Clinical and EEG characteristics of Juvenile Myoclonic Epilepsy

European Journal of Neurology, 2006

Although diagnosis of juvenile myoclonic epilepsy (JME), a common form of idiopathic generalized epilepsy, is based on clinical and electroencephalogram (EEG) criteria, at times clinical symptoms may be misleading, like the occurrence of asymmetric myoclonic jerks. Thus EEG assumes an important role in these cases, it can fail to show the classical polyspike and slow wave (PSW) discharges of JME, specially in a routine evaluation in older patients. We analyzed retrospectively EEG results of 35 patients with JME [Commission on Classification and Terminology of the International League Against Epilepsy (ILAE) Epilepsia 1989; 30: 389] aged 12-44 years. (mean 22.7 years) at first medical evaluation. EEG findings of 35 patients (19 females, 16 males) with JME consisted of normal tracings in 22.9 and 54.3% had at least one normal exam. EEG abnormalities present in 27 patients (77.1%) consisted of isolated generalized slowing in two and generalized discharges in 25: irregular spike and wave complexes (SWC) in 76%; PSW in 48%; SWC faster than 3 Hz in 20%; spikes, sharp waves, and irregular slow waves in 24%; asymmetric generalized epileptiform discharges in 40%; and associated focal paroxysms in 12%. Thus JME is classically associated to PSW on EEG, the most frequent abnormality was irregular SWC. Generalized paroxysms could occur in an asymmetric fashion and rarely associated to focal activity.

Epilepsia, 2005

Purpose: A few reports have described focal electroencephalographic or clinical features or both of juvenile myoclonic epilepsy (JME), but without video-EEG documentation. We examined focal clinical and EEG features in patients with JME who underwent video-EEG monitoring.

Journal of Neurology, Neurosurgery & Psychiatry, 1992

Fifteen cases of juvenile myoclonic epilepsy (IME) were identified from one hundred and eighty consecutive patients referred to a new epilepsy clinic at St Thomas' Hospital between April 1989 and December 1990, a prevalence of 8*3%. Of these, only one was referred with a puta- tive diagnosis of JME. Diagnosis of the other patients on referral included "epilepsy", "grand mal", "temporal lobe epi- lepsy", "photoconvulsive epilepsy" and "alcohol-induced epilepsy". At least 11 of the 15 patients had been seen by a neurol- ogist in the United Kingdom before referral. Definitive diagnosis was delayed by a mean of 14-5 years. In seven patients inappropriate anticonvulsants had been prescribed. Control of seizures was improved in most patients after diagnosis. Factors responsible for the delay in diagnosis include lack of familiarity with the syndrome, failure to elicit a history of myoclonic jerking and high prevalence of focal abnormalities on the EEG. Precipitation offits by alcohol and sleep deprivation may not be recognised by the physician as part of the syndrome of JME. Diagnosis may also be delayed in patients whose absence and generalised tonicclonic seizures pre-date myoclonic jerks.

Seizure-european Journal of Epilepsy, 2014

Juvenile myoclonic epilepsy (JME) is the most common type of genetic (idiopathic) generalized epilepsy, comprising 5-10% of all epilepsies. 1 Onset is usually in the second decade, and the cardinal symptom is early-morning myoclonic seizures (MC), often precipitated by sleep deprivation. Approximately 90% of patients have generalized tonic-clonic seizures (GTC), and one third has absence seizures. 2 Although response to appropriate treatment is good for most patients, 3,4 JME has been considered a lifelong disorder with a high risk of seizure relapse on discontinuation of antiepileptic drugs (AEDs). 5-7 Nevertheless, four long-term follow-up studies have shown that some patients may stop AED treatment and remain seizure free. 8-11 In contrast to the seemingly positive seizure outcome in the majority, there is expanding evidence of an unfavorable psychosocial outcome in many patients. 9,12 This has been ascribed to a subtle frontal lobe dysfunction in JME. 13,14 As long-term studies of JME are scarce, there is a need for more clinical research on the course and prognosis of this syndrome. Thus, we aimed to assess the severity of the disorder in a cohort of patients after at least 20 years of follow-up, and to study clinical characteristics in relation to seizure and psychosocial outcome. 2. Methods In 1992, consecutive patients with JME at Trondheim University Hospital were identified for recruitment in a study on the association with human leukocyte antigens. 15 The clinical diagnosis of JME was based on the 1989 classification of epilepsies and epileptic syndromes by the International League Against

Seizure, 1998

Of 1300 epileptic patients 76 (5.8%) were found to have juvenile myoclonic epilepsy (JME). These 76 patients were examined at the epilepsy outpatient clinic of Bakirkoy State Hospital for Neurological and Psychiatric Diseases between 1991 and 1996 and data obtained were analysed retrospectively. Clinically typical absence seizures were reported in 40.8%, myoclonic jerks in lOO%, and generalized tonic<lonic seizures in 82.9% of the patients. Neurological and mental examination was normal for all patients with the exception of three cases; two with essential tremor and one with minimal dysarthria. Precipitating factors were noted in 85.5% of cases. Abnormal EEG was recorded in 73 (6.1%) patients. Abnormalities mainly consisted of generalized discharges of spike/polyspike and slow-wave (86.6%) and generalized paroxysmal theta or delta (9.2%). Fifteen (19.7%) had focal abnormalities and 20 (26.4%) had photoconvulsive discharges. Of the 76 patients, 40 (52.6%) were not diagnosed at the initial interview; definite diagnosis was delayed by a mean of 5.9 years. As a result of misdiagnosis at the initial interview 40 patients had been administered AED except for valproate. After reassessment of clinical and EEG findings, the medication was changed to valproate therapy. As a result, 65 of our JME patients (85.5%) were seizure free after a one-year follow-up period.

