Idiopathic generalized epilepsy (IGE) is often not recognized with serious consequences on the sufferers. We examined factors contributing to the missed diagnosis of IGE in 41 adults attending our epilepsy clinic with diagnosis of partial epilepsy who had semiology or EEG findings suggesting a possible differential diagnosis. After careful re-evaluation, the diagnosis of IGE was established in 25 patients: 22 (88%) with JME, one with juvenile absence, one with perioral myoclonia with absences, one with eyelid myoclonia with typical absences. Myoclonic jerks, the hallmark of the JME and other IGE, were not usually reported by patients or misdiagnosed as focal motor seizures. Brief and infrequent absence seizures and focal EEG abnormalities were other factors contributing to not recognizing JME. All 25 patients did not achieve seizure control before re-evaluation of diagnosis. After appropriate diagnosis of IGE and change of AED to valproate or valproic acid, 19 (76%) became seizure free and six (24%) had a significant improvement on seizure control. Association with lamotrigine provided further improvement in three of these patients. An appropriate questioning to identify myoclonic and absence seizures and a proper interpretation in the context of whole clinical constellation are essential for a correct seizure classification and diagnosis of IGE in adults.603 B788796Proposal for revised clinical and electroencephalographic classification of epileptic seizures (1981) Epilepsia, 22, pp. 489-501Proposal for revised classification of epilepsies and epileptic syndromes (1989) Epilepsia, 30, pp. 389-399Panayiotopoulos, C.P., Tahan, R., Obeid, T., Juvenile myoclonic epilepsy: Factors of error involved in the diagnosis and treatment (1991) Epilepsia, 32, pp. 672-676Panayiotopoulos, C.P., Obeid, T., Waheed, G., Differentiation of typical absence seizures in epileptic syndromes: A video EEG study of 224 seizures in 20 patients (1989) Brain, 112, pp. 1039-1056Aliberti, V., Grunewald, R.A., Panayiotopoulos, C.P., Chroni, E., Focal electroencephalographic abnormalities in juvenile myoclonic epilepsy (1994) Epilepsia, 35, pp. 297-301Panayiotopoulos, C.P., Koutroumanidis, M., Giannakodimos, S., Agathonikou, A., Idiopathic generalised epilepsy in adults manifested by phantom absences, generalised tonic-clonic seizures, and frequent absence status (1997) J Neurol Neurosurg Psychiatry, 63, pp. 622-627Berkovic, S.F., Andermann, F., Andermann, E., Gloor, P., Concepts of absence epilepsies: Discrete syndromes or biological continuum (1987) Neurology, 37, pp. 993-1000Guideline seven: A proposal for standard montages to be used in clinical EEG (1994) J Clin Neurophysiol, 11, pp. 30-36Panayiotopoulos, C.P., Perioral myoclonia with abscences: A new syndrome (1994) Epileptic Seizures and Syndromes, pp. 143-153. , Wolf P. (ed) London: John Libbey & CompanyAppleton, R.E., Panayiotopoulos, C.P., Acomb, B.A., Beirne, M., Eyelid myoclonia with typical absences: An epilepsy syndrome (1993) J Neurol Neurosurg Psychiatry, 56, pp. 1312-1316Williamson, P., Spencer, S.S., Clinical and EEG features of complex partial seizures of extratemporal origin (1986) Epilepsia, 27 (SUPPL.), pp. 46-63Quesney, L.F., Cendes, F., Olivier, A., Dubeau, F., Andermann, F., Intracranial electroencephalographic investigation in frontal lobe epilepsy (1995) Adv Neurol, 66, pp. 243-258Panayiotopoulos, C.P., Chroni, E., Daskalopoulos, C., Baker, A., Rowlinson, S., Walsh, P., Typical absence seizures in adults: Clinical, EEG, video-EEG findings and diagnostic/syndromic considerations (1992) J Neurol Neurosurg Psychiatry, 55, pp. 1002-1008Gelisse, P., Genton, P., Thomas, P., Rev, M., Samuelian, J.C., Dravet, C., Clinical factors of drug resistance in juvenile myoclonic epilepsy (2001) J Neurol Neurosurg Psychiatry, 70, pp. 240-243Lombroso, C.T., Consistent EEG focalities detected in subjects with primary generalized epilepsies monitored for two decades (1997) Epilepsia, 38, pp. 797-812Janz, D., Juvenile myoclonic epilepsy: Epilepsy with impulsive petit mal (1989) Cleve Clin J Med, 56 (SUPPL.), pp. S23-33Yacubian, E.M.T., Epilepsia mioclonica juvenil (2000) Epilepsia, pp. 215-222. , Guerreiro CAM, Guerreiro MM, Cendes F, Lopes-Cendes I (eds.) São Paulo: Lemos EditorialMontalenti, E., Imperiale, D., Rovera, A., Bergamasco, B., Benna, P., Clinical features, EEG findings and diagnostic pitfalls in juvenile myoclonic epilepsy: A series of 63 patients (2001) J Neurol Sci, 184, pp. 65-70Janz, D., The idiopathic generalized epilepsies of adolescence with childhood and juvenile age of onset (1997) Epilepsia, 38, pp. 4-11Panayiotopoulos, C.P., Obeid, T., Tahan, A.R., Juvenile myoclonic epilepsy: A 5-year prospective study (1994) Epilepsia, 35, pp. 285-296Delgado-Escueta, A.V., Enrile-Bacsal, F., Juvenile myoclonic epilepsy of Janz (1984) Neurology, 34, pp. 285-294Capovilla, G., Rubboli, G., Beccaria, F., Lorenzetti, M.E., Montagnini, A., Resi, C., A clinical spectrum of the myoclonic manifestations associated with typical absences in childhood absence epilepsy. A video-polygraphic study (2001) Epileptic Disord, 3, pp. 57-62King, M.A., Newton, M.R., Jackson, G.D., Epileptology of the first-seizure presentation: A clinical, electroencephalographic, and magnetic resonance imaging study of 300 consecutive patients (1998) Lancet, 352, pp. 1007-1011Meencke, H.J., Janz, D., Neuropathological findings in primary generalized epilepsy: A study of eight cases (1984) Epilepsia, 25, pp. 8-21Opeskin, K., Kalnins, R.M., Halliday, G., Cartwright, H., Berkovic, S.F., Idiopathic generalized epilepsy: Lack of significant microdysgenesis (2000) Neurology, 55, pp. 1101-1106Genton, P., Gelisse, P., Thomas, P., Dravet, C., Do carbamazepine and phenytoin aggravate juvenile myoclonic epilepsy? (2000) Neurology, 55, pp. 1106-1109Fernando-Dongas, M.C., Radtke, R.A., Vanlandingham, K.E., Husain, A.M., Characteristics of valproic acid resistant juvenile myoclonic epilepsy (2000) Seizure, 9, pp. 385-388Genton, P., When antiepileptic drugs aggravate epilepsy (2000) Brain Dev, 22, pp. 75-80Liporace, J.D., Sperling, M.R., Dichter, M.A., Absence seizures and carbamazepine in adults (1994) Epilepsia, 35, pp. 1026-102
