Cognitive Impairment in Juvenile Myoclonic Epilepsy

Background and purpose

Cognitive impairments are frequent consequences of epilepsy, with intellectual ability reportedly being lower in patients with idiopathic generalized epilepsies than in the general population. However, neuropsychological investigations have been rarely performed in patients with juvenile myoclonic epilepsy (JME). We aimed to quantify the cognitive function in JME patients using various neuropsychological tests.

Methods

We compared cognitive function in 27 JME patients with that in 27 healthy volunteers using tests examining cognitive performance, such as the verbal and visual memory, frontal function, attention, IQ score, and mood. In the JME group, we examined risk factors for cognitive function such as age, sex, family history, education level, age at seizure onset, seizure frequency, EEG abnormality, disease duration, and previous intake of antiepileptic drugs.

Results

Verbal learning was significantly lower in JME patients than in controls, and attention and verbal fluency were impaired in JME patients compared with controls. However, general intellectual ability and mood did not differ between the groups. Early onset of seizure and long duration of disease were closely related to impaired cognitive function.

Conclusions

JME patients may exhibit impaired cognitive function, in terms of memory and execution, despite having normal intelligence and mood.     

Genetic architecture of idiopathic generalized epilepsy: clinical genetic analysis of 55 multiplex families

PURPOSE: In families with idiopathic generalized epilepsy (IGE), multiple IGE subsyndromes may occur. We performed a genetic study of IGE families to clarify the genetic relation of the IGE subsyndromes and to improve understanding of the mode(s) of inheritance. METHODS: Clinical and genealogic data were obtained on probands with IGE and family members with a history of seizures. Families were grouped according to the probands' IGE subsyndrome: childhood absence epilepsy (CAE), juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), and IGE with tonic-clonic seizures only (IGE-TCS). The subsyndromes in the relatives were analyzed. Mutations in genes encoding alpha1 and gamma 2 gamma-aminobutyric acid (GABA)-receptor subunits, alpha1 and beta1 sodium channel subunits, and the chloride channel CLC-2 were sought. RESULTS: Fifty-five families were studied. 122 (13%) of 937 first- and second-degree relatives had seizures. Phenotypic concordance within families of CAE and JME probands was 28 and 27%, respectively. JAE and IGE-TCS families had a much lower concordance (10 and 13%), and in the JAE group, 31% of relatives had CAE. JME was rare among affected relatives of CAE and JAE probands and vice versa. Mothers were more frequently affected than fathers. No GABA-receptor or sodium or chloride channel gene mutations were identified. CONCLUSIONS: The clinical genetic analysis of this set of families suggests that CAE and JAE share a close genetic relation, whereas JME is a more distinct entity. Febrile seizures and epilepsy with unclassified tonic-clonic seizures were frequent in affected relatives of all IGE individuals, perhaps representing a nonspecific susceptibility to seizures. A maternal effect also was seen. Our findings are consistent with an oligogenic model of inheritance.     

Linkage analysis between idiopathic generalized epilepsies and the GABAA receptor α5, β3 and γ3 subunit gene cluster on chromosome 15

Introduction - We tested the hypothesis that genetic variants within the GABA_Aα₅, β₃ and γ₃ subunit gene cluster on chromosome 15q11-q13 confer genetic susceptibility to common subtypes of idiopathic generalized epilepsy (IGE). Material and methods - Ninety-four families were selected from IGE patients with either juvenile myoclonic epilepsy (JME), juvenile (JAE) or childhood absence epilepsy (CAE). Cosegregation was tested between dinucleotide polymorphisms associated with the human GABA_Aα₅, β₃ and γ₃ subunit gene cluster and three different IGE trait models. Results - Evidence against linkage to the GABA_Aα₅, β₃ and γ₃ subunit gene cluster was found in the entire family set and subsets selected from either CAE or JAE. In 61 families of JME patients, a maximum lod score (Z_max=1.40 at θ_max=0.00) was obtained for a broad IGE spectrum ("idiopathic" generalized seizure or generalized spike and wave discharges in the electroencephalogram) assuming genetic heterogeneity (α=0.37; P =0.06) and an autosomal recessive mode of inheritance. Conclusion - The possible hint of linkage in families of JME patients emphasizes the need for further studies to determine whether a recessively inherited gene variant within the GABA_Aα₅, β₃ and γ₃ subunit gene cluster contributes to the pathogenesis of "idiopathic" generalized seizures and associated EEG abnormalities in a proportion of families.     

