Clinical genetic study in juvenile myoclonic epilepsy

PurposeTo evaluate clinical features of probands with juvenile myoclonic epilepsy (JME) and affected members of their families in order to study clinical genetics of JME.MethodThirteen unrelated families with at least two members with history of seizures were identified; clinical and genealogic data were collected from JME probands and family members.ResultsAll probands had myoclonic and generalized tonic–clonic seizures (GTCS), while absences occurred in 25% of them. The average age of seizure onset was 13 years. Totally 22 members from 13 families had history of seizures with average age of seizure onset at 18 years. Ten family members had JME, three had epilepsy with GTCS, two had juvenile absence epilepsy, one had adult onset myoclonic epilepsy and six of the affected individuals had unclassified type of epilepsy. In five families, JME was the solely clinical feature. JME dominated among siblings, while phenotypic heterogeneity was observed in second and third degree relatives. In three multi-generation families, members with adult onset genetic generalized epilepsies (GGE) were identified.ConclusionWe found phenotypic heterogeneity regarding epilepsy type and age of seizure onset. Using pedigree analysis, we found no evidence for preferential maternal or any other distinctive inheritance pattern. Further study is needed to confirm and clarify the results.     

Some clinical and EEG aspects of benign juvenile myoclonic epilepsy

Twelve patients with benign juvenile myoclonic epilepsy (BJME) representing 4% of our population of epileptics (n = 275) are presented. Only two patients (17%) had myoclonic jerks as the only seizure type. Seven (58%) had generalized tonic-clonic seizures (GTCS) and myoclonus. Three patients (25%) had absence seizures (AS), GTCS, and myoclonic jerks. Electroencephalographic evidence of photosensitivity was found in four (33%). Auditory precipitation of seizures was found in one patient. As is the case with other primary generalized epilepsies, the onset of BJME seems to be age specific. In our series the mean age of onset in years was 4.3 for AS, 14.75 for myoclonic jerks, and 16.4 for GTCS. It took an average of 8.5 years from the onset of BJME (range, 2-20 years) and 6.5 years from the onset of GTCS (range, 2 months-6 years) until the condition was properly recognized. Five patients experienced at least one episode of myoclonic status epilepticus. Generalized, paroxysmal, symmetric polyspike and slow wave discharges are the typical EEG finding. These complexes, however, showed considerable interpatient variability. Sleep deprivation proved to be the most valuable activating procedure. Valproic acid monotherapy effectively controlled myoclonic jerks as well as associated GTCS in most patients.     

青少年肌阵挛性癫(癎)的临床特点及误诊原因分析

目的研究青少年肌阵挛性癫痫（JME）的临床特点及导致误诊的主要原因。方法对61例JME患者的临床和脑电图（EEG）资料进行回顾性分析。结果肌阵孪是最常见的首发症状，其次为肌阵挛加全身强直一阵孪发作（GTCS）。导致误诊最常见的原因是医师对肌阵挛发作缺乏认识，其次是临床和EEG的非对称性表现。结论JME的正确诊断依赖于医师对此综合征的深刻了解，EEG只能作为辅助诊断工具。     

Clinical factors of drug resistance in juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy is a comparatively benign form of idiopathic generalised epilepsy. Little is known about the prevalence of difficult to treat or drug resistant patients. Among 155 consecutive patients with newly diagnosed juvenile myoclonic epilepsy evaluated between 1981 and 1998 and followed 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 pseudoresistant patients (9.7%: lack of compliance (eight), insufficient treatment (three), abnormal lifestyle (four)) and 24 patients (15.5%) who had persisting seizures despite adequate therapy and lifestyle. Clinical features associated with drug resistance were (1) the presence of psychiatric problems (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 (chi(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 photoparoxysmal response, results of conventional neuroimagings (CT and MRI), and delayed diagnosis were not significantly associated with drug resistance. There is thus a significant subgroup of patients with juvenile myoclonic epilepsy who pose difficult therapeutic problems, and the prevalence of resistant cases may be increased in the experience of a referral epilepsy centre.     

Treatment of juvenile myoclonic epilepsy

Drug treatment of juvenile myoclonic epilepsy (JME) is mainly based on clinical experience and prospective and retrospective studies, with little evidence from randomized clinical trials. There are almost no head-to-head comparisons between old and new antiepileptic drugs (AEDs). Valproate is the drug of the first choice in men with JME. In women, lamotrigine (LTG) should be preferred regarding teratogenicity and side effects of valproate. Levetiracetam (LEV) is also effective. Recent data suggest that it may soon be used as first line treatment. Some AEDs can aggravate JME. In addition to AEDs, nonpharmacological treatments are important in JME. JME usually requires lifelong treatment because seizures nearly always return after withdrawal of therapy.     

