An automated and objective technique of statistical parametric mapping was employed in the analysis of structural MRI from 20 patients with juvenile myoclonic epilepsy (JME) and 30 control subjects studied at the Institute of Neurology, London, UK. An increase in cortical grey matter was observed in the mesial frontal lobes of JME patients. Significant structural abnormalities in cortical grey matter were present in 5 of 20 JME patients studied individually; 2 had bilateral areas of increased grey matter volume in temporoposterior and mesioparietal regions, while 3 had decreased grey matter volume in frontal areas. 
COMMENT. Juvenile myoclonic epilepsy, a syndrome of idiopathic generalized epilepsy, is shown to have a structural cause in some patients.