Chapter 66 - Genetic Epilepsies—Generalized

Abstract

This chapter discusses various aspects of genetic epilepsies. Idiopathic generalized epilepsy is characterized by recurrent primarily generalized seizures occurring in the absence of detectable brain lesions and/or metabolic abnormalities. In primarily generalized seizures, the initial behavioral, electrical, and physiological changes are bilateral from the onset. Six primary generalized epilepsy syndromes as well as the syndrome of febrile seizures, appear to have a genetic etiology. A study reported a variant of benign myoclonic epilepsy in six infants with myoclonic seizures which were identified as reflex myoclonic epilepsy in infancy. In these infants the seizures did not occur spontaneously, in contrast to benign myoclonic epilepsy in infancy. The seizures were always precipitated by a stimulus, usually acoustic or tactile stimuli. Childhood absence epilepsy (CAE) characteristically begins between 4 and 8 years of age, with absence seizures with a peak age of onset of 6 to 7 years. Absence seizures can be easily suppressed in 80% of the patients by treatment with valproate. The patients have normal intelligence and no focal neurologic signs. The juvenile myoclonic epilepsy and generalized clonic-tonic-clonic seizures are also elaborated.