Neurocognitive and behavioral functioning in frontal lobe epilepsy: a review

Theory of mind in epilepsy

Epilepsy is characterized by recurrent, chronic, and unprovoked seizures. Epilepsy has a significant negative impact on a patient's quality of life even if seizures are well controlled. In addition to the distress caused by seizures, patients with epilepsy (PwE) may suffer from cognitive impairment with serious social consequences such as poor interpersonal relationships, loss of employment, and reduced social networks. Pathological changes and functional connectivity abnormalities observed in PwE can disrupt the neural network responsible for the theory of mind. Theory of mind is the ability to attribute mental states to other people (intentions, beliefs, and emotions). It is a complex aspect of social cognition and includes cognitive and affective constructs. In recent years, numerous studies have assessed the relationship between social cognition, including the theory of mind, in PwE, and suggested impairment in this domain. Interventions targeting the theory of mind can be potentially helpful in improving the quality of life of PwE.

Overlapping and distinct phenotypic profiles in Alzheimer's disease and late onset epilepsy: a biologically-based approach

Due to shared hippocampal dysfunction, patients with Alzheimer's dementia and late-onset epilepsy (LOE) report memory decline. Multiple studies have described the epidemiological, pathological, neurophysiological, and behavioral overlap between Alzheimer's Disease and LOE, implying a bi-directional relationship. We describe the neurobiological decline occurring at different spatial in AD and LOE patients, which may explain why their phenotypes overlap and differ. We provide suggestions for clinical recognition of dual presentation and novel approaches for behavioral testing that reflect an "inside-out," or biologically-based approach to testing memory. New memory and language assessments could detect-and treat-memory impairment in AD and LOE at an earlier, actionable stage.

Frontal lobe epilepsy: an eye tracking study of memory and attention

Objective

To explore the characteristics and mechanisms of working memory impairment in patients with frontal lobe epilepsy (FLE) through a memory game paradigm combined with eye tracking technology.

Method

We included 44 patients with FLE and 50 healthy controls (HC). All participants completed a series of neuropsychological scale assessments and a short-term memory game on an automated computer-based memory evaluation platform with an eye tracker.

Results

Memory scale scores of FLE patients including digit span (U = 747.50, p = 0.007), visual recognition (U = 766.50, p = 0.010), and logical memory (U = 544.00, p < 0.001) were significantly lower than HC. The patients with FLE took longer to complete the four levels of difficulty of the short-term memory game than healthy controls (level 1: U = 2974.50, p = 0.000; level 2: U = 3060.50, p = 0.000; level 3: U = 2465.00, p = 0.000; level 4: U = 2199.00, p = 0.000). During the memory decoding period, first fixation on the targets took significantly longer for FLE patients for all difficulty levels compared to controls (level 1: U = 3407.00, p = 0.008; level 2: U = 3618.00, p = 0.036; level 3: U = 3345.00, p = 0.006; level 4: U = 2781.00, p = 0.000). The average fixation duration per target among patients with FLE was found to be significantly longer compared to HC (level 1: U = 2994.50, p = 0.000; level 2: U = 3101.00, p = 0.000; level 3: U = 2559.50, p = 0.000; level 4: U = 2184.50, p = 0.000). The total fixation duration on AOI/total completion time of FLE patients was significantly lower than those of HC for levels 1 to 3 (level 1: U = 1557.00, p = 0.000; level 2: U = 2333.00, p = 0.000; level 3: U = 2757.00, p = 0.000). Furthermore, the eye tracking data during the memory decoding phase were correlated with neuropsychological scale scores (p < 0.05).

Conclusion

Patients with FLE exhibited short-term memory impairment probably due to deficits in attentional maintenance, especially during the memory decoding phase. Eye tracking technology provided the possibility to help separate and quantify visual attention from memory processing, contributing to exploring underlying mechanisms of memory impairment in FLE.

Application of the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) to frontal lobe epilepsy using multicenter data

RATIONALE

The International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) was recently introduced as a consensus-based, empirically-driven taxonomy of cognitive disorders in epilepsy and has been effectively applied to patients with temporal lobe epilepsy (TLE). The purpose of this study was to apply the IC-CoDE to patients with frontal lobe epilepsy (FLE) using national multicenter data.

METHODS

Neuropsychological data of 455 patients with FLE aged 16 years or older were available across four US-based sites. First, we examined test-specific impairment rates across sites using two impairment thresholds (1.0 and 1.5 standard deviations below the normative mean). Following the proposed IC-CoDE guidelines, patterns of domain impairment were determined based on commonly used tests within five cognitive domains (language, memory, executive functioning, attention/processing speed, and visuospatial ability) to construct phenotypes. Impairment rates and distributions across phenotypes were then compared with those found in patients with TLE for which the IC-CoDE classification was initially validated.

RESULTS

The highest rates of impairment were found among tests of naming, verbal fluency, speeded sequencing and set-shifting, and complex figure copy. The following IC-CoDE phenotype distributions were observed using the two different threshold cutoffs: 23-40% cognitively intact, 24-29% single domain impairment, 13-20% bi-domain impairment, and 18-33% generalized impairment. Language was the most common single domain impairment (68% for both thresholds) followed by attention and processing speed (15-18%). Overall, patients with FLE reported higher rates of cognitive impairment compared with patients with TLE.

CONCLUSIONS

These results demonstrate the applicability of the IC-CoDE to epilepsy syndromes outside of TLE. Findings indicated generally stable and reproducible phenotypes across multiple epilepsy centers in the U.S. with diverse sample characteristics and varied neuropsychological test batteries. Findings also highlight opportunities for further refinement of the IC-CoDE guidelines as the application expands.

Ameliorative effects of Albizia adianthifolia aqueous extract against pentylenetetrazole-induced epilepsy and associated memory loss in mice: Role of GABAergic, antioxidant defense and anti-inflammatory systems

Albizia adianthifolia (Schumach.) (Fabaceae) is a medicinal herb used for the treatment of epilepsy and memory impairment. This study aims to investigate the anticonvulsant effects of Albizia adianthifolia aqueous extract against pentylenetetrazole (PTZ)-induced spontaneous convulsions in mice; and determine whether the extract could mitigate memory impairment, oxidative/nitrergic stress, GABA depletion and neuroinflammation. Ultra-high performance liquid chromatography/mass spectrometry analysis was done to identify active compounds from the extract. Mice were injected with PTZ once every 48 h until kindling was developed. Animals received distilled water for the normal group and negative control groups, doses of extract (40, 80, or 160 mg/kg) for the test groups and sodium valproate (300 mg/kg) for the positive control group. Memory was measured using Y maze, novel object recognition (NOR) and open field paradigms, while the oxidative/nitrosative stresses (MDA, GSH, CAT, SOD and NO), GABAergic transmission (GABA, GABA-T and GAD) and neuro-inflammation (TNF-α, IFN-γ, IL- 1β, and IL-6) were determined. Brain photomicrograph was also studied. Apigenin, murrayanine and safranal were identified in the extract. The extract (80-160 mg/kg) significantly protected mice against seizures and mortality induced by PTZ. The extract significantly increased the spontaneous alternation and the discrimination index in the Y maze and NOR tests, respectively. PTZ kindling induced oxidative/nitrosative stress, GABA depletion, neuroinflammation and neuronal cells death was strongly reversed by the extract. The results suggest that the anticonvulsant activity of Albizia adianthifolia extract is accompanied by its anti-amnesic property, and may be supported by the amelioration of oxidative stress, GABAergic transmission and neuroinflammation.

