Comprehensive postictal neuropsychology improves focus localization in epilepsy.

In recent years, new techniques such as single photon emission computed tomography (SPECT), positron emission tomography (PET) and magnetic resonance imaging (MRI) have been used to improve the localization of epileptic foci during the noninvasive evaluation procedure for epilepsy surgery. Since ictal/or immediate postictal SPECT studies were shown to localize epileptic foci better than interictal SPECT, we addressed the question of whether immediate postictal neuropsychological examination would show the same effect. Neuropsychological examinations were carried out postictally and interictally using a broad range of tests. Postictal results were analyzed with regard to lateralizing and localizing information about the epileptogenic region. Seventeen patients suffering from temporal and extratemporal pharmacoresistant epilepsy were investigated postictally with a subset of tests used for the interictal neuropsychological examination. A significant improvement in focus localization was seen in comparison with interictal neuropsychology (p = 0.014). We conclude that neuropsychology can yield lateralizing and sometimes localizing information, even for extratemporal foci, if carried out during the postictal period and based on a global analysis of the clinical neuropsychological picture.