成年期确诊的青少年肌阵挛性癫痫的临床特点

目的分析成年期确诊的青少年肌阵挛性癫痫(JME)的临床特点。方法对75例成年期确诊的JME患者进行回顾性分析。结果 75例患者43例有误诊经历,最长误诊时间达26年。75例患者均有肌阵挛发作(MJ),其中2例仅有MJ发作,2例合并失神发作(AS),57例合并全面强直-阵挛发作(GTCS),14例三种发作形式均有。EEG检查75例均发现全导广泛性棘慢或多棘慢复合波,23例有局灶性放电。23例既往曾服用卡马西平、奥卡西平、苯妥英钠或拉莫三嗪出现发作增多现象。随访0.5~4年,51例选择丙戊酸钠、托吡酯或左乙拉西坦单药治疗无发作,8例患者选择两种以上药物方能控制,5例停药后复发。结论JME多见于青少年期,步入成年期后误诊率更高。JME临床表现以MJ为主,常伴有GTCS或AS,EEG为弥漫性3.5~5 Hz棘慢波或多棘慢波,部分有局灶性放电。治疗可选择丙戊酸钠、托吡酯或左乙拉西坦,而卡马西平、奥卡西平、苯妥英钠可加重临床发作。JME患者停药后复发率高,推荐患者终身服药。     

Management of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is a common form of epilepsy and a fairly lifelong disorder that may significantly lower a patient's expectations and potential for a full life. Luckily, it is also a highly treatable disorder, and up to 85% of patients with JME will enjoy satisfactory seizure control. Among anticonvulsants, valproate still stands out as the most efficacious drug, but may be poorly tolerated by some, and is considered unsafe for the fetuses of pregnant women. Alternatives have emerged in recent years, especially levetiracetam, but also topiramate, zonisamide or lamotrigine. In some cases, combination therapy may be useful or even required. One should not forget the potential aggravation induced not only by some commonly used anticonvulsants, especially carbamazepine and oxcarbazepine, but also, in some patients, by lamotrigine. In special settings, older drugs like benzodiazepines and barbiturates may be useful. But the management of JME should also include intervention in lifestyle, with strict avoidance of sleep deprivation and the management of copathologies, including the cognitive and psychiatric problems that are often encountered. With adequate management, there will only remain a small proportion of patients with uncontrolled epilepsy and all of its related problems. Juvenile myoclonic epilepsy is a condition in which the clinician has a fair chance of significantly helping the patient with medication and counseling.This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?     

Epidemiology of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is a widely recognized presumed genetic, electroclinical idiopathic generalized epilepsy syndrome. The prevalence of JME in large cohorts has been estimated to be 5% to 10% of all epilepsies and around 18% of idiopathic generalized epilepsies but may be lower in some settings. There is a marked female predominance. However, some of the basic epidemiology of JME is not well known, possibly because the syndrome is not sharply defined. A questionnaire study about the diagnostic criteria for JME suggests that diagnosis of JME can be made with the history of myoclonus plus a single generalized tonic-clonic seizure plus generalized fast spike–waves or polyspike–waves on the EEG. However, until these diagnostic criteria are fully accepted, the detailed epidemiology of JME will remain imprecise.This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?     

Neurophysiology of juvenile myoclonic epilepsy

Juvenile myclonic epilepsy (JME) can be firmly diagnosed by a careful interview of the patient focusing on the seizures and by the EEG with the help, if necessary, of long-term video-EEG monitoring using sleep and/or sleep deprivation. Background activity is normal. The interictal EEG shows diffuse or generalized spike-wave (SW) and polyspike-wave (PSW) discharges. In some patients, non-specific changes or misleading features such as focal changes are found. Changes are mostly seen at sleep onset and at awakening. Provoked awakenings are more likely to activate interictal paroxysmal abnormalities than spontaneous awakenings. The presence of a photoparoxysmal response with or without myoclonic jerks (MJ) is common (30% of the cases). Myoclonic jerks are associated with a discharge of fast, irregular, generalized PSWs that predominate anteriorly. Myoclonic jerks appear to be associated with rhythmic EEG (spike) potentials at around 20 Hz. These frequencies are in the range of movement-related fast sensorimotor cortex physiological rhythms. The application of jerk-locked averaging technique has provided findings consistent with a cortical origin of MJ. Paired TMS (transcranial magnetic stimulation) studies showed a defective intracortical inhibition, due to impaired GABA-A mediated mechanisms. In this review, we present the EEG characteristics of JME with particular emphasis on the pathophysiology of MJ and on the role of sleep deprivation on interictal and ictal changes.This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?     

