-old man developed the acute onset of diplopia, dizziness, left hemiparesis, and slurred speech. Magnetic resonance imaging of the brain showed an area of increased signal on diffusion-weighted images of the dorsal pontomesencephalic junction on the right side. This finding was consistent with an acute ischemic infarct (Figure 1). Over the next 6 months, his symptoms improved. However, 9 months after the initial stroke, he developed the gradual onset of dysarthria, gait ataxia, and tremor. These symptoms progressed in severity during the next 9 to 10 months, at which time we first met and examined him. He had been diagnosed with multiple system atrophy at another academic center. On examination, he had severe cerebellar dysarthria with explosive, scanning speech, square wave jerks and nystagmus, palatal myoclonus, limb ataxia, bilateral tremor (worse on left side), and mild left hemiparesis (video 1 and video 2). His follow-up magnetic resonance imaging demonstrated increased signal on T2 and fluid-attenuated inversion recovery sequences in the right inferior olivary complex (Figure 2).
Bruno MK, Wooten GF. Hypertrophic Olivary Degeneration. Arch Neurol. 2012;69(2):274. doi:10.1001/archneurol.2011.657