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Objective: This study evaluated the diagnostic performance of a widely available cognitive screener, the Montreal cognitive assessment (MoCA), to detect cognitive impairment in older patients (age ≥ 55) with epilepsy residing in the US, using the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) as the gold standard., Methods: Fifty older adults with focal epilepsy completed the MoCA and neuropsychological measures of memory, language, executive function, and processing speed/attention. The IC-CoDE taxonomy divided participants into IC-CoDE Impaired and Intact groups. Sensitivity and specificity across several MoCA cutoffs were examined. Spearman correlations examined relationships between the MoCA total score and clinical and demographic variables and MoCA domain scores and individual neuropsychological tests., Results: IC-CoDE impaired patients demonstrated significantly lower scores on the MoCA total, visuospatial/executive, naming, language, delayed recall, and orientation domain scores (Cohen's d range: 0.336-2.77). The recommended MoCA cutoff score < 26 had an overall accuracy of 72%, 88.2% sensitivity, and 63.6% specificity. A MoCA cutoff score < 24 yielded optimal sensitivity (70.6%) and specificity (78.8%), with overall accuracy of 76%. Higher MoCA total scores were associated with greater years of education (p = 0.016) and fewer antiseizure medications (p = 0.049). The MoCA memory domain was associated with several standardized measures of memory, MoCA language domain with category fluency, and MoCA abstraction domain with letter fluency., Significance: This study provides initial validation of the MoCA as a useful screening tool for older adults with epilepsy that can be used to identify patients who may benefit from comprehensive neuropsychological testing. Further, we demonstrate that a lower cutoff (i.e., <24) better captures cognitive impairment in older adults with epilepsy than the generally recommended cutoff and provides evidence for construct overlap between MoCA domains and standard neuropsychological tests. Critically, similar efforts in other regions of the world are needed., Plain Language Summary: The Montreal cognitive assessment (MoCA) can be a helpful tool to screen for cognitive impairment in older adults with epilepsy. We recommend that adults 55 or older with epilepsy who score less than 24 on the MoCA are referred to a neuropsychologist for a comprehensive evaluation to assess any changes in cognitive abilities and mood., (© 2024 The Author(s). Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Objective: Efforts to understand the global variability in cognitive profiles in patients with epilepsy have been stymied by the lack of a standardized diagnostic system. This study examined the cross-cultural applicability of the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) in a cohort of patients with temporal lobe epilepsy (TLE) in India that was diverse in language, education, and cultural background., Methods: A cohort of 548 adults with TLE from Mumbai completed a presurgical comprehensive neuropsychological evaluation. The IC-CoDE taxonomy was applied to derive cognitive phenotypes in the sample. Analyses of variance were conducted to examine differences in demographic and clinical characteristics across the phenotypes, and chi-squared tests were used to determine whether the phenotype distribution differed between the Mumbai sample and published data from a multicenter US sample., Results: Using the IC-CoDE criteria, 47% of our cohort showed an intact cognitive profile, 31% a single-domain impairment, 16% a bidomain impairment, and 6% a generalized impairment profile. The distribution of cognitive phenotypes was similar between the Indian and US cohorts for the intact and bidomain phenotypes, but differed for the single and generalized domains. There was a larger proportion of patients with single-domain impairment in the Indian cohort and a larger proportion with generalized impairment in the US cohort. Among patients with single-domain impairment, a greater proportion exhibited memory impairment in the Indian cohort, whereas a greater proportion showed language impairment in the US sample, likely reflecting differences in language administration procedures and sample characteristics including a higher rate of mesial temporal sclerosis in the Indian sample., Significance: Our results demonstrate the applicability of IC-CoDE in a group of culturally and linguistically diverse patients from India. This approach enhances our understanding of cognitive variability across cultures and enables harmonized and inclusive research into the neuropsychological aspects of epilepsy., (© 2024 International League Against Epilepsy.)

Introduction: Given the prevalence and staggering cost of neurological disorders, there is dire need for effective early detection and intervention tools. Emerging evidence suggests that multidisciplinary lifestyle interventions (MLI) may mitigate the risk and progression of neurological disorders. The objectives of this protocol are (1) to test the impact of MLI on the progression of neurological disorders and (2) to identify multi-omic biomarkers for early stages of neurological disease and the impact of MLIs on these biomarkers., Methods and Analysis: We present the Multidisciplinary lifestyle Interventions for Neurological Disorders during the Silent phase (MINDS) protocol, a randomized controlled trial of MLI in neurologically healthy older adults (≥ 50 years old) exhibiting elevated risk for common neurological disorders: stroke, epilepsy, Parkinson's Disease, or Alzheimer's disease and related dementias. Participants will be randomly assigned to intervention (n = 100) or control (n = 100) groups. The intervention group will receive 3 months of weekly 2-hour sessions on diet education, yoga, music therapy, and cognitive skills training. The participants' neurological health and engagement in relevant lifestyle practices will be assessed at regular intervals for 12 months. Neuroimaging and samples for multi-omic analyses will be collected at baseline, and at 3 months and 12 months after enrollment. Primary outcomes will be signs of progression of the neurological disorder risk that qualified them for study enrollment or a clinical diagnosis of the disorder. Secondary and exploratory outcomes will be based on self-reported health and multi-omic data. Data analysis will include between-group and longitudinal within-group analyses., Perspectives: The MINDS protocol and trial aims to clarify the impact of MLI on the progression of neurological disorder risk or diagnosis in older adults and to identify biomarkers that can be used to confirm MLI efficacy. The ability to validate the impact of MLI on neurological disorder progression based on biomarker data allows the identification of individuals most likely to benefit from such therapies in the early stages of neurological disease., Trial Registration: The trial is registered on the National Institutes of Health (NIH) ClinicalTrials.gov (NCT05984056) site. It was registered on August 2nd, 2023. The trial has full approval of the Cleveland Clinic Internal Review Board., (© 2024. The Author(s).)

