Incidence of SUDEP in a cohort of patients with refractory epilepsy: the role of surgery and lesion localization / Incidência de SUDEP numa coorte de pacientes com epilepsia refratária: papel da cirurgia e da localização da lesão

OBJECTIVE: The aim of this study was to verify incidence and characteristics of sudden unexpected death in patients (SUDEP) with refractory epilepsy and its relation to previous surgery and lesion localization. METHOD: A cross sectional study was carried out in a cohort of 550 patients with refractory epilepsy followed up by the Epilepsy Surgery Program of the University Hospital of PUCRS, Porto Alegre, Brazil, between January, 1992 and July, 2002. Patients were allocated in two groups (operated and non operated). Seizure type, distribution of interictal spikes and MRI findings were correlated with the SUDEP outcome. RESULTS: The estimated incidence of probable SUDEP amounted to 29:1000 individuals. Probable SUDEP occurred in 1.2 percent of the 166 patients of the non operated group and in 3.7 percent of the 384 patients who were operated (OR=3.02, 95 percent CI 0.69-13.16) (p=0.11). Comparing patients who died to patients alive in the operated group a significant difference was observed concerning the following variables: SUDEP patients had a predominance of generalized seizures (p=0.002), extratemporal lesion on MRI (p<0.001) and epileptiform activity over extratemporal regions (p=0.001). CONCLUSION: In surgically treated patients with refractory epilepsy, an extratemporal location of the lesion and of the epileptiform discharges significantly correlated to SUDEP. Thus it is possible that in those patients; the underlying disease may play a role in the pathogenesis of SUDEP.

OBJETIVO: O objetivo deste estudo é avaliar a incidência e características de morte súbita em pacientes com epilepsia refratária (SUDEP) e sua relação com cirurgia prévia e localização da lesão. MÉTODO: Estudo de Coorte realizado com 550 pacientes com epilepsia refratária seguidos no Programa de Epilepsia do Hospital Universitário da PUCRS, Porto Alegre, Brasil, entre Janeiro, 1992 e Julho, 2002. Os pacientes foram distribuídos em dois grupos (operados e não operados). Tipo de epilepsia, distribuição das descargas interictais e achados em RNM foram correlacionados com SUDEP. RESULTADOS: A incidência estimada de SUDEP foi 29:1000 indivíduos. A incidência de provável SUDEP nos 166 pacientes do grupo de não operados foi 1,2 por cento e nos 384 pacientes no grupo operado 3,7 por cento (OR=3,02, 95 por cento IC 0,69-13,16) (p=0,11). Comparando os pacientes que morreram com os sobreviventes do grupo operado houve diferença significativa nas seguintes variáveis: pacientes com SUDEP apresentam uma predominância de crises epilépticas generalizadas (p=0,002), lesões extratemporais na RNM (p<0,001) e atividade epileptiforme na região extratemporal (p=0,001). CONCLUSÃO: A localização da lesão e as descargas extratemporais em pacientes tratados cirurgicamente com epilepsia refratária correlacionaram-se significativamente com SUDEP. Então, é possível que nestes pacientes uma doença sobrejacente possa estar envolvida na patogênese da SUDEP.

Surgical Treatment of Epilepsy: Extratemporal Operative Methods

The extratemporal operative approaches for intractable epilepsy are reviewed. Intracranial recordings are often necessary for extratemporal epilepsy to define the lateratization as well as the localization of epileptogenic regions and tailor the resection. The operative procedures include cortical resections, corpus callosotomy, and functional hemispherectomy. The author presents an overview of indications for surgery, oprative methods, and risks in the medically intractable epileptic patient with extratemporal focus.