The new approach to classification: rethinking cognition and behavior in epilepsy

Cognitive phenotypes in patients with drug-resistant temporal lobe epilepsy: Relationships with cortisol and affectivity

OBJECTIVE

Drug-resistant temporal lobe epilepsy (TLE) is a neurological disorder characterized by cognitive deficits. This study examined whether patients with TLE and different cognitive phenotypes differ in cortisol levels and affectivity while controlling for demographic and clinical variables. Methods: In this cross-sectional study, 79 adults with TLE underwent neuropsychological evaluation in which memory, language, attention/processing speed, executive function, and affectivity were assessed. Six saliva samples were collected in the afternoon to examine the ability of the hypothalamic-pituitary-adrenal (HPA) axis to descend according to the circadian rhythm (C1 to C6). The cortisol area under the curve concerning ground (AUCg) was computed to examine global cortisol secretion.

RESULTS

Three cognitive phenotypes were identified: memory impairment, generalized impairment, and no impairment. The memory-impairment phenotype showed higher cortisol levels at C4, C5, and C6 than the other groups (p = 0.03, η2 = 0.06), higher cortisol AUCg than the generalized-impairment phenotype (p = 0.004, η2 = 0.14), and a significant reduction in positive affectivity after the evaluation (p = 0.026, η2 = 0.11). Higher cortisol AUCg and reductions in positive affectivity were significant predictors of the memory-impairment phenotype (p < 0.001; Cox and Snell R2 = 0.47).

CONCLUSIONS

Patients with memory impairment had a slower decline in cortisol levels in the afternoon, which could be interpreted as an inability of the HPA axis to inhibit itself. Thus, chronic stress may influence hippocampus-dependent cognitive function more than other cognitive functions in patients with TLE.

Repeat testing enhances long-term verbal memory in children with epilepsy

To (i) determine whether accelerated long-term forgetting (ALF) can be found using standardized verbal memory test materials in children with genetic generalized epilepsy (GGE) and temporal lobe epilepsy (TLE), and (ii) to establish whether ALF is impacted by executive skills and repeat testing over long delays. One hundred and twenty-three children aged 8 to 16, (28 with GGE, 23 with TLE, and 72 typically developing; TD) completed a battery of standardized tests assessing executive functioning and memory for two stories. Stories were recalled immediately and after a 30-min delay. To examine whether repeat testing impacts long-term forgetting, one story was tested via free recall at 1-day and 2-weeks, and the other at 2-weeks only. Recognition was then tested for both stories at 2-weeks. Children with epilepsy recalled fewer story details, both immediately and after 30-min relative to TD children. Compared to TD children, the GGE group, but not the TLE group, showed ALF, having significantly poorer recall of the story tested only at the longest delay. Poor executive skills were significantly correlated with ALF for children with epilepsy. Standard story memory materials can detect ALF in children with epilepsy when administered over long delays. Our findings suggest that (i) ALF is related to poor executive skills in children with epilepsy, and (ii) repeated testing may ameliorate ALF in some children.

Robotic assessment of sensorimotor and cognitive deficits in patients with temporal lobe epilepsy

OBJECTIVE

Individuals with temporal lobe epilepsy (TLE) frequently demonstrate impairments in executive function, working memory, and/or declarative memory. It is recommended that screening for cognitive impairment is undertaken in all people newly diagnosed with epilepsy. However, standard neuropsychological assessments are a limited resource and thus not available to all. Our study investigated the use of robotic technology (the Kinarm robot) for cognitive screening.

METHODS

27 participants with TLE (17 left) underwent both a brief neuropsychological screening and a robotic (Kinarm) assessment. The degree of impairments and correlations between standardized scores from both approaches to assessments were analysed across different neurocognitive domains. Performance was compared between people with left and right TLE to look for laterality effects. Finally, the association between the duration of epilepsy and performance was assessed.

RESULTS

Across the 6 neurocognitive domains (attention, executive function, language, memory, motor and visuospatial) assessed by our neuropsychological screening, all showed scores that significantly correlated with Kinarm tasks assessing the same cognitive domains except language and memory that were not adequately assessed with Kinarm. Participants with right TLE performed worse on most tasks than those with left TLE, including both visuospatial (typically considered right hemisphere), and verbal memory and language tasks (typically considered left hemisphere). No correlations were found between the duration of epilepsy and either the neuropsychological screening or Kinarm assessment.

SIGNIFICANCE

Our findings suggest that Kinarm may be a useful tool in screening for neurocognitive impairment in people with TLE. Further development may facilitate an easier and more rapid screening of cognition in people with epilepsy and distinguishing patterns of cognitive impairment.

Neurophysiology, Neuropsychology, Epilepsy, 2022: Hills We Have Climbed and the Hills Ahead. Cognition and Sensory Systems in Healthy and Diseased Subjects

This article summarizes selected presentations from a session titled "Cognition and Sensory Systems in Healthy and Diseased Subjects", held to highlight and honor the work of Dr. Marilyn Jones-Gotman. The session was part of a two-day symposium, "Neurophysiology, Neuropsychology, Epilepsy, 2022: Hills We Have Climbed and the Hills Ahead". The session presented research on epilepsy and sensory systems by colleagues and former trainees of Dr. Jones-Gotman. The extended summaries provide an overview of historical and current work in the neuropsychology of epilepsy, neuropsychological and neuroimaging approaches to understanding brain organization, sex differences in brain mechanisms underlying neurological disorders, dietary influences on brain function and cognition, and expertise in olfactory training and language experiences and their implications for brain organization and structure.

Neuropsychiatric and Cognitive Comorbidities in Epilepsy

PURPOSE OF REVIEW

This article discusses psychiatric and cognitive comorbidities of epilepsy over the lifespan and illustrates opportunities to improve the quality of care of children and adults with epilepsy.

RECENT FINDINGS

One in 3 people with epilepsy have a lifetime history of psychiatric disorders, and they represent an important prognostic marker of epilepsy. Contributors are diverse and display a complex relationship. Cognitive comorbidities are also common among those living with epilepsy and are increasingly recognized as a reflection of changes to underlying brain networks. Among the cognitive comorbidities, intellectual disability and dementia are common and can complicate the diagnostic process when cognitive and/or behavioral features resemble seizures.

SUMMARY

Comorbidities require consideration from the first point of contact with a patient because they can determine the presentation of symptoms, responsiveness to treatment, and the patient's day-to-day functioning and quality of life. In epilepsy, psychiatric and cognitive comorbidities may prove a greater source of disability for the patient and family than the seizures themselves, and in the case of essential comorbidities, they are regarded as core to the disorder in terms of etiology, diagnosis, and treatment.

Accelerated long-term forgetting in children with temporal lobe epilepsy: A timescale investigation of material specificity and executive skills

Recently, children with temporal lobe epilepsy (TLE) were found to be at risk of accelerated long-term forgetting (ALF). In this study, we examined the temporal trajectory of ALF, while exploring the relationship between ALF, executive skills, and epilepsy variables. Fifty-one children, (23 with TLE and 28 typically developing) completed a battery of neuropsychological tests of verbal and visual memory, executive skills, and two experimental memory tasks (verbal and visual) involving recall after short (30-min) and extended (1-day and 2-week) delays. Side of seizure focus and hippocampal integrity were considered. On the visual task (Scene Memory), children with TLE performed comparably to typically developing children following a 30-min and 1-day delay, although worse than typically developing children at 2 weeks: ALF was observed in children with right TLE focus. The two groups did not differ on the experimental verbal memory task. Children with TLE also had worse performance than typically developing children on standardized verbal memory test and on tests of executive skills (i.e., verbal generativity, inhibition, working memory, complex attention). Only complex attention was associated with visual ALF. ALF was present for visuo-spatial materials in children with TLE at two weeks, and children with right TLE were most susceptible. A relationship was identified between complex attention and long-term forgetting. The findings extend our understanding of difficulties in long-term memory formation experienced by children with TLE.

