A comprehensive neuropsychological description of cognition in drug-refractory juvenile myoclonic epilepsy

Novelty preference assessed by eye tracking: A sensitive measure of impaired recognition memory in epilepsy

OBJECTIVE

Epilepsy patients often report memory deficits despite normal objective testing, suggesting that available measures are insensitive or that non-mnemonic factors are involved. The Visual Paired Comparison Task (VPCT) assesses novelty preference, the tendency to fixate on novel images rather than previously viewed items, requiring recognition memory for the "old" images. As novelty preference is a sensitive measure of hippocampal-dependent memory function, we predicted impaired VPCT performance in epilepsy patients compared to healthy controls.

METHODS

We assessed 26 healthy adult controls and 31 epilepsy patients (16 focal-onset, 13 generalized-onset, 2 unknown-onset) with the VPCT using delays of 2 or 30 s between encoding and recognition. Fifteen healthy controls and 17 epilepsy patients (10 focal-onset, 5 generalized-onset, 2 unknown-onset) completed the task at 2-, 5-, and 30-minute delays. Subjects also performed standard memory measures, including the Medical College of Georgia (MCG) Paragraph Test, California Verbal Learning Test-Second Edition (CVLT-II), and Brief Visual Memory Test-Revised (BVMT-R).

RESULTS

The epilepsy group was high functioning, with greater estimated IQ (p = 0.041), greater years of education (p = 0.034), and higher BVMT-R scores (p = 0.024) compared to controls. Both the control group and epilepsy cohort, as well as focal- and generalized-onset subgroups, had intact novelty preference at the 2- and 30-second delays (p-values ≤ 0.001) and declined at 30 min (p-values > 0.05). Only the epilepsy patients had early declines at 2- and 5-minute delays (controls with intact novelty preference at p = 0.003 and p ≤ 0.001, respectively; epilepsy groups' p-values > 0.05).

CONCLUSIONS

Memory for the "old" items decayed more rapidly in overall, focal-onset, and generalized-onset epilepsy groups. The VPCT detected deficits while standard memory measures were largely intact, suggesting that the VPCT may be a more sensitive measure of temporal lobe memory function than standard neuropsychological batteries.

Mathematics Skills in Epilepsy: A Systematic Review and Meta-Analysis

Mathematics incorporates a broad range of skills, which includes basic early numeracy skills, such as subitizing and basic counting to more advanced secondary skills including mathematics calculation and reasoning. The aim of this review was to undertake a detailed investigation of the severity and pattern of early numeracy and secondary mathematics skills in people with epilepsy. Searches were guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Twenty adult studies and 67 child studies were included in this review. Overall, meta-analyses revealed significant moderate impairments across all mathematics outcomes in both adults (g= -0.676), and children (g= -0.593) with epilepsy. Deficits were also observed for specific mathematics outcomes. For adults, impairments were found for mathematics reasoning (g= -0.736). However, two studies found that mathematics calculation was not significantly impaired, and an insufficient number of studies examined early numeracy skills in adults. In children with epilepsy, significant impairments were observed for each mathematics outcome: early numeracy (g= -0.383), calculation (g= -0.762), and reasoning (g= -0.572). The gravity of impairments also differed according to the site of seizure focus for children and adults, suggesting that mathematics outcomes were differentially vulnerable to the location of seizure focus.

Neuromorphometric associations with mood, cognition, and self-reported exercise levels in epilepsy and healthy individuals

Regular physical activity may promote beneficial neuroplasticity, e.g., increased hippocampus volume. However, it is unclear whether self-reported physical exercise in leisure (PEL) levels are associated with the brain structure features demonstrated by exercise interventions. This pilot study investigated the relationship between PEL, mood, cognition, and neuromorphometry in patients with idiopathic generalized epilepsy (IGEs) compared to healthy controls (HCs). Seventeen IGEs and 19 age- and sex-matched HCs underwent magnetic resonance imaging (MRI) at 3T. The Baecke Questionnaire of Habitual Physical Activity, Profile of Mood States, and Montreal Cognitive Assessment (MoCA) assessed PEL, mood, and cognition, respectively. Structural MRI data were analyzed by voxel- and surface-based morphometry. IGEs had significantly lower PEL (p < 0.001), poorer mood (p = 0.029), and lower MoCA scores (p = 0.027) than HCs. These group differences were associated with reduced volume, decreased gyrification, and altered surface topology (IGEs < HCs) in frontal, temporal and cerebellar regions involved in executive function, memory retrieval, and emotional regulation, respectively. These preliminary results support the notion that increased PEL may promote neuroplasticity in IGEs, thus emphasizing the role of physical activity in promoting brain health in people with epilepsy.