Objective: Patients with temporal lobe epilepsy (TLE) are often at a high risk for cognitive and psychiatric comorbidities. Several cognitive phenotypes have been identified in TLE, but it is unclear how phenotypes relate to psychiatric comorbidities, such as anxiety and depression. This observational study investigated the relationship between cognitive phenotypes and psychiatric symptomatology in TLE., Methods: A total of 826 adults (age = 40.3, 55% female) with pharmacoresistant TLE completed a neuropsychological evaluation that included at least two measures from five cognitive domains to derive International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) cognitive phenotypes (i.e., intact, single-domain impairment, bi-domain impairment, generalized impairment). Participants also completed screening measures for depression and anxiety. Psychiatric history and medication data were extracted from electronic health records. Multivariable proportional odds logistic regression models examined the relationship between IC-CoDE phenotypes and psychiatric variables after controlling for relevant covariates., Results: Patients with elevated depressive symptoms had a greater odds of demonstrating increasingly worse cognitive phenotypes than patients without significant depressive symptomatology (odds ratio [OR] = 1.123-1.993, all corrected p's < .05). Number of psychotropic (OR = 1.584, p < .05) and anti-seizure medications (OR = 1.507, p < .001), use of anti-seizure medications with mood-worsening effects (OR = 1.748, p = .005), and history of a psychiatric diagnosis (OR = 1.928, p < .05) also increased the odds of a more severe cognitive phenotype, while anxiety symptoms were unrelated., Significance: This study demonstrates that psychiatric factors are not only associated with function in specific cognitive domains but also with the pattern and extent of deficits across cognitive domains. Results suggest that depressive symptoms and medications are strongly related to cognitive phenotype in adults with TLE and support the inclusion of these factors as diagnostic modifiers for cognitive phenotypes in future work. Longitudinal studies that incorporate neuroimaging findings are warranted to further our understanding of the complex relationships between cognition, mood, and seizures and to determine whether non-pharmacologic treatment of mood symptoms alters cognitive phenotype., (© 2023 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Approximately 50% of individuals who undergo resective epilepsy surgery experience seizure recurrence. The heterogenous post-operative outcomes are not fully explained by clinical, imaging and electrophysiological variables. We hypothesized that molecular features may be useful in understanding surgical response, and that individuals with epilepsy can be classified into molecular subtypes that are associated with seizure freedom or recurrence after surgical resection. Pre-operative blood samples, brain tissue and post-operative seizure outcomes were collected from a cohort of 40 individuals with temporal lobe epilepsy, 23 of whom experienced post-operative seizure recurrence. Messenger RNA and microRNA extracted from the blood and tissue samples were sequenced. The messenger RNA and microRNA expression levels from the blood and brain were each subjected to a novel clustering approach combined with multiple logistic regression to separate individuals into genetic clusters that identify novel subtypes associated with post-operative seizure outcomes. We then compared the microRNAs and messenger RNAs from patient blood and brain tissue that were significantly associated with each subtype to identify signatures that are similarly over- or under-represented for an outcome and more likely to represent endophenotypes with common molecular aetiology. These target microRNAs and messenger RNAs were further characterized by pathway analysis to assess their functional role in epilepsy. Using blood-derived microRNA and messenger RNA expression levels, we identified two subtypes of epilepsy that were significantly associated with seizure recurrence (clusters A1 and B4) (adjusted P < 0.20). A total of 551 microRNAs and 2486 messenger RNAs were associated with clusters A1 and B4, respectively (adjusted P < 0.05). Clustering of brain-tissue messenger RNA expression levels revealed an additional subtype (C2) associated with seizure recurrence that had high overlap of dysregulated messenger RNA transcripts with cluster B4. Clusters A1, B4 and C2 also shared significant overlap of subjects, which altogether suggests a coordinated mechanism by which microRNA and messenger RNA transcripts may be related to seizure recurrence. Epileptic subtypes A1, B4 and C2 reveal both known and novel microRNA and messenger RNA targets in seizure recurrence. Furthermore, targets identified in A1 and B4 are quantifiable in pre-operative blood samples and could potentially serve as biomarkers for surgical resection outcomes., Competing Interests: D.M.R. holds an equity stake in Clarified Precision Medicine, LLC., and has received research support from Novo Nordisk and consulting honoraria from Interpares Biomedicine and Pharmazaam, LLC. C.E. is the Sondra J. and Stephen R. Hardis Endowed Chair of Cancer Genomic Medicine at the Cleveland Clinic., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Understanding the exact molecular mechanisms involved in the aetiology of epileptogenic pathologies with or without tumour activity is essential for improving treatment of drug-resistant focal epilepsy. Here, we characterize the landscape of somatic genetic variants in resected brain specimens from 474 individuals with drug-resistant focal epilepsy using deep whole-exome sequencing (>350×) and whole-genome genotyping. Across the exome, we observe a greater number of somatic single-nucleotide variants in low-grade epilepsy-associated tumours (7.92 ± 5.65 single-nucleotide variants) than in brain tissue from malformations of cortical development (6.11 ± 4 single-nucleotide variants) or hippocampal sclerosis (5.1 ± 3.04 single-nucleotide variants). Tumour tissues also had the largest number of likely pathogenic variant carrying cells. low-grade epilepsy-associated tumours had the highest proportion of samples with one or more somatic copy-number variants (24.7%), followed by malformations of cortical development (5.4%) and hippocampal sclerosis (4.1%). Recurring somatic whole chromosome duplications affecting Chromosome 7 (16.8%), chromosome 5 (10.9%), and chromosome 20 (9.9%) were observed among low-grade epilepsy-associated tumours. For germline variant-associated malformations of cortical development genes such as TSC2, DEPDC5 and PTEN, germline single-nucleotide variants were frequently identified within large loss of heterozygosity regions, supporting the recently proposed 'second hit' disease mechanism in these genes. We detect somatic variants in 12 established lesional epilepsy genes and demonstrate exome-wide statistical support for three of these in the aetiology of low-grade epilepsy-associated tumours (e.g. BRAF) and malformations of cortical development (e.g. SLC35A2 and MTOR). We also identify novel significant associations for PTPN11 with low-grade epilepsy-associated tumours and NRAS Q61 mutated protein with a complex malformation of cortical development characterized by polymicrogyria and nodular heterotopia. The variants identified in NRAS are known from cancer studies to lead to hyperactivation of NRAS, which can be targeted pharmacologically. We identify large recurrent 1q21-q44 duplication including AKT3 in association with focal cortical dysplasia type 2a with hyaline astrocytic inclusions, another rare and possibly under-recognized brain lesion. The clinical-genetic analyses showed that the numbers of somatic single-nucleotide variant across the exome and the fraction of affected cells were positively correlated with the age at seizure onset and surgery in individuals with low-grade epilepsy-associated tumours. In summary, our comprehensive genetic screen sheds light on the genome-scale landscape of genetic variants in epileptic brain lesions, informs the design of gene panels for clinical diagnostic screening and guides future directions for clinical implementation of epilepsy surgery genetics., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Objective: This study was undertaken to evaluate the cross-cultural application of the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) to a cohort of Spanish-speaking patients with temporal lobe epilepsy (TLE) living in the United States., Methods: Eighty-four Spanish-speaking patients with TLE completed neuropsychological measures of memory, language, executive function, visuospatial functioning, and attention/processing speed as part of the Neuropsychological Screening Battery for Hispanics. The contribution of demographic and clinical variables to cognitive performance was evaluated. A sensitivity analysis was conducted by examining the base rates of impairment across several impairment thresholds. The IC-CoDE taxonomy was then applied, and the base rate of cognitive phenotypes for each cutoff was calculated. The distribution of phenotypes was compared to the published IC-CoDE taxonomy data, which utilized a large, multicenter cohort of English-speaking patients with TLE., Results: Across the different impairment cutoffs, memory was the most impaired cognitive domain, with impairments in list learning ranging from 50% to 78%. Application of the IC-CoDE taxonomy utilizing a -1.5-SD cutoff revealed an intact cognitive profile in 47.6% of patients, single-domain impairment in 23.8% of patients, bidomain impairment in 14.3% of patients, and generalized impairment in 14.3% of the sample. This distribution was comparable to the phenotype distribution observed in the IC-CoDE validation sample., Significance: We demonstrate a similar pattern and distribution of cognitive phenotypes in a Spanish-speaking epilepsy cohort compared to an English-speaking sample. This suggests stability in the underlying phenotypes associated with TLE and applicability of the IC-CoDE for guiding cognitive diagnostics in epilepsy research that can be applied to culturally and linguistically diverse samples., (© 2023 International League Against Epilepsy.)

Background: Individuals with PTEN hamartoma tumor syndrome (PHTS) demonstrate a distinct neurobehavioral profile suggesting primary disruption of frontal lobe symptoms, with more severe cognitive deficits in those with associated autism spectrum disorder (ASD) that extend to other areas of neurobehavioral function as well (e.g., adaptive behavior, sensory deficits). The current study sought to characterize longitudinal neurobehavioral profiles in individuals with PHTS who completed serial assessments (2-3 evaluations) over a 2-year time period., Methods: Comprehensive neurobehavioral evaluations were conducted on 92 participants (age range 6-21) with PHTS and/or ASD. Spaghetti plots and linear mixed effects models were used to visualize the individual patient profiles and group trends and examine the group differences in cognitive/behavioral test scores over time. Practice-adjusted reliable change indices (RCIs) and standardized regression-based change scores (SRBs) were calculated for those measures in the battery with adequate sample sizes and test-retest reliabilities for future use in assessing neurobehavioral change in children and young adults with PHTS., Results: Wide individual differences were observed at baseline across all measures. Encouragingly, baseline differences between patient groups persisted at the same magnitude over a 2-year time period with no differences in longitudinal neurobehavioral profiles within any one group. Test-retest reliabilities were generally high, ranging from 0.62 to 0.97, and group mean change from baseline to 12 months was small (range - 3.8 to 3.7). A Microsoft Excel calculator was created that clinicians and researchers can use to automatically calculate RCI and SRB thresholds at both 80% and 90% confidence intervals using test scores from a given child or young adult with PHTS., Conclusions: Our results suggest that the neurobehavioral phenotypes observed in individuals with PHTS remain relatively stable over time, even in those with ASD. The RCIs and SRBs provided can be used in future research to examine patient outcomes at the individual level as well as to detect negative deviations from the expected trajectory that can be used to inform intervention strategies., (© 2022. The Author(s).)

Memory dysfunction is prevalent in temporal lobe epilepsy (TLE), but little is known about the underlying molecular etiologies. Single-nucleus RNA sequencing technology was used to examine differences in cellular heterogeneity among left (language-dominant) temporal neocortical tissues from patients with TLE with (n = 4) or without (n = 2) impairment in verbal episodic memory. We observed marked cell heterogeneity between memory phenotypes and identified numerous differentially expressed genes across all brain cell types. The most notable differences were observed in glutamatergic (excitatory) and GABAergic (inhibitory) neurons with an overrepresentation of genes associated with long-term potentiation, long-term depression, and MAPK signaling, processes known to be essential for episodic memory formation., (© 2022. The Author(s).)

Memory dysfunction is prevalent in temporal lobe epilepsy, but little is known about the underlying pathophysiological etiologies. Here, we use spatial quantitation to examine differential expression of targeted proteins and transcripts in four brain regions essential for episodic memory (dentate gyrus, CA3, CA1, neocortex) between temporal lobe epilepsy patients with and without episodic memory impairment. Brain tissues were obtained from dominant temporal lobectomies in 16 adults with pharmacoresistant temporal lobe epilepsy associated with hippocampal sclerosis. Verbal memory tests from routine pre-operative clinical care were used to classify episodic memory as impaired or intact. Digital spatial profiling of a targeted protein panel and the whole transcriptome was performed using tissue sections from the temporal neocortex and hippocampus. We performed differential expression and pathway enrichment analysis between the memory groups within each temporal lobe region. Several proteins associated with neurodegenerative disease were overexpressed in the neocortex of patients with impaired memory, corroborating our prior findings using bulk transcriptomics. Spatial transcriptomics identified numerous differentially expressed transcripts in both neocortical and hippocampal subregions between memory groups, with little overlap across subregions. The strongest molecular signal was observed in the CA3 hippocampal subregion, known to play an essential role in memory encoding. Enrichment analyses revealed BDNF as a central hub in CA3-related networks regulating phenotype-relevant processes such as cognition, memory, long-term potentiation and neuritogenesis ( P adj < 0.05). Results suggest memory impairment in temporal lobe epilepsy with hippocampal sclerosis is associated with molecular alterations within temporal lobe subregions that are independent from hippocampal cell loss, demographic variables and disease characteristics. Importantly, each temporal subregion shows a unique molecular signature associated with memory impairment. While many differentially expressed transcripts and proteins in the neocortex have been associated with neurodegenerative disorders/processes, differentially expressed transcripts in hippocampal subregions involve genes associated with neuritogenesis and long-term potentiation, processes essential for new memory formation., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain.)