Neurobehavioural comorbidities of epilepsy: towards a network-based precision taxonomy

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.

Memory complaints, clinical aspects, and self-esteem in adult people with epilepsy

Memory complaints are common in adult people with epilepsy (PWEs). However, the associated clinical aspects are not yet fully understood.

Objective

This study aims to relate the occurrence of memory complaints in PWEs with clinical aspects and self-esteem.

Methods

To relate the data obtained from the Memory Complaint Questionnaire (MAC-Q) with clinical aspects, 71 PWEs were assessed using the Rosenberg Self-Esteem Scale (SES), the Mini Mental State Examination (MMSE), and the Brief Cognitive Battery-Edu. These data were compared with 55 individuals in a control group (CG).

Results

Memory complaints (MAC-Q≥25) were significantly higher in PWEs, when compared with individuals in the CG [35 (49.3%) vs. 15 (27.2%); Student's t-test; p=0.012]. Objective cognitive performance was lower in PWEs. Memory complaints were associated with a lower educational level, the presence of depression, SES, MMSE, incidental memory, and the clock-drawing test scores in PWEs.

Conclusions

Memory complaints were more frequent in PWEs than in individuals in the CG, and there was a relationship with cognitive deficit, educational level, depression, and low self-esteem.

Cognitive and behavioral profiles of pediatric surgical candidates with frontal and temporal lobe epilepsy

BACKGROUND

We aimed to prospectively analyze memory and executive and social cognitive functioning in patients with drug-resistant frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE) with focal lesions and isolate the impact of intellectual ability on specific deficits.

METHODS

A neuropsychological evaluation was performed in 23 children with FLE, 22 children with TLE, and 36 healthy pediatric controls (HCs). Patients in the epilepsy groups had a range of lesions, including low-grade epilepsy-associated tumors (LEAT), focal cortical dysplasia (FCD) type II, and mesial temporal sclerosis (MS).

RESULTS

There were no significant differences between children with FLE and TLE regarding memory, executive, or social cognitive functioning. General Ability Index (GAI) was a predictor of memory, executive function, and social cognition scores and was influenced by age at onset, duration of epilepsy, and number of antiepileptic drugs (AEDs) prescribed at the time of assessment. Working Memory Index scores of patients with TLE, which measure verbal mnesic processing, were significantly lower than those of HCs and patients with TLE. The greatest differences in both clinical groups compared to HCs were recorded in cognitive executive functions, and patients with FLE had lower scores in this domain. Regarding behavioral executive functions, patients with TLE presented impaired emotional control and impulse inhibition and patients with FLE exhibited decreased flexibility.

CONCLUSION

Consistent with previous research, our findings provide further detailed evidence of small differences in cognitive performance among children with FLE and TLE. These differences emerge on analysis of the factors with which deficits are associated.

Cognitive profiles in patients with epileptic and nonepileptic seizures evaluated using a brief cognitive assessment tool

BACKGROUND

There is a need for the development of brief tools to screen for cognitive impairments in epilepsy patients in order to prioritize and direct formal comprehensive cognitive testing. Yet, shorter cognitive screening tools are limited in their breadth of cognitive domains or have not been intensively studied on an epilepsy population. This study used a brief cognitive screening tool in order to compare cognitive profiles between patients with epilepsy and those with nonepileptic seizures.

METHODS

Patients admitted to the Royal Melbourne Hospital video-EEG monitoring unit between 2005 and 2017 were included. Patients were categorized according to seizure etiology (epileptic, psychogenic or other nonepileptic seizures), epilepsy syndrome (focal or generalized; temporal lobe (TLE) or extra-temporal lobe epilepsy (ETLE)), seizure frequency, and anti-seizure medications (ASMs). Attention, visuoconstructional, memory, executive, and language functioning were assessed with the Neuropsychiatry Unit Cognitive Assessment Tool (NUCOG). General linear mixed models were computed to investigate cognitive profiles according to diagnostic group and other clinicodemographic variables.

RESULTS

800 patients were included in the analysis (61% female and 39 % male, median age 36 years). Patients with both epileptic seizures and psychogenic seizures (n = 25) had the lowest total scores on NUCOG, followed by patients with epileptic seizures (n = 411), psychogenic seizures (n = 185), and nonepileptic seizures (n = 179, p = 0.002). Specifically, patients with epileptic seizures performed worse than those with nonepileptic seizures in the executive, language, and memory domain, and had lower language domain scores than those with psychogenic seizures. Patients with bilateral TLE had poorer performance than those with unilateral TLE, particularly for memory function. Specific ASMs and polypharmacy but not seizure frequency had a negative effect on cognition (p < 0.001). NUCOG scores did not differ between focal and generalized epilepsies, or between TLE and ETLE.

CONCLUSION

The NUCOG differentiated cognitive profiles in patients with uncontrolled seizures due to different etiologies. Bilateral TLE and medication adversely affected cognitive performance, and overall patients with epilepsy performed worse than those with nonepileptic seizures. These results provide further evidence for sensitivity of the NUCOG for detecting cognitive impairment in patients with seizure disorders.

Getting Physical: A Specific Boost for Cognition in Epilepsy?

Effect of Combined Physical Training on Cognitive Function in People With Epilepsy: Results From a Randomized Controlled Trial

Feter N, Alt R, Häfele CA, et al. Epilepsia. 2020;61(8):1649-1658. doi:10.1111/epi.16588. PMID: 32602966.

Objective:

To examine the effect of 12-week exercise program on cognitive function in people with epilepsy.

Methods:

Twenty-one physically inactive patients were randomized into 2 groups: the exercise group (EG) or the control group. Exercise group performed 12 weeks of combined physical training. Control group was advised to maintain usual daily activities. Exercise group received a structured, individually supervised exercise program with two 60-minute sessions per week. Each session included warmup (5 minutes), aerobic (15-20 minutes at 14-17 on Borg scale), strength (2-3 sets, 10-15 repetitions), and 5-minute active stretches. Sociodemographic characteristics, clinical information, memory (Digit Span Test [DST]), executive function (Trail Making Test [TMT] A and B), Stroop Color and Word Test, a verbal fluency task, global cognitive function (Montreal Cognitive Assessment [MoCA]), anthropometric measurements (weight, height, and hip and waist circumferences), cardiorespiratory fitness (maximal oxygen consumption [V.o₂max]), and strength (dynamometer) were measured at baseline and after the 12-week intervention.

Results:

Exercise decreased time spent on TMT-A from baseline to postintervention (difference = −7.9 seconds, 95% CI = −14.5 to −1.3, P = .023). Exercise group improved total number of words on the verbal fluency task after intervention (difference = 8.1 words, 95% CI = 3.0-13.2, P = .002). Exercise group also improved the score on MoCA at 1.7 (95% CI = 0.1-3.3, P = .043) points. We observed a 22.4% (95% CI = 13.1-31.6, P = .021) improvement in executive function in EG. No effect of group, time, or group × time was observed on any other cognitive test. Changes in V˙o₂max were negatively associated with changes in performance on DST (r = −0.445, P = .049) and overall memory score (r = −0.544, P = .042).

Significance:

This randomized controlled trial provided the first evidence that combined physical training improves executive function in adults with epilepsy, showing main improvements in attention and language tasks. Physical exercise should be encouraged for people with epilepsy to reduce the burden on cognitive function associated with this disease.

A methodological perspective on the cognitive outcome of epilepsy surgery in children and adolescents

PURPOSE

The purpose of the study was to explore the impact of timing and test specificity of cognitive outcome measures after pediatric epilepsy surgery.

METHODS

A consecutive national cohort of 114 children with medically resistant epilepsy having had resective epilepsy surgery were screened for children tested with a complete age-appropriate Wechsler Intelligence test at two or three time-points. This provided 43 children for analyses. Composite subscale scores were assessed in comparison to index and intelligence quotient (IQ) scores.

