Imaging of propagated sites of epileptic discharges in repeated 123I-IMP SPECT scans.

Single-photon emission computed tomographic (SPECT) brain scans with N-isopropyl-(iodine-123-p-iodoamphetamine (123I-IMP) were performed twice at an interval of about 2.5 years in the interictal period in an adult patient with occipital-lobe epilepsy. The first SPECT scan showed an abnormal image of decreased 123I-IMP uptake in the right occipital lobe. This abnormal image was regarded as the primary focus of his epilepsy on the basis of its regional agreement with right-occipital spikes consistently seen in interictal electroencephalographic recordings throughout his clinical history. In the second scan, he showed multiple abnormal images of decreased uptake in the right frontotemporal lobes and left occipital lobe together with the right occipital lobe. These additional abnormal images were considered to be propagated sites of epileptic discharges.