Outpatient visit behavior in patients with epilepsy: Generalized Epilepsy is more frequently non-attendance than Focal Epilepsy

BACKGROUND

Patients with epilepsy (PWE), especially those with Idiopathic Epilepsy (GE), are at a high risk of disadvantage caused by non-adherence. It has been suggested that medical visit behavior may be a surrogate indicator of medication adherence. We hypothesized that patients with IGE would adhere poorly to visits.

METHODS

This was a retrospective study of PWE who visited the Department of Psychiatry and Neurology at Hokkaido University Hospital between January 2017 and December 2019. Demographic and clinical information on PWE were extracted from medical records and visit data from the medical information system. Non-attendance of outpatient appointments was defined as "not showing up for the day of an appointment without prior notice." Mixed-effects logistic regression analysis was conducted with non-attendance as the objective variable.

RESULTS

Of the 9151 total appointments, 413 were non-attendances, with an overall non-attendance rate of 4.5%. IGE was a more frequent non-attendance than Focal Epilepsy (FE) (odds ratio (OR) 1.94; 95% confidence interval (CI) 1.17-3.21; p = 0.010). History of public assistance receipt was associated with higher non-attendance (OR 2.04; 95% CI 1.22-3.43; p = 0.007), while higher education (OR 0.64; 95% CI 0.43-0.93; p = 0.021) and farther distance to a hospital (OR 0.33; 95% CI 0.13-0.88; p = 0.022), and higher frequency of visits (OR 0.18; 95% CI 0.04-0.86; p = 0.031) were associated with fewer non-attendances. In a subgroup analysis of patients with GE, women were associated with fewer non-attendance (OR 0.31; 95% CI 0.14-0.72; p = 0.006).

CONCLUSIONS

GE was more frequent in the non-attendance group than in the FE group. Among patients with GE, females were found to have non-attendance less frequently; however, there was no clear difference in the odds of non-attendance between Juvenile Myoclonic Epilepsy (JME) and IGE other than JME.

Neurocognitive profile in patients with idiopathic generalized epilepsies: Differences between patients, their biological siblings, and healthy controls

BACKGROUND

Idiopathic generalized epilepsy (IGE) is one of the most common epilepsies and is believed to have a strong genetic origin. Patients with IGE present largely heterogeneous neurocognitive profiles and might show some neurocognitive impairments. Furthermore, IGE siblings may demonstrate worse results in neuropsychological tests as well. In our study, we aimed to map the neurocognitive profile both in patients with IGE and the siblings. We also sought to establish a neurocognitive profile for each IGE syndrome.

METHODS

The research sample included 110 subjects (IGE n = 46, biological siblings BS n = 16, and healthy controls n = 48) examined. Subjects were neuropsychologically examined in domains of intelligence, attention, memory, executive, and motor functions. The data obtained from the examination were statistically processed to determine whether and how IGE patients (including distinct syndromes) and the siblings differed neurocognitively from healthy controls (adjusted z-scores by age, education, and gender, and composite z-scores of cognitive domains). Data on anti-seizure medication, including defined daily doses, were obtained and included in the analysis.

RESULTS

IGE patients and their biological siblings performed significantly worse in most of the neuropsychological tests than healthy controls. The neurocognitive profile of composite z-scores showed that IGE and biological siblings had equally significantly impaired performance in executive functions. IGE group also demonstrated impaired composite attention and motor function scores. The profile of individual IGE syndromes showed that JAE, JME, and EGTCS had significantly worse performance in composite execution score and motor function score. JAE presented significantly worse performance in intelligence and attention. JME exhibited significantly worse composite score in the attention domain. Anti-seizure medication, depression, and quality of life were unrelated to cognitive performance in IGE group. The level of depression significantly predicted the overall value of quality of life in patients with IGE, while cognitive domains, sociodemographic, and clinical factors were unrelated.

CONCLUSION

Our study highlights the importance to consider the neurocognitive profile of IGE patients that can lead to difficulties in their education, acceptance, and management of coping strategies. Cognitive difficulties of IGE siblings could support a hypothesis that these impairments emerge from heritable traits.

Evaluation of Event-Related Potentials in Assessing Cognitive Functions of Adult Patients with Epilepsy of Unknown Etiology

Background: Cognitive impairment (CI) is an important consequence of epilepsy. The aim of the study was to assess cognitive performance in patients with epilepsy, using neuropsychological tests (NT) and event-related potentials (ERPs), with regard to demographic and clinical data. Methods: The study comprised 50 patients with epilepsy of unknown etiology and 46 healthy controls. Based on the NT results, the patients were divided into subgroups with/without CI. Parameters of P300 potential were compared between the patients and controls. P300 parameters and NT results were referred to demographics and clinical characteristics of epilepsy. Results: Based on the NT, 66% of patients were assigned as cognitively impaired. Median P300 latency was significantly (p < 0.0002) prolonged in the study group. Subgroups of patients with and without CI significantly (p < 0.034) differed in education level and vocational activity, duration of epilepsy, age at its onset and frequency of polytherapy. P300 parameters showed significant (p < 0.03) relationships with duration of epilepsy, type and frequency of seizures and polytherapy. Conclusions: Cognitive impairment and ERPs abnormalities occur in a majority of patients with epilepsy of unknown etiology. Characteristics of epilepsy and socioeconomic status are related to cognitive performance. ERPs may complement neuropsychological methods in the assessment of cognition in patients with epilepsy.