Arousal deregulation in the co-shaping of neuropsychological dysfunction in frontal and mesial temporal lobe epilepsy

OBJECTIVE

Our work aims to investigate the role of physiological arousal in the expression of neuropsychological deficits in frontal lobe epilepsy (FLE) and mesial temporal lobe epilepsy (mTLE), by drawing on the Lurian theory of brain function.

METHODS

For this study a total of 43 patients with focal onset epilepsy has been taken; twenty-four patients with FLE, 19 patients with mTLE and 26 healthy controls, all matched for age and education. Participants underwent a comprehensive neuropsychological assessment including various cognitive domains, such as attention, episodic memory, speed of information processing, response inhibition and mental flexibility, working memory, verbal fluency (phonological & semantic).

RESULTS

There were no significant differences between FLE and mTLE patients in terms of neuropsychological performance. However, both FLE and mTLE patients showed significantly worse performance in several cognitive domains than HCs. The results seem to support our hypothesis that aberrant physiological arousal, as reflected in patients' worse performance in vigilance and attention, response inhibition, and processing speed, along with other disease-specific variables, may co-determine neuropsychological dysfunction and/or impairment in both FLE and mTLE.

CONCLUSION

Identifying a differential arousal-related neuropsychological affection in FLE and mTLE, among the known deleterious effects of the functional deficit zone and other disease-related variables, may further our understanding of the underlying cognitive-pathophysiological mechanisms in focal epilepsy syndromes.

Hemodynamic correlates of emotion regulation in frontal lobe epilepsy patients and healthy participants

The ability to regulate emotions is indispensable for maintaining psychological health. It heavily relies on frontal lobe functions which are disrupted in frontal lobe epilepsy. Accordingly, emotional dysregulation and use of maladaptive emotion regulation strategies have been reported in frontal lobe epilepsy patients. Therefore, it is of clinical and scientific interest to investigate emotion regulation in frontal lobe epilepsy. We studied neural correlates of upregulating and downregulating emotions toward aversive pictures through reappraisal in 18 frontal lobe epilepsy patients and 17 healthy controls using functional magnetic resonance imaging. Patients tended to report more difficulties with impulse control than controls. On the neural level, patients had diminished activity during upregulation in distributed left-sided regions, including ventrolateral and dorsomedial prefrontal cortex, angular gyrus and anterior temporal gyrus. Patients also showed less activity than controls in the left precuneus for upregulation compared to downregulation. Unlike controls, they displayed no task-related activity changes in the left amygdala, whereas the right amygdala showed task-related modulations in both groups. Upregulation-related activity changes in the left inferior frontal gyrus, insula, orbitofrontal cortex, anterior and posterior cingulate cortex, and precuneus were correlated with questionnaire data on habitual emotion regulation. Our results show that structural or functional impairments in the frontal lobes disrupt neural mechanisms underlying emotion regulation through reappraisal throughout the brain, including posterior regions involved in semantic control. Findings on the amygdala as a major target of emotion regulation are in line with the view that specifically the left amygdala is connected with semantic processing networks.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Cognitive phenotypes in frontal lobe epilepsy

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.

Disorganization of language and working memory systems in frontal versus temporal lobe epilepsy

Cognitive impairment is a common comorbidity of epilepsy and adversely impacts people with both frontal lobe (FLE) and temporal lobe (TLE) epilepsy. While its neural substrates have been investigated extensively in TLE, functional imaging studies in FLE are scarce. In this study, we profiled the neural processes underlying cognitive impairment in FLE and directly compared FLE and TLE to establish commonalities and differences. We investigated 172 adult participants (56 with FLE, 64 with TLE and 52 controls) using neuropsychological tests and four functional MRI tasks probing expressive language (verbal fluency, verb generation) and working memory (verbal and visuo-spatial). Patient groups were comparable in disease duration and anti-seizure medication load. We devised a multiscale approach to map brain activation and deactivation during cognition and track reorganization in FLE and TLE. Voxel-based analyses were complemented with profiling of task effects across established motifs of functional brain organization: (i) canonical resting-state functional systems; and (ii) the principal functional connectivity gradient, which encodes a continuous transition of regional connectivity profiles, anchoring lower-level sensory and transmodal brain areas at the opposite ends of a spectrum. We show that cognitive impairment in FLE is associated with reduced activation across attentional and executive systems, as well as reduced deactivation of the default mode system, indicative of a large-scale disorganization of task-related recruitment. The imaging signatures of dysfunction in FLE are broadly similar to those in TLE, but some patterns are syndrome-specific: altered default-mode deactivation is more prominent in FLE, while impaired recruitment of posterior language areas during a task with semantic demands is more marked in TLE. Functional abnormalities in FLE and TLE appear overall modulated by disease load. On balance, our study elucidates neural processes underlying language and working memory impairment in FLE, identifies shared and syndrome-specific alterations in the two most common focal epilepsies and sheds light on system behaviour that may be amenable to future remediation strategies.

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.

Postoperative improvement of executive function and adaptive behavior in children with intractable epilepsy

INTRODUCTION

An alteration in postoperative cognitive function varies according to the patients' background characteristics, such as etiology, focus, and seizure duration. Accurate prediction and assessment of postoperative cognitive function is difficult in each patient. Adaptive behavior could describe the typical performance of daily activities and represents the ability to translate cognitive potential into real-world skills. We examined the relationship between alterations of executive function (EF) and adaptive behavior in school children undergoing surgery for intractable epilepsy.

METHODOLOGY

We enrolled 31 children with focal resection or corpus callosotomy for intractable epilepsy [mean age at surgery, 12.5 years; 16 boys; mean intellectual quotient, 73.3]. We surveyed answered questionnaires on attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and adaptive behavior using the Vineland Adaptive Behavior Scale, 2nd edition (VABS-II), and performed continuous performance tests (CPTs) on children pre- and postoperatively.

