CHANGES IN REGIONAL CEREBRAL BLOOD-FLOW BEYOND THE TEMPORAL-LOBE IN UNILATERAL TEMPORAL-LOBE EPILEPSY

Purpose: Single photon emission computed tomography (SPECT) is widely used to evaluate functional abnormalities during the epileptic event. Changes in regional cerebral blood flow (rCBF) are well defined in pat ients with temporal lobe epilepsy (TLE) undergoing surgical resection. Nonetheless, the interpretation of ictal abnormalities in CBF beyond the temporal lobes has not been carefully addressed. Methods: We asses sed 4 patients with pathologically proven unilateral TLE who had signi ficant ipsilateral frontal hypoperfusion in ictal studies with no othe r abnormalities but chronic epilepsy accounting for such findings. Pat ients were assessed as candidates for surgery by interictal EEG, neuro psychological studies, brain magnetic resonance imaging, scalp electro de video-EEG monitoring, and ictal SPECT. Results: Characteristic hype rperfusion was evident over the temporal lobe ipsilateral to the EEG f ocus, with significant hypoperfusion over the frontal region in 3 pati ents. In patient 4, frontal hypoperfusion was not statistically signif icant. Conclusions: SPECT demonstrated relative rCBF changes beyond th e epileptogenic zone in unilateral TLE. Our findings provide further i nsight into the pathophysiological changes underlying this condition.