Juvenile myoclonic epilepsy

Juvenile myoclonus epilepsy (JME) is a common epileptic syndrome, the etiology of which is genetically determined. Its onset occurs from 6 through 22 years of age, and affected patients present with myoclonic jerks, often associated with generalized tonic-clonic seizures - the most common association - and absence seizures. JME is non-progressive, and there are no abnormalities on clinical examination or intellectual deficits. Psychiatric disorders may coexist. Generalized polyspike-and-waves are the most characteristic electroencephalographic pattern. Usual neuroimaging studies show no abnormalities. Atypical presentations should be entertained, as they are likely to induce misdiagnosis. Prevention of precipitating factors and therapy with valproic acid (VPA) are able to control seizures in the great majority of patients. Whenever VPA is judged to be inappropriate, other antiepileptic drugs such as lamotrigine may be considered. Treatment should not be withdrawn, otherwise recurrences are frequent.

A epilepsia mioclônica juvenil é uma síndrome epiléptica comum, cuja etiologia é fundamentada na genética. Inicia-se entre 6 e 22 anos e os indivíduos apresentam mioclonias, que podem ser acompanhadas por crises tônico-clônicas generalizadas - associação mais comum - e crises de ausência. A doença não é progressiva, e não há alterações detectáveis no exame físico ou déficits intelectuais. Distúrbios psiquiátricos podem coexistir. Polipontas-ondas lentas generalizadas constituem o padrão eletrencefalográfico ictal típico. Não há anormalidades em exames de imagem convencionais. Apresentações atípicas devem ser consideradas, pois predispõem a erros de diagnóstico. A prevenção de fatores desencadeantes e o uso de ácido valpróico (VPA) controlam as crises epilépticas na grande maioria dos casos. Quando o VPA é inapropriado, outras drogas como a lamotrigina podem ser utilizadas. O tratamento não deve ser interrompido, visto que as recidivas são freqüentes.

Epilepsia mioclónica juvenil: benigna y crónica / Juvenile myoclonic epilepsy: bening and chronic

La epilepsia mioclónica juvenil representa el 4,3-10,7% de todas las epilepsias y se manifiesta en la segunda década de lavida. Es de base genética con el locus en el cromosoma 6p. El curso es benigno, no afecta el área cognitiva.El tratamiento es fármaco dependiente (crónico) y tiene períodosde remisión prolongados. Los EEG suelen presentar alteraciones persistentes. En los tres pacientes presentados la duración del tratamiento(durante el período de seguimiento) fue 11, 15 y 16 años. Las drogas de elección fueron ácido valproico y lamotrigina.Palabras clave: epilepsia mioclónica juvenil, tratamiento crónico,cognición normal.

Juvenile myoclonic epilepsy in Libyan patients

The aim of this paper is to study the clinical, electroencephalographic features, response to treatment and the outcome of juvenile myoclonic epilepsy in Libyan patients. A total of 12 patients with prevalence of 1.7% among 704 patients with epilepsies, 3 males [25%], 9 females [75%], age of onset is between [9-17 years] with a mean of 13.8 years, myoclonic jerks were the presenting symptoms in 7[58.4%] patients, 4[33.3%] of them their myoclonic jerks[MJ] were severe enough to make them fall down to the ground, generalized tonic clonic seizures [GTCS] in 5[41.6%] patients, one [8.3%] patient had symptoms of typical absence [TA] in association with the [MJ], no family history of epilepsy was found in all patients. Waking interictal electroencephalographic features showed normal background in all the 12[100%] patients, 3 [25%] patients were photosensitive with characteristic 4 HZ/sec spike and wave. All 12 [100%] patients responded well to small dose of sodium valproate 600mg/day and were seizure free for 3years. The out come in all the 12 [100%] patients showed relapse of the myoclonic jerks after the withdrawing of the treatment

EEG recording after sleep deprivation in a series of patients with juvenile myoclonic epilepsy

