Abstracts

RATIONALE: To report the outcome of surgical treatment in an histologically homogeneous, large sample of patients with extratemporal(ET) TTFCD, focusing on the stability of surgical results and the role of reoperations.Most surgical series of CD include patients(i)with histologically different types of lesions;(ii)with variable proportions of temporal and ET lesions; and (iii)followed by a limited amount of time. METHODS:We evaluated 59 ET patients followed post-operatively for at least 4 years(mean 7.4 years),all of whom had,on pathology,focal regions of abnormal cortical citoarchitecture and aberrant dysplastic neurons.Three fourths also had ballon cells.The lesions involved ET cortex in all. Surgical outcome in respect to seizure control was analyzed at year 1 and then at the most recent follow up.Correlations between surgical outcome and anatomical,neurophysiologic, and surgical variables were also sought. RESULTS:Sixty-two% of the lesions involved, at least partially, rolandic, language,or visual cortex.After a first operation,22 of 59 patients(37%)had favorable results, (only 16/59, or 27% were seizure free).Twelve patients(21%)were in a different (worse)outcome class at last follow up-3 to 15 years later- as compared with outcome at year 1.Eight of these 12 (67%) went from a satisfactory to a clearly unsatisfactory result.Reoperations in 18 patients(30%of the series)increased the proportion of patients with satisfactory results to 50% and the seizure free rate to 37%.The degree of completeness of resection of the lesion, and of cortical regions displaying either continuous or very active epileptogenic discharges on acute ECoG strongly correlated with surgical outcome. CONCLUSIONS: incomplete resections of the dysplastic lesion or highly epileptogenic cortical tissue are associated with failures which may manifest either in the short or long term ("running up phenomenon"). Some of the failures can be reversed with reoperations.