RESULT

ADHD and ASD symptoms improved after epilepsy surgery. The omission error (OE) in the CPT variable improved after epilepsy surgery, especially in children with a shorter preoperative period. Improved ASD symptoms led to an increased score of the coping skills subdomain. The reduced OE observed after surgery also increased the score of the community skills subdomain.

CONCLUSION

Improvement in EF and ASD symptoms resulted in better adaptive behavior postoperatively. These results were important for the pre- and postoperative evaluation and re-evaluation of children with epilepsy requiring special education and related services.

Association between lack of functional connectivity of the frontal brain region and poor response inhibition in children with frontal lobe epilepsy

PURPOSE

We investigated the relationship between electroencephalographic (EEG) functional connectivity and executive function in children with frontal lobe epilepsy (FLE).

METHODS

We enrolled 24 children with FLE (mean age, 11.0 years; 13 boys) and 22 sex-, age-, and intelligence-matched typically developing children (TDC) to undergo 19-channel EEG during light sleep. We estimated functional connectivity using the phase lag index (PLI) that captures the synchronization of EEG. We also performed continuous performance tests (CPTs) on the children and obtained questionnaire responses on attention deficit hyperactivity disorder and oppositional defiant disorder (ODD).

RESULTS

The average gamma PLI was lower in the FLE group than in the TDC group, especially between long-distance frontoparietal pairs, between interhemispheric frontal pairs, and between interhemispheric parietotemporal pairs. Gamma PLIs with long-distance frontoparietal and interhemispheric frontal pairs were positively associated with inattention, ODD scores, omission error, and reaction time in the FLE group but not in the TDC group. Conversely, they were negatively associated with age, hyperactivity score, and commission error.

CONCLUSIONS

A lack of functional connectivity of the frontal brain regions in children with FLE was associated with poor response inhibition.

Altered White Matter Structural Network in Frontal and Temporal Lobe Epilepsy: A Graph-Theoretical Study

Temporal lobe epilepsy (TLE) and frontal lobe epilepsy (FLE) are the largest subgroup of partial epilepsy, and focal cortical dysplasias (FCDs) are highly epileptogenic brain lesions and are a frequent cause for antiepileptic drug (AED)-resistant focal epilepsies that mostly occur in the temporal and frontal lobes. We performed a graph-theoretical study based on the diffusion tensor imaging (DTI) data of patients with FLE or TLE caused by FCDs or lesions with high suspicion of FCDs and evaluated their cognitive function by the Chinese version of the Montreal Cognitive Assessment-Basic (MoCA-BC). The construction of the white matter structural network and graph-theoretical analysis was performed by Pipeline for Analysing Brain Diffusion Images (PANDA) and Graph-theoretical Network Analysis (GRETNA). We used the nonparametric analysis of covariance to compare the differences in diffusion metrics, network attributes and nodal attributes among FLE, TLE, and healthy control (HC) groups and then performed post hoc pairwise comparisons. Nonparametric Spearman partial correlation analysis was performed to analyse the correlation of network attributes with the age of onset, duration of disease, and MoCA-BC scores in patients with FLE and TLE. The results showed that the white matter structural network in patients with FLE and TLE was impaired in a more extensive set of regions than the FCD location. The similarities in white matter alterations between FLE and TLE suggested that their epileptogenic network might affect the fronto-temporal white matter tracts and thalamo-occipital connections, which might be responsible for the overlapping cognitive deficits in FLE and TLE. The white matter impairments in patients with FLE were more severe than those in patients with TLE, which might be explained by more affected nodes in the areas of DMN in patients with FLE.

Depression could modulate neuropsychological status in epilepsy

While cognition and depression have often been studied in patients with epilepsy, only a few studies have so far attempted to link these two domains, and more specifically to investigate the specific impact of depression on cognition in epilepsy. In this review, we performed an extensive search of the literature database to provide a better understanding of this subject. Using several inclusion criteria (adult population, quantitative depression/neuropsychological assessment, statistical analyses of the impact of depression on cognitive scores, patients with epilepsy (PWE) and no other neurological disease, and studies including at least 20 patients), we identified 20 articles (out of 712 search results) that investigated both depression and cognition in PWE. Their results were summarized using a narrative and descriptive approach. This review highlights a variable impact of depression on cognition in PWE, depending on the laterality of the seizure onset zone, the type of epilepsy and the surgical context. We emphasize the need for a systematic depression assessment in these patients, especially since depressed PWE will benefit from prompt and appropriate care to help them avoid cognitive decline, particularly in a surgical context.

Neuroimaging of memory in frontal lobe epilepsy

In a large percentage of epilepsies, seizures have focal onset. These epilepsies are associated with a wide range of behavioral and cognitive deficits sometimes limited to the functions encompassed within the ictal onset zone but, more frequently, expanding beyond it. The presence of impairments associated with neuroanatomical areas outside of the ictal onset zone suggests distal propagation of epileptic activity via brain networks and interconnected whole-brain neural circuitry. In patients with frontal lobe epilepsy (FLE), using functional magnetic resonance imaging (fMRI) to identify deficits in working, semantic, and episodic memory may provide a lens through which to understand typical and atypical network organization. A network approach to focal epilepsy is relevant in these patients because of the frequently noted early age of seizure onset. Early seizure-related disruption in healthy brain development may result in a significant brain reorganization, development of compensation-related mechanisms of dealing with function abnormalities and disruptions, and the propagation of epileptic activity from the focus to widespread brain areas (functional deficit zones). Benefits of a network approach in the study of focal epilepsy are discussed along with considerations for future neuroimaging studies of patients with FLE.

Assessing various sensorimotor and cognitive functions in people with epilepsy is feasible with robotics

BACKGROUND

Epilepsy is a common neurological disorder characterized by recurrent seizures, along with comorbid cognitive and psychosocial impairment. Current gold standards of assessment can quantify cognitive and motor performance, but may not capture all subtleties of behavior. Here, we study the feasibility of assessing various upper limb sensorimotor and cognition functions in people with epilepsy using the Kinarm robotic assessment system. We quantify performance across multiple behavioral domains and additionally consider the possible effects of epilepsy subtype and medication.

METHODS

We recruited individuals with a variety of epilepsy subtypes. Participants performed 8 behavioral tasks that tested motor, cognitive, and sensory domains. We collected data on the same tasks from a group of control participants that had no known neurological impairments. We quantified performance using Task Scores, which provide a composite measure of overall performance on a given task and are adjusted for age, sex, and handedness.