Idiopathic generalized epilepsy: Phenotypic and electroencephalographic observations in a large cohort from South India

Purpose:

We studied the phenotype and electroencephalographic (EEG) features, and therapeutic aspects of idiopathic generalized epilepsies (IGEs) in South Indian population.

Patients and Methods:

This prospective cross-sectional hospital-based study was carried out on non-consecutive 287 patients (age 22.2 ± 7.7 years; M:F = 139:148) with IGE syndrome. Their clinical and EEG observations were analyzed.

Results:

Majority of the patients had onset of seizures <20 years of age (n = 178; 62%). Thirty one patients (10.8%) had family history of epilepsy. Nearly half of them (49.9%) had <5 years of duration of seizures. The type of IGEs included Juvenile myoclonic epilepsy (JME): 115 (40.1%); IGE with generalized tonic-clonic seizures (GTCS) only: 102 (39.02%); childhood absence epilepsy (CAE): 35 (12.2%); GTCS on awakening: 15 (5.2%); Juvenile absence epilepsy (JAE): 11 (3.8%); and unclassified seizures: 9 (3.1%). The triggering factors noted in 45% were sleep deprivation (20%), non-compliance and stress in 5% each. The EEG (n = 280) showed epileptiform discharges in about 50% of patients. Epileptiform discharges during activation was observed in 40/249 patients (16.1%): Hyperventilation in 32 (12.8%) and photic stimulation in 19 (7.6%). The seizures were well controlled with anti-epileptic drugs (AEDs) in 232 (80.8%) patients and among them, 225 (78.4%) patients were on monotherapy. Valproate (n = 131) was the most frequently prescribed as monotherapy.

Conclusions:

This is one of the largest cohort of patients with IGE. This study reiterates the importance of segregating IGE syndrome and such analysis will aid to the current understanding and management.     

Idiopathic generalized epilepsies with versive or circling seizures

OBJECTIVES: To describe the electroclinical features of the idiopathic generalized epilepsies (IGEs) with versive or circling seizures. METHODS: Sixteen patients with versive or circling seizures and interictal electroclinical features of IGE were studied. Patients with insufficient clinical or imaging data, with a follow-up period less than 1 year or with partial seizures in addition to the versive or circling ones were excluded from the study. All patients underwent full interictal clinical and neurophysiological studies. The EEG patterns of 13 versive or circling seizures from 4 patients were also analyzed. RESULTS: A specific IGE syndrome was recognized in 9 out of the 16 patients (56%). More specific, 1 patient had childhood absence epilepsy (CAE), 4 had juvenile absence epilepsy (JAE), and 4 had juvenile myoclonic epilepsy (JME). No specific IGE syndrome was recognizable in the remaining 7 patients (44%). These 7 patients had a juvenile epileptic syndrome (mean age at onset of seizures was 15.7 years) characterized by versive or circling seizures followed or not by generalized tonic-clonic fits. Three main EEG patterns were identified during versive or circling seizures: 1) generalized spike-and-wave discharges at 3-4 cps; 2) generalized polyspike-and-wave discharges at 1 to 2.5 cps beginning with generalized fast activity at 12-14 cps, and 3) generalized spike-and-wave discharges at 3-4 cps intermingled with fast activity at 12-14 cps. Most patients had good response to treatment on a single drug regimen (mainly valproic acid). CONCLUSIONS: Versive or circling seizures may occur in the context of an IGE. Although many individuals share the features of different IGE syndromes including CAE, JAE and JME, a consistent number of patients, who show circling or versive seizures solely, remain without a specific syndromic diagnosis. When occurring in the context of IGE, circling or versive seizures do not worsen the prognosis.     

EEG features of absence seizures in idiopathic generalized epilepsy: Impact of syndrome, age, and state

Purpose:   Factors influencing the electroencephalography (EEG) features of absence seizures in newly presenting children with idiopathic generalized epilepsy (IGE) have not been rigorously studied. We examined how specific factors such as state, provocation, age, and epilepsy syndrome affect the EEG features of absence seizures.
Methods:   Children with untreated absence seizures were studied using video-EEG recording. The influence of state of arousal, provocation (hyperventilation, photic stimulation), age, and epilepsy syndrome on specific EEG features was analyzed.
Results:   Five hundred nine seizures were evaluated in 70 children with the following syndromes: childhood absence epilepsy (CAE) 37, CAE+ photoparoxysmal response (PPR) 10, juvenile absence epilepsy (JAE) 8, juvenile myoclonic epilepsy (JME) 6, and unclassified 9. Polyspikes occurred in all syndromes but were more common in JME. They were brought out by drowsiness and sleep in fragments of generalized spike and wave (GSW). Polyspikes were more likely to occur during photic stimulation, but were not influenced by age independently. GSW was more likely to be disorganized in JME than JAE, and in JAE than CAE. Increasing age and levels of arousal were more likely to result in organized GSW. Factors specific to each child independently influenced EEG features; the nature of these factors has not been identified.
Discussion:   The EEG features of absence seizures are influenced by a complex interaction of age, epilepsy syndrome, level of arousal, provoking factors, and other intrinsic factors. Epilepsy syndrome alone cannot predict specific features of GSW; however, JME is more frequently associated with polyspikes and disorganization of the paroxysm.     