Drug resistance in idiopathic generalized epilepsies: Evidence and concepts

Although approximately 10%-15% of patients with idiopathic generalized epilepsy (IGE)/genetic generalized epilepsy remain drug-resistant, there is no consensus or established concept regarding the underlying mechanisms and prevalence. This review summarizes the recent data and the current hypotheses on mechanisms that may contribute to drug-resistant IGE. A literature search was conducted in PubMed and Embase for studies on mechanisms of drug resistance published since 1980. The literature shows neither consensus on the definition nor a widely accepted model to explain drug resistance in IGE or one of its subsyndromes. Large-scale genetic studies have failed to identify distinct genetic causes or affected genes involved in pharmacokinetics. We found clinical and experimental evidence in support of four hypotheses: (1) "network hypothesis"-the degree of drug resistance in IGE reflects the severity of cortical network alterations, (2) "minor focal lesion in a predisposed brain hypothesis"-minor cortical lesions are important for drug resistance, (3) "interneuron hypothesis"-impaired functioning of γ-aminobutyric acidergic interneurons contributes to drug resistance, and (4) "changes in drug kinetics"-genetically impaired kinetics of antiseizure medication (ASM) reduce the effectiveness of available ASMs. In summary, the exact definition and cause of drug resistance in IGE is unknown. However, published evidence suggests four different mechanisms that may warrant further investigation.

Understanding frontal lobe function in epilepsy: Juvenile myoclonic epilepsy vs. frontal lobe epilepsy

AIM

To compare neuropsychological function in juvenile myoclonic epilepsy (JME) and frontal lobe epilepsy (FLE) since frontal circuitry is involved in both conditions. By drawing on previously theory-guided hypotheses and findings, a particular emphasis is placed on the way different cognitive-pathophysiological mechanisms act upon to produce frontal dysfunction in JME (frontal-executive and attention-related problems: vigilance, reaction times, processing speed, and response inhibition) and in FLE (reflecting the coproduct of the functional deficit zone), respectively.

METHODS

A total of 16 patients with JME, 34 patients with FLE, and 48 normal controls, all matched for age and education, were administered a comprehensive battery of tests to assess frontal-executive functions, as well as attention, memory, and learning domains. Participants did not take medications other than antiepileptics or have a psychiatric history.

RESULTS

Patients with FLE overall showed worse neuropsychological performance compared to both JME and HCs. With respect to JME, patients with FLE did significantly worse in measures of verbal and nonverbal executive function, short-term-, and long-term- auditory-verbal memory and learning, immediate and delayed episodic recall, visual attention and motor function, visuo-motor coordination and psychomotor speed, speed of visual information processing, and vocabulary. Patients with JME performed significantly worse compared to FLE only in associative semantic processing, while the former outperformed all groups in vocabulary, visuomotor coordination, and psychomotor speed.

CONCLUSION

We suggest that selective impairments of visual- and mostly auditory-speed of information processing, vigilance, and response inhibition may represent a salient neuropsychological feature in JME. These findings suggest the existence of an aberrantly working executive-attention system, secondary to pathological reticulo-thalamo-cortical dynamics. Contrariwise, cortically (frontal and extra-frontal) and subcortically induced malfunction in FLE is determined by the functional deficit zone i.e., the ensemble of cortical and subcortical areas that are functionally abnormal between seizures.

Genetic generalized epilepsies in adults - challenging assumptions and dogmas

Genetic generalized epilepsy (GGE) syndromes start during childhood or adolescence, and four commonly persist into adulthood, making up 15-20% of all cases of epilepsy in adults. These four GGE syndromes are childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and epilepsy with generalized tonic-clonic seizures alone. However, in ~20% of patients with GGE, characteristics of more than one syndrome are present. Novel insights into the genetic aetiology, comorbidities and prognosis of the GGE syndromes have emerged and challenge traditional concepts about these conditions. Evidence has shown that the mode of inheritance in GGE is mostly polygenic. Neuropsychological and imaging studies indicate similar abnormalities in unaffected relatives of patients with GGE, supporting the concept that underlying alterations in bilateral frontothalamocortical networks are genetically determined. Contrary to popular belief, first-line anti-seizure medication often fails to provide seizure freedom in combination with good tolerability. Nevertheless, long-term follow-up studies have shown that with advancing age, many patients can discontinue their anti-seizure medication without seizure relapses. Several outcome predictors have been identified, but prognosis across the syndromes is more homogeneous than previously assumed. Overall, overlap in pathophysiology, seizure types, treatment responses and outcomes support the idea that GGEs are not separate nosological entities but represent a neurobiological continuum.

