Abstract
A 35-year-old man with Down's syndrome showed epileptic falling spells. He had suffered from a traumatic right-sided epidural haematoma 3 years before. It had been neurosurgically treated, but MRI taken 5 days later had revealed a small contracoup contusion at the left temporal lobe. His falling spell was a brief tonic seizure without disturbance of consciousness. Background activities of EEG consisted of slow alpha waves interspersed with sporadic theta waves and the amplitude at the left temporal area was lower than the opposite one. Interictal EEG showed sharp waves or sharp and slow wave complexes predominantly at the right temporo-centro-parietal area as well as diffuse, though predominantly at frontal areas, bursts of slow waves with high amplitude. The EEG suggested focal epileptic activities evolving into secondary generalization. SPECT of the brain showed the hypoperfusion at the left temporal area and at the right posterotemporo-parietal area, where the hypoperfusion was somewhat reduced after the improvement of seizures. Seizures were well controlled with phenytoin combined with phenobarbital. The incidence of epilepsy in the Down's syndrome has been reported to increase after the middle age in association with the development of Alzheimer's neuropathology. When those people would sustain head injuries, it was necessary to follow carefully using SPECT and EEG.