Epileptogenesis, the transformation of the brain to a long-lasting state characterized by recurrent seizures, can occur due to genetic or acquired mechanisms. The mutant genes for three idiopathic syndromes (begin familial neonatal convulsions, generalized epilepsy with febrile seizures plus and autosomal dominant nocturnal frontal lobe epilepsy) and two of the progressive myoclonus epilepsies (Unverricht-Lundborg disease and Lafora disease) have been identified. The underlying genetic defects for common idiopathic generalized syndromes, such as absence epilepsies and juvenile myoclonic epilepsy, have not yet been precisely determined. Acquired epileptogenesis can be an acute or chronic process. The role of acute epileptogenesis in the final clinical expression of human epilepsy is unclear but needs further investigation. Among the chronic acquired partial epilepsies, temporal lobe epilepsy (TLE) due to hippocampal sclerosis has been extensively studied. Two hypotheses of epileptogenesis, involving structural reorganization, have been proposed -mossy fiber sprouting and dormant basket cell. Altered neurotransmitter expression, including increased activation of glutamate receptors and decreased GABA-mediated inhibition, is also important. Kindling and secondary epileptogenesis may play a role in some patients with intractable TLE. An autoimmune mechanism has been implicated in Rasmussen's encephalitis. Generalized absence epilepsy appears to result from a perturbation of the thalamocortical circuit. Clinical differences between seizures in neonates and infants, and those occurring in adults are likely related to maturational differences in cellular and molecular mechanisms. In the future, new therapies to prevent epileptogenesis (antiepileptogenic drugs) may be developed based on improved knowledge of the basic mechanisms of epilepsy.
|Original language||English (US)|
|Number of pages||10|
|State||Published - Mar 25 2002|
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