Single photon imaging computed tomography (SPECT) for localization of epileptogenic focus in patients with...

Interictal and ictal HIPDM-SPECT brain scans were obtained in 38 patients who eventually underwent temporal lobectomy for treatment of medically intractable complex partial seizures (CPS). Interictal studies revealed decreased regional cerebral perfusion (rCP) in the temporal lobe corresponding to the eventual site of surgery in 76% of the patients. Similarly, ictal studies demonstrated increased rCP in 91% of the patients. Of the 33 patients who had both interictal and ictal SPECT studies, 23 (70%) showed increased rCP in the ictal state and decreased rCP in the interictal state in the same temporal lobe which was subsequently removed. The SPECT scans were particularly helpful in providing confirmatory evidence for localization and in deciding to undertake temporal lobectomy in 16 patients whose EEG studies had provided less secure localization. Our experience suggests that interictal and ictal SPECT brain imaging can be easily obtained and provides reliable localizing information in the epileptic patients being considered for temporal lobectomy.