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.     

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).     

Focal clinical and electroencephalographic features in patients with juvenile myoclonic epilepsy

Jayalakshmi SS, Srinivasa Rao B, Sailaja S. Focal clinical and electroencephalographic features in patients with juvenile myoclonic epilepsy.
Acta Neurol Scand: 2010: 122: 115–123.
© 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objective – To identify prevalence and factors associated with occurrence of focal clinical and electroencephalogram (EEG) abnormalities in patients with juvenile myoclonic epilepsy (JME). Materials and methods – Clinical asymmetries in the seizures and focal EEG abnormalities were analyzed in 266 patients with JME. Results – All the patients had myoclonic jerks (MJ) and generalized tonic‐clonic seizures (GTCS); 56 (21%) had absence seizures. Asymmetry in clinical seizures was reported in 45 (16.9%) and focal EEG abnormalities were noted in 92 (45.5%) patients. Amplitude asymmetry or focal onset of generalized discharges was noted in 41 (44.6%) and independent focal EEG abnormalities in 30 (32.6%) patients. A statistically significant association was seen with the presence of GTCS and MJ (P = 0.007), a family history of epilepsy (P = 0.001) and drug resistance (P = 0.04) and the occurrence of focal EEG abnormalities. Conclusion – Patients with JME showed focal clinical and EEG features. These features should not be misinterpreted as indicative of partial epilepsy.     

Outcome of lamotrigine treatment in juvenile myoclonic epilepsy

Bodenstein‐Sachar H, Gandelman‐Marton R, Ben‐Zeev B, Chapman J, Blatt I. Outcome of lamotrigine treatment in juvenile myoclonic epilepsy.
Acta Neurol Scand: 2011: 124: 22–27.
© 2011 John Wiley & Sons A/S. Objectives – To determine the response rate of patients with juvenile myoclonic epilepsy (JME) to lamotrigine (LTG) and identify predictive factors for treatment response. Material and methods – Medical records of 62 patients with JME were reviewed for demographic, clinical, and EEG parameters. We determined clinical response to LTG and compared LTG responders with non‐responders. Results – There were 35 LTG responders (56%) and 27 non‐responders (44%). JME patients without generalized tonic clonic seizures (GTCS) responded better to LTG (P = 0.04). Valproic acid (VPA) failure because of adverse events rather than lack of efficacy (P = 0.069) and delay in diagnosis (P = 0.07) showed a tendency toward good response to LTG. Conclusions – LTG should be considered a drug of first choice for JME patients without GTCS. LTG as second‐line treatment after VPA failure seems more appropriate for those patients whose reason for VPA failure is poor tolerability rather than lack of efficacy.     

Phenotypic analysis of juvenile myoclonic epilepsy in Indian families

OBJECTIVES: Phenotypic analysis of juvenile myoclonic epilepsy (JME) is presented to document the variations in disease expression. MATERIAL AND METHODS: Information on seizure type and frequency, seizure precipitating factors, electro-encephalographic (EEG) data, response to antiepileptic drugs (AEDs) and family history was collected on 500 Indian probands and 61 relatives with JME. RESULTS: The overall clinical features, EEG characteristics, and familial occurrence were similar to other reports. JME probands and relatives having absences (56 of 561, 10%), those with only myoclonic jerks (MJ) or MJ with one generalized tonic clonic seizure (GTCS) in remission without treatment (five of 561, 1%) and those who required valproic acid (VPA) and another AED for seizure control (19 of 561, 3%) are examples of differential disease expression within JME. Seizures among those having photoparoxysmal response (PPR) on EEG responded very well to VPA alone while those with all three seizure types (MJ, GTCS and absences) were poor responders. CONCLUSIONS: Recognition of clinical 'subtypes' among JME could have therapeutic implications and help improve JME phenotypic characterization for molecular studies.     

Hirayama disease with juvenile myoclonic epilepsy: A case report

Hirayama disease (HD) is rare, but benign anterior horn cell disease, predominantly affecting young men. One of the symptoms, besides weakness, is abnormal movement in the hand. Juvenile myoclonic epilepsy (JME) is one of the most common types of generalized epilepsies and can be recognized by a myoclonic jerk and electroencephalography (EEG) features. We report the case of a 19-year-old male who had HD, with unilateral abnormal movement in the hand, which was diagnosed as JME. We should consider performing an EEG in patients with HD, who present with atypical hand movements, in order to differentiate it from seizure.     

CBF changes in drug naive juvenile myoclonic epilepsy patients

Abstract Purpose The role of thalamus and brainstem in generalized epilepsy has been suggested in previous studies. The aim of the present study was to assess regional cerebral blood flow (rCBF) abnormality in juvenile myoclonic epilepsy (JME) patients. Methods ^99mTc-ethylcysteinate dimer brain single photon emission computed tomography (SPECT) was performed in 19 drug naive JME patients and 25 normal controls with the similar age and gender distribution. Differences of rCBF between a JME group and a normal control group were examined by the statistical parametric mapping of brain SPECT images using independent t test. The regression analyses in SPM were also performed between rCBF and the age of seizure onset or the disease duration in JME group. Results Compared to normal controls, the JME group showed a significant rCBF reduction in bilateral thalami, red nucleus, midbrain, pons, left hippocampus, and in the cerebelli (FDR corrected p < 0.01) whereas rCBF increase in the left superior frontal gyrus (uncorrected p < 0.001 but FDR corrected p > 0.05). Disease duration was negatively correlated with rCBF in bilateral frontal cortices, caudate nuclei, brainstem and cerebellar tonsils. Conclusions Our results suggest that abnormal neural networks in the thalamus, hippocampus, brainstem and cerebellum are associated with JME.     

