Temporal lobe epilepsy and neuropathology. Histological findings in resected temporal lobes correlated to surgical results and clinical aspects.

Neuropathological findings were studied in 74 patients with drug-resistant temporal lobe epilepsy who underwent unilateral temporal lobe resection in 1960-1969 in Denmark. In 60 per cent of the patients a well-defined neuropathological abnormality was revealed (i.e. 13 cases of focal lesions, including four small tumours, 21 cases of gliosis, and 10 cases of perivascular infiltration), in 23 per cent the findings were either questionably abnormal or without structural abnormality, while in the last 18 per cent sequelae of a previous operation dominated the histology. The general trend was for the postoperative clinical outcome to be better, the more specific and circumscribed the histological abnormality. There was no correlation between the neuropathological findings and the preoperative types of seizures. Postoperative recurrence of seizures was more often observed in patients with gliosis than in those with other histological diagnoses. A positive correlation existed between a history of cerebral infection and the presence of perivascular lymphocytic and histiocytic infiltration, and gliosis was a frequent finding in patients with epilepsy of unknown aetiology. No other significant correlation was found between the neuropathological abnormalities and the clinical, hereditary, aetiological, and social aspects.