Idiopathic Generalized Epilepsies of Adolescence

Summary:  The prevalence of idiopathic generalized epilepsies (IGEs) has been assessed as being 15–20% of all epilepsies. The seizure types in IGEs are typical absences, myoclonic jerks, and generalized tonic–clonic seizures (TCS), alone or in varying combinations and with variable severity. The seizures tend to be more frequent on awakening and with sleep deprivation. This group of clinical conditions includes among others, age-related epilepsy syndromes of adolescence such as juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), and IGE with generalized TCS or epilepsy with grand mal on awakening (EGMA). The classification of IGEs follows two schools of thought; one maintains that IGEs are a group of different and separate syndromes while the other suggests that IGEs are one biological continuum. Patients with IGEs may have mild impairment of cognitive functions, especially verbal memory and other frontal lobe functions, despite a normal IQ, and some seem to have characteristic personality traits, although further studies are needed to support this theory. They appear to lack a degree of self-control, to neglect their physical needs, and are poorly compliant with therapy. Some patients become obstinate and are impressionable. The cognitive and behavioral aspects of these patients suggest an involvement of frontal lobes.     

A study of idiopathic generalised epilepsy in an Irish population.

Idiopathic generalised epilepsy (IGE) is subdivided into syndromes based on clinical and EEG features. PURPOSE: The aim of this study was to characterise all cases of IGE with supportive EEG abnormalities in terms of gender differences, seizure types reported, IGE syndromes, family history of epilepsy and EEG findings. We also calculated the limited duration prevalence of IGE in our cohort. METHODS: Data on abnormal EEGs were collected retrospectively from two EEG databases at two tertiary referral centres for neurology. Clinical information was obtained from EEG request forms, standardised EEG questionnaires and medical notes of patients. RESULTS: two hundred twenty-three patients met our inclusion criteria, 89 (39.9%) male and 134 (60.1%) females. Tonic clonic seizures were the most common seizure type reported, 162 (72.65%) having a generalised tonic clonic seizure (GTCS) at some time. IGE with GTCS only (EGTCSA) was the most common syndrome in our cohort being present in 94 patients (34 male, 60 female), with 42 (15 male, 27 female) patients diagnosed with Juvenile myoclonic epilepsy (JME), 23 (9 male, 14 female) with Juvenile absence epilepsy (JAE) and 20 (9 male, 11 female) with childhood absence epilepsy (CAE). EEG studies in all patients showed generalised epileptiform activity. CONCLUSIONS: More women than men were diagnosed with generalised epilepsy. Tonic clonic seizures were the most common seizure type reported. EGTCSA was the most frequent syndrome seen. Gender differences were evident for JAE and JME as previously reported and for EGTCSA, which was not reported to date, and reached statistical significance for EGTCA and JME.     

EEG frequency profiles of idiopathic generalised epilepsy syndromes

The objective of this study was to investigate EEG frequency profiles (topographic distribution of spectral power data) in well-defined idiopathic generalised epilepsy (IGE) syndromes: juvenile absence epilepsy (JAE), juvenile myoclonic epilepsy (JME), epilepsy with grand mal seizures on awakening (EGMA), and in the unified 'common IGE' (CIGE) group of these patients. Methods: Absolute and relative (percent) power values were computed from waking EEG activity by Fast Fourier Transform (FFT). Each patient group was compared to an age-matched group of healthy control persons. Results: There was a general tendency for diffuse (absolute and relative) delta-theta-alpha power excess and relative beta power deficit in all IGE groups as compared to controls. Statistically significant (P相似文献   

Growing up with epilepsy: a two-year investigation of cognitive development in children with new onset epilepsy

