Myoclonus after brain anoxia is more commonly observed in adults. Peri
natal anoxia, however, on rare occasions causes myoclonus as the main
neurologic abnormality, In this paper we described a case of cerebral
palsy complicated by chorea and tremulous movements of the foot in whi
ch there were no risk factors except perinatal asphyxia. The patient h
ad unique symptoms, action myoclonus associated with the movements of
hyperkinesie volitionnelle. This case illustrated two points, One is t
hat abnormal involuntary movements attributed to perinatal brain insul
ts had changed as the brain matured, The other is that some movements
were very similar to those of the post-anoxic action myoclonus, common
ly seen in patients who sustain brain damage in adulthood.