In efforts to understand the cognitive heterogeneity within and across epilepsy syndromes, cognitive phenotyping has been proposed as a new taxonomy aimed at developing a harmonized approach to cognitive classification in epilepsy. Data- and clinically driven approaches have been previously used with variability in the phenotypes derived across studies. In our study, we utilize latent profile analysis to test several models of phenotypes in a large multicentre sample of patients with temporal lobe epilepsy and evaluate their demographic and clinical profiles. For the first time, we examine the added value of replacing missing data and examine factors that may be contributing to missingness. A sample of 1178 participants met the inclusion criteria for the study, which included a diagnosis of temporal lobe epilepsy and the availability of comprehensive neuropsychological data. Models with two to five classes were examined using latent profile analysis and the optimal model was selected based on fit indices, posterior probabilities and proportion of sample sizes. The models were also examined with imputed data to investigate the impact of missing data on model selection. Based on the fit indices, posterior probability and distinctiveness of the latent classes, a three-class solution was the optimal solution. This three-class solution comprised a group of patients with multidomain impairments, a group with impairments predominantly in language and a group with no impairments. Overall, the multidomain group demonstrated a worse clinical profile and comprised a greater proportion of patients with mesial temporal sclerosis, a longer disease duration and a higher number of anti-seizure medications. The four-class and five-class solutions demonstrated the lowest probabilities of a group membership. Analyses with imputed data demonstrated that the four-class solution was the optimal solution; however, there was a weak agreement between the missing and imputed data sets for the four-Class solutions (κ = 0.288, P < 0.001). This study represents the first to use latent profile analysis to test and compare multiple models of cognitive phenotypes in temporal lobe epilepsy and to determine the impact of missing data on model fit. We found that the three-phenotype model was the most meaningful based on several fit indices and produced phenotypes with unique demographic and clinical profiles. Our findings demonstrate that latent profile analysis is a rigorous method to identify phenotypes in large, heterogeneous epilepsy samples. Furthermore, this study highlights the importance of examining the impact of missing data in phenotyping methods. Our latent profile analysis-derived phenotypes can inform future studies aimed at identifying cognitive phenotypes in other neurological disorders., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Epilepsy surgery is the treatment of choice for patients with drug-resistant seizures. A timely evaluation for surgical candidacy can be life-saving for patients who are identified as appropriate surgical candidates, and may also enhance the care of nonsurgical candidates through improvement in diagnosis, optimization of therapy, and treatment of comorbidities. Yet, referral for surgical evaluations is often delayed while palliative options are pursued, with significant adverse consequences due to increased morbidity and mortality associated with intractable epilepsy. The Surgical Therapies Commission of the International League Against Epilepsy (ILAE) sought to address these clinical gaps and clarify when to initiate a surgical evaluation. We conducted a Delphi consensus process with 61 epileptologists, epilepsy neurosurgeons, neurologists, neuropsychiatrists, and neuropsychologists with a median of 22 years in practice, from 28 countries in all six ILAE world regions. After three rounds of Delphi surveys, evaluating 51 unique scenarios, we reached the following Expert Consensus Recommendations: (1) Referral for a surgical evaluation should be offered to every patient with drug-resistant epilepsy (up to 70 years of age), as soon as drug resistance is ascertained, regardless of epilepsy duration, sex, socioeconomic status, seizure type, epilepsy type (including epileptic encephalopathies), localization, and comorbidities (including severe psychiatric comorbidity like psychogenic nonepileptic seizures [PNES] or substance abuse) if patients are cooperative with management; (2) A surgical referral should be considered for older patients with drug-resistant epilepsy who have no surgical contraindication, and for patients (adults and children) who are seizure-free on 1-2 antiseizure medications (ASMs) but have a brain lesion in noneloquent cortex; and (3) referral for surgery should not be offered to patients with active substance abuse who are noncooperative with management. We present the Delphi consensus results leading up to these Expert Consensus Recommendations and discuss the data supporting our conclusions. High level evidence will be required to permit creation of clinical practice guidelines., (© 2022 International League Against Epilepsy.)

Objective: Seizure outcomes after brain surgery for drug-resistant epilepsy (DRE) are very heterogeneous and difficult to predict with models utilizing the current clinical, imaging, and electrophysiological variables. In this pilot study, we investigated whether genetic and molecular biomarkers (e.g., genomic, transcriptomic) can provide additional insight into differential response to surgery., Methods: Post-operative seizure-outcomes were collected at last follow-up (>6 months) for 201 adult patients with DRE who underwent surgery between 2004 and 2020. Resected tissue was sent for miRNA sequencing ( n = 132) and mRNA sequencing ( n = 135). Following the selection of 10 genes ( SCN1A, NBEA, PTEN, GABRA1, LGL1, DEPDC5, IL1A, ABCB1, C3, CALHM1 ), we investigated SNPs in those 10 genes from previously acquired exome sequencing data ( n = 106). Logistic regression was performed to test for associations between individual features (mRNAs, miRNAs, and SNPs) and post-operative seizure-outcome with an exploratory FDR P < 0.25 as the threshold for significance. Post-operative time-to-seizure analyses were performed for each SNP using a Cox proportional hazards model., Results: The majority of patients (83%) had temporal lobe epilepsy. Mean age at surgery was 38.3 years, and 56% were female. Three SNPs (rs10276036, rs11975994, rs1128503) in multi-drug resistance gene, ABCB1 , were associated with post-operative seizure outcomes. Patients with alternate alleles in ABCB1 were more likely to be seizure-free at last follow-up (52-56% reduction in seizure recurrence; FDR P = 0.24). All three SNPs were in linkage disequilibrium and highly correlated with each other. Median post-operative time-to-seizure was 63 months for patients with 2 alternate alleles, 24-33 months with 1 alternate allele, and 10-11 months with 0 alternate alleles. These SNPs improved outcome prediction beyond MRI and sex alone. No independent miRNAs or mRNAs were significantly associated with seizure-outcome ( P > 0.05). However, pathway analysis identified "cancer drug resistance by drug efflux" (mir-154 and mir-379) as enriched ( P = 0.02), supporting the role of drug response genes in post-operative seizure recurrence., Significance: ABCB1 may have a role in epileptogenesis and surgery outcomes independent of its drug efflux activity necessitating further investigation. SNPs in ABCB1 may serve as independent predictors of post-operative outcome., Competing Interests: Author DR has an equity stake in Clarified Precision Medicine, LLC. DR has received research support from Novo Nordisk, consulting honoraria from Interpares Biomedicine and Pharmazaam, LLC. Author CE is the Sondra J. and Stephen R. Hardis Endowed Chair of Cancer Genomic Medicine at the Cleveland Clinic. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Louis, Busch, Lal, Hockings, Hogue, Morita-Sherman, Vegh, Najm, Ghosh, Bazeley, Eng, Jehi and Rotroff.)

Objective: Neuropsychological profiles are heterogeneous both across and within epilepsy syndromes, but especially in frontal lobe epilepsy (FLE), which has complex semiology and epileptogenicity. This study aimed to characterize the cognitive heterogeneity within FLE by identifying cognitive phenotypes and determining their demographic and clinical characteristics., Method: One hundred and six patients (age 16-66; 44% female) with FLE completed comprehensive neuropsychological testing, including measures within five cognitive domains: language, attention, executive function, processing speed, and verbal/visual learning. Patients were categorized into one of four phenotypes based on the number of impaired domains. Patterns of domain impairment and clinical and demographic characteristics were examined across phenotypes., Results: Twenty-five percent of patients met criteria for the Generalized Phenotype (impairment in at least four domains), 20% met criteria for the Tri-Domain Phenotype (impairment in three domains), 36% met criteria for the Domain-Specific Phenotype (impairment in one or two domains), and 19% met criteria for the Intact Phenotype (no impairment). Language was the most common domain-specific impairment, followed by attention, executive function, and processing speed. In contrast, learning was the least impacted cognitive domain. The Generalized Phenotype had fewer years of education compared to the Intact Phenotype, but otherwise, there was no differentiation between phenotypes in demographic and clinical variables. However, qualitative analysis suggested that the Generalized and Tri-Domain Phenotypes had a more widespread area of epileptogenicity, whereas the Intact Phenotype most frequently had seizures limited to the lateral frontal region., Significance: This study identified four cognitive phenotypes in FLE that were largely indistinguishable in clinical and demographic features, aside from education and extent of epileptogenic zone. These findings enhance our appreciation of the cognitive heterogeneity within FLE and provide additional support for the development and use of cognitive taxonomies in epilepsy., (© 2022 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Cognitive and behavioural comorbidities are prevalent in childhood and adult epilepsies and impose a substantial human and economic burden. Over the past century, the classic approach to understanding the aetiology and course of these comorbidities has been through the prism of the medical taxonomy of epilepsy, including its causes, course, characteristics and syndromes. Although this 'lesion model' has long served as the organizing paradigm for the field, substantial challenges to this model have accumulated from diverse sources, including neuroimaging, neuropathology, neuropsychology and network science. Advances in patient stratification and phenotyping point towards a new taxonomy for the cognitive and behavioural comorbidities of epilepsy, which reflects the heterogeneity of their clinical presentation and raises the possibility of a precision medicine approach. As we discuss in this Review, these advances are informing the development of a revised aetiological paradigm that incorporates sophisticated neurobiological measures, genomics, comorbid disease, diversity and adversity, and resilience factors. We describe modifiable risk factors that could guide early identification, treatment and, ultimately, prevention of cognitive and broader neurobehavioural comorbidities in epilepsy and propose a road map to guide future research., (© 2021. Springer Nature Limited.)