Purpose: To characterize patterns and determinants of normal and abnormal cognitive development in children with new onset epilepsy compared to healthy controls. Methods: Longitudinal (2‐year) cognitive growth was examined in 100 children, age 8–18 years, including healthy controls (n = 48) and children with new onset epilepsy (n = 52). Cognitive maturation was examined as a function of the presence/absence of two neurobehavioral comorbitiies (attention deficit hyperactivity disorder and/or academic problems) identified at the time of epilepsy diagnosis. Groups were compared across a comprehensive neuropsychological battery assessing intelligence, academic achievement, language, memory, executive function, and psychomotor speed. Results: Children with new onset epilepsy without neurobehavioral comorbidities were comparable to healthy controls at baseline, rate of cognitive development, and follow‐up assessment across all neuropsychological domains. In contrast, the presence of neurobehavioral comorbidities was associated with significantly worse baseline and prospective cognitive trajectories across all cognitive  domains, especially executive functions. Conclusion: The presence of neurobehavioral comorbidities at the time of epilepsy onset is a major marker of abnormal cognitive development both prior to and after the onset of epilepsy.     

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).     

Shared functional network abnormality in patients with temporal lobe epilepsy and their siblings

Aim

Temporal lobe epilepsy is a neurological network disease in which genetics played a greater role than previously appreciated. This study aimed to explore shared functional network abnormalities in patients with sporadic temporal lobe epilepsy and their unaffected siblings.

Methods

Fifty-eight patients with sporadic temporal lobe epilepsy, 13 unaffected siblings, and 30 healthy controls participated in this cross-sectional study. We examined the task-based whole-brain functional network topology and the effective functional connectivity between networks identified by group-independent component analysis.

Results

We observed increased global efficiency, decreased clustering coefficiency, and decreased small-worldness in patients and siblings (p < 0.05, false discovery rate-corrected). The effective network connectivity from the ventral attention network to the limbic system was impaired (p < 0.001, false discovery rate-corrected). These features had higher prevalence in unaffected siblings than in normal population and was not correlated with disease burden. In addition, topological abnormalities had a high intraclass correlation between patients and their siblings.

Conclusion

Patients with temporal lobe epilepsy and their unaffected siblings showed shared topological functional disturbance and the effective functional network connectivity impairment. These abnormalities may contribute to the pathogenesis that promotes the susceptibility of seizures and language decline in temporal lobe epilepsy.     

Idiopathische generalisierte Epilepsien

Idiopathic epilepsies are genetically determined. The inheritance can be either monogenic, considering a single gene mutation as sufficient to cause the phenotype, or mainly complex, when the epileptic phenotype is determined by several genetic factors. The most important and most common subtypes of idiopathic generalized epilepsies (IGE) are childhood and juvenile absence epilepsies (CAE, JAE), juvenile myoclonic epilepsy (JME), and epilepsy with grand mal (generalized tonic-clonic) seizures on awakening (EGMA); closely related are early onset absence epilepsy (EOAE) and generalized/genetic epilepsy with febrile seizures plus (GEFS+). The IGE subtypes are characterized by primary generalized seizure types, an age-dependent onset, typical pathological EEG patterns, a benign course and normal psychomotor development. In recent years, an increasing number of mutations mainly associated with rare monogenic idiopathic epilepsy syndromes have been identified in genes encoding subunits of voltage- or ligand-gated ion channels, such as mutations in Na⁺ channel and GABA_(A) receptor subunits in GEFS+. A few mutations have also been detected in the common forms of IGE, mainly in GABA_(A) receptor subunits conferring a neuronal dysinhibition. For absence seizures, particularly EOAE, mutations in the glucose transporter type 1 (GLUT1) have been described, leading to a reduced transport rate of glucose across the blood-brain barrier. Recently, chromosomal microdeletions were found in up to 2.5% of IGE patients as a significant risk factor. Due to the complex genetic trait, the genetic enigma of IGE is just starting to be unraveled. The next generation sequencing techniques available now enable exome- and genome-wide sequence analyses, which the authors hope will contribute to understanding the pathophysiology of these common forms of epilepsy.     

Neuropsychological profile of patients with juvenile myoclonic epilepsy: a controlled study of 50 patients

The purpose of this study was to verify possible cognitive dysfunction in patients with juvenile myoclonic epilepsy (JME) and its relationship to factors related to epilepsy and schooling. Fifty subjects diagnosed with JME and 50 controls underwent neuropsychological assessment evaluating intellectual functions, attention, memory, executive functions, and language. The patients were further divided into two subgroups on the basis of educational level: < or = 11 and >11 years of formal education. Participants diagnosed with JME scored significantly below age-, education-, and gender-matched controls on neuropsychological measures of attention, immediate verbal memory, mental flexibility, control of inhibition, working memory, processing speed, verbal delayed memory, visual delayed memory, naming, and verbal fluency. A positive correlation was observed between duration of epilepsy and cognitive decline. However, in the group of patients with >11 years of education, this correlation was not significant. In this series of patients with JME, neuropsychological evaluation suggests widespread cognitive dysfunction outside the limits of the frontal lobes. The duration of epilepsy correlated with cognitive decline, and patients with higher education manifested less progression of deficits.     