Alterations of the intrinsic amygdala-hippocampal network in juvenile myoclonic epilepsy

INTRODUCTION

Several lines of evidence suggest that the amygdala-hippocampus is involved in the epileptogenic network of juvenile myoclonic epilepsy (JME). The aim of this study was to investigate the alterations in the individual nuclei of the amygdala and hippocampal subfields, and the intrinsic amygdala-hippocampal network of patients with JME compared to healthy controls.

METHODS

This retrospective study conducted at a single tertiary hospital involved 35 patients with newly diagnosed JME, and 34 healthy subjects. We calculated the individual structural volumes of 18 nuclei in the amygdala, and 38 hippocampal subfields using three-dimensional volumetric T1-weighted imaging and FreeSurfer program. We also performed an analysis of the intrinsic amygdala-hippocampal global and local network based on these volumes using a graph theory and Brain Analysis using Graph Theory (BRAPH) program. We investigated the differences in these volumes and network measures between patients with JME and healthy controls.

RESULTS

There were no significant volume differences in the nuclei of the amygdala and hippocampal subfields between patients with JME and healthy controls. However, we found significant differences in the global network between patients with JME and healthy controls. The mean clustering coefficient was significantly decreased in patients with JME compared to healthy controls (0.473 vs. 0.653, p = .047). In addition, specific regions in the hippocampal subfields showed significant differences in the local network between the two groups. The betweenness centrality of the right CA1-head, right hippocampus-amygdala-transition area, left hippocampal fissure, left fimbria, and left CA3-head, was increased in patients with JME compared to healthy controls.

CONCLUSION

The intrinsic amygdala-hippocampal global and local networks differed in patients with JME compared to healthy controls, which may be related to the pathogenesis of JME, and memory dysfunction in patients with JME.

Relationships between cognitive function, seizure control, and self-reported leisure-time exercise in epilepsy

Exercise may be a strategy for improvement of cognitive deficits commonly present in people with idiopathic generalized epilepsies (IGE). We investigated the relationship between cognition and level of physical exercise in leisure (PEL) in people with IGE who have been seizurefree for at least 6 months (IGE-) as compared to those who have not been seizurefree (IGE+) and healthy controls (HCs). We hypothesized that higher level of physical exercise is associated with better cognitive functioning in patients with IGE and HCs, and that seizure control affects both PEL levels and cognitive functioning in patients with IGE. We recruited 75 participants aged 18-65: 31 people with IGE (17 IGE-, 14 IGE+) and 44 HCs. Participants completed assessments of quality of life (SF-36), physical activity levels (Baecke questionnaire and International Physical Activity Questionnaire (IPAQ)) and cognition (Montreal Cognitive Assessment (MoCA), Hopkins Verbal Learning Test - Revised (HVLT), and flanker task). Group differences (HCs vs. IGE; HCs vs. IGE+ vs. IGE-) were assessed. Pearson correlations examined linear relationships between PEL and cognitive performance. Groups were similar in age and sex. Compared to HCs, patients with IGE had higher body mass index, fewer years of education, and consistently scored worse on all measures except flanker task accuracy on incongruent trials. When examining IGE- and IGE+ subgroups, compared to HCs, both had higher body mass index, and fewer years of education. Healthy controls scored significantly better than one or both of the IGE groups on SF-36 scores, PEL levels, IPAQ activity level, MoCA scores, HVLT learning and long-delay free-recall scores, and flanker task accuracy on congruent trials. Among patients with IGE, there were no significant differences between age of epilepsy onset, duration of epilepsy, number of anti-seizure drugs (ASDs) currently being used, or the group distribution of type of IGE. In the combined sample (IGE+, IGE- and HCs), PEL positively correlated with MoCA scores (Pearson's r = 0.238; p = 0.0397) and with flanker task accuracy on congruent trials (Pearson's r = 0.295; p = 0.0132). Overall, patients with IGE performed worse than HCs on cognitive and physical activity measures, but the cognitive impairments were more pronounced for IGE+, while physical exercise levels were less for patients with IGE regardless of seizure control. While positive relationships between leisure-time PEL and cognitive performance are promising, further investigations into how exercise levels interact with cognitive functioning in epilepsy are needed.

Social outcome and psychiatric comorbidity of generalized epilepsies - A case-control study

OBJECTIVE

To investigate social outcome and psychiatric comorbidity of patients with idiopathic/genetic generalized epilepsies (IGEs) and its subtypes (epilepsy with generalized tonic-clonic seizures alone [EGTCS], juvenile absence epilepsy [JAE], and juvenile myoclonic epilepsy [JME]).