Germline heterozygous PTEN mutations have been associated with high prevalence of autism spectrum disorder (ASD) and elevated rates and severity of broadly defined behavioral problems. However, limited progress has been made toward understanding whether PTEN mutation is associated with specific psychiatric co-morbidity profiles when compared to idiopathic ASD. The current study aimed to utilize a cross-measure approach to compare concurrent psychiatric characteristics across children and adolescents with PTEN mutation with ( PTEN -ASD; n = 38) and without ASD ( PTEN -No ASD; n = 23), and ASD with macrocephaly but no PTEN mutation (macro-ASD; n = 25) using the Child Behavior Checklist (CBCL) and the Aberrant Behavior Checklist (ABC). There were significant group effects for the CBCL Internalizing and Externalizing broad symptom score, the majority of specific CBCL syndrome scores, and all ABC subscale scores. Post-hoc comparisons revealed greater behavioral symptoms in the ASD groups ( PTEN -ASD and macro-ASD) compared to the PTEN -no ASD group on nearly all subtest scores examined. There were no statistically significant differences between the PTEN -ASD and macro-ASD groups; however, there was a trend for the macro-ASD group showing higher levels of aggressive behaviors. Our findings provide evidence of specific behavior profiles across PTEN -No ASD, PTEN -ASD, and macro-ASD groups and highlight the importance of early identification of behavioral vulnerabilities in individuals with PTEN mutations in order to provide access to appropriate evidence-based interventions., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Steele, Uljarević, Rached, Frazier, Phillips, Libove, Busch, Klaas, Martinez-Agosto, Srivastava, Eng, Sahin and Hardan.)

Objective: Focal cortical dysplasia (FCD) is a major cause of difficult-to-treat epilepsy in children and young adults, and the diagnosis is currently based on microscopic review of surgical brain tissue using the International League Against Epilepsy classification scheme of 2011. We developed an iterative histopathological agreement trial with genetic testing to identify areas of diagnostic challenges in this widely used classification scheme., Methods: Four web-based digital pathology trials were completed by 20 neuropathologists from 15 countries using a consecutive series of 196 surgical tissue blocks obtained from 22 epilepsy patients at a single center. Five independent genetic laboratories performed screening or validation sequencing of FCD-relevant genes in paired brain and blood samples from the same 22 epilepsy patients., Results: Histopathology agreement based solely on hematoxylin and eosin stainings was low in Round 1, and gradually increased by adding a panel of immunostainings in Round 2 and the Delphi consensus method in Round 3. Interobserver agreement was good in Round 4 (kappa = .65), when the results of genetic tests were disclosed, namely, MTOR, AKT3, and SLC35A2 brain somatic mutations in five cases and germline mutations in DEPDC5 and NPRL3 in two cases., Significance: The diagnoses of FCD 1 and 3 subtypes remained most challenging and were often difficult to differentiate from a normal homotypic or heterotypic cortical architecture. Immunohistochemistry was helpful, however, to confirm the diagnosis of FCD or no lesion. We observed a genotype-phenotype association for brain somatic mutations in SLC35A2 in two cases with mild malformation of cortical development with oligodendroglial hyperplasia in epilepsy. Our results suggest that the current FCD classification should recognize a panel of immunohistochemical stainings for a better histopathological workup and definition of FCD subtypes. We also propose adding the level of genetic findings to obtain a comprehensive, reliable, and integrative genotype-phenotype diagnosis in the near future., (© 2021 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

This paper addresses the absence of an international diagnostic taxonomy for cognitive disorders in patients with epilepsy. Initiated through the 2020 Memorandum of Understanding between the International League Against Epilepsy and the International Neuropsychological Society, neuropsychological representatives from both organizations met to address the problem and consequences of the absence of an international diagnostic taxonomy for cognitive disorders in epilepsy, overview potential solutions, and propose specific solutions going forward. The group concluded that a classification of cognitive disorders in epilepsy, including an overall taxonomy and associated operational criteria, was clearly lacking and sorely needed. This paper reviews the advantages and shortcomings of four existing cognitive diagnostic approaches, including taxonomies derived from the US National Neuropsychology Network, DSM-V Neurocognitive Disorders, the Mild Cognitive Impairment classification from the aging/preclinical dementia literature, and the Research Domain Criteria Initiative. We propose a framework to develop a consensus-based classification system for cognitive disorders in epilepsy that will be international in scope and be applicable for clinical practice and research globally and introduce the International Classification of Cognitive Disorders in Epilepsy (IC-CODE) project., (© 2021 The Authors. Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Epilepsy incidence and prevalence peaks in older adults yet systematic studies of brain ageing and cognition in older adults with epilepsy remain limited. Here, we characterize patterns of cortical atrophy and cognitive impairment in 73 older adults with temporal lobe epilepsy (>55 years) and compare these patterns to those observed in 70 healthy controls and 79 patients with amnestic mild cognitive impairment, the prodromal stage of Alzheimer's disease. Patients with temporal lobe epilepsy were recruited from four tertiary epilepsy surgical centres; amnestic mild cognitive impairment and control subjects were obtained from the Alzheimer's Disease Neuroimaging Initiative database. Whole brain and region of interest analyses were conducted between patient groups and controls, as well as between temporal lobe epilepsy patients with early-onset (age of onset <50 years) and late-onset (>50 years) seizures. Older adults with temporal lobe epilepsy demonstrated a similar pattern and magnitude of medial temporal lobe atrophy to amnestic mild cognitive impairment. Region of interest analyses revealed pronounced medial temporal lobe thinning in both patient groups in bilateral entorhinal, temporal pole, and fusiform regions (all P < 0.05). Patients with temporal lobe epilepsy demonstrated thinner left entorhinal cortex compared to amnestic mild cognitive impairment (P = 0.02). Patients with late-onset temporal lobe epilepsy had a more consistent pattern of cortical thinning than patients with early-onset epilepsy, demonstrating decreased cortical thickness extending into the bilateral fusiform (both P < 0.01). Both temporal lobe epilepsy and amnestic mild cognitive impairment groups showed significant memory and language impairment relative to healthy control subjects. However, despite similar performances in language and memory encoding, patients with amnestic mild cognitive impairment demonstrated poorer delayed memory performances relative to both early and late-onset temporal lobe epilepsy. Medial temporal lobe atrophy and cognitive impairment overlap between older adults with temporal lobe epilepsy and amnestic mild cognitive impairment highlights the risks of growing old with epilepsy. Concerns regarding accelerated ageing and Alzheimer's disease co-morbidity in older adults with temporal lobe epilepsy suggests an urgent need for translational research aimed at identifying common mechanisms and/or targeting symptoms shared across a broad neurological disease spectrum., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

This randomized, double-blind controlled trial of everolimus in individuals with germline phosphatase and tensin homolog mutations ( PTEN ) was designed to evaluate the safety of everolimus compared with placebo and to evaluate the efficacy of everolimus on neurocognition and behavior compared to placebo as measured by standardized neurocognitive and motor measures as well as behavioral questionnaires. The safety profile of everolimus is characterized by manageable adverse events that are generally reversible and non-cumulative. The primary safety endpoint of this study was drop-out rate due to side effects, comparing everolimus versus placebo. We also sought to determine the frequency of adverse events by type and severity. The main efficacy endpoint was a neurocognitive composite computed in two ways: 1) an average for working memory, processing speed, and fine motor subtests; and 2) the same average as above except weighted 2/3, and an additional average based on all other available neurocognitive testing measures assessing the additional domains of nonverbal ability, visuomotor skills, verbal learning, and receptive and expressive language, weighted 1/3. Secondary efficacy endpoints examined the effect of everolimus on overall global clinical improvement, autism symptoms, behavioral problems, and adaptive abilities as measured by validated, standardized instruments. We predicted that the rate of adverse events would be no more than 10% higher in the everolimus group compared to placebo, and overall severity of side effects would be minimal. We also expected that individuals receiving everolimus would show more improvement, relative to those taking placebo, on the composite neurocognitive index., Competing Interests: Authors declare no conflict of interest., (© 2021 The Author(s).)