Na epilepsia mioclônica juvenil (EMJ), uma síndrome epiléptica ainda subdiagnosticada, as crises são dependentes do ciclo vigília-sono e de fatores precipitantes, entre os quais a privação de sono (PS) é um dos mais importantes. A interpretação inadequada dos EEGs contribui para atraso no diagnóstico. Ainda não foi realizada investigação quantitativa sobre os efeitos da PS. Avaliamos o efeito da PS nos EEGs de 41 pacientes entre 16 e 50 anos (média 25,4) com EMJ em dois registros eletrencefalográficos, separados por intervalo de 48 horas. Os exames foram realizados às 7 horas da manhã, precedidos por um período de 6 horas de sono (EEG de rotina) e após PS (EEG com PS). Seguimos o mesmo protocolo que incluiu o registro em vigília em repouso, fotostimulação, hiperventilação e pós hiperventilação. O efeito da PS foi analisado sobre o número, duração, morfologia, localização e predominância das anormalidades nos diferentes estágios. Calculamos o índice de descargas por minuto. Dos 41 pacientes, 4 tiveram ambos os registros normais. Em 37 (90,2%) houve algumas descargas epileptiformes (DE). O número de pacientes com DE ascendeu de 26 (70,3%) no EEG de rotina para 32 (86,5%) no exame em PS. A presença de descargas de espícula-onda generalizadas e multispícula-onda aumentou de 20 (54,1%) e 13 (35,1%) no primeiro EEG para 29 (78,4%) e 19 (51,4%) no segundo, respectivamente (p<0,05 e p<0,01). Quanto à localização, o número de descargas ascendeu de 21 (56,8%) para 30 (81,1%) (p<0,01). O índice de descargas (ID) também aumentou; enquanto 8 pacientes (21,6%) apresentaram ID maior no EEG de rotina, 25 (67,6%) o tiveram no EEG em PS, principalmente durante sonolência e sono (p<0,01). Ainda mais, os paroxismos também foram mais longos no EEG em PS. EEG em PS é um instrumento poderoso para o diagnóstico de EMJ podendo contribuir significantemente na caracterização desta síndrome.

Juvenile myoclonic epilepsy: analysis of factors implied in delayed diagnosis and prognosis after clinical and electroencephalographical characterization

Considered a common epileptic syndrome, corresponding to 2.8 - 11.9 per cent of all epilepsies, Juvenile Myoclonic Epilepsy (JME) is still not well diagnosed, a fact that may bring about important deleterious consequences, Valproato (VPA) is considered the drug of choice for seizure control. With the aim to characterize the factors implied in the delay of diagnosis (DD) and the response after adequate therapeutic institution we analyzed 41 JME patients attended to since october 2000. The initial diagnosis, the DD and factors implied in it and prognosis after establishment of adequate treatment since most of the patients were receiving antiepileptic drugs (AED) other than VPA were characterized. Only 8 out of the 41 patients (19,5 per cent) had had syndromic diagnosis while 33 (80,5 per cent) had not yet had, being more frequently labeled as undeterminate epulepsy. The diagnosis was established in a mean of 8.2 yr. 15 days to 34 yr.). The factors identified in the DD were: omission in 4 (9.7 per cent) and asymmetry of the myoclonia in 12 (29.3 per cent): normal first EEGs in 16 (41 per cent); presence of focal abnormalities in the EEGs in 12 (31.7 per cent). At the time of the stdy, the sleep-deprived EEG was abnormal in 32 (86.5 per cent) and showed generalized spike-waves in 29 (78.4 per cent) or multispike-waves in 19 (51.4 per cent). There was a frontocentral predominance in 30 (81.1 per cent) being asymmetric in 12. Focal discharges were obsersed in 12 (29.2 per cent). The mean in years of DD was 11.6 yr. for the group with asymmetric compared to 8,5 yr. in those with symmetric paroxysms. VPA associated with avoidance of precipitant factors (APF) led to complete seizure control in 29 of all patients in the first year. This rate dropped to 16 in the third year. The main factor inplied in this drop was non-compliance. JME continues to be misdiagnosed and the response to VPA + APF in one year is excellent suggesting pharmacosenstivity. Despite all the instructions it is very difficult for JME patients to regorously follow medical advices over the yeras

Pitfalls in diagnosis of epilepsy of Janz and its implications.

84 patients of juvenile myoclonic epilepsy (JME) of Janz were studied. Diagnosis was confirmed using clinical and electro-encephalographic (EEG) criterias. 58 (78%) patients of JME were referred as 'refractory or uncontrolled seizures'. Ignoring myoclonic episodes and non-use of activation procedures in EEG were important reasons for diagnostic delay. Sodium valproate (VPA) or clonazepam are the drugs of choice while phenobarbitone (PB), carbamazepine (CZ), and phenytoin (PHT) are ineffective. Clinical spectrum of JME is slightly different in India. Family history of epilepsy or JME is not forthcoming and there is gross delay in the diagnosis. Other differences include age of presentation and mild cognitive impairment. All juvenile patients of generalized epilepsy, not responding to more commonly used CZ, PB and PHT should be strongly suspected for JME by carefully searching for myoclonus.

