[Usefulness of near-infrared spectroscopy for identification of epileptic foci in two localization-related epilepsy patients].

We monitored cerebral blood volume (CBV) using near-infrared spectroscopy (NIRS) of two patients with symptomatic localization-related epilepsy who had no epileptic discharges in ictal scalp EEG. Case 1 was a 9-month-old boy who was suspected to have frontal lobe epilepsy. Although epileptic discharges were not identified on his ictal EEG due to motion artifacts, NIRS demonstrated an increase of CBV of the left brain during the seizure. Ictal single photon emission CT (SPECT) was dominant at the left side. Case 2 was a 3-year-old girl who was suspected to have temporal lobe epilepsy. Ictal EEG tracings, theta waves revealed prominent but did not enable identification of the focus. She had cortical dysplasia in the right cerebral hemisphere. NIRS monitoring demonstrated an increase in CBV in the right frontal region, which began 10 minutes before the seizure onset and lasted for 3 hours. Thus NIRS is a sensitive and non-invasive procedure for monitoring CBV changes during the seizure, and is useful in identification of the epileptic focus.