Occurrence of only myoclonic jerks in juvenile myoclonic epilepsy

Objectives - The clinical data on individuals who were diagnosed to have juvenile myoclonic epilepsy (JME) on the basis of myoclonic jerks alone has been analysed. The points in favour and against individuals with only myoclonic jerks being classified as "affected" for research on JME are discussed.
Materials and methods - We studied 15 persons diagnosed with JME on the basis of only myoclonic jerks in a series of 161 patients with JME and their relatives. Detailed information on the seizure types in JME patients and their family members was collected. All affected individuals were examined by one person and had at least one conventional scalp EEG. CT/MRI of the brain was done as and when indicated.
Results - Nine of these were probands while 6 were the relatives of JME patients. The EEG was abnormal in 8 of 9 probands and 1 of 6 relatives with only myoclonic jerks. All the 9 probands and 2 relatives with only myoclonic jerks were treated with anti-epileptic drugs. Three of the 4 relatives had spontaneous remission of jerks after variable intervals. Four of 15 persons with only myoclonic jerks had a first degree relative with definite JME.
Conclusions - It appears that persons with myoclonic jerks alone may represent a benign subgroup of JME that may be genetically distinct from classic JME and the jerks may even spontaneously remit in a few cases. It is suggested that those persons with only myoclonic jerks and a first degree relationship with a definite diagnosis of JME can be classified as "affected" for inclusion into molecular studies, till molecular tools are available to settle the issue of phenotypic variations in hereditary neurological disorders like JME.     

Lacosamide treatment of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy is the most common form of idiopathic generalized epilepsy with onset at puberty or late teenage years. About 80-90% of patients with juvenile myoclonic epilepsy respond to appropriate antiepileptic treatment and achieve seizure freedom, and about 15% of patients become intractable. Valproic acid, levetiracetam, lamotrigine, topiramate and zonisamide are used as first line or adjunctive therapy of this disorder. Lacosamide is approved for adjunctive treatment of partial onset epilepsies. The role of lacosamide in treatment of idiopathic generalized epilepsy including juvenile myoclonic epilepsy is unknown. We present three patients with classic clinical and electrographic features of juvenile myoclonic epilepsy that were maintained on lacosamide (one on monotherapy and two as adjuvant therapy). There were no special pharmacodynamic actions causing exacerbation or worsening of myoclonic jerks or generalized seizures in these three patients. In conclusion, although, the data from our three patients' suggest that lacosamide may be effective in the treatment of juvenile myoclonic epilepsy, larger studies are needed to explore efficacy and role of lacosamide in the treatment of this disorder.     

Lifetime prognosis of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is among the most common types of genetic epilepsies, displaying a good prognosis when treated with appropriate drugs, but with a well-known tendency to relapse after withdrawal. The majority of patients with JME have continuing seizures after a follow-up of two decades. However, 17% are able to discontinue medication and remain seizure-free thereafter. Clinicians should remember that there is a small but still considerable subgroup of JME patients whose seizures are difficult to treat before informing patients with newly-diagnosed JME about their “benign” prognosis. This resistant course is not fully explained, though there are many suggested factors. The dominating myoclonic seizures disappear or diminish in severity in the fourth decade of life. Despite the favorable seizure outcome in most of the cases, 3/4 of patients with JME have at least one major unfavorable social outcome. The possible subsyndromes of JME, its genetic background, and its pathophysiological and neuroimaging correlates should be further investigated.This article is part of a supplemental special issue entitled Juvenile Myoclonic Epilepsy: What is it Really?     

The treatment of juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy is a common type of epilepsy with onset occurring during adolescence. This review provides a collection of evidence relating to the treatment of this type of epilepsy. Historically, the large majority of patients become seizure-free when treated with valproate. Over recent years, there has been a marked improvement in the pharmacological armamentarium by the physicians. Currently, administration of new antiepileptic drugs, such as levetiracetam, lamotrigine and topiramate, seems to have beneficial effects in the patients with poor response to valproate.     