Objective: To characterize the nature and prevalence of cognitive disorders in older adults with temporal lobe epilepsy (TLE) and compare their cognitive profiles to patients with amnestic mild cognitive impairment (ie, aMCI)., Methods: Seventy-one older patients with TLE, 77 aMCI, and 69 normal aging controls (NACs), all 55-80 years of age, completed neuropsychological measures of memory, language, executive function, and processing speed. An actuarial neuropsychological method designed to diagnose MCI was applied to individual patients to identify older adults with TLE who met diagnostic criteria for MCI (TLE-MCI). A linear classifier was performed to evaluate how well the diagnostic criteria differentiated patients with TLE-MCI from aMCI. In TLE, the contribution of epilepsy-related and vascular risk factors to cognitive impairment was evaluated using multiple regression., Results: Forty-three TLE patients (60%) met criteria for TLE-MCI, demonstrating marked deficits in both memory and language. When patients were analyzed according to age at seizure onset, 63% of those with an early onset (<50 years) versus 56% of those with late onset (≥ 50 years) met criteria for TLE-MCI. A classification model between TLE-MCI and aMCI correctly classified 81.1% (90.6% specificity, 61.3% sensitivity) of the cohort based on neuropsychological scores. Whereas TLE-MCI showed greater deficits in language relative to aMCI, patients with aMCI showed greater rapid forgetting on memory measures. Both epilepsy-related risk factors and the presence of leukoaraiosis on MRI contributed to impairment profiles in TLE-MCI., Significance: Cognitive impairment is a common comorbidity in epilepsy and it presents in a substantial number of older adults with TLE. Although the underlying etiologies are unknown in many patients, the TLE-MCI phenotype may be secondary to an accumulation of epilepsy and vascular risk factors, signal the onset of a neurodegenerative disease, or represent a combination of factors., (© 2020 International League Against Epilepsy.)

Objective: To develop a model to predict the probability of mood decline in adults following temporal lobe resection for the treatment of pharmacoresistant epilepsy., Methods: Variable selection was performed on 492 patients from the Cleveland Clinic using best subsets regression. After completing variable selection, a subset of variables was requested from four epilepsy surgery centers across North America (n = 100). All data were combined to develop a final model to predict postoperative mood decline (N = 592). Internal validation with bootstrap resampling was performed. A clinically significant increase in depressive symptoms was defined as a 15% increase in Beck Depression Inventory-Second Edition score and a postoperative raw score > 11., Results: Fourteen percent of patients in the Cleveland Clinic cohort and 22% of patients in the external cohort experienced clinically significant increases in depressive symptoms following surgery. The final prediction model included six predictor variables: psychiatric history, resection side, relationship status, verbal fluency score, age at preoperative testing, and presence/absence of malformation of cortical development on magnetic resonance imaging. The model had an optimism-adjusted c-statistic of .70 and good calibration, with slight probability overestimation in higher risk patients., Significance: Clinicians can utilize our nomogram via a paper tool or online calculator to estimate the risk of postoperative mood decline for individual patients prior to temporal lobe epilepsy surgery., (© 2021 International League Against Epilepsy.)

Background: PTEN is a well-established risk gene for autism spectrum disorder (ASD). Yet, little is known about how PTEN mutations and associated molecular processes influence neurobehavioral function in mutation carriers with (PTEN-ASD) and without ASD (PTEN no-ASD). The primary aim of the present study was to examine group differences in peripheral blood-derived PTEN pathway protein levels between PTEN-ASD, PTEN no-ASD, and idiopathic macrocephalic ASD patients (macro-ASD). Secondarily, associations between protein levels and neurobehavioral functions were examined in the full cohort., Methods: Patients were recruited at four tertiary medical centers. Peripheral blood-derived protein levels from canonical PTEN pathways (PI3K/AKT and MAPK/ERK) were analyzed using Western blot analyses blinded to genotype and ASD status. Neurobehavioral measures included standardized assessments of global cognitive ability and multiple neurobehavioral domains. Analysis of variance models examined group differences in demographic, neurobehavioral, and protein measures. Bivariate correlations, structural models, and statistical learning procedures estimated associations between molecular and neurobehavioral variables. To complement patient data, Western blots for downstream proteins were generated to evaluate canonical PTEN pathways in the PTEN-m3m4 mouse model., Results: Participants included 61 patients (25 PTEN-ASD, 16 PTEN no-ASD, and 20 macro-ASD). Decreased PTEN and S6 were observed in both PTEN mutation groups. Reductions in MnSOD and increases in P-S6 were observed in ASD groups. Elevated neural P-AKT/AKT and P-S6/S6 from PTEN murine models parallel our patient observations. Patient PTEN and AKT levels were independently associated with global cognitive ability, and p27 expression was associated with frontal sub-cortical functions. As a group, molecular measures added significant predictive value to several neurobehavioral domains over and above PTEN mutation status., Limitations: Sample sizes were small, precluding within-group analyses. Protein and neurobehavioral data were limited to a single evaluation. A small number of patients were excluded with invalid protein data, and cognitively impaired patients had missing data on some assessments., Conclusions: Several canonical PTEN pathway molecules appear to influence the presence of ASD and modify neurobehavioral function in PTEN mutation patients. Protein assays of the PTEN pathway may be useful for predicting neurobehavioral outcomes in PTEN patients. Future longitudinal analyses are needed to replicate these findings and evaluate within-group relationships between protein and neurobehavioral measures., Trial Registration: ClinicalTrials.gov Identifier NCT02461446.

Focal epilepsy (FE) is clinically highly heterogeneous. It has been shown recently that not only rare but also a subset of common genetic variants confer risk for FE. The relatively modest power of genetic studies in FE suggests a high genetic heterogeneity of FE when grouped as one disorder. We hypothesize that the clinical heterogeneity of FE is correlated with genetic heterogeneity on a common risk variant level. To test the hypothesis, we used an FE polygenic risk score "FE-PRS" that combines small effect sizes of thousands of common variants from the largest FE-GWAS (genome-wide association study) into a single measure. We grouped 414 individuals with FE according to common clinical features into subgroups, either by one feature at a time or by all features combined in a cluster analysis. We examined their association with FE-PRS compared to 20 435 matched population controls and observed heterogeneous FE-PRS burden among the subgroups. The highest phenotypic variance explained by FE-PRS was identified in a cluster analysis-defined FE subgroup where all individuals had unknown etiologies and psychiatric comorbidities, and the majority had early onset seizures. Our results indicate that genetic factors associated with FE have differential burden among FE subtypes. Future studies using better-powered FE-PRS might have clinical utility., (© 2020 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Objective: To characterize seizure and cognitive outcomes of sparing vs removing an magnetic resonance imaging (MRI)-normal hippocampus in patients with temporal lobe epilepsy., Methods: In this retrospective cohort study, we reviewed clinical, imaging, surgical, and histopathological data on 152 individuals with temporal lobe epilepsy and nonlesional hippocampi categorized into hippocampus-spared (n = 74) or hippocampus-resected (n = 78). Extra-hippocampal lesions were allowed. Pre- and postoperative cognitive data were available on 86 patients. Predictors of seizure and cognitive outcomes were identified using Cox-proportional hazard modeling followed by treatment-specific model reduction according to Akaike information criterion, and built into an online risk calculator., Results: Seizures recurred in 40% within one postoperative year, and in 63% within six postoperative years. Male gender (P = .03), longer epilepsy duration (P < .01), normal MRI (P = .04), invasive evaluation (P = .02), and acute postoperative seizures (P < .01) were associated with a higher risk of recurrence. We found no significant difference in postoperative seizure freedom rates at 5 years between those whose hippocampus was spared and those whose hippocampus was resected (P = .17). Seizure outcome models built with pre- and postoperative data had bootstrap validated concordance indices of 0.65 and 0.72. The dominant hippocampus-spared group had lower rates of decline in verbal memory (39% vs 70%; P = .03) and naming (41% vs 79%; P = .01) compared to the hippocampus-resected group. Partial hippocampus sparing had the same risk of verbal memory decline as for complete removal., Significance: Sparing or removing an MRI-normal hippocampus yielded similar long-term seizure outcome. A more conservative approach, sparing the hippocampus, only partially shields patients from postoperative cognitive deficits. Risk calculators are provided to facilitate clinical counseling., (© 2020 International League Against Epilepsy.)

Epilepsy incidence and prevalence peaks in older adults, yet systematic studies of brain aging and epilepsy remain limited. We investigated topological network disruption in older adults with temporal lobe epilepsy (TLE; age > 55 years). Additionally, we examined the potential network disruption overlap between TLE and amnestic mild cognitive impairment (aMCI), the prodromal stage of Alzheimer disease. Measures of network integration ("global path efficiency") and segregation ("transitivity" and "modularity") were calculated from cortical thickness covariance from 73 TLE subjects, 79 aMCI subjects, and 70 healthy controls. Compared to controls, TLE patients demonstrated abnormal measures of segregation (increased transitivity and decreased modularity) and integration (decreased global path efficiency). aMCI patients also displayed increased transitivity and decreased global path efficiency, but these differences were less pronounced than in TLE. At the local level, TLE patients demonstrated decreased local path efficiency focused in the bilateral temporal lobes, whereas aMCI patients had a more frontal-parietal distribution. These results suggest that network disruption at the global and local level is present in both disorders, but global disruption may be a particularly salient feature in older adults with TLE. These findings motivate further research into whether these network changes have distinct cognitive correlates or are progressive in older adults with epilepsy., (© 2020 International League Against Epilepsy.)