Evolución de la clasificación de la epilepsia: parte II / Evolution of epilepsy classification: part II

No es posible determinar el pronóstico y el tratamiento sólo con base en el tipo clínico de crisis. Después de la clasificación de la Liga Internacional Contra la Epilepsia (LICE) en 1981, cuyo principal aporte fue la distinción entre crisis convulsivas parciales y generalizadas, la comisión formada específicamente para mejorar el conocimiento del fenómeno epiléptico realizó varias reuniones para definir las características más importantes de las crisis convulsivas y de la epilepsia. Se introdujo el concepto de síndrome epiléptico, el cual distingue los tipos de crisis convulsivas, los datos del electroencefalograma, los padecimientos neurológicos relacionados, el pronóstico y la potencial respuesta a la medicación anticonvulsiva. Se hizo énfasis en una nueva clasificación de epilepsia, síndromes epilépticos y trastornos aparentemente ictales, adoptada por la LICE en el Congreso Mundial de Neurología (1985). Esta clasificación mantiene la distinción entre epilepsia generalizada y parcial e introduce los conceptos etiológicos de epilepsia sintomática, idiopática y criptogénica (causa supuesta, pero oculta). Además, en ella se enumeran las definiciones y características elementales de las diferentes categorías de epilepsias y de los síndromes epilépticos reconocidos. Para propósitos de comunicación es importante que exista unanimidad en la terminología. La moneda común es el lenguaje uniforme, a lo que ha contribuido esta clasificación.

Factors of error involved in the diagnosis of juvenile myoclonic epilepsy: A study from South India.

The study was aimed at finding possible factors for delay in the diagnosis of juvenile myoclonic epilepsy (JME) in a developing country. Data was analyzed retrospectively through the medical records and prospectively through a re-evaluation of the history and EEGs of patients with JME registered in a university hospital in south India. Of the 131 patients, 23 (17.5%) patients were seen by neurologists before registration in the clinic. Diagnosis of JME was established in 118 patients at the time of registration and in 13 (10%) patients during follow-up in the clinic. The mean interval between onset of disease and the diagnosis was 6.8 + 6.3 years. In 20 patients the diagnosis was established 10 years after the onset. The mean interval between the first evaluation and diagnosis was 24. 2 months in the 13 patients in whom the diagnosis was established during follow-up in the clinic. Lack of familiarity with the clinical syndrome was probably the factor for delay in the diagnosis in 108 patients seen by practising physicians. The factors for delay in the diagnosis in patients seen by neurologists included failure to ask about myoclonic jerks resulting in misinterpretation of EEGs in 28 patients, misinterpretation of absences and/or unilateral jerks in 4 patients, and failure to ask about myoclonic jerks and misinterpretation of focal EEG abnormalities in 4 patients. This study suggests that the possible factors of error in the diagnosis of JME among the neurologists were similar to the observations reported from the developed countries; whereas the factor for delay in the diagnosis of JME among practising physicians was lack of familiarity with the epileptic syndrome.

Myoclonus and epilepsies.

The possible associations of myoclonic phenomenae, progressive or non-progressive encephalopathies and epileptic features are reviewed, with special emphasis on pediatric age. This leads to recognize the following five groups of conditions: (1) Myoclonus without encephalopathy and without epilepsy; (2) Encephalopathies with non-epileptic myoclonus; (3) Progressive encephalopathies presenting myoclonus seizures of epileptic syndromes (Progressive myoclonus epilepsies); (4) Epileptic encephalopathies with myoclonic seizures; (5) Myoclonic epilepsies. Within the first group, which also includes physiologic myoclonus, a more thorough description of "Benign sleep myoclonus of newborn" and "Benign myoclonus of early infancy" is given. Characteristics of group 2 are "Kinsbourne Syndrome" and certain types of "Hyperekplexia" which pose interesting differential diagnosis with stimulus-sensitive epilepsies. In group 3, the concept of progressive encephalopathies is stressed. The fourth group refers to severe epilepsies, mainly on infancy and childhood, which lead to mental retardation irrespective of their aetiology. Group 5 comprises the true myoclonic epilepsies, differentiating syndromes recognized as idiopathic--such as "Benign myoclonic epilepsy of infancy" and "Juvenile myoclonic epilepsy"--from those which are cryptogenic and carry a more cautious prognosis--as "Cryptogenic myoclonic and myoclonoastatic epilepsies" and "Severe myoclonic epilepsy of infancy". Other epileptic syndromes not usually considered as myoclonic epilepsies, but presenting sometimes as myoclonic seizures, are finally referred.