RESULTS

We collected data from 46 individuals with epilepsy and 92 control participants. The assessment was well-tolerated, with no adverse events recorded. Cognitive tasks testing spatial working memory, executive function, and motor response inhibition were the most frequently impaired in the epilepsy cohort, with 33/46 (72%) being outside the normal range on at least one of these tasks. Additionally, 29/46 (63%) were impaired on at least one task testing primarily motor skill, and 14/46 (30%) were impaired on a proprioceptive sensory task. People with either focal epilepsy or generalized epilepsy performed significantly worse on both motor and cognitive tasks than control participants after correcting for multiple comparisons. There were no statistical differences between generalized and focal epilepsy groups on Task Scores. Finally, individuals taking topiramate trended toward having worse performance on a spatial working memory task than other individuals with epilepsy who were not taking topiramate.

CONCLUSIONS

Kinarm robotic assessment is feasible in individuals with epilepsy and is well-tolerated. Our robotic paradigm can detect impairments in various sensorimotor and cognitive functions across the population with epilepsy. Future studies will explore the role of epilepsy subtype and medications.

Pre- and postoperative verbal memory and executive functioning in frontal versus temporal lobe epilepsy

There is accumulating evidence for considerable overlap in preoperatively affected cognitive functions in patients with temporal lobe epilepsy (TLE) and frontal lobe epilepsy (FLE). The current study investigated whether it is possible to differentiate between patients with FLE and TLE prior to surgery, based on measures of verbal memory and executive functioning. Furthermore, the postoperative cognitive development was compared. Pre- and postoperative data from 109 patients with FLE and 194 patients with TLE were retrospectively analyzed. Preoperatively, there were no differences in verbal memory, and postoperatively, no distinctive cognitive change was found between patients with FLE and TLE. However, patients with FLE performed worse on a cognitive switching task. Notably, irrespective of localization, patients with a presumed epileptogenic area in the language-dominant hemisphere performed worse than patients with seizures that originated in the nonlanguage-dominant hemisphere on measures of verbal memory, both pre- and postoperatively. In sum, the results suggest that verbal memory scores may be less valuable for differentiation between TLE and FLE, while measures of executive functioning may help identify patients with FLE. Additionally, rather than the localization, epilepsy lateralization critically impacts the evaluation of verbal memory functioning in both TLE and FLE. The results are discussed in light of the current frameworks of functional disturbances in epileptic networks.

Are frontal and temporal lobe epilepsy dissociable in their memory functioning?

There is controversy in the literature as to how dissociable frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE) are in terms of memory deficits. Some researchers have demonstrated that FLE is associated with greater executive dysfunction including working memory, whereas TLE is associated with greater memory impairment. Others have found the two groups to be comparable in memory functioning. Hence, we examined this question in children with FLE and TLE versus typically developing controls. We found most of the expected effects when the groups with focal onset epilepsy were compared to controls. Specifically, children with left TLE performed worse on verbal short-term memory/learning and long-term memory measures. In contrast, children with right TLE exhibited a more global pattern of difficulty on short-term memory/learning measures but performed worse than controls on long-term memory for faces. Children with FLE performed worse than controls on verbal working memory. Nevertheless, laterality effects were mild, as children with right and left TLE did not differ significantly from each other. Further, children with FLE did not differ from those with TLE on most measures except delayed facial recognition, where children with right TLE performed worse. In addition, attention problems and poor behavioral regulation were related to encoding problems in both the total epilepsy sample and in children with TLE specifically. Hence, our findings overall are consistent with prior studies indicating that children with TLE and FLE are commensurate in most aspects of memory impairment when compared to each other, likely related to rapid propagation between the frontal and temporal lobes, as would be expected with an excitatory lesion.

Impact of epilepsy duration, seizure control and EEG abnormalities on cognitive impairment in drug-resistant epilepsy patients

Cognitive impairment frequently occurs in epilepsy patients. Patients with drug-resistant epilepsy (DRE) have poor drug responsivity and higher seizure frequency which consequently lead to brain damage and may have implications on cognitive status. In the present study, we assessed a frequency and degree of cognitive impairment in 52 patients with drug-sensitive epilepsy (DSE) and 103 DRE patients at three time points (baseline, after 12 and 18 months). Degree of cognitive decline was assessed with Montreal Cognitive Assessment (MoCA) scale. We examined the possible correlation between demographic and clinical characteristics and cognitive deterioration in epilepsy patients. Patients in the DRE group had significantly lower MoCA score than patients in the DSE group at baseline (28.83 ± 2.05 vs. 29.69 ± 0.61, p = 0.003), after 12 months (27.36 ± 2.40 vs. 29.58 ± 1.22, p = 0.000) and 18 months (26.86 ± 2.73 vs. 29.33 ± 1.47, p = 0.000). Patients with DRF epilepsy had significantly lower MoCA score than patients with DSF epilepsy at three time points (28.71 ± 2.48 vs. 29.86 ± 0.35, p = 0.015; 27.22 ± 2.72 vs. 29.52 ± 1.37, p = 0.000; 26.80 ± 2.99 vs. 29.31 ± 1.56, p = 0.000). After 12 and 18 months of follow-up, patients with DRG epilepsy had significantly lower MoCA score than patients with DSG epilepsy (27.52 ± 2.01 vs. 29.65 ± 1.02, p = 0.000; 26.94 ± 2.43 vs. 29.35 ± 1.40, p = 0.000). Illness duration negatively correlated with cognitive status (p = 0.005); seizure control and EEG findings positively correlated with MoCA score (p = 0.000). Illness duration, seizure control, drug responsivity, and EEG findings are significant predictors of MoCA score (p < 0.05). Clinicians have to pay attention to patients with drug-resistant epilepsy and concepts of aggressive treatment to minimize the adverse effects of epilepsy on cognition.

The burden of parenting children with frontal lobe epilepsy

OBJECTIVE

Caring for a child with a chronic illness adds stress to the typical parenting stress in healthy developing children. This stress can place a heavy burden on parents and may increase when a child displays problem behavior. In general, parenting and child's behavior problems are associated. Furthermore, externalizing (more outgoing) behavior is reported frequently in children with frontal lobe epilepsy (FLE). Therefore, in this study, we first investigated the burden of parents of children with FLE, and second, we investigated the relation between the experienced burden and reported behavioral problems. The validity of parents' reports on proxy measures as well as duration of epilepsy is taken into account.

METHODS

Thirty-one parents of children with FLE completed validated questionnaires about behavioral problems and burden of parenting. To examine if parents tend to be inconsistent or unusually negative, we used the two validity scales of the Behavioral Rating Inventory of Executive Function (BRIEF) (Negativity and Inconsistency).

