Correlation of criteria used for localizing epileptic foci in patients considered for surgical therapy of epilepsy

Abstract

Criteria for anterior temporal lobectomy, performed on seven patients with partial complex seizures, were derived from a battery of fourteen presurgical tests. Seven tests were routine studies aimed at identifying a focus of epileptic excitability, while seven were designed to reveal areas of focal functional deficit. Conflicting information was frequently obtained from the tests of epileptic excitability, suggesting that it is probably inaccurate to view patients with partial complex seizures as having a single epileptogenic focus. Presurgical evaluation must therefore be aimed at identifying the focus most responsible for the patient's habitual seizures. Tests of focal functional deficit provided useful nonconflicting confirmatory information in each of the seven patients studied. The most reliable information was obtained from depth electrode implantation, and this procedure should be considered essential except when all evidence of surface-recorded epileptic excitability, including ictal onset, and evidence of focal functional deficit agree.

Staggered spondaic word test in epileptic patients

“…According to several authors, [14][15][16][17][18][19][20] dendritic and neuronal losses are always present in epileptic patients. These losses are independent of crisis type, and if we consider the anatomical and histopathological disorders responsible for poor performance by epileptic patients in the auditory skills evaluated in the SSW test, these authors' findings would explain such performance observed in both groups of epileptic patients studied here.…”

Conditions Sufficient for Nonsynaptic Epileptogenesis in the CA1 Region of Hippocampal Slices

“…Similarly, in intact animal models (Engel and Ackerman 1980;Gotman 1984) and human studies (Engel et al 1981;Gotman and Marciani 1985) interictal electroencephalographic (EEG) spiking does not always correlate with seizure frequency or severity. The absence of interictal activity during low-Ca 2ϩ , zero-Mg 2ϩ plus Cd 2ϩ , and zero-Mg 2ϩ plus veratridine bursting is consistent with these findings.…”

“…The human ␤1 subunit prolongs neuronal depolarization when co-expressed in vitro with a rat brain sodium channel ␣ subunit RBII. Point mutations in the voltage-sensor regions of the sodium channel ␣-subunit SCN1A have been associated with seizures in two families (Escayg et al 2000). Another candidate gene for epilepsy, the SCN5A sodium channel (previously thought to be expressed only in heart tissue) is selectively expressed in only the limbic system of the brain (Hartmann et al 1999).…”

Study of Cerebral Function with Positron Computed Tomography

“…Huntington's disease patients who demonstrated dementia have been studied by the same methods (Kuhl et al ., 1981. While these patients con sistently demonstrated profound striatal hypo metabolism, they typically had preserved cortical metabolic rates (Fig.…”