ACUTE HEMIPLEGIA SYNDROME IN CHILDHOOD

Three types of clinical features at the onset are well known to be cha racteristic of acute hemiplegia syndrome (AHS). Type 1 comprises statu s epilepticus of hemiconvulsions with fever. Representative diseases o f this type are the infectious diseases of the central nervous system, acute encephalopathy and cerebral vascular diseases. Type 2 comprises status epilepticus of hemiconvulsions without fever. Cerebral vascula r diseases and epilepsy are the major ones of this type. Type 3 compri ses hemiplegia or hemiparesis of sudden onset without fever or convuls ions. Most patients with this type had cerebral vascular diseases, abo ut half of which were moyamoya disease in Japan. Recent progress in ne uroimaging studies has allowed considerable elucidation of the etiolog y of AHS. Gadolinium-enhanced MRI showed minimal lesions such as capsu lar infarction more clearly than plain MRI. Acetazolamide test Tc-99m- HMPAO SPECT imaging is one of the useful assisted diagnostic technique s for moyamoya disease, because it reveals the reserve capacity of the collaterals. [I-123]IMP SPECT is useful for the diagnosis and follow- up of acute disseminated encephalomyelitis (ADEM), as the images of th e lesions coincide well with the MRI ones. Tc-99m-HMPAO SPECT in a cas e with alternating hemiplegia revealed normoperfusion in the ictal per iods. Four cases of AHS are reported here.