RESULTS

Only parents of children with FLE who have had epilepsy for 5 years or longer report more problems on the Nijmeegse Vragenlijst voor de Opvoedingssituatie (NVOS) subscales 'Able to manage', 'Child is a burden', and 'Good Interaction' compared with the healthy controls. The subscale 'Child is a burden' significantly predicts scores in about 20% to 49% on the main scales of the Child Behavior Checklist (CBCL), the Global Executive Composite (GEC), and Behavioral Regulation Index (BRI) of the BRIEF. Only 6% of parents scored in the clinical range of the negativity scale of the BRIEF. For the inconsistency scale, this was 45%.

CONCLUSION

Parents of children with FLE do not report excessive parental burden. Longer duration of epilepsy might be a risk factor in experiencing burden. The findings suggest a link between parental burden and behavioral problems in children with FLE. Externalizing behavioral problems are the most marked behavioral problems, which relate to the parental burden. Parents tend to be inconsistent in their ratings.

Working memory in pediatric frontal lobe epilepsy

Thirty-two children with frontal lobe epilepsy (FLE) were assessed using different working memory measures. In addition, parents and teachers completed the working memory scale of the Behavioral Rating Inventory of Executive Functioning (BRIEF) to assess the children's "daily life behavior." Results suggested minimal working memory deficits as assessed with performance-based measures. However, the BRIEF showed more working memory deficits suggesting that, on a daily life level, working memory problems seem to be associated with FLE. We discuss why the results of the performance-based measures are not consistent with results of the BRIEF.HighlightsParents as well as teachers report working memory dysfunction in daily life to the same extent.Performance based measures show minimal deficits of working memory.Correlation between working memory tasks and proxy measures are low.

The neuropsychological profile of parietal and occipital lobe epilepsy

Despite the extensive body of research in clinical neurology on the functional organization of posterior cortices, parietal and occipital lobe epilepsy (PLE and OLE) have not as yet received the attention afforded frontal and temporal lobe epilepsy (FLE and TLE), perhaps due to their low prevalence. Posterior epilepsies however, represent a challenge for epileptology in general and neuropsychological differential diagnosis in particular. Our main purpose was to examine the likely existence of a pattern of cognitive dysfunction characterizing patients suffering from seizures with a parietal and/or occipital ictal onset. We hypothesized that such patients would present difficulties in the visuospatial and visuoconstructive domains, since spatial analysis and synthesis is an inherent feature of posterior cortical systems. Participants were 14 patients with epilepsy and 14 healthy controls matched for demographic characteristics (gender, age, and education level). We used an extensive battery of neuropsychological tests to assess auditory-verbal memory and learning, episodic memory, attention and working memory, verbal abilities, haptic perception, arithmetic abilities, and executive functions. Special attention was given to visuospatial abilities. Depression and anxiety symptoms were assessed through a self-administered questionnaire. Nonparametric (Mann-Whitney U test) statistical tests were conducted. We found that patients with epilepsy performed significantly worse in visuoconstruction, verbal, and executive functions compared to their healthy matches. Finally, we interpret our findings from the perspective of Luria of mental functions organized into functional systems and the current trends in epileptology to view epilepsy as a system (network) problem.

Emotional asymmetries in refractory medial temporal and frontal lobe epilepsy: Their impact on predicting lateralization and localization of seizures

BACKGROUND

Emotional disturbances have been reported in patients with epilepsy. Although conflicting results emanate from relevant studies, depressive symptoms are seen more often in temporal lobe epilepsy (TLE) whereas, hypomanic/manic symptoms usually accompany frontal lobe epilepsy (FLE); the above psychiatric symptoms are especially seen in refractory epilepsy. However, neocortical TLE and medial TLE are considered as distinct epileptic syndromes, and there is limited literature on comparison of affective traits in medial TLE (MTLE) and FLE.

AIM

In the present study, we sought to investigate affective traits among epilepsy surgery candidates suffering refractory left medial TLE (LMTLE), right medial TLE (RMTLE), left FLE (LFLE), and right FLE (RFLE).

RESULTS

Our results revealed that patients with MTLE scored significantly higher than the ones with FLE in depression, anxiety, asthenia, and melancholia as measured by the Symptoms Rating Scale for Depression and Anxiety (SRSDA), while patients with FLE scored significantly higher in mania than those with MTLE. Moreover, patients with MTLE scored significantly higher than their FLE counterparts on the anxiety scale of the State Trait Personality Inventory (STPI)-trait version. When laterality of the seizure focus was taken into account, no differences were found among both patients with MTLE and patients with FLE, with exception for the Trail Making Test part B (TMT-B) in which patients with RMTLE performed significantly worse than patients with LMTLE. Seizure frequency was higher for FLE.

CONCLUSIONS

We provide evidence for an anterior-frontal versus a posterior-medial temporal cerebral functional asymmetry with regard to the manifestation of manic and depressive emotional traits in FLE and MTLE, respectively. Our results are mainly discussed within the frame of their contribution in localizing and to a lesser extent in lateralizing seizures foci in epilepsy surgery candidates. We suggest that this is of great importance in the context of preoperative monitoring of epilepsy surgery, especially when neuropsychologists are called upon to provide anatomical information in defining the functional deficit zone.

Executive and behavioral functioning in pediatric frontal lobe epilepsy

OBJECTIVE

Epilepsy, as a chronic and neurological disease, is generally associated with an increased risk for social and emotional behavior problems in children. These findings are mostly derived from studies on children with different epilepsy types. However, there is limited information about the associations between frontal lobe epilepsy (FLE) and cognitive and behavioral problems. The aim of this study was to examine relationships between FLE and executive and behavioral functioning reported by parents and teachers.

MATERIAL AND METHODS

Teachers and parents of 32 children (18 boys, 14 girls, mean age 9; 2 years ±1;6) with a confirmed diagnosis of FLE completed the Behavioral Rating Inventory of Executive Function (BRIEF), the Child Behavior Checklist (CBCL), and Teacher Report Form (TRF).

RESULTS

About 25 to 35% of the parents and teachers rated children in the abnormal range of the main scales of the BRIEF, CBCL, and TRF. Teachers tend to report more metacognition problems, whereas parents tend to report more behavior regulation problems. Children with left-sided FLE showed more problems than children with bilateral or right-sided FLE. The whole range of executive dysfunctioning is linked to behavioral dysfunctioning in FLE, but ratings vary across settings and informants. The epilepsy variables age of onset, lateralization, drug load, and duration of epilepsy had only a small and scattered contribution.

