Relação entre neurogênese hipocampal e história clínica de pacientes adultos portadores de epilepsia refratária do lobo temporal.

Abstract

Epilepsy is a neurological disorder characterized by the permanent predisposition of the brain to generate epileptic seizures, which affects about 1% of the world population. In Brazil, the disease can reach 2% to 4% of the population. Most patients have a good prognosis for drug treatment, however 30% of patients are refractory to treatment. Among the epilepsies that do not present a good prognosis is the Temporal Lobe Epilepsy (ELT). ELT is characterized morphologically by a selective loss of hippocampal neurons, concomitantly with increased hippocampal neurogenesis. It is believed that this exacerbated neurogenesis contributes to epileptogenesis (onset of epilepsy); however, the role of this increased neurogenesis in patients with TLE remains unknown. We used hippocampus from patients with epilepsy, who underwent a surgical procedure in which unilateral hippocampal resection was performed. From the analysis of the same, a possible relationship between neurogenic patterns and the evolution of the disease was investigated. Interviews with patients who underwent surgery demonstrated that the triggering event (precipitant) of epilepsy occurred in the first years of life of the patients. In addition, they were high intensity events, and also presented a high frequency of epileptic seizures and drug refractoriness. Immunohistochemical analysis of hippocampi showed equivalently that there was a perceptible dispersion of the granule cell layer, indicating a possible ectopic migration in labeling for neuroblasts (immature neurons), which are generated in neurogenesis. The results obtained in this work are pioneer, given that they are based on both clinical and histopathological findings, and the relationship between hippocampal neurogenesis and clinical history proposes a new research vision. These findings may also help in a new perspective of differential treatment in temporal lobe epilepsies.