SURGICAL PATHOLOGY OF CHRONIC EPILEPTIC SEIZURE DISORDERS - EXPERIENCE WITH 63 SPECIMENS FROM EXTRATEMPORAL CORTICECTOMIES, LOBECTOMIES ANDFUNCTIONAL HEMISPHERECTOMIES

The surgical treatment of chronic pharmacoresistant epilepsies is incr easing rapidly Although several studies have reported on histopatholog ical findings in temporal lobe epilepsy, little is known about the sur gical pathology of other seizure disorders. Here we report the histopa thological findings in 63 consecutive surgical specimens of patients w ho were operated for chronic pharmacoresistant epileptic seizures othe r than temporal lobe epilepsy (37 corticectomies, 19 functional hemisp herectomies, 5 lobectomies, 1 multilobectomy, and 1 frontal lobe deaff erentiation combined with a temporal lobectomy). There were structural lesions in 85.7% of the specimens. In 16 cases (25.4%) the predominan t lesions were malformative (focal glioneuronal hamartias and hamartom as, vascular malformations, abundant ectopic neurons in the white matt er, microgyria, and arachnoid cyst). Lesions indicating pre- or perina tal necrosis such as porencephaly, ulegyria, and congenital hemiatroph y were present in 7 cases (11.1%). Twelve specimens (19.0%) contained low-grade neoplasms (7 gangliogliomas, 3 astrocytomas, 1 oligodendrogl ioma and 1 oligoastrocytoma). There were 3 cases of Rasmussen encephal itis, 1 specimen with atrophy and gliosis due to previous herpetic enc ephalitis and 1 case with an old abscess wall. Posttraumatic or postop erative changes were the predominant finding in 7 specimens (11.1%). I n 7 patients there were only nonspecific changes such as cortical atro phy and gliosis or old hemorrhage. No structural alterations were iden tified in 9 specimens (14.3%). The findings suggest that the structura l lesions observed in the great majority of the specimens were closely related to the pathogenesis of intractable seizures.