CONCLUSION

Ratings on the BRIEF, CBCL, and TRF are moderately to highly correlated, suggesting a (strong) link between executive and behavioral functioning. Subtle differences between parents and teachers ratings suggest different executive function demands in various settings.

Sleep architecture in adults with epilepsy: a systematic review

OBJECTIVES

To assess whether sleep architecture differs in subgroups of adults with epilepsy or in adults with epilepsy compared to control populations.

METHODS

We completed a systematic review of papers published in two databases up to May 2018, with adults with epilepsy who have undergone either two consecutive nights of in-laboratory polysomnography (PSG) or one night of ambulatory PSG. Our review followed the PRISMA statements and guidelines and the protocol was registered in the PROSPERO platform prior to initiation of the review process (record CRD42018084009).

RESULTS

Five studies out of 872 fulfilled our eligibility criteria. Only one study reported a significant difference in any sleep architecture parameter in group comparisons. Crespel et al., found that wake after sleep onset (WASO) time in minutes was higher in patients with refractory temporal lobe epilepsy when compared to refractory frontal lobe epilepsy (78.2 ± 5.3 vs. 28.1 ± 2.2; p < 0.01) and healthy controls (78.2 ± 5.3 vs. 27.9 ± 18.9; p < 0.007).

CONCLUSIONS

Only a few studies objectively assessed sleep in adults with epilepsy while controlling for key factors that influence sleep. However, even those reports are heterogeneous in regards to methodology and population characteristics. Further studies are required to access the extent of sleep architectural abnormalities in adults with epilepsy.

Psychosocial outcome in epilepsy after extratemporal surgery

OBJECTIVE

Only limited data exist on psychosocial long-term outcome after epilepsy surgery in patients with extratemporal epilepsy. The aim of this study was to investigate psychosocial outcome after extratemporal epilepsy surgery and to assess factors predicting favorable outcome.

METHOD

Sixty-five out of 104 eligible patients who had undergone extratemporal epilepsy surgery at our epilepsy center between 1990 and 2015 (mean age: 42.2. years; 75% of the resections in the frontal lobe) completed a questionnaire asking about seizure status, employment status, marital and living situation, driving status, depressive symptoms, and quality of life (QOL). Follow-up was on average 9.2years after surgery (range: 1-26years).

RESULTS

Thirty-eight (58%) patients were free of disabling seizures (Engel class I), and 28 (43%) have not experienced any seizures after surgery (Engel class IA). Employment rate in the primary labor market remained at 45%, but more patients lost employment (14%) than gained employment (8%). Postoperative employment was predicted by preoperative employment (p=.007), seizure freedom (p=.025), older age at seizure onset (p=.018), younger age at follow-up (p=.035), and female gender (p=.048). Seizure-free patients were more likely to be driving; have a partner, particularly in males; and have lower depressive scores. Quality of life at follow-up was best predicted by employment (p=.012), partnership (p=.025), and seizure freedom (p=.025). In contrast, recurrence of seizures and early seizure onset were associated with poor psychosocial outcome, particularly in men.

CONCLUSION

The study provides support that extratemporal surgery can lead to improved QOL and favorable psychosocial outcome. Seizure freedom is important but not the only determinant of good psychosocial outcome.

The relationship between dispositional empathy and prefrontal cortical functioning in patients with frontal lobe epilepsy

BACKGROUND & OBJECTIVE

Rehabilitation focuses brain-behavior relationship which highlights interaction between psychological and neurobiological factors for better patient care. There is a missing link in the literature about socio-cognitive aspects of frontal lobe epilepsy. Our objective was to examine prefrontal cortical functioning (PCF) and empathic abilities in patients with frontal lobe epilepsy (FLE). Further, we analyzed whether any relationship between components of dispositional empathy and PCF exists in patients with FLE.

METHODS

The study was designed in an experimental paradigm. Sixty patients with FLE were recruited from Sheikh Zayed and Jinnah hospital, Pakistan. Sixty healthy individuals in response to an advertisement took part in the study as control subjects. Participants completed interpersonal reactivity index. Following they performed clock drawing test and word-color identification task switching experiment.

RESULT

Patients with FLE demonstrated weaker PCF (i.e., cognitive flexibility and executive function) as compared to healthy control subjects. Patients with FLE scored lesser on cognitive empathy as compared to healthy control subjects. On contrary, there was no significant difference between patient and control group on affective empathy. Cognitive not affective empathy was potential predictor of PCF.

CONCLUSION

Cognitive empathy is a significant marker of prefrontal cortical functioning (PCF) in FLE. Higher cognitive empathy would lead to efficient PCF.

Preoperative neuropsychological presentation of patients with refractory frontal lobe epilepsy

BACKGROUND

This study investigated whether certain cognitive deficits are associated with frontal lobe epilepsy (FLE) aiming to contribute with localization data to the preoperative assessment of epilepsy surgery candidates.

METHODS

We evaluated 34 patients with refractory FLE, 37 patients with refractory medial temporal lobe epilepsy (MTLE), and 22 healthy individuals in attention, psychomotor speed, motor function, verbal memory span, verbal fluency, response inhibition/interference, concept formation and set shifting, anticipation and planning, global memory.

RESULTS

Neuropsychological performances of FLE and MTLE were similar, with the only exception the WCST-number of categories index, measuring mental flexibility, in which MTLE patients performed significantly worse than FLE patients. Left-FLE patients presented more perseverative responding compared to both other patient groups and healthy controls (HCs), while left-MTLE patients showed worse sorting abilities than the other epilepsy groups.

CONCLUSIONS

Our findings suggest a weak cognitive differentiation between FLE and MTLE, probably attributed to the intricate nature of fronto-temporal connectivity frequently resulting in overlapping deficits as well as the confounding effects of seizure-related variables. In clinical practice, a highly individualized (idiographic) neuropsychological approach along with the inclusion of concurrent EEG recordings (e.g., interictal coupling) may be of help for neuropsychologists in identifying FLE patients from those with medial temporal pathology presenting frontal dysfunction as a secondary cognitive symptom.

Neuropsychological consequences of sleep disturbance in children with epilepsy

A growing body of research reveals strong relationships between sleep disturbance, sleep architecture, and neuropsychological functioning in children. Children with epilepsy experience numerous neuropsychological comorbidities, including cognitive deficiencies and emotional/behavioral difficulties; thus, it is reasonable to consider the moderating role of sleep in this population. This review summarizes findings involving the prevalence and characteristics of sleep problems often experienced by children with epilepsy. The complex and bidirectional relationship between sleep and seizure frequency is discussed. Research pertaining to the relationship between sleep disturbance and daytime cognition as well as behavior reveals a substantial association between these variables. Clinically relevant practices related to the assessment and treatment of sleep-related complications are reviewed, and directions for further research involving intervention and assessment are also reviewed.

