We reported a 39-year-old man with punch drunk syndrome who had cerebellar ataxia, seizure and dementia. CT scan of the brain revealed remarkable atrophy and enlargement of the ventricular system. MRI of the brain showed severe atrophy which was especially evident in the frontal base. On RI cisternography both early ventricular reflux at 3 hours and delayed ventricular stasis at 52 hours were found, which resembled the findings of the normal pressure hydrocephalus. The MRI and RI cisternographic findings suggested that the remarkable brain atrophy and enlargement of the ventricular system were caused by repeated KARATE traumas including minor brain contusion or subarachnoid hemorrhage in the base of the brain, since traumatic brain contusions affect particularly the orbital surfaces of the frontal lobes and the lateral and inferior surfaces of the temporal lobes. Communicating hydrocephalus may be one of the pathogenesis of punch drunk syndrome.