Objective: Memory dysfunction is prevalent in many neurological disorders and can have a significant negative impact on quality of life. The genetic contributions to memory impairment in epilepsy, particularly temporal lobe epilepsy (TLE), remain poorly understood. Here, we compare the brain transcriptome between TLE patients with and without verbal memory impairments to identify genes and signaling networks important for episodic memory., Methods: Brain tissues were resected from 23 adults who underwent dominant temporal lobectomy for treatment of pharmacoresistant epilepsy. To control for potential effects of APOE on memory, only those homozygous for the APOE ε3 allele were included. A battery of memory tests was performed, and patients were stratified into two groups based on preoperative memory performance. The groups were well matched on demographic and disease-related variables. Total RNA-Seq and small RNA-Seq were performed on RNA extracted from the brain tissues. Pathway and integrative analyses were subsequently performed., Results: We identified 1092 differentially expressed transcripts (DETs), with the majority (71%) being underexpressed in brain tissues from patients with impaired memory compared to those from patients with intact memory. Enrichment analysis revealed overrepresentation of genes in pathways pertaining to brain-related neurological dysfunction, including a subset associated with neurodegenerative diseases, memory, and cognition (APP, MAPT, PINK1). Despite including patients with identical APOE genotypes, we identify APOE as a differentially expressed gene associated with memory status. Small RNA-Seq identified four differentially expressed microRNAs (miRNAs) that were predicted to target a subset (22%) of all DETs. Integrative analysis showed that these miRNA-predicted DET targets impact brain-related pathways and biological processes also pertinent to memory and cognition., Significance: TLE-associated memory status may be influenced by differences in gene expression profiles within the temporal lobe. Upstream processes influencing differential expression signatures, such as miRNAs, could serve as biomarkers and potential treatment targets for memory impairment in TLE., (© 2020 International League Against Epilepsy.)

Psychogenic nonepileptic seizures (PNES) are diagnosed in approximately 30% of patients referred to tertiary care epilepsy centers. Little is known about the molecular pathology of PNES, much less about possible underlying genetic factors. We generated whole-exome sequencing and whole-genome genotyping data to identify rare, pathogenic (P) or likely pathogenic (LP) variants in 102 individuals with PNES and 448 individuals with focal (FE) or generalized (GE) epilepsy. Variants were classified for all individuals based on the ACMG-AMP 2015 guidelines. For research purposes only, we considered genes associated with neurological or psychiatric disorders as candidate genes for PNES. We observe in this first genetic investigation of PNES that six (5.88%) individuals with PNES without coexistent epilepsy carry P/LP variants (deletions at 10q11.22-q11.23, 10q23.1-q23.2, distal 16p11.2, and 17p13.3, and nonsynonymous variants in NSD1 and GABRA5). Notably, the burden of P/LP variants among the individuals with PNES was similar and not significantly different to the burden observed in the individuals with FE (3.05%) or GE (1.82%) (PNES vs. FE vs. GE (3 × 2 χ 2 ), P = 0.30; PNES vs. epilepsy (2 × 2 χ 2 ), P = 0.14). The presence of variants in genes associated with monogenic forms of neurological and psychiatric disorders in individuals with PNES shows that genetic factors are likely to play a role in PNES or its comorbidities in a subset of individuals. Future large-scale genetic research studies are needed to further corroborate these interesting findings in PNES.

Objective: To define left temporal lobe regions where surgical resection produces a persistent postoperative decline in naming visual objects., Methods: Pre- and postoperative brain magnetic resonance imaging data and picture naming (Boston Naming Test) scores were obtained prospectively from 59 people with drug-resistant left temporal lobe epilepsy. All patients had left hemisphere language dominance at baseline and underwent surgical resection or ablation in the left temporal lobe. Postoperative naming assessment occurred approximately 7 months after surgery. Surgical lesions were mapped to a standard template, and the relationship between presence or absence of a lesion and the degree of naming decline was tested at each template voxel while controlling for effects of overall lesion size., Results: Patients declined by an average of 15% in their naming score, with wide variation across individuals. Decline was significantly related to damage in a cluster of voxels in the ventral temporal lobe, located mainly in the fusiform gyrus approximately 4-6 cm posterior to the temporal tip. Extent of damage to this region explained roughly 50% of the variance in outcome. Picture naming decline was not related to hippocampal or temporal pole damage., Significance: The results provide the first statistical map relating lesion location in left temporal lobe epilepsy surgery to picture naming decline, and they support previous observations of transient naming deficits from electrical stimulation in the basal temporal cortex. The critical lesion is relatively posterior and could be avoided in many patients undergoing left temporal lobe surgery for intractable epilepsy., (© 2020 International League Against Epilepsy.)

Objective: To identify cognitive phenotypes in temporal lobe epilepsy (TLE) and test their reproducibility in a large, multi-site cohort of patients using both data-driven and clinically driven approaches., Method: Four-hundred seven patients with TLE who underwent a comprehensive neuropsychological evaluation at one of four epilepsy centers were included. Scores on tests of verbal memory, naming, fluency, executive function, and psychomotor speed were converted into z-scores based on 151 healthy controls (HCs). For the data-driven method, cluster analysis (k-means) was used to determine the optimal number of clusters. For the clinically driven method, impairment was defined as >1.5 standard deviations below the mean of the HC, and patients were classified into groups based on the pattern of impairment., Results: Cluster analysis revealed a three-cluster solution characterized by (a) generalized impairment (29%), (b) language and memory impairment (28%), and (c) no impairment (43%). Based on the clinical criteria, the same broad categories were identified, but with a different distribution: (a) generalized impairment (37%), (b) language and memory impairment (30%), and (c) no impairment (33%). There was a 82.6% concordance rate with good agreement (κ = .716) between the methods. Forty-eight patients classified as having a normal profile based on cluster analysis were classified as having generalized impairment (n = 16) or an isolated language/memory impairment (n = 32) based on the clinical criteria. Patients with generalized impairment had a longer disease duration and patients with no impairment had more years of education. However, patients demonstrating the classic TLE profile (ie, language and memory impairment) were not more likely to have an earlier age at onset or mesial temporal sclerosis., Significance: We validate previous findings from single-site studies that have identified three unique cognitive phenotypes in TLE and offer a means of translating the patterns into a clinical diagnostic criteria, representing a novel taxonomy of neuropsychological status in TLE., (© 2020 International League Against Epilepsy.)

Epilepsy is clinically heterogeneous, and neurological or psychiatric comorbidities are frequently observed in patients. It has not been tested whether common risk variants for generalized or focal epilepsy are enriched in people with other disorders or traits related to brain or cognitive function. Here, we perform two brain-focused phenome association studies of polygenic risk scores (PRS) for generalized epilepsy (GE-PRS) or focal epilepsy (FE-PRS) with all binary brain or cognitive function-related traits available for 334,310 European-ancestry individuals of the UK Biobank. Higher GE-PRS were associated with not having a college or university degree (P = 3.00x10-4), five neuroticism-related personality traits (P<2.51x10-4), and having ever smoked (P = 1.27x10-6). Higher FE-PRS were associated with several measures of low educational attainment (P<4.87x10-5), one neuroticism-related personality trait (P = 2.33x10-4), having ever smoked (P = 1.71x10-4), and having experienced events of anxiety or depression (P = 2.83x10-4). GE- and FE-PRS had the same direction of effect for each of the associated traits. Genetic factors associated with GE or FE showed similar patterns of correlation with genetic factors associated with cortical morphology in a subset of the UKB with 16,612 individuals and T1 magnetic resonance imaging data. In summary, our results suggest that genetic factors associated with epilepsies may confer risk for other neurological and psychiatric disorders in a population sample not enriched for epilepsy., Competing Interests: The authors have declared that no competing interests exist.

Rare genetic variants can cause epilepsy, and genetic testing has been widely adopted for severe, paediatric-onset epilepsies. The phenotypic consequences of common genetic risk burden for epilepsies and their potential future clinical applications have not yet been determined. Using polygenic risk scores (PRS) from a European-ancestry genome-wide association study in generalized and focal epilepsy, we quantified common genetic burden in patients with generalized epilepsy (GE-PRS) or focal epilepsy (FE-PRS) from two independent non-Finnish European cohorts (Epi25 Consortium, n = 5705; Cleveland Clinic Epilepsy Center, n = 620; both compared to 20 435 controls). One Finnish-ancestry population isolate (Finnish-ancestry Epi25, n = 449; compared to 1559 controls), two European-ancestry biobanks (UK Biobank, n = 383 656; Vanderbilt biorepository, n = 49 494), and one Japanese-ancestry biobank (BioBank Japan, n = 168 680) were used for additional replications. Across 8386 patients with epilepsy and 622 212 population controls, we found and replicated significantly higher GE-PRS in patients with generalized epilepsy of European-ancestry compared to patients with focal epilepsy (Epi25: P = 1.64×10-15; Cleveland: P = 2.85×10-4; Finnish-ancestry Epi25: P = 1.80×10-4) or population controls (Epi25: P = 2.35×10-70; Cleveland: P = 1.43×10-7; Finnish-ancestry Epi25: P = 3.11×10-4; UK Biobank and Vanderbilt biorepository meta-analysis: P = 7.99×10-4). FE-PRS were significantly higher in patients with focal epilepsy compared to controls in the non-Finnish, non-biobank cohorts (Epi25: P = 5.74×10-19; Cleveland: P = 1.69×10-6). European ancestry-derived PRS did not predict generalized epilepsy or focal epilepsy in Japanese-ancestry individuals. Finally, we observed a significant 4.6-fold and a 4.5-fold enrichment of patients with generalized epilepsy compared to controls in the top 0.5% highest GE-PRS of the two non-Finnish European cohorts (Epi25: P = 2.60×10-15; Cleveland: P = 1.39×10-2). We conclude that common variant risk associated with epilepsy is significantly enriched in multiple cohorts of patients with epilepsy compared to controls-in particular for generalized epilepsy. As sample sizes and PRS accuracy continue to increase with further common variant discovery, PRS could complement established clinical biomarkers and augment genetic testing for patient classification, comorbidity research, and potentially targeted treatment., (© The Author(s) (2019). Published by Oxford University Press on behalf of the Guarantors of Brain.)

