Scalp EEG in temporal lobe epilepsy surgery

Electroencephalography (EEG) with standard scalp and additional noninvasive electrodes plays a major role in the selection of patients for temporal lo be epilepsy surgery. Recent studies have provided data supporting the value of interictal and postictal EEG in assessing the site of ictal onset. Scal p ictal rhythms are morphologically complex but at least one pattern (a fiv e cycles/second rhythm maximum at the sphenoidal or anterior temporal elect rode) occurs in >50% of patients and has a high predictive value and intero bserver reliability for temporal lobe originating seizures. Thorough interi ctal and ictal scalp EEG evaluation, in conjunction with modern neuroimagin g, is sufficient for proceeding to surgery without invasive recordings in s ome patients. Further studies are required to define the scalp ictal charac teristics of mesial vs. lateral temporal lobe epilepsy.