FUNCTIONAL IMAGING IN IDIOPATHIC GENERALIZED EPILEPSY

Positron emission tomography has offered the possibility to investigat e the pathophysiology of idiopathic generalized epilepsies. Absence ep ilepsies demonstrate normal cerebral glucose metabolism and benzodiaze pine receptor density. Conversely, juvenile myoclonic epilepsies are a ssociated with frontal hypometabolism, which aggravates during a worki ng memory task. Typical 3 Hz spike and wave discharges lead to a diffu se hypermetabolism. The latter resembles that observed during GAERS ra ts absences, and clearly differs from the hypometabolism encountered i n partial epilepsies associated with generalized spike and wave discha rges. Overall, functional imaging data provide further evidence of syn dromic specificities in idiopathic generalized epilepsies.