Germline mutations in PTEN, the gene that encodes phosphatase and tensin homolog, have been identified in up to 20% of children with autism spectrum disorder (ASD) and macrocephaly and are associated with marked abnormalities in the white matter of the brain. This study sought to characterize the neurobehavioral phenotype of PTEN-ASD. Comprehensive neurobehavioral evaluations were conducted in 36 participants (ages 3-21 years) with PTEN-ASD and compared to two groups of controls: non-syndromic ASD with macrocephaly (Macro-ASD, n = 25) and those with PTEN mutations without ASD (PTEN-no ASD, n = 23). Linear regression analysis or Kruskal-Wallis tests were used to examine group differences on neurobehavioral measures (cognitive, behavioral, sensory, and adaptive functioning) and, for select measures, one-sample t-tests were used to compare group performance to healthy control norms. These analyses revealed a distinct neuropsychological profile associated with mutations in PTEN suggesting primary disruption of frontal lobe systems (i.e., attention, impulsivity, reaction time, processing speed, and motor coordination). Cognitive deficits in PTEN-ASD are more severe than those in PTEN-no ASD and extend to other areas of neurobehavioral function, specifically, adaptive behavior and sensory deficits. While core ASD symptoms are similar in PTEN-ASD and Macro-ASD, PTEN-ASD had lower clinical ratings of autism severity and showed more sensory abnormalities suggestive of less sensory responsiveness. Together, these results suggest that PTEN-ASD has a distinct neurobehavioral phenotype compared to idiopathic ASD that is likely to warrant special consideration for overall assessment and treatment.

Objective: The International League Against Epilepsy (ILAE) proposed a classification system for hippocampal sclerosis (HS) based on location and extent of hippocampal neuron loss. The literature debates the usefulness of this classification system when studying memory in people with temporal lobe epilepsy (TLE) and determining memory outcome after temporal lobe resection (TLR). This study further explores the relationship between HS ILAE subtypes and episodic memory performance in patients with TLE and examines memory outcomes after TLR., Methods: This retrospective study identified 213 patients with TLE who underwent TLR and had histopathological evidence of HS (HS ILAE type 1a = 92; type 1b = 103; type 2 = 18). Patients completed the Wechsler Memory Scale-3rd Edition prior to surgery, and 78% of patients had postoperative scores available. Linear regressions examined differences in preoperative memory scores as a function of pathology classification, controlling for potential confounders. Fisher's exact tests were used to compare pathology subtypes on the magnitude of preoperative memory impairment and the proportion of patients who experienced clinically meaningful postoperative memory decline., Results: Individuals with HS ILAE type 2 demonstrated better preoperative verbal memory performance than patients with HS ILAE type 1; however, individual data revealed verbal and visual episodic memory impairments in many patients with HS ILAE type 2. The base rate of postoperative memory decline was similar among all 3 pathology groups., Significance: This is the largest reported overall sample and the largest subset of patients with HS ILAE type 2. Group data suggest that patients with HS ILAE type 2 perform better on preoperative memory measures, but individually there were no differences in the magnitude of memory impairment. Following surgery, there were no statistically significant differences between groups in the proportion of patients who declined. Future research should focus on quantitative measurements of hippocampal neuronal loss, and multicenter collaboration is encouraged., (Wiley Periodicals, Inc. © 2018 International League Against Epilepsy.)

Objective: To summarize the existing literature on resective epilepsy surgery (RES) in older adults (≥60 years old) and examine seizure and neuropsychological outcomes in a single-center large cohort of older adults undergoing RES and their comparison to a consecutive, younger (25- to45-year-old) adult population who underwent RES in routine clinical practice., Methods: First, a comprehensive literature review was performed. Then, we identified older adults who underwent RES at our center (2000-2015). Outcome analysis was performed on patients who had ≥1 year of clinical follow-up. A younger cohort of patients who underwent RES during the same period was selected for comparison. The 2 groups were compared with respect to demographic and disease variables as well as key clinical outcomes., Results: Seizure outcomes on 58 older patients were reported in existing literature; 72% achieved Engel class I outcome ≥1 year postoperatively. Sixty-four older adults underwent RES at our center, accounting for 2.8% of all RES during the study period. A total of 51 older adults (M age  = 65) among them had ≥1-year clinical follow-up; 80% achieved Engel I outcome after a mean follow-up of 3.2 years. This was comparable to the 68% Engel class I outcome among 50 consecutive younger adults, despite later age of onset, longer epilepsy duration, and more comorbidities (all p < 0.001) among older adults. The majority (86%) of older adults were referred to our center after years of suffering from drug-resistant epilepsy. There were no group differences in surgical complications. However, 1 older adult passed away post-RES. There was no difference in post-RES neuropsychological outcomes compared to younger adults, except significantly higher number of older adults showed a decline in confrontational naming., Significance: RES in well-selected older adults is a safe and effective therapy, and advanced age should not preclude consideration of surgical therapy in older adults with pharmacoresistant epilepsy.

Children with epilepsy have a high rate of mood and behavior problems; yet few studies consider the emotional and behavioral impact of surgery. No study to date has been sufficiently powered to investigate effects of both side (left/right) and site (temporal/frontal) of surgery. One hundred patients (aged 6-16) and their families completed measures of depression, anxiety, and behavioral function as part of neuropsychological evaluations before and after surgery for pharmacoresistant epilepsy. Among children who had left-sided surgeries (frontal = 16; temporal = 38), there were significant interactions between time (pre to post-operative neuropsychological assessment) and resection site (frontal/temporal) on anhedonia, social anxiety, and withdrawn/depressed scales. Patients with frontal lobe epilepsy (FLE) endorsed greater pre-surgical anhedonia and social anxiety than patients with temporal lobe epilepsy (TLE) with scores normalizing following surgery. While scores on the withdrawn/depressed scale were similar between groups before surgery, the FLE group showed greater symptom improvement after surgery. In children who underwent right-sided surgeries (FLE = 20; TLE = 26), main effects of time (patients in both groups improved) and resection site (caregivers of FLE patients endorsed greater symptoms than those with TLE) were observed primarily on behavior scales. Individual data revealed that a greater proportion of children with left FLE demonstrated clinically significant improvements in anhedonia, social anxiety, and aggressive behavior than children with TLE. This is the first study to demonstrate differential effects of both side and site of surgery in children with epilepsy at group and individual levels. Results suggest that children with FLE have greater emotional and behavioral dysfunction before surgery, but show marked improvement after surgery. Overall, most children had good emotional and behavioral outcomes, with most scores remaining stable or improving.

Purpose: We sought to characterize cognition in individuals with germline PTEN mutations (n = 23) as well as in PTEN mutation-negative individuals with classic Cowden syndrome or Bannayan-Riley-Ruvalcaba syndrome (n = 2)., Methods: Twenty-five individuals completed a comprehensive neuropsychological evaluation. One sample t-tests and effect sizes were used to examine differences in participant test scores compared with normal controls. Composite scores were created for each patient within each of the cognitive domains assessed and classified as above average, average, or below average according to normative standards. χ(2) analyses compared these classifications to expected proportions in normal control samples., Results: The mean intelligence quotient was in the average range, and the range of intellectual functioning was very wide (from extremely low to very superior). However, in a large subset of patients, scores were lower than expected on measures of motor functioning, executive functioning, and memory recall, suggesting disruption of frontal circuits in these participants., Conclusion: This is the first study to characterize cognition in individuals with PTEN mutations and associated syndromes using a comprehensive neuropsychological battery. Contrary to previous reports suggesting an association with intellectual disability, the mean intelligence quotient was average, and there was a broad range of intellectual abilities. Specific evidence of disruption of frontal circuits may have implications for treatment compliance and cancer surveillance, and further investigation is warranted.

This study sought to determine if word-finding difficulties (WFDs), which are common in adults with dominant temporal lobe epilepsy (TLE), are related to performance on verbal cognitive measures, including memory. One hundred six individuals with left TLE and pathologically confirmed mesial temporal sclerosis completed comprehensive preoperative neuropsychological evaluations. Patients were divided into two groups based on the degree of benefit received from phonemic cueing on a confrontation naming task. Cognitive performance was then compared between patients with greater and fewer WFDs. Patients with greater WFDs demonstrated poorer performance on many verbal cognitive measures compared to those with fewer WFDs. In contrast, there were no significant differences between groups on any of the nonverbal cognitive measures. Chi-square analyses indicated that below average verbal memory performance occurred at a significantly higher rate for patients with greater WFDs (42-46%) as compared to patients with fewer WFDs (18-24%). Results showed that WFDs confound performance on verbal cognitive measures in adult patients with left TLE, particularly on measures with high demands for lexical retrieval. This suggests that when patients have word-retrieval difficulties, measures of verbal memory and verbal intelligence may be underestimated and potentially lead to misinterpretation of test performance and misinformation regarding risk of declines after surgical resection., (Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.)