RESULTS

We found a main effect of time in seizure-free children for full-scale IQ (FSIQ); F(2, 42) = 6.49 with higher T2 measures compared with T1 (M_Diff = 5.46, p = .006). There was a difference in FSIQ scores between seizure-free and nonseizure-free children at T2; M = 7.31, 95% confidence interval (CI) [0.05 to 14.57], t(38) = 2.04, p = .049, favoring seizure-free children. A statistical difference between composite scale scores and index scores was found with medium to large effect. The correlation of medical treatment (anti-epileptic drug (AED)) change and score differences in FSIQ outcome was significant (p = .041), with less AED correlated with a higher FSIQ. All children with left-temporal surgery had a stable or improved verbal comprehension composite subscale score outcome at T2 regardless of seizure status.

CONCLUSION

Our results correspond to some longitudinal studies with outcome measures >2 years, in contrast to short-term studies ≤2 years with a stable outcome. Our study supports the fact that the specificity of the used tests and the timing of assessments after pediatric epilepsy surgery are essential factors for the clinical validity of outcome measures. However, there are further needs of extensive longitudinal studies to provide a better understanding of life-long cognitive development and impact after childhood epilepsy surgery.

Neuroticism in temporal lobe epilepsy is associated with altered limbic-frontal lobe resting-state functional connectivity

Neuroticism, a core personality trait characterized by a tendency towards experiencing negative affect, has been reported to be higher in people with temporal lobe epilepsy (TLE) compared with healthy individuals. Neuroticism is a known predictor of depression and anxiety, which also occur more frequently in people with TLE. The purpose of this study was to identify abnormalities in whole-brain resting-state functional connectivity in relation to neuroticism in people with TLE and to determine the degree of unique versus shared patterns of abnormal connectivity in relation to elevated symptoms of depression and anxiety. Ninety-three individuals with TLE (55 females) and 40 healthy controls (18 females) from the Epilepsy Connectome Project (ECP) completed measures of neuroticism, depression, and anxiety, which were all significantly higher in people with TLE compared with controls. Resting-state functional connectivity was compared between controls and groups with TLE with high and low neuroticism using analysis of variance (ANOVA) and t-test. In secondary analyses, the same analytics were performed using measures of depression and anxiety and the unique variance in resting-state connectivity associated with neuroticism independent of symptoms of depression and anxiety identified. Increased neuroticism was significantly associated with hyposynchrony between the right hippocampus and Brodmann area (BA) 9 (region of prefrontal cortex (PFC)) (p < 0.005), representing a unique relationship independent of symptoms of depression and anxiety. Hyposynchrony of connection between the right hippocampus and BA47 (anterior frontal operculum) was associated with high neuroticism and with higher depression and anxiety scores (p < 0.05), making it a shared abnormal connection for the three measures. In conclusion, increased neuroticism exhibits both unique and shared patterns of abnormal functional connectivity with depression and anxiety symptoms between regions of the mesial temporal and frontal lobe.

Oxcarbazepine monotherapy in children with benign epilepsy with centrotemporal spikes improves quality of life

Background

Benign epilepsy with centrotemporal spikes (BECTS) is the most common type of childhood idiopathic focal epilepsy. BECTS is associated with pervasive cognitive deficits and behavior problems. While seizures can be easily controlled, it is crucial to select anti-epileptic drugs that do not impair cognition, do not cause psychosocial effects, and improve the quality of life. Previous studies showed effects of oxcarbazepine (OXC) monotherapy on the cognitive and psychosocial profiles of patients with BECTS. Here, we studied the effects of OXC monotherapy on the neuropsychologic profiles and quality of life in patients with BECTS in China.

Methods

Thirty-one patients aged 6 to 12 years newly diagnosed with BECTS were recruited. A psychometric assessment was performed before and during the follow-up of OXC monotherapy with Cognitive Computerized Task Battery, Depression Self-Rating Scale for children, Screen for Child Anxiety Related Emotional Disorders, and Quality of Life in Epilepsy-31 (QOLIE-31). The results of the assessments were compared to explore the effect of OXC monotherapy in patients with BECTS.

Results

Thirty children with BECTS completed the study. Five of ten cognitive test scores improved after treatment via OXC monotherapy, including visual tracing (F = 14.480, P < 0.001), paired associated learning (language) (F = 6.292, P < 0.001), paired associated learning (number) (F = 9.721, P < 0.05), word semantic (F = 6.003, P < 0.05), and simple subtraction (F = 6.229, P < 0.05). Of the neuropsychology data concerning the quality of life, statistically significant improvements were observed in emotion (F = 4.946, P < 0.05), QOLIE-social (F = 5.912, P < 0.05), and QOLIE-total (F = 14.161, P < 0.001).

Conclusions

OXC is safe and does not impair neuropsychologic functions, with no obvious mood burden on children with BECTS. Most importantly, OXC has positive impacts on children's perception of quality of life, especially in terms of happiness and life satisfaction.

Network, clinical and sociodemographic features of cognitive phenotypes in temporal lobe epilepsy

This study explored the taxonomy of cognitive impairment within temporal lobe epilepsy and characterized the sociodemographic, clinical and neurobiological correlates of identified cognitive phenotypes. 111 temporal lobe epilepsy patients and 83 controls (mean ages 33 and 39, 57% and 61% female, respectively) from the Epilepsy Connectome Project underwent neuropsychological assessment, clinical interview, and high resolution 3T structural and resting-state functional MRI. A comprehensive neuropsychological test battery was reduced to core cognitive domains (language, memory, executive, visuospatial, motor speed) which were then subjected to cluster analysis. The resulting cognitive subgroups were compared in regard to sociodemographic and clinical epilepsy characteristics as well as variations in brain structure and functional connectivity. Three cognitive subgroups were identified (intact, language/memory/executive function impairment, generalized impairment) which differed significantly, in a systematic fashion, across multiple features. The generalized impairment group was characterized by an earlier age at medication initiation (P < 0.05), fewer patient (P < 0.001) and parental years of education (P < 0.05), greater racial diversity (P < 0.05), and greater number of lifetime generalized seizures (P < 0.001). The three groups also differed in an orderly manner across total intracranial (P < 0.001) and bilateral cerebellar cortex volumes (P < 0.01), and rate of bilateral hippocampal atrophy (P < 0.014), but minimally in regional measures of cortical volume or thickness. In contrast, large-scale patterns of cortical-subcortical covariance networks revealed significant differences across groups in global and local measures of community structure and distribution of hubs. Resting-state fMRI revealed stepwise anomalies as a function of cluster membership, with the most abnormal patterns of connectivity evident in the generalized impairment group and no significant differences from controls in the cognitively intact group. Overall, the distinct underlying cognitive phenotypes of temporal lobe epilepsy harbor systematic relationships with clinical, sociodemographic and neuroimaging correlates. Cognitive phenotype variations in patient and familial education and ethnicity, with linked variations in total intracranial volume, raise the question of an early and persisting socioeconomic-status related neurodevelopmental impact, with additional contributions of clinical epilepsy factors (e.g., lifetime generalized seizures). The neuroimaging features of cognitive phenotype membership are most notable for disrupted large scale cortical-subcortical networks and patterns of functional connectivity with bilateral hippocampal and cerebellar atrophy. The cognitive taxonomy of temporal lobe epilepsy appears influenced by features that reflect the combined influence of socioeconomic, neurodevelopmental and neurobiological risk factors.

Task-Specific Interictal Spiking: Adding to the Complexity

[Box: see text]

Prognostic role of Mini-Mental State Pediatric Examination (MMSPE) on neuropsychological functioning

OBJECTIVE

The aim of this study was to evaluate the ability of the Mini-Mental State Pediatric Examinations (MMSPE) in the individuation of neuropsychological impairments.

