We described a 41-year-old man with chorea-acanthocytosis, who presented severe choreoathetosis in all the limbs, neck, face and tongue. Especially, the oral area was affected most strikingly. He had difficulty in eating, because he pushed foods out of the mouth with the tongue. He received left posteroventral pallidotomy (PVP). His involuntary movements became much less enough for the patient to eat with a spoon in a sitting position by himself. Six months after the first operation, although involuntary movement on the right hand remained reduced, choreoballistic movement appeared on the left side. He received PVP on the right side. The choreoballistic movement was remarkably improved after the right PVP. No neurological aggravation has been found for 7 months after the second PVP. Bilateral PVP was fully effective as for the improvement of the activity of daily life. The output from the internal globus pallidus (GPi) is well-known to be inhibitory. Therefore, it is understandable that the coagulation of GPi results in improvement of hypokinesia and rigidity in patients with Parkinson's disease. However, some clinical reports, including ours, have described the significant reduction of hyperkinetic choreoballistic movement after PVP. The exact mechanism of these surgical effects has not been elucidated yet, and further clinical and basic studies are needed to answer this question.