Cureus, 2018

Juvenile myoclonic epilepsy (JME) is a genetically and clinically diverse disorder which is characterized by myoclonic jerks, usually after awakening from sleep. It affects both genders equally and manifests during the second decade of life. The various precipitating factors include stress, light, sleep deprivation, and alcohol. A history of morning clumsiness supported by typical electroencephalography (EEG) findings, together with a normal clinical examination all point towards a diagnosis of JME. We present the case of a nine-year-old girl who presented with cognitive dysfunction in addition to myoclonic jerks. She had normal brain imaging and her labs were negative for other causes of dementia. Her EEG findings revealed polyspikes with normal background activity. She was treated with antiepileptic drugs (AEDs) for control of seizures.

Annals of Neurology, 1989

We report a prospective clinical and electroencephalographic study of 19 patients with juvenile myoclonic epilepsy and absence seizures. Absences began 1 to 9 (4.5 f 2.5) years before myoclonic jerks and generalized tonic-clonic seizures. Clinical manifestations during the absence ictus showed great variation, ranging from subtle or no overt features to severe impairment of consciousness, and severity was age related. Simple and complex absence seizures can occur in the same patient. The electroencephalographic features were distinct, with many interictal discharges, fragmentation of the paroxysms, and frequent polyspikes of varying numbers and amplitude for each spike-slow wave component. The combined clinical-electroencephalographic manifestations were characteristic and allow differentiation of absences in juvenile myoclonic epilepsy from typical absence seizures in other epileptic syndromes. Panayiotopoulos CP, Obeid T, Waheed G. Absences in juvenile myoclonic epilepsy: a clinical and video-electroencephalographic study. Ann Neurol 1989;25:391-397 Juvenile myoclonic epilepsy (JME) was described mainly by Janz [l-41 and was classified recently as a generalized idiopathic and age-related epileptic syndrome [5}. It appears near puberty and is characterized by seizures with bilateral, single, or repetitive arrhythmic, irregular myoclonic jerks, predominantly in the arms { S } . Often, generalized tonic-clonic [5} or clonictonic-clonic [bf seizures occur. Absences are an infrequent [4} and inconspicuous [7} feature of the syndrome. They occur in 10 to 15% of patients with JME and are described as simple typical absences associated with a fast, spike-wave, 3.5to 4-Hz electroencephalographic (EEG) pattern [3,

Epilepsia, 2006

Epilepsia, 2007

According to the WHO 50 million people suffer from epilepsy; 80% of them live in resource poor countries (WHO, 2001). In these settings, classification of seizures in view of adequate treatment has been difficult due to lack of diagnostic tools such as electroencephalograms (EEG) and imaging. Drawing from a vast working experience of many years in neurology in developing countries, the authors developed a classification system for seizures suitable for local circumstances. Considering clinical, diagnostic, prognostic and therapeutic needs, we adjusted the International Classification of Epileptic Seizures (ICES) and opted for a simple-structured, easy-to-understand classification of epileptic seizures which is still in accordance with the ICES and in fact shares many similarities with the ILAE version of guidelines for epidemiologic studies on epilepsy (ILAE 1981, ILAE 1993). EEG and neuroimaging are normally not available in developing countries, thus the diagnosis is based on clinical symptomatology alone. We suggest the following classification: 1) Generalised types of seizures: Generalised seizures within a specific age range: primary generalised seizures that start within a specific age group (mainly between 6 and 25 years). There is no obvious cause for the seizures, brain damage is absent. There may however be a positive family history, suggesting a possible genetic background. Seizures of this group may also be termed idiopathic generalised epilepsies. Generalised seizures outside a specific age range: primary generalised seizures that lie outside the specific age range of most of the idiopathic generalised epilepsies, but have no focal start and no clinical signs of brain damage. There may be a cause which cannot be diagnosed with the currently available ancillary means, thus these seizures may be termed "cryptogenic". 2) Partial types of seizures: Generalised seizures with diffuse brain damage: clinically seizures start in a generalised way, however, diffuse brain damage is obvious, which is the major difference when compared to group 1. Causes are mainly due to static encephalopathies. All age groups can be affected, but there tends to be a shift to the younger ages. Generalised seizures with focal signs: secondary generalised seizures with a focal start or clear unilateral seizures but without major brain damage. There may be developmental delay, subtle signs of brain damage and/or focal neurology. Causes are often due to progressive encephalopathies. All age groups can be affected. Complex partial seizures: as defined by the ILAE (ILAE 1981). Simple partial seizures: as defined by the ILAE (ILAE 1981).