ICTAL SPECT FINDINGS IN TYPICAL ABSENCE SEIZURES

Single photon emission computed tomography (SPECT) is known to reveal localized hyperperfusion during partial seizures, but is rarely perfor med in idiopathic generalized epilepsies. We report the ictal SPECT fi ndings in a typical absence seizure. This 35-year-old woman with child hood absence epilepsy underwent prolonged electroencephalogram (EEG)-v ideo monitoring, during which many stereotyped typical absence seizure s were recorded. These consisted of brief staring spells with arrest o f activity, associated with generalized 3 Hz spike-wave complexes on E EG. Following intravenous (i.v.) injection of 17.6 millicuries of Tc-9 9m Bicisate, SPECT was performed. The injection was performed during h yperventilation that induced a typical absence. Compared to the baseli ne SPECT scan that was normal, the ictal scan showed a generalized red uction in cortical activity. These findings do not support the ''corti cal'' theory of typical absence seizures and the genesis of the 3 Hz s pike-wave complexes. They may indeed support the subcortical or ''cent rencephalic'' hypothesis. (C) 1998 by Elsevier Science Inc. All rights reserved.