METHODS

A cohort of 402 adult patients with IGE from the Danish island Funen was matched with 4020 randomly selected geography-, age-, and sex-matched controls via the Danish Civil Registration System. Based on register data, we compared social status measured by cohabitant status, educational attainment, income, affiliation to labor market, and psychiatric comorbidity.

RESULTS

As compared to controls, patients with IGE had similar cohabitant status but fewer children (no children: 59.0% vs 50.9%), and lower educational level (primary school only: 46.0% vs 37.3%), employment rate (outside of workforce: 56.7% vs 46.5%), and income (low income: 32.6% vs 24.9%) (P < 0.001 for all comparisons). Having IGE was associated with higher a proportion of psychiatric comorbidity (IGE, 22.6%; controls, 13.0%) (P < 0.001). Seizure-free patients did not differ from controls; patients with persistent seizures had lower incomes and employment rates. In the IGE subgroup analyses, JME was associated with worse social status in all parameters studied (eg, 65.9% of JME patients were outside the workforce vs 44.5% of matched controls; P < 0.001), whereas no adverse social status was identified in patients with EGTCS and JAE.

SIGNIFICANCE

Patients with IGE in general and JME in particular have poorer social status and more psychiatric comorbidity than matched population controls without epilepsy. Poor seizure control was associated with social status and may contribute to negative socioeconomic consequences associated with IGE.

Evaluating Executive Functions in Patients with Juvenile Myoclonic Epilepsy Using Frontal Assessment Battery

Objective

In this study, we aimed to evaluate the executive profile of juvenile myoclonic epilepsy (JME) patients using the Frontal Assessment Battery (FAB) as a bedside screening tool and investigate its association with seizure proximity, family history of epilepsy, and polytherapy/monotherapy with antiepileptic drugs (AEDs).

Background

JME patients have deficits in various aspects of executive functions. FAB has proved to be a useful tool for evaluating executive functions in clinical settings.

Methods

Thirty-one JME patients and 110 healthy controls (HCs) were enrolled in this study. The participants were assessed using six subsets of FAB, including conceptualization, mental flexibility, motor programming, sensitivity to interference, inhibitory control, and environmental autonomy.

Results

Compared to HCs, JME patients showed lower scores in conceptualization, mental flexibility, programming, sensitivity to interference, and total FAB. The number of AEDs (polytherapy versus monotherapy) and duration of time since the last seizure had no significant effect on FAB scores in JME patients. We found significant associations between disease duration and conceptualization, mental flexibility, inhibitory control, and total FAB score only in JME patients with recent seizure. Finally, receiver operating characteristic (ROC) analysis showed area under the curve (AUC) of 0.971 (95% confidence interval (CI): 0.947–0.994) for FAB total score, 0.933 for conceptualization (95% CI: 0.973-894), and 0.836 for mental flexibility (95% CI: 0.921-751).

Conclusions

In summary, JME patients had deficits in different aspects of executive functions. FAB is a useful clinical tool for evaluation of executive functions in JME patients.

Meta-analysis of response inhibition in juvenile myoclonic epilepsy

BACKGROUND

Patients with juvenile myoclonic epilepsy (JME) show evidence of cognitive impulsivity that may be linked to later adverse psychosocial outcomes. Here, we quantify the strength of association and estimate effect size (ES) of response inhibition by pooling available evidence in a meta-analysis.

METHODS

We conducted a systematic review of the literature using Ovid MEDLINE and Ovid EMBASE databases (covering 2001-2019) with a search strategy using combinations of the specific Medical Subject Headings (MeSH) terms 'juvenile myoclonic epilepsy, cognitive impulsivity, response inhibition, Stroop, cognition, personality, traits' using the 'explode' feature where possible. We also searched within references of retrieved articles. We included studies reporting ESs describing established measures of response inhibition in teenage and adult patients with JME.

RESULTS

Using the ESs pooled from 16 studies comprising 1047 patients and controls, we found ESs for response inhibition to be homogeneous with a significant moderate mean ES of d = 0.50 (95% confidence interval [CI]: 0.37-0.63).

CONCLUSIONS

We confirm that reduced response inhibition is a consistently observed homogeneous trait in patients with JME.

Cognitive functioning in new-onset juvenile myoclonic epilepsy

PURPOSE

Juvenile myoclonic epilepsy (JME) is a common genetic generalized epilepsy syndrome. Adult patients with JME have shown a neuropsychological profile suggestive of subtle frontal dysfunction, but studies of cognitive functioning in the early phases of JME are rare. We analyzed the cognitive performance data of 18 patients who had undergone a neuropsychological assessment either at the time of JME diagnosis and before the initiation of an antiepileptic drug (AED) treatment (11 patients) or during the first 6 years after JME diagnosis (seven patients).

METHODS

The cognitive performance of the18 patients with JME (mean age: 18.1, range: 15-33 years) and 18 healthy controls (mean age: 18.7, range: 15-25 years) was compared in a retrospective study. The assessed cognitive domains were visuomotor speed, attention, executive function, and verbal memory.

