Segmental zoster paresis (SZP) is a clinically rare complication of herpes zoster. But it has not been reported that acute cerebral motor cortical infarction coincidentally occurred in SZP. A 86-year-old woman was admitted due to pain, tingling sensation, and weakness of left arm. She had an acute onset of pain and tingling sensation in left arm at first day, shoulder weakness at second day, and multifocal vesicles at fourth day. Deep tendon reflexes of left arm were decreased than right. Electromyography showed an axonal polyneuropathy at superior trunk level of left brachial plexus. Median and ulnar sensory evoked potential tests were normal. Brain MRI showed a high signal in right primary motor cortex on diffusion weighted image. We report a case of acute cerebral motor cortical infarction coincidentally occurred in SZP.