Nodal approach reveals differential impact of lateralized focal epilepsies on hub reorganization

The impact of the hemisphere affected by impairment in models of network disease is not fully understood. Among such models, focal epilepsies are characterised by recurrent seizures generated in epileptogenic areas also responsible for wider network dysfunction between seizures. Previous work focusing on functional connectivity within circumscribed networks suggests a divergence of network integrity and compensatory capacity between epilepsies as a function of the laterality of seizure onset. We evaluated the ability of complex network theory to reveal changes in focal epilepsy in global and nodal parameters using graph theoretical analysis of functional connectivity data obtained with resting-state fMRI. Graphs of functional connectivity networks were derived from 19 right and 13 left focal epilepsy patients and 15 controls. Topological metrics (degree, local efficiency, global efficiency and modularity) were computed for a whole-brain, atlas-defined network. We also calculated a hub disruption index for each graph metric, measuring the capacity of the brain network to demonstrate increased connectivity in some nodes for decreased connectivity in others. Our data demonstrate that the patient group as a whole is characterised by network-wide pattern of reorganization, even while global parameters fail to distinguish between groups. Furthermore, multiple metrics indicate that epilepsies with differently lateralized epileptic networks are asymmetric in their burden on functional brain networks; with left epilepsy patients being characterised by reduced efficiency and modularity, while in right epilepsy patients we provide the first evidence that functional brain networks are characterised by enhanced connectivity and efficiency at some nodes whereas reduced in others.

Thought suppression predicts task switching deficits in patients with frontal lobe epilepsy

OBJECTIVE

To examine the relationship between task switching and thought suppression in connection with frontal lobe epilepsy (FLE).

METHODS

This experimental study included 30 patients with FLE admitted to the Services and Jinnah Hospital, Lahore, Pakistan between February and November 2013, and 30 healthy individuals from the local community. Participants performed a task switching experiment where they switched between emotion and age categorizations among faces. In addition, they completed a thought suppression questionnaire.

RESULTS

There were 3 important results: (i) Patients with FLE showed weaker task switching abilities than healthy individuals. This result is attributed toward executive dysfunctions in patients with FLE. (ii) Contrary to the control group, patients with FLE showed larger switch cost for the age than the emotion categorization. This result can be seen in the context of social cognition deficits and poor inhibitory control in patients with FLE. In addition, larger switch costs reflected a binding effect with facial emotion as compared to age. The integration might represent emotion as an intrusive facial dimension that interrupted task switching performance. (iii) Patients with FLE had more recurrent suppression of thoughts than controls. Thought suppression was a significant predictor for switch costs. High scores on thought suppression were correlated with task switching deficits.

CONCLUSION

The results suggest that thought suppression causes significant cognitive decline.

Executive functioning and depressed mood before and after unilateral frontal lobe resection for intractable epilepsy

Executive dysfunction occurs in a variety of patients who have sustained damage to the frontal lobes. In individuals with frontal lobe epilepsy (FLE) or after unilateral frontal lobe resection (FLR), a unique neuropsychological profile linking executive functions (EF) with the frontal lobe has been elusive, with conflicting findings in the literature. Some studies show greater risk of executive impairment with left-sided FLE or FLR, while others report greater risk for right-sided patients. Some studies report no relationship between FLE and EF impairment, while others show EF impairment regardless of side of seizure foci or surgery. In patients with temporal lobe epilepsy, executive dysfunction is associated with depressed mood possibly reflecting disruption of cortical-limbic pathways and/or frontal-striatal circuitry. Although not previously examined, depression level may affect executive functioning in those with FLE or FLR. We hypothesized that FLE patients with poor mood state would show greater executive dysfunction than FLE patients without poor mood state. The relationship among EF, side of surgery and depressed mood before and 8 months after unilateral FLR was evaluated in 64 patients using validated measures of EF and mood state (Beck Depression Inventory-II). Results indicated that individuals with depressed mood before surgery had greater difficulty on a task of mental flexibility compared to patients without preoperative depressed mood. Further, individuals with depressed mood before surgery had significant increases in perseverative responding and completed fewer categories on a card-sorting task after surgery compared to patients without preoperative depressed mood. Regression analyses showed that among side of surgery, seizure freedom status after surgery and depression status, only pre-surgical depression status explained a significant amount of variance in executive functioning performance after surgery. Results suggest that clinically elevated depressive symptoms before surgery are a risk factor for moderate declines in EF after surgery. Results may be attributable to reduced cognitive reserve in patients with depressive symptoms, or may reflect a common cause attributable to damage to unilateral dorsal and ventral lateral frontal lobe.

Abnormal modular organization of functional networks in cognitively impaired children with frontal lobe epilepsy

Many children with frontal lobe epilepsy (FLE) have significant cognitive comorbidity, for which the underlying mechanism has not yet been unraveled, but is likely related to disturbed cerebral network integrity. Using resting-state fMRI, we investigated whether cerebral network characteristics are associated with epilepsy and cognitive comorbidity. We included 37 children with FLE and 41 healthy age-matched controls. Cognitive performance was determined by means of a computerized visual searching task. A connectivity matrix for 82 cortical and subcortical brain regions was generated for each subject by calculating the inter-regional correlation of the fMRI time signals. From the connectivity matrix, graph metrics were calculated and the anatomical configuration of aberrant connections and modular organization was investigated. Both patients and controls displayed efficiently organized networks. However, FLE patients displayed a higher modularity, implying that subnetworks are less interconnected. Impaired cognition was associated with higher modularity scores and abnormal modular organization of the brain, which was mainly expressed as a decrease in long-range and an increase in interhemispheric connectivity in patients. We showed that network modularity analysis provides a sensitive marker for cognitive impairment in FLE and suggest that abnormally interconnected functional subnetworks of the brain might underlie the cognitive problems in children with FLE.

Psychiatric comorbidity in patients with pharmacoresistant focal epilepsy and psychiatric outcome after epilepsy surgery

There are only a few studies in which both preoperative psychiatric comorbidity in pharmacoresistant focal epilepsy and its outcome after epilepsy surgery have been investigated. In this study, 144 patients evaluated for epilepsy surgery received psychiatric examination, 84 proceeding to intervention were reassessed postoperatively. Preoperatively, 60% met criteria for ICD-10- or epilepsy-specific psychiatric diagnosis. Twenty-seven percent, predominantly female, suffered from dysphoric disorder (DD) associated with temporal epileptogenic foci. Prevalence of DD correlated with complex partial seizure frequency and presence of ictal fear suggesting limbic-cortical dysregulation. Psychotic syndromes were linked to a history of febrile convulsions and left-sided temporomesial epileptogenic foci. High seizure frequency and early epilepsy onset predisposed to the development of personality disorders. Postoperative assessment revealed 18% of patients with "de novo" interictal affective disorders after surgery. Symptoms in 48% of patients with preoperative affective syndromes and 60% of patients with DD remitted after surgery. Seizure freedom and improved psychosocial status predicted remission of preoperative psychopathology.