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.     

Cortical thickness abnormality in juvenile myoclonic epilepsy

Previous studies on gray matter concentration changes in patients with juvenile myoclonic epilepsy (JME) are inconsistent. To investigate cortical abnormality in JME differently, we measured the cortical thickness in 19 JME patients and 18 normal controls. Results showed that the cortical thicknesses of superior/middle/medial frontal gyri, and superior/middle/ inferior temporal gyri were decreased in JME patients. Moreover, cortical thicknesses of precentral gyrus and medial orbital gyrus of right hemispheres were negatively correlated with disease duration. These findings suggest that JME brains have cortical gray matter atrophy in the frontal and temporal lobes.     

Focal epilepsy recruiting a generalised network of juvenile myoclonic epilepsy: a case report

We report a patient with juvenile myoclonic epilepsy who subsequently developed temporal lobe epilepsy, which gradually became clinically dominant. Video telemetry revealed both myoclonic seizures and temporal lobe seizures. The temporal lobe seizures were accompanied by a focal recruiting rhythm with rapid generalisation on EEG, in which the ictal EEG pattern during the secondary generalised phase was morphologically similar to the ictal pattern during myoclonic seizures. The secondary generalised seizures of the focal epilepsy responded to sodium valproate, similar to the myoclonic epilepsy. In this rare case of coexistent Juvenile Myoclonic Epilepsy and Temporal lobe epilepsy, the possibility of focal epilepsy recruiting a generalised epileptic network was proposed and discussed.     

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.     

青少年肌阵挛癫痫发作过程脑电信号子波熵分析

目的 采用子波熵研究青少年肌阵挛癫痫（JME）发作过程的动态变化,探索其发作的动力学机制,为监测癫痫发作提供更好的指标。方法 采用Gauss连续子波变换对10例JME患者（JME组）癫痫发作的脑电信号进行分解,在此基础上行子波功率谱分析,并计算整体子波熵（En）和分尺度子波熵[En（a）],根据视觉脑电结果将熵值分为发作间期、发作前期和发作期,观察JME发作全过程子波熵值的动态变化,总结其变化规律并与正常对照组比较。结果 JME组发作期整体子波熵值较发作间期和正常对照组降低（P<0.017）,前头部更明显。分尺度子波熵中,11尺度发作期子波熵值较发作间期和正常对照组增高（P<0.017）;9尺度发作期子波熵值低于发作间期和正常对照组（P<0.017）。结论 JME发作时整体子波熵降低,提示全脑活动较发作间期和正常对照变得单一而规律,全脑信息的丰富度和复杂度下降。分尺度子波熵中11尺度发作期子波熵值增高,而9尺度发作期子波熵值降低,提示发作时11尺度脑电活动频率增加,而其他尺度脑电活动频率降低。发作期各导联整体子波熵值下降程度存在差异性,前头部更明显,提示JME放电起源可能与额区皮质相关。     

Juvenile myoclonic epilepsy: non-classic electroencephalographical presentation in adult patients.

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.     

Mixed myoclonic‐absence status epilepticus in juvenile myoclonic epilepsy

Myoclonic status epilepticus or mixed absence‐myoclonic status is uncommon in juvenile myoclonic epilepsy (JME), often precipitated by sleep deprivation, withdrawal of medication, or inadequate antiepileptic drugs (Thomas et al., 2006 ; Crespel et al., 2013 ). Such episodes respond well to benzodiazepines or valproate (Crespel et al., 2013 ). We present the video‐EEG of a 24‐year‐old woman with JME and bipolar disorder. She had a confusional state five days after withdrawal of clonazepam (14 mg/d) and introduction of oxazepam (200 mg/d), followed by catatonic stupor with subtle myoclonus of the face and the arms. The EEG showed absence status (figures 1, 2), which stopped after IV injection of clonazepam (1 mg) (figure 3). Consciousness returned to normal [Published with video sequence and figures 1 ].     

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.     

Clinical and electroencephalographic findings prior to the onset of juvenile myoclonic epilepsy: A case series

The purpose of this study was to investigate the timing of generalized electroencephalographic abnormalities in patients with juvenile myoclonic epilepsy who were followed up long term before the onset of juvenile myoclonic epilepsy. We enrolled juvenile myoclonic epilepsy patients whose course of epilepsy had been observed for >5 years before the onset of juvenile myoclonic epilepsy, those who had undergone electroencephalogram recording more than twice before the onset of juvenile myoclonic epilepsy, and those who had terminated antiseizure medications for at least 2 years before the onset of juvenile myoclonic epilepsy. Patients who had transitioned from childhood absence epilepsy to juvenile myoclonic epilepsy were excluded. We retrospectively reviewed the medical records and neurophysiological data of the patients. Four patients met the inclusion criteria. One patient was diagnosed with febrile seizures during childhood, and the remaining three had transitioned to juvenile myoclonic epilepsy from other epileptic disorders, such as self-limited epilepsy with autonomic seizures, genetic epilepsy with febrile seizure plus, or nonspecific genetic generalized epilepsy. All patients exhibited generalized spike–wave discharges or photoparoxysmal responses for >2 years before the onset of juvenile myoclonic epilepsy. The four patients had transitioned to juvenile myoclonic epilepsy from other epileptological preconditions. Patients with juvenile myoclonic epilepsy may show generalized electroencephalographic abnormality many years prior to the onset of symptoms. Generalized spike–waves on the electroencephalogram during the course of any type of epilepsy or febrile seizure may be a risk factor for developing juvenile myoclonic epilepsy.