RESULTS

The patients with JME and the healthy controls did not differ in any of the assessed cognitive domains. The clinical variables did not correlate to cognitive performance. Furthermore, cognitive performance did not differ between the patients evaluated at the time of diagnosis and before the initiation of AEDs and the patients evaluated during the first 6 years after diagnosis and with an AED treatment.

CONCLUSIONS

The cognitive performance of patients with new-onset JME was similar to healthy controls. We could not detect the frontal dysfunction that has been suggested to be associated with JME. Patients were in adolescence or early adulthood with a short duration of epilepsy, which may have contributed to the discovery of no cognitive impairments.

Cognitive Function in Genetic Generalized Epilepsies: Insights From Neuropsychology and Neuroimaging

Genetic generalized epilepsies (GGE), previously called idiopathic generalized epilepsies, constitute about 20% of all epilepsies, and include childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and epilepsy with generalized tonic-clonic seizures alone (CAE, JAE, JME, and GGE-GTCS, respectively). GGE are characterized by high heritability, likely underlain by polygenetic mechanisms, which may relate to atypical neurodevelopmental trajectories. Age of onset ranges from pre-school years, for CAE, to early adulthood for GGE-GTCS. Traditionally, GGE have been considered benign, a belief contrary to evidence from neuropsychology studies conducted over the last two decades. In JME, deficits in executive and social functioning are common findings and relate to impaired frontal lobe function. Studies using neuropsychological measures and cognitive imaging paradigms provide evidence for hyperconnectivity between prefrontal and motor cortices, aberrant fronto-thalamo-cortical connectivity, and reduced fronto-cortical and subcortical gray matter volumes, which are associated with altered cognitive performance. Recent research has also identified associations between abnormal hippocampal morphometry and fronto-temporal activation during episodic memory. Longitudinal studies on individuals with newly diagnosed JME have observed cortical dysmaturation, which is paralleled by delayed cognitive development compared to the patients' peers. Comorbidities and cognitive deficits observed in other GGE subtypes, such as visuo-spatial and language deficits in both CAE and JAE, have also been correlated with atypical neurodevelopment. Although it remains unclear whether cognitive impairment profiles differ amongst GGE subtypes, effects may become more pronounced with disease duration, particularly in absence epilepsies. Finally, there is substantial evidence that patients with JME and their unaffected siblings share patterns of cognitive deficits, which is indicative of an underlying genetic etiology (endophenotype), independent of seizures and anti-epileptic medication.

Praxis induction and its relationship with cognition in genetic generalized epilepsy

INTRODUCTION

Praxis induction (PI) is a reflex trait defined as the precipitation of epileptic discharges (ED) or seizures by cognition-guided tasks that often involve visuomotor coordination and decision-making. This is a characteristic of genetic generalized epilepsy (GGE), and especially of juvenile myoclonic epilepsy (JME). Additionally, several studies have described dysexecutive traits in these patients. Our objective was to analyze PI in the different syndromes of GGE and explore the relationship between PI and cognitive performance.

METHODS

Sixty-one adult patients with GGE underwent video-electroencephalograph (EEG) during which a neuropsychological activation protocol (NPAP) was performed: reading, writing, calculations, crosswords, and tangram. Praxis induction was defined by the presence of ED during the NPAP with a persistence of at least twice seen on the basal EEG. All patients also underwent a comprehensive cognitive evaluation.

RESULTS

We observed PI in 22 out of 61 patients (36%). Grouped by syndrome, PI was more frequent in adult patients with persistent childhood or juvenile absence epilepsy (JAE, 60%), followed by JME (42.1%) and in a lesser grade in patients with only tonic-clonic generalized seizures (9%). Patients classified as having PI did not obtain worse results in the cognitive evaluation. The presence of ED during the performance of a test was associated with a trend to lower results in that specific test.

SIGNIFICANCE

Our study showed a relevant presence of PI in patients whose absence epilepsy persists into adulthood, and not only in JME, the syndrome classically associated with PI. According to our results, PI as a reflex trait does not imply necessarily a poorer cognitive phenotype, but the induction of frequent ED during the tasks could be associated with transient cognitive impairment.

The Timing, Nature, and Range of Neurobehavioral Comorbidities in Juvenile Myoclonic Epilepsy

BACKGROUND

Accumulating evidence suggests that considerable cognitive and psychiatric comorbidity is associated with juvenile myoclonic epilepsy, for which the etiology remains controversial. Our goal was to comprehensively characterize the status of multiple neurobehavioral comorbidities in youth with new- or recent-onset juvenile myoclonic epilepsy, before effects of chronic seizures and medications.