Neuropsychological performance and seizure-related risk factors in patients with temporal lobe epilepsy: a retrospective cross-sectional study

The aim of this study was to identify the neuropsychological features in patients with temporal lobe epilepsy (TLE) and their correlation with seizure-related variables. For this purpose, we carried out a retrospective analysis of data from 65 patients with TLE who had undergone a comprehensive neuropsychological assessment. The results suggest that the majority of patients with TLE were impaired in more than one cognitive domain, and among these patients, the mean proportions with defective semantic memory, language, motor/psychomotor speed, verbal episodic memory, and executive function were > 50% each. Moreover, age at seizure onset was the strongest predictor of general intellectual impairment, and number of antiepileptic drugs and seizure frequency could significantly predict deficits in verbal memory, language, and psychomotor speed. However, epilepsy duration was a less potent predictor of cognitive deficit than has been reported in cross-sectional studies.     

Somatosensory Evoked Potentials in Juvenile Myoclonic Epilepsy

We analyzed the somatosensory evoked potentials (SEP) of 35 patients with juvenile myoclonic epilepsy (JME), 26 patients with idiopathic generalized epilepsy (IGE), and a control group consisting of 24 healthy people. The N19-P25 interval was significantly prolonged in the IGE group both as compared with the JME and control groups. This finding may be related to antiepileptic drug (AED) treatment, principally phenytoin (PHT). No differences were noted in N19 amplitude in any group. The P25 and N33 amplitudes were significantly higher in the JME group. In 5 patients of the JME group (14%) "giant SEP" were observed, but no differences were evident in the electroclinical characteristics with respect to the other JME patients. JME is one of the causes of giant-SEP.     

Electroencephalographic studies of family members of patients with juvenile myoclonic epilepsy]

Juvenile myoclonic epilepsy (JME) is a common idiopathic generalized epilepsy (IGE); it has a clinical and probably a strong genetic relation to the other IGE forms. Generalized spike/polyspike-wave discharges (SW/PSW) are typical of all IGEs. The aim of our study was to determine the incidence of epilepsy and SW/PSW in EEG of family members of 12 JME patients. 35 first degree relatives aged over 15 years were examined. 40 min EEG with 5 min HV were recorded. IGE was diagnosed in 3 (8.6%) persons: JME in 2 and childhood absence epilepsy (CAE) in 1 person. Six more relatives (17.1%) had typical SW/PSW traits in EEG. Thus the IGE features were found in 9 (25.7%) individuals--members of 7 out of 12 families (58%). EEG of 7 other relatives (20%) revealed non-specific episodic diffuse or focal abnormalities. The above results reveal higher incidence of different kinds of ICEs and typical EEG traits in families of JME patients. This findings confirm familial susceptibility to IGE and may be helpful in genetical counselling.     

Delineating behavioral and cognitive phenotypes in juvenile myoclonic epilepsy: Are we missing the forest for the trees?

IntroductionPatients with juvenile myoclonic epilepsy (JME) have executive dysfunction and impulsive traits. There are lines of evidence that JME is a heterogeneous epilepsy syndrome considering outcome. In this study, we aimed to analyze this heterogeneity beyond seizure control. The objective was to identify whether the pattern of cognitive dysfunction and impulse control is also heterogeneous, in an attempt to establish possible differences in patients with easy- and hard-to-control epilepsies.MethodsEssentially, 57 patients with JME were compared with 44 controls. Patients and controls were assessed with a neuropsychological battery for executive, attention, and memory functions. The expression of impulsive traits was evaluated with the Temperament and Character Inventory — novelty seeking domain. Then, patients were categorized according to seizure control as having easy- and hard-to-control JME.ResultsPatients with hard-to-control JME showed worse performance in 12 out of 25 neuropsychological tests than those with easy-to-control JME. Patients with hard-to-control JME also demonstrated significantly higher scores in novelty seeking — subfactor impulsiveness (p = 0.002).SignificanceOur study demonstrated the existence of distinct or more severe cognitive and psychiatric profiles in a subset of patients with JME. Patients with treatment-refractory seizures seem to present a broader impairment related to both cognitive deficits and impulsive traits. These findings suggest that patients with JME are not equally compromised by executive and memory deficits or dysfunction, neither by their impulsive traits. Thus, there is a need for a better characterization of patients with JME to include diverse phenotypes since our results suggest a possible existence of distinct groups of patients with JME.