Resection of seizure foci is an effective treatment for the control of medically intractable epilepsy. However, cognitive morbidity can occur as a result of surgical intervention. This morbidity is dependent on several factors, including location and extent of resection, disease characteristics, patient demographic characteristics, and functional status of the tissue to be resected. In this review article, the authors provide a summary of the neurocognitive outcomes of epilepsy surgery with an emphasis on presurgical predictors of postsurgical cognitive decline.

Purpose: Diffusion tensor imaging (DTI) provides information about magnitude (diffusivity) and directionality (fractional anisotropy, FA) of water diffusion and allows visualization of major white matter tracts. The arcuate fasciculus (AF) connects anterior (Broca's) and posterior (Wernicke's) language areas. We hypothesized that essential language areas identified by direct cortical stimulation would colocalize with areas revealing subcortical connectivity via the AF., Methods: Fourteen patients with pharmacoresistant left hemispheric epilepsy and left hemisphere language dominance underwent invasive evaluations for localization of epileptogenicity and functional mapping. DTI and T1-weighted volumetric magnetic resonance imaging (MRI) scans were coregistered, and subdural grid electrodes identified on postimplantation computed tomography (CT) scans were also coregistered to the MRI scans. The AF was reconstructed from a region lateral to the corona radiata on the FA map. Colocalization, defined as <1 cm between the AF and the electrode positions delineating language cortex, was visually assessed with excellent reliability (Cronbach's alpha = 0.98)., Results: A total of 71 subdural grid contacts were overlying language cortex. Nineteen contacts in eight patients were over Broca's area, 16 of which (84.2%) colocalized with the AF. Fifty-two contacts in 10 patients were over Wernicke's area, with colocalization in 29 patients (55.8%). Colocalization was significantly greater in anterior regions than in posterior regions [chi(2)(1) = 4.850, p < 0.05]., Discussion: The AF, as visualized with DTI, colocalized well with anterior language areas, but less so with posterior language areas, inferring that the latter are more spatially dispersed.

The Boston Naming Test (BNT) is often used in the evaluation of surgical epilepsy patients to assess left temporal lobe function. In 2005, Busch et al. demonstrated the diagnostic utility of the BNT in predicting ultimate side of surgery in patients with temporal lobe epilepsy. BNT raw score significantly predicted ultimate side of surgery, moderated by Full Scale IQ (FSIQ), age at seizure onset, and duration of epilepsy. The final regression equation correctly predicted side of surgery in 69.5% of the sample. The current study demonstrated excellent cross-validation of this equation in an independent sample of 104 patients who eventually underwent temporal lobectomies, correctly predicting side of surgery in 67.3% of patients. The combination of the two samples resulted in a new, more-stable regression equation that correctly predicted side of surgery in 68.8% of the combined sample. These results further support the clinical utility of the BNT in predicting side of surgery.

Previous studies have typically focused on the ability of cognitive symptom validity tests to identify cognitive symptom exaggeration in the context of head injury or memory loss. Few published studies have examined the detection of simulated attention-deficit/hyperactivity disorder (ADHD) or reading disorder (RD). The present study examined the accuracy of symptom validity measures in the detection of simulated ADHD and RD. Results indicated that several commonly used symptom validity measures show good validity for detecting simulated ADHD and RD. Total Validity Indicator Profile (VIP) scores and hard item accuracy score from the Victoria Symptom Validity Test (VSVT) were the most accurate at distinguishing simulation of ADHD and RD from adequate effort. Percentages of control participants and participants in simulation conditions scoring below a specified cut score are provided to give clinicians an estimate of the simulator (true) positive and control (false) positive rates.

Aims: To use Diffusion Tensor Imaging (DTI) to explore structural integrity and connectivity of the uncinate fasciculus (UF) in patients with temporal lobe epilepsy (TLE) and its relationship to memory performance., Methods: DTI and UF reconstruction were performed in 28 patients with TLE (18 left, 10 right) and 10 normal controls. Differences between left and right UF fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and correlations between DTI measures and memory scores in the TLE groups were computed., Results: In controls, FA was higher in the left than right UF (p < 0.01). In left TLE, FA values were lower and ADC values higher than controls in the left UF and ADC values were higher in the right UF (all p < 0.05). In right TLE, ADCs were higher in the left and right UF compared to controls, and FA was reduced in the left UF (all p < 0.05). In left TLE, ADCs in the left UF were negatively correlated with Auditory Immediate (p < 0.05) and Delayed Memory (p < 0.01). Visual Delayed Memory was positively correlated with reduced FA in the ROI of the right UF and increased radial diffusivities (p < 0.05). No significant correlations were found in right TLE. Thus, DTI values correlated with memory scores in the expected direction in patients with left TLE., Conclusions: Abnormal diffusion measures in the UF ipsilateral to the epileptogenic zone suggest that integrity of the UF is related to memory performance in patients with left TLE. Larger sample sizes are needed to evaluate structure-function correlations further.

Purpose: Neuropsychological assessment can be of assistance in determining seizure lateralization in cases where EEG and MRI findings do not provide clear lateralizing data. While several studies have examined the lateralizing value of individual neuropsychological measures, clinicians are still in need of a statistically sound method that permits the incorporation of multiple neuropsychological variables to predict seizure lateralization in the individual patient., Method: The present study investigated the lateralizing value of several commonly used neuropsychological measures in a large sample of patients (n = 217) who eventually underwent surgical resection to treat their epilepsy. Side of surgery was used to operationally define seizure lateralization. A comparison of the relative utility of a multivariate versus univariate approach to predict seizure lateralization was conducted in temporal epilepsy cases., Results: The results provide evidence for the incremental validity of neuropsychological measures, other than memory and IQ tests, in the prediction of seizure lateralization in patients with medically intractable epilepsy. These data indicate that a multivariate approach increases the accuracy of prediction of seizure lateralization for temporal lobe epilepsy cases., Conclusion: This study supports the use of a multivariate approach using neuropsychological measures to predict seizure lateralization in temporal epilepsy surgical candidates. Regression formulas are provided to enhance the clinical utility of these findings.

Previous studies have focused on the ability of cognitive symptom validity tests to identify simulated malingering or distinguish between clinical samples of individuals at low or high risk of cognitive symptom exaggeration. However, no published studies have examined the latent structure of negative response bias on cognitive tests: measures of cognitive symptom exaggeration may evaluate a continuum of poor effort/invalid responding or a dichotomy of adequate versus inadequate effort. The present study examined whether Victoria Symptom Validity Test (VSVT) indices evaluate a latent dimension or category of response distortion. The VSVT and personality data were obtained from 300 individuals who participated in neuropsychological evaluations as part of standard clinical care. Results indicated that VSVT accuracy scores measure a latent category of inadequate/adequate effort. Individuals classified as taxon members showed significantly poorer performance IQ and memory relative to individuals not classified as exhibiting distortion. The base rate of the identified cognitive symptom exaggeration taxon was estimated to be approximately .13-.14 in the present sample. Likelihood ratios are presented to assist clinical detection of individuals exhibiting the category of cognitive symptom exaggeration.

Purpose: Confrontation naming tasks have long been presumed to be sensitive to left temporal dysfunction and, consequently, are frequently used in the evaluation of surgical epilepsy patients. Despite wide and frequent use, few studies have examined the utility of confrontation naming tasks in individuals with temporal lobe epilepsy (TLE)., Methods: The current study examined the presurgical Boston Naming Test (BNT) performance of 217 right-handed adult patients with intractable TLE (left, 108; right, 109) to determine the utility of this measure in predicting ultimate side of surgery., Results: The results support the clinical utility of the BNT in determining ultimate side of surgery and suggest that the BNT has incremental validity over and above presurgical delayed memory and intelligence scores. This relation was found to be moderated by Full Scale IQ (FSIQ), age at seizure onset, and duration of epilepsy. The use of a logistic regression equation to predict side of surgery revealed that prediction of left temporal surgery was best among patients with low BNT scores, high FSIQs, and late age at seizure onset. In contrast, right temporal surgery was best predicted among patients with high BNT scores, low FSIQs, and short duration of epilepsy., Conclusions: This study supports the clinical utility of the BNT in the preoperative evaluation of candidates for TLE surgery and highlights the importance of examining potential moderating variables when making predictions about side of surgery. This study further provides clinicians with a regression equation that can be used to predict side of surgery in patients with temporal lobe epilepsy.

Studies of the association between polymorphisms of the serotonin transporter gene (5-HTT) and trait anxiety have produced inconsistent results, raising questions about the strength of the relationship and the methodological conditions under which the relationship holds. We conducted a meta-analysis of existing studies to provide formal statistical measures of the strength of the linked polymorphic region of the serotonin transporter gene (5-HTTLPR)-anxiety relationship. For the entire collection of 26 studies, results provided no support for a relationship between anxiety and the presence of the short form of the 5-HTTLPR polymorphism. There was strong evidence of the presence of moderating variables, however, and subsequent analysis revealed that choice of the measure of trait anxiety was significant. Studies using the Neuroticism scale of Costa and McCrae were found to produce a small positive effect (d=0.23). Other potential moderators (country of study origin, type of subject) did not have a meaningful impact on d statistics. These findings indicate that 5-HTTLPR may in fact have a small but reliable influence on personality, particularly in the manifestation of trait anxiety when measured with a neuroticism scale based on the five-factor model of personality. Our results suggest that the success of future personality genetics research will be maximized by the use of personality measures from both the psychobiological and five-factor models.