CLINICAL OBSERVATIONS OF JUVENILE MYOCLONIC EPILEPSY IN 131 PATIENTS - A STUDY IN SOUTH-INDIA

We studied clinical features of 131 patients with juvenile myoclonic e pilepsy (JME). The prevalence was 7.7% among the epileptic patients re gistered. The mean age at onset was 13.37+/-4.93 years and the diagnos is was established at a mean age of 19.53+/-7.85 years. Absence seizur es were reported by 27 (20.6%) patients, myoclonic jerks by 131 (100%) and generalized tonic-clonic seizures (GTCS) by 111 (84.7%). The tria d of absence seizures, myoclonic jerks and GTCS was noted in 23 (17.58 ) patients, 88 (67.2%) had myoclonic jerks and GTCS, 4 (3%) had absenc e seizures and myoclonic jerks and 16 (12.2%) had only myoclonic jerks . Early onset absences were seen in 21 (16%) patients and the onset wa s late in 6 (4.6%). Absences antedated other types of seizures in all the patients. Myoclonic jerks were predominantly unilateral or had uni lateral onset in 22 (16.8%). In 17 (13%) patients GTCS antedated myocl onic jerks. Myoclonic jerks had characteristic circadian distribution in 112 (85.5%) patients. On awakening GTCS occurred in 87 (78.4%) pati ents and in 3 (3.6%) patients they were purely nocturnal. Sleep depriv ation was the most important precipitating factor (54.2%). Initial ele ctroencephalogram (EEG) showed classical generalized spike or multiple -spike slow-wave paroxysms in 81% of records. Focal EEC abnormalities were noted in 20.6%, of records. The most common focal abnormality was voltage asymmetry. A family history of epilepsy was noted in 31 (23.6 %) probands. Diagnosis of JME was made in all the cases in the clinic. The factors responsible for delay in diagnosis of the 36 patients see n by neurologists included failure to ask or interpret the history whi ch was otherwise suggestive of myoclonic jerks in all 36 (100%) cases, the type of seizure for which the patients sought medical attention, and misinterpretation of EEGs in 28 patients. Diagnosis of partial epi lepsy was made in seven patients. The factors responsible for such dia gnoses were, unilateral jerks in one patient, unilateral jerks and abs ence seizures in three patients and focal EEG abnormalities in three p atients.