Focus diagnosis of epilepsy using near-infrared spectroscopy.

Purpose: We sought to establish a noninvasive method for focus diagnosis of epilepsy.

Methods: We examined the use of multichannel near-infrared spectroscopy (NIRS). It is known as a noninvasive method of functional brain mapping. We monitored cerebral blood volume change with NIRS during long-term EEG monitoring of epilepsy in 32 cases with intractable epilepsies to diagnose the epileptogenic focus.

Results: In 96% of cases, NIRS showed significant hyperperfusion in the side of seizure foci, whereas ictal SPECT showed hyperperfusion in 69% of cases.

Conclusions: Ictal NIRS is a reliable method to evaluate the focus side in epilepsy, especially when it is coupled with ictal SPECT.