Colour vision in juvenile myoclonic epilepsy

Aims. To determine the integrity of colour perception, related to photic sensitivity, in patients with juvenile myoclonic epilepsy. Methods. Twenty‐four patients with photoparoxysmal response, 27 patients without photoparoxysmal response, and 32 healthy individuals were investigated using the Farnsworth Munsell‐100 Hue test to calculate error scores for total colour, blue/yellow, and red/green. Results. No significant differences were observed regarding blue/yellow, red/green or total error score between juvenile myoclonic epilepsy patients with or without photoparoxysmal response. However, the data for all three scores were significantly higher in both patient groups compared to the healthy control group. In both patient groups, the blue/yellow error score was significantly higher than the red/green error score. Conclusions. We were unable to identify a relationship between photoparoxysmal response and colour vision in patients with juvenile myoclonic epilepsy. We believe that the underlying reason why juvenile myoclonic epilepsy patients had significantly higher blue/yellow, red/green, and total error score compared to the healthy control group may be due to GABA dysfunction, which is considered to play a role in the pathophysiology of this disease as well as the physiology of colour vision.     

Mapping genes in juvenile myoclonic epilepsy

The genetics of the various forms of epilepsy can be best understood by knowing where the affected gene is located. Genetic methodologies used to explore the genetics of epilepsy now include segregation analysis, linkage analysis and recombinant DNA technology. Juvenile myoclonic epilepsy (JME), a form of idiopathic epilepsy with a strong genetic component, provides informative pedigrees for linkage studies. Preliminary results demonstrate the heterogenous nature of the JME syndrome.     

Psychiatric comorbidity in juvenile myoclonic epilepsy

OBJECTIVE: To assess the prevalence of psychiatric disturbances among patients with juvenile myoclonic epilepsy (JME). METHODS: Forty-three patients with JME (22 female, 21 male, mean age 32.4+/-13, range 15-63) were assessed by means of the Structured Clinical Interviews for DSM-IV (SCID-I and SCID-II). Current and lifetime psychiatric diagnoses were assigned. RESULTS: Thirty-five percent of the JME patients suffered from one or more psychiatric disorders (Axis I and Axis II). Personality disorders were present in 23% and Axis I disorders in 19%. Altogether, 47% had a psychiatric disorder at any time of their life. CONCLUSIONS: Psychiatric diagnoses are slightly higher than in representative community samples. The substantially increased number of personality disorders in JME patients might be attributed to frontal lobe deficits.     

Cognitive function in juvenile myoclonic epilepsy

In this study, we examined 35 patients with juvenile myoclonic epilepsy (JME) and 35 healthy volunteers. We used tests of cognitive performance (mini mental state examination, verbal and visual memory, visuospatial, frontal function, attention). In the JME group, we examined age, sex, family history, education level, age of seizure onset, seizure types, characteristics of EEG, duration of the therapy, drug dose and level, and verbal IQ level. Additionally, patients initially diagnosed as JME and patients who were initially under inappropriate drug therapy because of misdiagnosis were compared. As a result, we found statistically significant differences between JME patients and the control group with respect to verbal and visual memory. Furthermore, JME patients had impaired frontal and visuospatial function compared with the control group. We detected negative effects of younger age, family history, and absence seizures on cognitive function in JME patients.     

Premature death in juvenile myoclonic epilepsy

OBJECTIVES: To report three cases of premature death in juvenile myoclonic epilepsy (JME), a benign form of idiopathic generalized epilepsy (IGE) in which no case of epilepsy-related death has been reported. MATERIAL AND METHODS: We retrospectively analyzed all medical records of JME patients first referred to two epilepsy centers (Marseilles, Nice) between 1981 and 1998. RESULTS: Among 170 consecutive JME cases, 3 female patients died prematurely. No autopsy was performed. The first had a history of severe anorexia nervosa (DSM IV: 307.1). She died at age 34 and 2 days, from severe inhalation pneumonia. The second is a woman with a history of infantile psychosis (DSM IV: 299.80) and with a case of IGE in her family. Her epilepsy was never controlled. At age 16, she was found cyanotic and unconscious one morning in the toilets. She died before resuscitation was undertaken. The third had a borderline personality (DSM IV: 301.83) and a history of alcoholism and low compliance. Her epilepsy was never well controlled. She also received neuroleptics. At age 42, she was found dead in her home. CONCLUSION: In the first case, death was apparently unrelated to epilepsy. In the second, an awakening seizure seems to be responsible. In the third, death is also possibly seizure-related. Cases two and three had persistent seizures and severe psychiatric disorders. Serious mental disorders seem to be risk factors for unexpected death. In JME, the overall death ratio was 1.4/1000 patient-years (or 0.9 if we exclude case 1).