METHODS

A total of 111 children aged eight to 18 years (41 new- or recent-onset juvenile myoclonic epilepsy and 70 first-degree cousin controls) underwent neuropsychological assessment (attention, executive, verbal, perceptual, speed), structured review of need for supportive academic services, parent reports of behavior and executive function (Child Behavior Checklist and Behavior Rating Inventory of Executive Function), and formal structured psychiatric interview and diagnosis (Kiddie Schedule for Affective Disorders and Schizophrenia-Present and Lifetime Version).

RESULTS

Children with juvenile myoclonic epilepsy performed worse than controls across all tested cognitive domains (F(1,105) = 3.85, P < 0.01), utilized more academic services (47% versus 19%, P = 0.002), had more parent-reported behavioral problems and dysexecutive function with lower competence (P < 0.001), and had a higher prevalence of current Axis I diagnoses (attention-deficit/hyperactivity disorder, depression, and anxiety; 54% versus 23%, P = 0.001). Academic and psychiatric problems occurred antecedent to epilepsy onset compared with comparable timeline in controls.

CONCLUSION

Comprehensive assessment of cognitive, academic, behavioral, and psychiatric comorbidities in youth with new- or recent-onset juvenile myoclonic epilepsy reveals a pattern of significantly increased neurobehavioral comorbidities across a broad spectrum of areas. These early evident comorbidities are of clear clinical importance with worrisome implications for future cognitive, behavioral, and social function. It is important for health care providers to avoid delays in intervention by assessing potential comorbidities early in the course of the disorder to optimize their patients' social, academic and behavioral progress.

The role of task-based neural activation research in understanding cognitive deficits in pediatric epilepsy

Children with epilepsy can experience significant cognitive dysfunction that can lead to academic underachievement. Traditionally believed to be primarily due to the effects of factors such as the chronicity of epilepsy, medication effects, or the location of the primary epileptogenic lesion;, recent evidence has indicated that disruption of cognition-specific distributed neural networks may play a significant role as well. Specifically, over the last decade, researchers have begun to characterize the mechanisms underlying disrupted cognitive substrates by evaluating neural network abnormalities observed during specific cognitive tasks, using task-based functional magnetic resonance imaging (fMRI). This targeted review assesses the current literature investigating the relationship between neural network abnormalities and cognitive deficits in pediatric epilepsy. The findings indicate that there are indeed neural network abnormalities associated with deficits in executive function, language, processing speed, and memory. Overall, cognitive dysfunction in pediatric epilepsy is associated with a decrease in neural network activation/deactivation as well as increased recruitment of brain regions not typically related to the specific cognitive task under investigation. The research to date has focused primarily on children with focal epilepsy syndromes with small sample sizes and differing research protocols. More extensive research in children with a wider representation of epilepsy syndromes (including generalized epilepsy syndromes) is necessary to fully understand these relationships and begin to identify underlying cognitive phenotypes that may account for the variability observed across children with epilepsy. Furthermore, more uniformity in fMRI protocols and neuropsychological tasks would be ideal to advance this literature.

The cognitive phenotype of idiopathic generalized epilepsy

OBJECTIVE

Dysexecutive traits have been described in idiopathic generalized epilepsy (IGE), but studies mainly focused on juvenile myoclonic epilepsy (JME). To better understand the neuropsychology of IGE, more research is needed on syndromes other than JME, controlling potential confounding factors as the cognitive effects of valproate and epileptic discharges (ED). We describe the neuropsychological profile of a group of patients with different syndromes of IGE including simultaneous video electroencephalography (EEG).

METHODS

We performed a comprehensive cognitive and neuropsychiatric evaluation with video-EEG on 61 adults with IGE (JME 19; IGE with generalized tonic-clonic seizures [GTCS] alone [IGE-GTCS] 22; childhood absence epilepsy [CAE] or juvenile absences epilepsy [JAE] persisting in adulthood 20). We compared results between patients (globally and by syndrome) and a control group of 21 individuals (similar age, educational level); p-values were adjusted for multiple testing according to a 0.05 false discovery rate.

RESULTS

Patients obtained significantly lower results than controls on visuospatial working memory, processing speed, cognitive flexibility and strategy, abstract visuospatial reasoning, arithmetic, and acquired knowledge. While CAE/JAE showed the lowest scores on cognitive assessment and highest anxiety index, IGE-GTCS showed the most favorable scores. Most tests were not influenced by valproate intake, and the dose did not correlate with cognitive performance in the test that yielded differences between patients and controls. Epileptic discharges during assessment were not frequent (10 patients, 1-4 tests).

SIGNIFICANCE

Our findings suggest that patients with IGE have significantly lower abilities in various executive functions and acquired knowledge, compared to population of same age and education. The low frequency of ED on simultaneous video-EEG and absence of correlation of scores with valproate dose reinforce that the obtained results are due to a cognitive phenotype in IGE. This phenotype may be influenced by syndrome, and patients with CAE/JAE persisting in the adult may have a wider neuropsychiatric impairment.

