Palatal myoclonus secondary to vertebral artery compression of the inferior olive.

A 47-year-old male with a 5-year history of palatal myoclonus was found on magnetic resonance imaging (MRI) examination to have an ectatic dominant left vertebral artery that compressed the left inferior olive. Microvascular decompression effectively eliminated his symptoms. This case and a similar case presented here with an ectatic vertebral-basilar system illustrate the value of standard MRI in conjunction with magnetic resonance angiography (MRA) in evaluating palatal myoclonus, and they suggest a potential role for decompressive surgery when persistent, highly symptomatic inferior olivary ischemia or compression occurs.