Neuropathological consequences of epilepsy.

Although the results of a number of histopathological studies have unequivo cally shown that epileptic seizures are frequently associated with neurodeg enerative mechanisms or other alterations in the brain structure, as it is not possible to carry out longitudinal studies the interpretation of these observations remains speculative. It is not clear whether these brain alter ations are the cause or the result of epileptic seizures. It is now widely accepted that epileptic seizures correspond to the synchronization of neuro nal activity and increase in their discharge frequency. It has been shown t hat this abnormal firing activity can lead to increase in intracellular cal cium concentration in the nerve cells. A rise in intracellular calcium leve ls can trigger other processes within the cell, or be cytotoxic if these le vels are sufficiently high. In this study, in the light of the most recent findings on cell death (apoptosis), the authors have examined the mechanism s whereby epileptic seizures can result in neuronal cell loss. (C) 2000 Edi tions scientifiques et medicales Elsevier SAS.