Alternating hemiplegia in infants: report of five cases.

Five cases of alternating hemiplegia in infancy are reported. Special consideration is given to the associated ictal manifestations (tonic seizures, dystonic posturing and abnormal movements bouts of nystagmus and acute autonomic disturbances), some of which were noted in every case. Previously reported cases are reviewed critically, 14 of whom are considered to belong to the same syndrome as the five presented here. The nosology of the syndrome is discussed, and the differences between alternating hemiplegia and the common types of hemiplegia or basilar migraine are emphasized. Whatever its exact nature, alternating hemiplegia in infancy constitutes a well-defined and recognizable syndrome, with a guarded mental and neurological prognosis.