METHOD

MMSPE was administered to 60 children attending a primary or lower secondary school suffering from neurological diseases, admitted to our neuropsychology services. All children performed both a MMSPE examination and a neuropsychological evaluation. Results of neuropsychological evaluation and MMSPE were dichotomized. Positive predictive value (PPV), negative predictive value (NPV), and accuracy were also calculated.

RESULTS

The diagnostic performance of MMSPE showed a good overall accuracy (0.83, CI 95% 0.64-0.91), NPV (0.81, CI 95% 0.73-1.00), PPV (0.87, CI 95% 0.68-0.94), specificity (0.91, CI 95% 0.81-1.00), sensitivity (0.74, CI 95% 0.57-0.90), and odds ratio of 28.5 (CI 95% 6.6-123), p < 0.001.

CONCLUSIONS

MMSPE has a good prognostic ability in predicting neuropsychological problems in the context of different neurological pediatric diseases. We suggest that this instrument could greatly improve pediatric clinical practice in identifying high-risk children.

Epilepsy Benchmarks Area IV: Limit or Prevent Adverse Consequence of Seizures and Their Treatment Across the Life Span

Epilepsy represents a complex spectrum disorder, with patients sharing seizures as a common symptom and manifesting a broad array of additional clinical phenotypes. To understand this disorder and treat individuals who live with epilepsy, it is important not only to identify pathogenic mechanisms underlying epilepsy but also to understand their relationships with other health-related factors. Benchmarks Area IV focuses on the impact of seizures and their treatment on quality of life, development, cognitive function, and other aspects and comorbidities that often affect individuals with epilepsy. Included in this review is a discussion on sudden unexpected death in epilepsy and other causes of mortality, a major area of research focus with still many unanswered questions. We also draw attention to special populations, such as individuals with nonepileptic seizures and pregnant women and their offspring. In this study, we review the progress made in these areas since the 2016 review of the Benchmarks Area IV and discuss challenges and opportunities for future study.

Memory Decline Following Epilepsy Surgery: Can We Predict Who Will Pay the Price?

Postoperative Memory Prognosis in Temporal Lobe Epilepsy Surgery: The Contribution of Postictal Memory

Sveikata L, Kavan N, Pegna AJ, et al. Epilepsia. 2019;60(8):1639-1649. doi:10.1111/epi.16281. Epub July 22, 2019. PMID: 31329286.

Objective:

The prediction of verbal memory decline after temporal lobe epilepsy (TLE) surgery remains difficult at an individual level. We evaluated the prognostic value of postictal memory testing in predicting the postoperative verbal memory function.

Methods:

Sixty-three consecutive patients were included in the analysis who underwent TLE surgery at our center with preoperative interictal/postictal and postoperative memory testing. Verbal memory was evaluated using the Rey Auditory Verbal Learning Test (RAVLT). We used reliable change indices with 90% confidence interval (90% RCIs) to evaluate a significant postoperative memory decline. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV), area under the curve (AUC), and accuracy (ACC) were calculated. The analysis was performed for all patients with TLE and for the subgroup with hippocampal sclerosis (HS).

Results:

Patients with left TLE (n = 31) had lower verbal memory scores on RAVLT than right TLE at 3 months (57% vs 78%) and 12 months (53% vs 78%) after surgery. The 90% RCI was estimated to be a loss of 4 out of 15 items. The predictive value was Sn = 42%, Sp = 84%, PPV = 39%, NPV = 86%, AUC = 0.630, and ACC = 76% to predict a verbal memory decline in the whole group (n = 63). In patients with HS (n = 41), the postictal verbal memory test had Sn = 50%, Sp = 88%, PPV = 50%, NPV = 88%, AUC = 0.689, and ACC = 81% to predict a significant postoperative decline.

Significance:

Postictal memory is a noninvasive bedside memory test that can help predict the postoperative verbal memory decline in patients with HS with an overall ACC of 81%.

Patterns of impaired social cognition in children and adolescents with epilepsy: The borders between different epilepsy phenotypes

Over the past decade, a growing number of studies have shown that children and adolescents with focal and generalized epilepsies have marked impairments in social cognition, including deficits in facial emotion perception (FEP) and Theory of Mind (ToM). At present, it remains unclear whether FEP and ToM impairments are comparable in children with focal and generalized epilepsies or whether distinct syndrome-specific deficits have emerged. This question of whether unique or overlapping social cognitive profiles exist in epilepsy is of interest, given that the revised International League Against Epilepsy (ILAE) classification guidelines propose that seizures arise from a diseased network (i.e., network account), rather than being confined to discrete regions near the site of seizure foci (i.e., localization account). The purpose of this review was as follows: (1) to summarize studies examining FEP and ToM in pediatric patients with epilepsy, (2) to examine epilepsy and psychosocial correlates of these difficulties, and (3) to determine whether patterns of sociocognitive impairment better support a localization or neural network account of epilepsy. Twelve studies were reviewed examining FEP (N = 5) and/or ToM (N = 8). Findings revealed significant FEP and ToM impairments across the studied subgroups with epilepsy, which did not differ between children with generalized and focal (localization-related) epilepsies nor among children with different subtypes of localization-related epilepsy. Similarly, other epilepsy variables (i.e., seizure frequency, side of seizure focus, number of antiepileptic drugs (AEDs) or surgical status) were not related to FEP or ToM, with the exception of younger age at seizure onset and longer duration of epilepsy. Several studies documented a significant relationship between impaired ToM and reduced social competence in pediatric patients with epilepsy, whereas evidence for a relationship between FEP and psychosocial functioning is currently weak. In conclusion, findings suggest that social cognitive impairments represent a shared feature of epilepsy in childhood. The results support a neural network account of epilepsy, in which a shared neural network of dysfunction may be underlying social cognitive deficits in this group. Further research is needed to examine the functional correlates of social cognitive impairments, as well as to evaluate screening tools and treatment methods to identify and address significant social and emotional difficulties in this patient group. This article is part of the Special Issue "Epilepsy and social cognition across the lifespan".

Ten things every neurologist needs to know about neuropsychological assessments and interventions in people with epilepsy

This paper describes 10 core features of a neuropsychological assessment with the aim of helping neurologists understand the unique contribution the evaluation can make within the wider context of diagnostic methods in epilepsy. The possibilities, limitations and cautions associated with the investigation are discussed under the following headings. (1) A neuropsychological assessment is a collaborative investigation. (2) Assessment prior to treatment allows for the accurate assessment of treatment effects. (3) The nature of an underlying lesion and its neurodevelopmental context play an important role in shaping the associated neuropsychological deficit. (4) Cognitive and behavioural impairments result from the essential comorbidities of epilepsy which can be considered as much a disorder of cognition and behaviour as of seizures. (5) Patients' subjective complaints can help us understand objective cognitive impairments and their underlying neuroanatomy, resulting in improved patient care. At other times, patient complaints reflect other factors and require careful interpretation. (6) The results from a neuropsychological assessment can be used to maximize the educational and occupational potentials of people with epilepsy. (7) Not all patients are able to engage with a neuropsychological assessment. (8) There are limitations in assessments conducted in a second language with tests that have been standardized on different populations from that of the patient. (9) Adequate intervals between assessments maximize sensitivity to meaningful change. (10) Patients should be fully informed about the purpose of the assessment and have realistic expectations of the outcome prior to referral.

Behaviour outcomes in children with epilepsy 1 year after surgical resection of the ventromedial prefrontal cortex

Early damage to the ventromedial prefrontal cortex (VM) has been associated with impaired behavioural functioning in children without epilepsy, yet behaviour in children with epilepsy and VM lesions has not been investigated. The primary aim of this study was to examine behavioural outcomes in children with epilepsy emanating from the VM preoperatively and one year after epilepsy surgery compared to the general population and matched epilepsy controls. Behavioural outcomes were defined as comprising both problems and competencies (i.e. social, school and co-curricular performance). A secondary aim was to examine whether seizure outcome, number of antiepileptic drugs (AEDs), or age at surgery related to behavioural outcomes. Ratings on the Child Behavior Checklist were examined preoperatively and 1 year after surgery for 20 children with epilepsy who had undergone surgical resection of the VM (N = 10) or temporal lobe (TL, N = 10). VM and TL groups were comparable on Full Scale IQ (40-101), age of seizure onset (0.5-9.0 years), age at surgery (3.1-16.9 years), seizure laterality (5 left in each group), age at assessments, sex (3 female in VM group, 2 female in TL group) and seizure outcome (7 seizure free in VM group, 6 seizure free in TL group). The VM group had significantly elevated behaviour problems (i.e. withdrawn, thought, social and attention problems) and reduced competencies (i.e. social and school) compared to the general population before and after surgery. VM and TL cases did not differ on any behaviour problem scales pre or postoperatively and neither group showed significant change in functioning over time; however, VM patients had significantly lower total competence than TL patients postoperatively. A significant seizure outcome × time interaction was observed: children who were seizure free following surgery (collapsed across surgical site) showed an improvement in total behaviour problems and aggression at 1 year follow-up, whereas children with ongoing seizures showed a deterioration in these domains. In conclusion, VM lesions in children with epilepsy are associated with behavioural problems but their profile does not differ from that of children with temporal lobe epilepsy. These results are consistent with the concept that seizures arise from epileptogenic networks that may affect multiple cortical areas, even when onset is in a focal site.

Music training is neuroprotective for verbal cognition in focal epilepsy

Focal epilepsy is a unilateral brain network disorder, providing an ideal neuropathological model with which to study the effects of focal neural disruption on a range of cognitive processes. While language and memory functions have been extensively investigated in focal epilepsy, music cognition has received less attention, particularly in patients with music training or expertise. This represents a critical gap in the literature. A better understanding of the effects of epilepsy on music cognition may provide greater insight into the mechanisms behind disease- and training-related neuroplasticity, which may have implications for clinical practice. In this cross-sectional study, we comprehensively profiled music and non-music cognition in 107 participants; musicians with focal epilepsy (n = 35), non-musicians with focal epilepsy (n = 39), and healthy control musicians and non-musicians (n = 33). Parametric group comparisons revealed a specific impairment in verbal cognition in non-musicians with epilepsy but not musicians with epilepsy, compared to healthy musicians and non-musicians (P = 0.029). This suggests a possible neuroprotective effect of music training against the cognitive sequelae of focal epilepsy, and implicates potential training-related cognitive transfer that may be underpinned by enhancement of auditory processes primarily supported by temporo-frontal networks. Furthermore, our results showed that musicians with an earlier age of onset of music training performed better on a composite score of melodic learning and memory compared to non-musicians (P = 0.037), while late-onset musicians did not differ from non-musicians. For most composite scores of music cognition, although no significant group differences were observed, a similar trend was apparent. We discuss these key findings in the context of a proposed model of three interacting dimensions (disease status, music expertise, and cognitive domain), and their implications for clinical practice, music education, and music neuroscience research.

Looking beyond lesions for causes of neuropsychological impairment in epilepsy

OBJECTIVE

Patients with temporal lobe epilepsy (TLE) are similar in their epileptology regardless of whether they have a lesion evident on MRI; this study aims to prospectively clarify whether they are also similar in their neuropsychological profiles.

METHODS

Participants comprised 152 adults: 79 patients with TLE and 73 healthy controls. Patients and controls did not differ in age, sex, or education (p > 0.05). Sixty-two percent of patients had an MRI-resolvable lesion (39% with presumed hippocampal sclerosis [HS-TLE], 61% with a lesion other than HS [MRI-positive TLE]); the remaining 38% of patients were lesion-negative. Psychometric measures well established in epilepsy were used.

RESULTS

Relative to controls, all 3 patient subgroups showed significantly impaired autobiographical, verbal, and visual memory (p < 0.05-0.001) and significantly more depression and anxiety (p < 0.05-0.01). Yet, contrary to expectations, the 3 TLE subgroups did not differ in their severity of memory or mood impairment (p > 0.05). Lower Full-Scale IQ predicted memory impairments across all TLE subtypes, with early age at seizure onset a predictor unique to MRI-negative TLE.

CONCLUSIONS

MRI-negative TLE is associated with memory and mood dysfunction equivalent to that seen in patients with hippocampal sclerosis and other MRI-resolvable pathologies. As such, neuropsychological impairments in TLE are not contingent on a macroscopic lesion and might be an intrinsic property of the underlying network disease.

Affective, neurocognitive and psychosocial disorders associated with traumatic brain injury and post-traumatic epilepsy

Survivors of traumatic brain injury (TBI) often develop chronic neurological, neurocognitive, psychological, and psychosocial deficits that can have a profound impact on an individual's wellbeing and quality of life. TBI is also a common cause of acquired epilepsy, which is itself associated with significant behavioral morbidity. This review considers the clinical and preclinical evidence that post-traumatic epilepsy (PTE) acts as a 'second-hit' insult to worsen chronic behavioral outcomes for brain-injured patients, across the domains of emotional, cognitive, and psychosocial functioning. Surprisingly, few well-designed studies have specifically examined the relationship between seizures and behavioral outcomes after TBI. The complex mechanisms underlying these comorbidities remain incompletely understood, although many of the biological processes that precipitate seizure occurrence and epileptogenesis may also contribute to the development of chronic behavioral deficits. Further, the relationship between PTE and behavioral dysfunction is increasingly recognized to be a bidirectional one, whereby premorbid conditions are a risk factor for PTE. Clinical studies in this arena are often challenged by the confounding effects of anti-seizure medications, while preclinical studies have rarely examined an adequately extended time course to fully capture the time course of epilepsy development after a TBI. To drive the field forward towards improved treatment strategies, it is imperative that both seizures and neurobehavioral outcomes are assessed in parallel after TBI, both in patient populations and preclinical models.

Composition and Use of Cannabis Extracts for Childhood Epilepsy in the Australian Community

Recent surveys suggest that many parents are using illicit cannabis extracts in the hope of managing seizures in their children with epilepsy. In the current Australian study we conducted semi-structured interviews with families of children with diverse forms of epilepsy to explore their attitudes towards and experiences with using cannabis extracts. This included current or previous users of cannabis extracts to treat their child's seizures (n = 41 families), and families who had never used (n = 24 families). For those using cannabis, extracts were analysed for cannabinoid content, with specific comparison of samples rated by families as "effective" versus those rated "ineffective". Results showed that children given cannabis extracts tended to have more severe epilepsy historically and had trialled more anticonvulsants than those who had never received cannabis extracts. There was high variability in the cannabinoid content and profile of cannabis extracts rated as "effective", with no clear differences between extracts perceived as "effective" and "ineffective". Contrary to family's expectations, most samples contained low concentrations of cannabidiol, while Δ9-tetrahydrocannabinol was present in nearly every sample. These findings highlight profound variation in the illicit cannabis extracts being currently used in Australia and warrant further investigations into the therapeutic value of cannabinoids in epilepsy.

Systematic review of structural and functional brain alterations in psychosis of epilepsy

This systematic review critically assesses structural and functional neuroimaging studies of psychosis of epilepsy (POE). We integrate findings from 18 studies of adults with POE to examine the prevailing view that there is a specific relationship between temporal lobe epilepsy (TLE) and POE, and that mesial temporal lobe pathology is a biomarker for POE. Our results show: (1) conflicting evidence of volumetric change in the hippocampus and amygdala; (2) distributed structural pathology beyond the mesial temporal lobe; and (3) changes in frontotemporal functional network activation. These results provide strong evidence for a revised conceptualisation of POE as disorder of brain networks, and highlight that abnormalities in mesial temporal structures alone are unlikely to account for its neuropathogenesis. Understanding POE as a disease of brain networks has important implications for neuroimaging research and clinical practice. Specifically, we suggest that future neuroimaging studies of POE target structural and functional networks, and that practitioners are vigilant for psychotic symptoms in all epilepsies, not just TLE.

Paradigm Shifts in the Neuropsychology of Epilepsy

This article reviews the major paradigm shifts that have occurred in the area of the application of clinical and experimental neuropsychology to epilepsy and epilepsy surgery since the founding of the International Neuropsychological Society. The five paradigm shifts discussed include: 1) The neurobiology of cognitive disorders in epilepsy - expanding the landscape of syndrome-specific neuropsychological impairment; 2) pathways to comorbidities: bidirectional relationships and their clinical implications; 3) discovering quality of life: The concept, its quantification and applicability; 4) outcomes of epilepsy surgery: challenging conventional wisdom; and 5) Iatrogenic effects of treatment: cognitive and behavioral effects of antiepilepsy drugs. For each area we characterize the status of knowledge, the key developments that have occurred, and how they have altered our understanding of the epilepsies and their management. We conclude with a brief overview of where we believe the field will be headed in the next decade which includes changes in assessment paradigms, moving from characterization of comorbidities to interventions; increasing development of new measures, terminology and classification; increasing interest in neurodegenerative proteins; transitioning from clinical seizure features to modifiable risk factors; and neurobehavioral phenotypes. Overall, enormous progress has been made over the lifespan of the INS with promise of ongoing improvements in understanding of the cognitive and behavioral complications of the epilepsies and their treatment. (JINS, 2017, 23, 791-805).

Pretreatment behavior and subsequent medication effects in childhood absence epilepsy

OBJECTIVE

To characterize pretreatment behavioral problems and differential effects of initial therapy in children with childhood absence epilepsy (CAE).

METHODS

The Child Behavior Checklist (CBCL) was administered at baseline, week 16-20, and month 12 visits of a randomized double-blind trial of ethosuximide, lamotrigine, and valproate. Total problems score was the primary outcome measure.

RESULTS

A total of 382 participants at baseline, 310 participants at the week 16-20 visit, and 168 participants at the month 12 visit had CBCL data. At baseline, 8% (95% confidence interval [CI] 6%-11%) of children with CAE had elevated total problems scores (mean 52.9 ± 10.91). At week 16-20, participants taking valproic acid had significantly higher total problems (51.7 [98.3% CI 48.6-54.7]), externalizing problems (51.4 [98.3% CI 48.5-54.3]), attention problems (57.8 [98.3% CI 55.6-60.0]), and attention-deficit/hyperactivity problems (55.8 [98.3% CI 54.1-57.6]) scores compared to participants taking ethosuximide (46.5 [98.3% CI 43.4-49.6]; 45.8 [98.3% CI 42.9-48.7]; 54.6 [98.3% CI 52.4-56.9]; 53.0 [98.3% CI 51.3-54.8]). Lack of seizure freedom and elevated week 16-20 Conner Continuous Performance Test confidence index were associated with worse total problems scores. At month 12, participants taking valproic acid had significantly higher attention problems scores (57.9 [98.3% CI 55.6-60.3]) compared to participants taking ethosuximide (54.5 [95% CI 52.1-56.9]).

CONCLUSIONS

Pretreatment and ongoing behavioral problems exist in CAE. Valproic acid is associated with worse behavioral outcomes than ethosuximide or lamotrigine, further reinforcing ethosuximide as the preferred initial therapy for CAE.

CLINICALTRIALSGOV IDENTIFIER

NCT00088452.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that for children with CAE, valproic acid is associated with worse behavioral outcomes than ethosuximide or lamotrigine.

Spatiotemporal mapping of epileptic spikes using simultaneous EEG-functional MRI

Epileptic spikes occur on the sub-second timescale and are known to involve not only epileptic foci but also large-scale distributed brain networks. There is likely to be a sequence of neural activity in multiple brain regions that occurs within the duration of a single spike, but standard electroencephalography-functional magnetic resonance imaging analyses, which use only the timing of the spikes to model the functional magnetic resonance imaging data, cannot determine the sequence of these activations. Our aim in this study is to temporally resolve these spatial activations to observe the spatiotemporal dynamics of the spike-related neural activity at a sub-second timescale. We studied eight focal epilepsy patients (age 11-42 years, six female) and used amplitude features of the electroencephalogram specific to different spike components (early and late peaks and troughs) to encode temporal information into our functional magnetic resonance imaging models. This enables us to associate each activation with a specific model of each of the spike components to infer the temporal order of these spike-related spatial activations. In seven of eight patients the distributed networks were associated with the late spike component. The focal activations were more variably coupled with time epochs, but tended to precede the distributed network effects. We also found that incorporating electroencephalogram features into the models increased sensitivity and in six patients revealed additional regions unseen in the standard analysis result. This included strong bilateral thalamus activation in two patients. We demonstrate the clinical utility of this approach in a patient who recently underwent a successful surgical resection of the region where we saw enhanced activation using electroencephalogram amplitude information specific to the early spike component. This focal cluster of activation was larger and more precisely tracked the anatomy compared to what was seen using the standard timing-based analysis. Our novel electroencephalography-functional magnetic resonance imaging data fusion approach, which utilizes information based on the single spike variability across all electroencephalogram channels, has the potential to help us better understand epileptic networks and aid in the interpretation of functional magnetic resonance imaging activation maps during treatment planning.

The Contribution of Cognitive Networks to Depression in Epilepsy

This review poses the question: Does disruption to cognitive brain networks in epilepsy contribute to the problem of comorbid depression? Initial evidence suggests that the network disease that gives rise to seizures has a predilection for the same cognition-related networks that regulate mood, with comorbidity reflective of more extensive disease. Framing both epilepsy and its psychiatric comorbidities in terms of dysfunction in overlapping (cognitive) networks raises the possibility that depression can be a primary feature of the disease in some cases and facilitates an epilepsy classification system where behavioral features of the disorder are embedded in a neurobiological mechanism.

Behavioral disinhibition and antiepileptic treatment in childhood epilepsy: A retrospective cohort study

OBJECTIVE

To test whether specific classes of antiepileptic drugs increase the risk for behavioral disinhibition, a frequent complication of treatment of childhood epilepsy.

METHODS

In a sample of children with active epilepsy and antiepileptic drug (AED) treatment (n = 146, age 4-17 years), we performed a retrospective chart analysis of the occurrence of symptoms indicating reduced behavioral disinhibition following AED treatment. We used a risk-set approach to analyze whether the presence or recent addition of AED categories defined by their mechanism of action were associated with enhanced risk for behavioral disinhibition symptoms.

RESULTS

Mean duration of follow-up was 2,343 days (range 218-6,292, standard deviation [SD] 1,437). Episodes of behavioral disinhibition were reported in 51 (34.9%) children, with variable latencies between latest change and occurrence of behavioral disinhibition symptoms (mean 67 days, range 2-367). Current use of AEDs targeting gamma-aminobutyric acid (GABA) (odds ratio [OR] 1.8, 95% confidence interval [CI] 1.02-3.29, p = 0.04) and SV2A-mediated neurotransmitter release (SV2A)-mediated (2.0, 1.13-3.60, p = 0.02) neurotransmitter release was associated with increased risk for behavioral disinhibition. Restricting the analysis to the 90 days before behavioral disinhibition episode occurrence revealed that only addition of GABAergic AEDs (OR = 26.88, 95% CI = 6.71-107.76, p < 0.001) was associated with behavioral disinhibition. In contrast to our expectations, seizure control was reported to have improved parallel to most behavioral disinhibition episodes.

SIGNIFICANCE

This exploration of behavioral disinhibition in relation to antiepileptic drug treatment indicates that GABA potentiating drugs are specifically associated with behavioral problems during treatment of childhood epilepsy. Behavioral disinhibition episodes often occurred while seizure control improved, which may have reduced alertness for the consequences of AEDs on interictal symptoms. Our findings may be related to the increasing evidence for a role for excitatory actions of GABA in childhood epilepsy.

Comparison of ILAE 2010 and semiological seizure classification in children with epilepsy

OBJECTIVE

The aim of this study was to compare both ILAE 2010 and semiological seizure classification (SSC) in terms of their applicability and utility and to predict epileptogenic zone in children with epilepsy.

METHODS

Both ILAE 2010 classification and SSC which is a part of five dimensional classification were applied for a total 138 children by dividing into younger (≤6y/o) and older (>6y/o) age groups over the last two years as retrospectively. After the assessment of the seizures types, epilepsy syndromes, and etiologies; the data were also compared to evaluate if having correlation between epileptogenic zone and seizure subtypes in both ILAE 2010 and SSC.

RESULTS

ILAE 2010 indicated that 66.7% of the patients had focal seizures, 15.9% had generalized seizures, and 14.4% had seizures of unknown origin. The SSC revealed that the most frequent seizure type was simple seizures (56.5%), second frequent one was complex motor seizures (46.4%) and dialeptic seizures (39.9%). To predict epileptogenic zone, SSC was found to be more specific than ILAE in terms of the more subgroups of SSC were related to the more subgroups of epileptogenic zone (p<0.05). Furthermore, there was a clear correlation between focal foci and specific seizure types in older ages, while many foci caused to same seizure types and tend to no clear focal foci with generalized onset in younger ages. On the other hand, the relationship between epileptogenic zone and etiology was more remarkable in the five dimensional classification.

SIGNIFICANCE

Preference of seizure classification system is unique for each patient and depends on requirements. Therefore, one dimension cannot be sufficient for evaluation the nature of the seizures in some patients. Furthermore, age related evolution of the seizure types should not be ignored due to ongoing maturation state of the brain. ILAE 2010 and SSC have weak and strong points compared to each other. Semiological seizure classification is more informative in terms of identifying the epileptogenic zone which may be important in specific occasions like pre-surgical work up, while ILAE is simple and easier method which can be applied for seizure description and their characteristics in daily practice.

The new approach to classification of focal epilepsies: Epileptic discharge and disconnectivity in relation to cognition

The new classification of epilepsy stratifies the disease into an acute level, based on seizures, and an overarching chronic level of epileptic syndromes (Berg et al., 2010). In this new approach, seizures are considered either to originate and evolve in unilateral networks or to rapidly encompass both hemispheres. This concept extends the former vision of focal and generalized epilepsies to a genuine pathology of underlying networks. These key aspects of the new classification can be linked to the concept of cognitive curtailing in focal epilepsy. The present review will discuss the conceptual implications for acute and chronic cognitive deficits with special emphasis on transient and structural disconnectivity. Acute transient disruption of brain function is the hallmark of focal seizures. Beyond seizures, however, interictal epileptic discharges (IEDs) are increasingly recognized to interfere with physiological brain circuitry. Both concomitant EEG and high-precision neuropsychological testing are necessary to detect these subtle effects, which may concern task-specific or default-mode networks. More recent data suggest that longstanding IEDs may affect brain maturation and eventually be considered as a biomarker of pathological wiring. This brings us to the overarching level of chronic cognitive and behavioral comorbidity. We will discuss alterations in structural connectivity measured with diffusion-weighted imaging and tractography. Among focal epilepsies, much of our current insights are derived from temporal lobe epilepsy and its impact on neuropsychological and psychiatric functioning. Structural disconnectivity is maximal in the temporal lobe but also concerns widespread language circuitry. Eventually, pathological wiring may contribute to the clinical picture of cognitive dysfunction. We conclude with the extrapolation of these concepts to current research topics and to the necessity of establishing individual patient profiles of network pathology with EEG, high-precision neuropsychological testing, and state-of-the-art neuroimaging. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy".

The implications of the new approach to classification: Adults with an intellectual disability

The new ILAE classification offers the potential for clarity and improved translation of the understanding of the nature of epilepsy in people with an intellectual disability. This is particularly true in the use of the term genetic epilepsy and the removal of the term cryptogenic. However, the definition of the "dyscognitive" nature of seizures needs greater definition in those with coexistent cognitive impairment. This is of particular importance when ameliorating risk associated with impaired consciousness. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy".

New classification efforts in epilepsy: Opportunities for clinical neurosciences

Classification is truly a scientific endeavor. In recent years, the use of the term in clinical epilepsy has diverged from the purpose of the intellectual process of classification in the sciences. As genetics and molecular biology come into their own, scientific classification may finally come to epilepsy and begin to shed light on the many aspects of brain disorders that are characterized by seizures but which are truly multifaceted disorders and deserve more comprehensive, multidisciplinary approaches than they have received previously. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy".

Rethinking cognition and behavior in the new classification for childhood epilepsy: Examples from frontal lobe and temporal lobe epilepsies

The new approach to classification of the epilepsies emphasizes the role of dysfunction in networks in defining types of epilepsies. This paper reviews the structural and neuropsychological deficits in two types of childhood epilepsy: frontal lobe and temporal lobe epilepsy. The evidence for and against a pattern of specificity of deficits in executive function and memory associated with these two types of epilepsies is presented. The evidence varies with the methodologies used in the studies, but direct comparison of the two types of epilepsies does not suggest a clear-cut mapping of function onto structure. These findings are discussed in light of the concept of network dysfunction. The evidence supports the conceptualization of epilepsy as a network disease. Implications for future work in the neuropsychology of pediatric epilepsy are suggested. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy".

The new approach to epilepsy classification: Cognition and behavior in adult epilepsy syndromes

The revised terminology and concepts for the organization of seizures and epilepsy proposed by the ILAE Commission on Classification and Terminology in 2010 allows for a number of new opportunities in the study of cognition and behavior in adults. This review examines the literature that has looked for behavioral and cognitive correlates of the newly recognized genetic epilepsies in adults. While some studies report clear cognitive phenotypes associated with specific genetic mutations in adults with epilepsy, others report remarkable clinical heterogeneity. In the second part of this review, we discuss some of the factors that may influence the findings in this literature. Cognitive function is the product of both genetic and environmental influences. Neuropsychological phenotypes under direct genetic influence may be wider and more subtle than specific deficits within discreet cognitive domains and may be reflected in broader, multidimensional measures of cognitive function than those tapped by scores on standardized tests of function. Future studies must be carefully designed to reflect these factors. It is also imperative that studies with negative findings are assigned as much value as those with positive results and published accordingly. This article is part of a Special Issue titled "The new approach to classification: Rethinking cognition and behavior in epilepsy.

Reprint of: The new approach to epilepsy classification: Cognition and behavior in adult epilepsy syndromes

The revised terminology and concepts for the organization of seizures and epilepsy proposed by the ILAE Commission on Classification and Terminology in 2010 allows for a number of new opportunities in the study of cognition and behavior in adults. This review examines the literature that has looked for behavioral and cognitive correlates of the newly recognized genetic epilepsies in adults. While some studies report clear cognitive phenotypes associated with specific genetic mutations in adults with epilepsy, others report remarkable clinical heterogeneity. In the second part of this review, we discuss some of the factors that may influence the findings in this literature. Cognitive function is the product of both genetic and environmental influences. Neuropsychological phenotypes under direct genetic influence may be wider and more subtle than specific deficits within discreet cognitive domains and may be reflected in broader, multidimensional measures of cognitive function than those tapped by scores on standardized tests of function. Future studies must be carefully designed to reflect these factors. It is also imperative that studies with negative findings are assigned as much value as those with positive results and published accordingly. This article is part of a Special Issue titled "The new approach to classification: Rethinking cognition and behavior in epilepsy".

