title: Neuropathological findings in 224 patients with temporal lobe epilepsy.
abstract: During the period between 1976 and 1990, 247 patients with pharmaco-resistant complex partial seizures and a documented unilateral epileptogenic area in the mediobasal temporal lobe underwent a selective amygdalo-hippocampectomy procedure at our institution. Biopsy specimens from 224 patients (91% of the total) were available for a retrospective histopathological and immunohistochemical review. The tissue specimens of 23 patients without evidence for a macroscopic lesion have been used for neurochemical studies and could not be evaluated histopathologically. The most common temporal lobe pathology were neoplasms in 126 patients, i.e. 56%. Tumor entities observed included 23 astrocytomas (18% of all tumors), 17 gangliogliomas (13%), 15 oligodendrogliomas (12%), 15 cases of glioblastoma multiforme (12%), 13 pilocytic astrocytomas (10%), 12 oligo-astrocytomas (10%), 11 anaplastic astrocytomas (9%) and 20 tumors of various other histologies. In 23 specimens (10%), small foci of oligodendroglia-like clear cells were found. The frequent association of these foci with low-grade gliomas or neural hamartomas raises the possibility that these structures may serve as precursor lesion for neuroepithelial tumors of the temporal lobe. In 98 cases, pathological changes of non-neoplastic origin were encountered. The most common diagnoses in this group included hippocampal gliosis/sclerosis (49 cases, 22%) and vascular malformations (20 cases, 9%). Hamartomas, i.e. focal accumulations of dysplastic neuro-glial cells were diagnosed in 14 patients (6%). In only four cases have we not been able to detect any microscopic pathology. These results indicate that a high proportion of pharmaco-therapy-resistant complex-partial seizures are caused by neoplasms of the temporal lobe, some of which appear to be strikingly overrepresented in this group of patients.
authors.affiliation: Department of Pathology (Neuropathology), University of Zürich, Switzerland.
authors.forename: K H
authors.initials: KH
authors.lastname: Plate
authors.forename: H G
authors.initials: HG
authors.lastname: Wieser
authors.forename: M G
authors.initials: MG
authors.lastname: Yasargil
authors.forename: O D
authors.initials: OD
authors.lastname: Wiestler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001927:Brain Diseases / Q000378:metabolism / Q000473:pathology; D001932:Brain Neoplasms / Q000378:metabolism / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D004833:Epilepsy, Temporal Lobe / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies