Falsa lateraliza??o no EEG de escalpo na epilepsia mesial temporal por esclerose hipocampal – relato de casos

摘要

Introduction: The temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS) frequently needs surgery approach. For this treatment, it is necessary to identify a unilateral focus of seizures. The HS visualized by MRI usually correlates with the discharge onset on scalp EEG. However, in a few patients, contralateral discharges are registered, not correlating with the image exam. In these cases, the epileptic focus remains not clear, and an invasive eletrophysiologic study is indicated. Objective: To describe 3 cases in which the initial investigation did not confirm the laterality of the seizures, illustrating the false lateralization on scalp EEG on TLE/HS. Commentaries: Since the discharges of the HS are originated from the deep brain, it would spread to the contralateral side before get surface. However, the long-term stimulation of the contralateral lobe would cause lesion on this side, and seizures are triggered independently (secondary epileptogenesis). In this case, the surgery approach is not indicated. The invasive investigation, by subdural strips and video-EEG monitoring, in cases of discordance of scalp EEG and MRI, are better for the surgery indication for TLE/HS, once the operatory results in case of bilateral focus could be catastrophic