Co-Occurrence of Astasia and Unilateral Asterixis Caused by Acute Mesencephalic Infarction

well controlled. However, there were no histories of hepatitis, smoking and heavy alcohol consumption. He has taken aspirin 100 mg, clinidipine 10 mg, imidapril 10 mg and acarbose 50 mg daily. At the emergency room, the blood pressure was 160/90 mm Hg, the pulse rate 78/min, the respiration rate 22/min and the body temperature 36.8 ° C. On neurologic examination, he was alert and oriented with fluent but mildly slurring speech. Cranial nerve functions and muscle strength were normal with the exception of minimal drift of the right upper extremity (Medical Research Council grade IV+/V). Sensory examination revealed normal findings. The reflexes were symmetrical, and the plantar responses were flexor. When both his hands were outstretched, postural lapses with arrhythmic losses of extensor muscle tone that developed upon instruction to maintain the wrist in an extended position, so-called asterixis, or flapping tremor, was observed in the right hand. Fingerto-nose test, rapid alternation movement and heel-to-shin test were all normal. On attempt to stand, however, he showed postural instability and gait disturbance unassisted due to a tendency to tilt backward or toward right, while his ability to sit was relatively preserved. Laboratory studies, including a complete blood cell and platelet count, the erythrocyte sedimentation rate, blood electrolytes, creatinine, liver enzymes, cholesterol, triglycerides and the prothrombin and partial thromboplastin Dear Sir, Astasia designates motor incoordination with inability to stand and is occasionally observed in patients with conversion hysteria [1] . Organic causes of astasia have been rarely reported. Unilateral asterixis may be caused by a focal structural brain lesion including stroke involving the thalamus, parietal lobe, frontal lobe, midbrain, basal ganglia and internal capsule, although asterixis was classically associated with metabolic derangement, particularly hepatic encephalopathy, which occurs usually bilaterally [2–5] . In addition, concurrent unilateral manifestation of astasia and asterixis due to focal cerebral lesions is extremely rare [2, 4] . To our knowledge, sudden concurrent development of asterixis and astasia as a consequence of a rostral midbrain infarction has not yet been reported. We report a patient with concurrent unilateral astasia and asterixis developed due to acute cerebral infarctions involving the rostral level of the midbrain without significant metabolic disorder.