Two distinct symptom-based phenotypes of depression in epilepsy yield specific clinical and etiological insights

Depression is common but underdiagnosed in epilepsy. A quarter of patients meet criteria for a depressive disorder, yet few receive active treatment. We hypothesize that the presentation of depression is less recognizable in epilepsy because the symptoms are heterogeneous and often incorrectly attributed to the secondary effects of seizures or medication. Extending the ILAE's new phenomenological approach to classification of the epilepsies to include psychiatric comorbidity, we use data-driven profiling of the symptoms of depression to perform a preliminary investigation of whether there is a distinctive symptom-based phenotype of depression in epilepsy that could facilitate its recognition in the neurology clinic. The psychiatric and neuropsychological functioning of 91 patients with focal epilepsy was compared with that of 77 healthy controls (N=168). Cluster analysis of current depressive symptoms identified three clusters: one comprising nondepressed patients and two symptom-based phenotypes of depression. The 'Cognitive' phenotype (base rate=17%) was characterized by symptoms taking the form of self-critical cognitions and dysphoria and was accompanied by pervasive memory deficits. The 'Somatic' phenotype (7%) was characterized by vegetative depressive symptoms and anhedonia and was accompanied by greater anxiety. It is hoped that identification of the features of these two phenotypes will ultimately facilitate improved detection and diagnosis of depression in patients with epilepsy and thereby lead to appropriate and timely treatment, to the benefit of patient wellbeing and the potential efficacy of treatment of the seizure disorder. This article is part of a Special Issue entitled "The new approach to classification: Rethinking cognition and behavior in epilepsy".

How neuropsychology can improve the care of individual patients with epilepsy. Looking back and into the future

Some of the roots of current clinical neuropsychology go back to the early days of epilepsy surgery. Looking back a huge number of publications have dealt with cognition in epilepsy. The major factors driving this work were questions relating to surgery, antiepileptic drugs and, more recently, also to underlying pathology. However, most factors affecting cognition in epilepsy have been discerned many years ago. The body of neuropsychological literature in this field has accumulated much knowledge, raising the question why, apart from epilepsy surgery settings, neuropsychology has still not been fully integrated in the routine care of patients with epilepsy. This review on the occasion of Seizure's 25th anniversary attempts to summarize clinically relevant diagnostic advances following a question guided, modular, and evidence-based approach. In doing so, we hope to attract the interest of readers to an exciting mode of assessment which does not only have theoretical but also practical relevance. The comorbidities of epilepsy are becoming an increasingly relevant topic. It is now widely accepted that, while epilepsy may be defined by the occurrence of epileptic seizures, these seizures represent only one of several possible sources of cognitive impairment. It is well-established that there are complex interactions between epilepsy, cognition and behavior, and that both seizures and problems with cognition or behavior may result from a common underlying pathology requiring treatment. With this review we aim to demonstrate that neuropsychology can make a highly valuable contribution to the care of individual patients by contributing to the diagnostic process and by serving as a tool for the monitoring of disease and treatment, thereby improving the quality and safety of patient care. On a national, European, and international level, first efforts are being made to homogenize diagnostics across epilepsy centers and countries in order to achieve a common language and core standards. This should improve communication within and outside the speciality, and help to generate the data required to allow the field to make further progress.

Mechanisms of memory impairment in epilepsy depend on age at disease onset

OBJECTIVE

In this study, we aimed to uncover distinct antecedents of autobiographic memory dysfunction in patients with epilepsy with early (childhood/adolescence) vs late (adulthood) disease onset.

METHODS

One hundred sixty-six adults participated: 92 patients with focal epilepsy, whose cognitive and psychiatric functioning were compared to that of 74 healthy controls. Predictors of autobiographic memory deficit were contrasted between patients with early-onset (n = 47) vs late-onset (n = 45) epilepsy.

RESULTS

Overall, people with epilepsy performed significantly worse on measures of both semantic and episodic autobiographic memory and showed markedly high rates of depressive symptoms and disorders (p < 0.001). Reduced autobiographic memory in patients with early-onset epilepsy was associated with young age at onset, more frequent seizures, and reduced working memory. In contrast, the difficulty that patients with late-onset epilepsy had in recalling autobiographic information was linked to depression and the presence of an MRI-identified lesion.

CONCLUSIONS

This study reveals that memory deficits in people with focal epilepsy have differing antecedents depending on the timing of the disease onset. While neurobiological factors strongly underpin reduced autobiographic function in patients with early-onset epilepsy, psychological maladjustment gives rise to the impairments seen in patients with late-onset epilepsy. More broadly, these findings support the practice of subtyping patients according to distinct clinical characteristics to find individualized predictors of cognitive dysfunction.

A pharmacological basis of herbal medicines for epilepsy

Epilepsy is the most common chronic neurological disease, affecting about 1% of the world's population during their lifetime. Most people with epilepsy can attain a seizure-free life upon treatment with antiepileptic drugs (AEDs). Unfortunately, seizures in up to 30% do not respond to treatment. It is estimated that 90% of people with epilepsy live in developing countries, and most of them receive no drug treatment for the disease. This treatment gap has motivated investigations into the effects of plants that have been used by traditional healers all over the world to treat seizures. Extracts of hundreds of plants have been shown to exhibit anticonvulsant activity in phenotypic screens performed in experimental animals. Some of those extracts appear to exhibit anticonvulsant efficacy similar to that of synthetic AEDs. Dozens of plant-derived chemical compounds have similarly been shown to act as anticonvulsants in various in vivo and in vitro assays. To a significant degree, anticonvulsant effects of plant extracts can be attributed to widely distributed flavonoids, (furano)coumarins, phenylpropanoids, and terpenoids. Flavonoids and coumarins have been shown to interact with the benzodiazepine site of the GABAA receptor and various voltage-gated ion channels, which are targets of synthetic AEDs. Modulation of the activity of ligand-gated and voltage-gated ion channels provides an explanatory basis of the anticonvulsant effects of plant secondary metabolites. Many complex extracts and single plant-derived compounds exhibit antiinflammatory, neuroprotective, and cognition-enhancing activities that may be beneficial in the treatment of epilepsy. Thus, botanicals provide a base for target-oriented antiepileptic drug discovery and development. In the future, preclinical work should focus on the characterization of the effects of plant extracts and plant-derived compounds on well-defined targets rather than on phenotypic screening using in vivo animal models of acute seizures. At the same time, available data provide ample justification for clinical studies with selected standardized botanical extracts and plant-derived compounds. This article is part of a Special Issue entitled "Botanicals for Epilepsy".

Indications and expectations for neuropsychological assessment in routine epilepsy care: Report of the ILAE Neuropsychology Task Force, Diagnostic Methods Commission, 2013-2017

The International League Against Epilepsy (ILAE) Diagnostic Methods Commission charged the Neuropsychology Task Force with the job of developing a set of recommendations to address the following questions: (1) What is the role of a neuropsychological assessment? (2) Who should do a neuropsychological assessment? (3) When should people with epilepsy be referred for a neuropsychological assessment? and (4) What should be expected from a neuropsychological assessment? The recommendations have been broadly written for health care clinicians in established epilepsy settings as well as those setting up new services. They are based on a detailed survey of neuropsychological assessment practices across international epilepsy centers, and formal ranking of specific recommendations for advancing clinical epilepsy care generated by specialist epilepsy neuropsychologists from around the world. They also incorporate the latest research findings to establish minimum standards for training and practice, reflecting the many roles of neuropsychological assessment in the routine care of children and adults with epilepsy. The recommendations endorse routine screening of cognition, mood, and behavior in new-onset epilepsy, and describe the range of situations when more detailed, formal neuropsychological assessment is indicated. They identify a core set of cognitive and psychological domains that should be assessed to provide an objective account of an individual's cognitive, emotional, and psychosocial functioning, including factors likely contributing to deficits identified on qualitative and quantitative examination. The recommendations also endorse routine provision of feedback to patients, families, and clinicians about the implications of the assessment results, including specific clinical recommendations of what can be done to improve a patient's cognitive or psychosocial functioning and alleviate the distress of any difficulties identified. By canvassing the breadth and depth of scope of neuropsychological assessment, this report demonstrates the pivotal role played by this noninvasive and minimally resource intensive investigation in the care of people with epilepsy.