Higher IQ in juvenile myoclonic epilepsy: Dodging cognitive obstacles and "masking" impairments

Executive deficits and impulsiveness are extensively reported in juvenile myoclonic epilepsy (JME). Previous literature suggests that intelligence may mediate these deficits. In this study, we evaluated and compared the performance of adults with JME with high and low intelligence quotient (IQ) and controls on tasks for executive function (EF) and impulsive traits. We investigated the neuropsychological performance of 53 adults with JME and below average IQ (57% women; 26.9 [±7.88] years; mean IQ: 89.8 [±5.1]), 26 adults with JME and average or above average IQ (53.8% women; 28.2 [±9.33] years; mean IQ: 110.7 [±8.3]), 38 controls with below average IQ (55% women; 28.4 [±8.4] years; mean IQ: 90.1 [±5.8]), and 31 controls with average or above average IQ (61.3% women; 32.20 [±11.3] years; mean IQ: 111.6 [±10.5]) with a comprehensive battery of neuropsychological tests that measure executive/attentional function. Impulsive traits were assessed using the Cloninger et al.'s Temperament and Character Inventory (novelty seeking (NS) domain). The group with JME with higher IQ presented worse performance compared with controls with higher IQ on Controlled Oral Word Association (COWA) and Wisconsin Card Sorting Test (WCST) (errors). This group showed worse performance than controls with lower IQ on Stroop Color-Word Test (SCT) 1, Trail Making (TM) A, COWA, and WCST (errors). Patients with lower IQ showed worse performance than controls with higher IQ on Digit Span Forward (DSF), Digit Span Backward (DSB), SCT1, SCT2, SCT3, TM A, COWA, and WCST (errors and failure to maintain set). Patients with lower IQ showed worse performance than controls with lower IQ on DSF, DSB, SCT1, SCT2, SCT3, TM A, TM B, COWA, and WCST (errors and failure to maintain set). Patients from groups with low and high IQ showed higher scores than controls with higher and lower IQ on impulsivity for NS1 and NS2 (except for patients with higher IQ versus controls with lower IQ). Adults with JME and higher IQ show less evidence of EF deficits compared with those with JME and below average IQ, suggesting that a higher degree of intellectual efficiency may act as a compensatory mechanism. However, it does not minimize some aspects of impulsive traits. Patients with JME and higher cognitive reserve may create strategies to dodge their cognitive obstacles. In this context, intelligence may protect and, at the same time, "mask" impairments that could be detected earlier.

Valproate: life-saving, life-changing

Antiepileptic medications, and valproate principally, are commonly prescribed teratogens. There is significant concern that we are not doing enough to educate clinicians and potential parents about the risks of valproate in pregnancy. There is clear advice from the Medicines and Healthcare products Regulatory Agency and the International League Against Epilepsy about the risks of valproate exposure in utero Reviews and guidelines that are focused on fetal risk, however, fall short in being able to fully replicate the complexity of a real clinical decision. Valproate is certainly life-changing if your child is one of the 10% with a major malformation or 30-40% with a neurodevelopmental disorder, but valproate is also potentially life-saving in the context of ensuring the best possible seizure control for some mothers with epilepsy. There are significant knowledge gaps regarding the risks to mothers who elect to take another drug, or to mother and baby if she comes off medication entirely. We also should be doing more to reduce rates of sudden unexpected death in epilepsy (SUDEP), which is recognised as a key target when evaluating all maternal deaths.

Executive functions and psychiatric symptoms in drug-refractory juvenile myoclonic epilepsy

PURPOSE

The pattern of executive dysfunction reported in juvenile myoclonic epilepsy (JME) resembles that of patients with cluster B personality disorders. This study examined whether executive dysfunction and maladaptive behavior reported in patients with JME are related.

METHOD

Sixty patients with drug-refractory JME were administered tests of intellect, memory, and executive dysfunction. Anxiety, depression, personality traits, impact of epilepsy, and perceived cognitive effects of antiepileptic drugs were measured.

RESULTS

Half of the cohort exhibited moderate to severe anxiety symptoms. The patients performed most poorly on naming ability and inhibition switching. Duration of epilepsy exacerbated poor performance on inhibition switching. Females presented with pathological scores for neurotic and introvert traits and males for introvert traits. Abnormal personality traits and psychiatric disorders were associated with worse intellectual and executive functioning. People with extreme Eysenck Personality Scale - Brief Version (EPQ-BV) scores demonstrated the greatest level of executive impairment. Furthermore, the same degree of dysfunction was not seen in any individual with unremarkable EPQ-BV scores.

CONCLUSION

This study indicates that specific patterns of executive dysfunction are related to maladaptive behavior in JME. Distinct behavioral patterns may be used to identify functional and anatomical differences between people with JME and for stratification to enable gene discovery.