Ictal brain imaging in presurgical evaluation of patients with medically intractable complex partial seizures

Abstract

At the Indiana University Medical Center, 99 patients with medically intractable complex partial seizures (MI‐CPS) had presurgical evaluation with subsequent anterior temporal lobectomy. The majority of the patients had single photon emission tomography (SPECT) performed interictally as well as during an actual epileptic seizure (ictal scan). Decreased regional cerebral perfusion (rCP) was seen in 54/94 (57%) of the interictal scans corresponding to the eventual site of the surgery. However, ictal scans provided a higher yield; increased rCP in the temporal lobe during an actual seizure was observed in 60/82 (73%) concordant to the side of surgery. SPECT is a useful, noninvasive method of localizing the epilepti‐form focus in patients with MI‐CPS considered for resective surgery. Both interictal and ictal SPECT need to be performed; combined interictal hypo‐perfusion and ictal hyperperfusion in the same focal area are unique to epileptogenic lesions. Ictal SPECT studies can be performed in the majority of patients during the period of continuous video/EEG monitoring with only a little additional effort. Combining the results of functional brain imaging (interictal and ictal SPECT, PET) with clinical semiology of seizures, surface and sphenoidal EEG, magnetic resonance imaging and other non‐invasive tests, anterior temporal lobectomy can be recommended in approximately two‐thirds of the patients without resorting to potentially dangerous intracranial EEG monitoring.

Temporal lobe epilepsy: analysis of patients with dual pathology

“…The details of the presurgical evaluation and criteria for surgery in our program have been reported previously (7)(8)(9)(10)(11)(12). The details of the presurgical evaluation and criteria for surgery in our program have been reported previously (7)(8)(9)(10)(11)(12).…”

Typical and Atypical Perfusion Patterns in Periictal SPECT of Patients with Unilateral Temporal Lobe Epilepsy

“…In the last two decades, several studies have confirmed the classic observation of ipsilateral ictal hyperperfusion as the hallmark SPECT finding for the lateralization of the epileptogenic temporal lobe (11–15). Some studies, however, have suggested that other complex ictal perfusion patterns, involving adjacent areas of the epileptogenic temporal lobe or extending to another brain region, may also contribute to the lateralization of the EZ (16–20).…”

Temporal Lobe Epilepsy Surgery: Outcome, Complications, and Late Mortality Rate in 215 Patients

“…All patients underwent a comprehensive presurgical evaluation including video-EEG recordings. The details of the presurgical evaluation and criteria for surgery in our program have been reported previously (6)(7)(8). Patients had a neurologic evaluation, neuropsychological testing, imaging studies, and prolonged video-EEG recordings with sphenoidal electrodes (18 also had intracranial recordings with subdural electrodes).…”