Generalized convulsive epilepsy: possible mechanisms

Neuronal mechanisms underlying focal convulsions and secondary generalized convulsions continue to be intensively investigated and many important path ophysiological processes are now recognized. Our understanding of primary g eneralized convulsions remains limited in spite of a variety of approaches. While there are well known clinical situations offering insights into some aspects of the pathophysiology, studies in animal models of generalized co nvulsions offer a deeper understanding of some of the processes likely to b e occurring. Animal studies have indicated that generalized convulsive epil epsies are likely to be comprised of several types of convulsion and that t hese arise from more than one neuronal network. In particular, the cortex a nd brain stem can interact in various ways to lead to convulsions and may e ven act independently. Pharmacological agents can produce specific changes in the excitability of neurons and cause generalized convulsions, so provid ing models of the possible neurophysiological defects in humans. Based on e lectrophysiological recordings of generalized convulsions in these animal m odels, we also suggest that the convulsion involves subcortical mechanisms and raise the idea that primary generalized convulsive epilepsy arises out of intensified (synchronized) normal brain rhythms.