Focal ��G abnormalities in juvenile myoclonic epilepsy

Background and Objective: Juvenile myoclonic epilepsy (JME) is a common genetically determined idiopathic generalized epilepsy. JME typically presents with generalized tonic-clonic, myoclonic or absence seizures or a combination of these. The EEG in untreated patients is usually abnormal, with generalized discharges of an irregular mixture of 3-6 Hz spike / poly-spike and slow waves, with intra-discharge fragmentation and unstable frequency. However, focal clinical and EEG features are often reported in JME. The aim of this study was to identify the prevalence of various focal EEG abnormalities in patients with JME. Methods: Clinical and EEG data of patients attending the Epilepsy Clinic of the Institute from July 2001 to June 2006 with a diagnosis of JME was analyzed. All the patients had GTCS and myoclonic jerks with or without absences. A 60 minute awake and sleep EEG (hyperventilation- 3 min and Photic stimulation 1-30Hz) after sleep deprivation was performed. The prevalence of various focal EEG abnormalities – focal onset (spike / slow wave) of generalized discharges, independent focal spike / sharp wave discharges, focal slowing (either associated with or independent of generalized discharges), phase reversals, asymmetry in generalized discharges and & photo paroxysmal response (PPR) were noted. Two consultants independently read all EEGs and findings in agreement were reported