Clinical factors of drug resistance in juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy is a comparatively benign form of idiopathic ge neralised epilepsy. Little is known about the prevalence of difficult to tr eat or drug resistant patients. Among 155 consecutive patients with newly d iagnosed juvenile myoclonic epilepsy evaluated between 1981 and 1998 and fo llowed up for at least 1 year (61 men, 94 women; aged 15-70 years, mean 33 (SD 10.3); onset of juvenile myoclonic epilepsy at the age of 14.5 (SD 3.7) , range 6-26; follow up 1-52 years, mean 13.5 (SD 9.9)), there were 15 pseu doresistant patients (9.7%: lack of compliance (eight), insufficient treatm ent (three), abnormal lifestyle (four)) and 24 patients (15.5%) who had per sisting seizures despite adequate therapy and lifestyle. Clinical features associated with drug resistance were (1) the presence of psychiatric proble ms (58.3% v 19%; chi (2) p<0.001) and (2) independently, the combination of seizure types (Fischer's exact 2 by 4, p=0.0026). Three types were present in 62.5% of resistant patients versus 23.3% in non-resistant patients (<ch i>(2), p=0.0001). None of the resistant patients had myoclonic jerks as the only seizure type or a combination of absences and myoclonic jerks. Family history of epilepsy, age at onset of seizures, sex, presence of photoparox ysmal response, results of conventional neuroimagings (CT and MRI), and del ayed diagnosis were not significantly associated with drug resistance. Ther e is thus a significant subgroup of patients with juvenile myoclonic epilep sy who pose difficult therapeutic problems, and the prevalence of resistant cases may be increased in the experience of a referral epilepsy centre.