Abstracts

Rationale: Although the prevalence of epilepsy is similar around the globe, the leading causes of epilepsy may be different from regions due to exposure to the risk factors such as infectious parasitic diseases. The objective of this study is to look for brain lesions in an incident cohort of patients with epilepsy. Methods: This is a cross-sectional study undertaken in a catchment area of Campinas, a city with 1.1 million inhabitants in Southeastern Brazil. The study was carried out at the district of Bar o Geraldo, with approximately 44.000 inhabitants using a dataset from a epidemiological survey in the same area as part of Demonstration Project of Global Campaign Against Epilepsy WHO/ILAE/IBE. We attempted to contact all the 174 individuals with age equal or above 13 years old and a confirmed diagnosis of epilepsy from the dataset. We were able to contact 139 patients, and 86 agreed to undergo MRI scan. The MR images were acquired in a 2T system (Elscint, Prestige, Haifa, Israel). The diagnostic protocol included coronal 3mm thick slice T1, T2 and proton density along the hippocampal axis; axial T1 and FLAIR sequences. We also acquired volumetric T1 isotropic voxel for multiplanar and curvilinear reconstruction. We did not use contrast agent. Results: Sixty-nine (36 women) of 86 MRI exams were of good quality and available for analysis. Sixteen (23%) had normal MRI. Hippocampal atrophy was observed in 39 (56%) patients: three in the context of dual pathology (cavernoma, heterotopia, cortical displasia), two as part of hemispheric lesions, 15 (22%) associated with other cortical atrophy and/or subcortical lesions suggestive of microangiopathy, and remaining 19 had isolated signs of hippocampal sclerosis. Signs of microangiopathy and stroke were observed in nine patients (13%). Cortical developmental malformation was observed in two cases. Two had diffuse brain atrophy and one had signs of gliosis and surgical intervention. Signs suggestive of neurocisticercosis were observed in four patients with hippocampal atrophy. Conclusions: Hippocampal sclerosis is the leading epileptogenic lesion in the general population of a developing country. The frequency of microvascular lesions appears high, which suggests that risk factors for stroke are neglected in patients with epilepsy.