Hypoxia-induced neonatal seizures diminish silent synapses and long-term potentiation in hippocampal CA1 neurons

Neonatal seizures can lead to epilepsy and long-term cognitive deficits into adulthood. Using a rodent model of the most common form of human neonatal seizures, hypoxia-induced seizures (HS), we aimed to determine whether these seizures modify long-term potentiation (LTP) and silent NMDAR-only synapses in hippocampal CA1. At 48-72 h after HS, electrophysiology and immunofluorescent confocal microscopy revealed a significant decrease in the incidence of silent synapses, and an increase in AMPARs at the synapses. Coincident with this decrease in silent synapses, there was an attenuation of LTP elicited by either tetanic stimulation of Schaffer collaterals or a pairing protocol, and persistent attenuation of LTP in slices removed in later adulthood after P10 HS. Furthermore, postseizure treatment in vivo with the AMPAR antagonist 2,3-dihydroxy-6-nitro-7-sulfonyl-benzo[f]quinoxaline (NBQX) protected against the HS-induced depletion of silent synapses and preserved LTP. Thus, this study demonstrates a novel mechanism by which early life seizures could impair synaptic plasticity, suggesting a potential target for therapeutic strategies to prevent long-term cognitive deficits.

Gender differences in risk-taking behaviour in youth with epilepsy: a Norwegian population-based study

OBJECTIVES

It is well known that behavioural problems and psychiatric disorders occur with greater prevalence in children and adolescents with epilepsy. Youth with epilepsy (YWE) may also be more susceptible to risk-taking behaviour, but this has seldom been studied. The aim of this study was to explore risk-taking behaviour in YWE.

MATERIAL AND METHODS

In this study, 19,995 young people (age range: 13-19 years) participated and completed an extensive questionnaire, including The Strengths and Difficulties Questionnaire self-report. A variable, risk-taking behaviour, was identified, including daily consumption of alcohol, substance abuse or having committed a criminal offence such as being in a fight with a weapon, committing a burglary or using threats to obtain money.

RESULTS

Two hundred and forty-seven youths reported currently having, or having had, epilepsy (lifetime prevalence: 1.2%). Of these, 8.3% reported daily alcohol consumption (1.0% in controls; P<0.001), 12.4% had tried illegal substances (5.5% of controls; P<0.001), and 19.7% had committed criminal offences (8.5% in controls; P<0.001). A gender difference was found: girls with epilepsy did not exhibit risk-taking behaviour more frequently than controls, but having epilepsy was a risk factor for such behaviour in boys (OR: 3.2).

CONCLUSION

Boys with epilepsy exhibit risk-taking behaviour more frequently than controls. Other risk factors for this behaviour were living with a single parent, low family income and psychiatric symptoms. This behavioural association should be addressed as it probably contributes to the negative social outcomes that frequently occur in the adult epilepsy population.

Thalamic T-type Ca²+ channels mediate frontal lobe dysfunctions caused by a hypoxia-like damage in the prefrontal cortex

Hypoxic damage to the prefrontal cortex (PFC) has been implicated in the frontal lobe dysfunction found in various neuropsychiatric disorders. The underlying subcortical mechanisms, however, have not been well explored. In this study, we induced a PFC-specific hypoxia-like damage by cobalt-wire implantation to demonstrate that the role of the mediodorsal thalamus (MD) is critical for the development of frontal lobe dysfunction, including frontal lobe-specific seizures and abnormal hyperactivity. Before the onset of these abnormalities, the cross talk between the MD and PFC nuclei at theta frequencies was enhanced. During the theta frequency interactions, burst spikes, known to depend on T-type Ca(2+) channels, were increased in MD neurons. In vivo knockout or knockdown of the T-type Ca(2+) channel gene (Ca(V)3.1) in the MD substantially reduced the theta frequency MD-PFC cross talk, frontal lobe-specific seizures, and locomotor hyperactivity in this model. These results suggest a two-step model of prefrontal dysfunction in which the response to a hypoxic lesion in the PFC results in abnormal thalamocortical feedback driven by thalamic T-type Ca(2+) channels, which, in turn, leads to the onset of neurological and behavioral abnormalities. This study provides valuable insights into preventing the development of neuropsychiatric disorders arising from irreversible PFC damage.

Behavioral changes in dogs associated with the development of idiopathic epilepsy

OBJECTIVES

The aim of the study was to demonstrate behavioral changes with the development of epilepsy in dogs, a species proposed as a naturally occurring animal model for human epilepsy.

METHODS

Owners of dogs diagnosed with idiopathic epilepsy (n=80) completed a modified, previously-validated behavioral and seizure questionnaire. Principal axis factor analysis identified behavioral factors, the scores for which were compared before and after the development of epilepsy.

RESULTS

Drug-naïve dogs showed an increase in the behavior factors Fear/Anxiety, Defensive Aggression, and Abnormal Perception. In dogs receiving antiepileptic medication, there were still increases in Fear/Anxiety and Abnormal Perception, but no longer in Defensive Aggression. Additional increases were observed in Abnormal Reactivity, Attachment Disorder, Demented Behavior, and Apathetic Behavior. Pharmacoresistant dogs had larger increases in Controlling Aggression, Abnormal Perception, and Demented Behavior than drug responders.

CONCLUSION

Our data suggest that dogs, like humans and rodents, exhibit neurobehavioral comorbidities with the development of epilepsy.

Traditional and non-traditional treatments for autism spectrum disorder with seizures: an on-line survey

BACKGROUND

Despite the high prevalence of seizure, epilepsy and abnormal electroencephalograms in individuals with autism spectrum disorder (ASD), there is little information regarding the relative effectiveness of treatments for seizures in the ASD population. In order to determine the effectiveness of traditional and non-traditional treatments for improving seizures and influencing other clinical factor relevant to ASD, we developed a comprehensive on-line seizure survey.

METHODS

Announcements (by email and websites) by ASD support groups asked parents of children with ASD to complete the on-line surveys. Survey responders choose one of two surveys to complete: a survey about treatments for individuals with ASD and clinical or subclinical seizures or abnormal electroencephalograms, or a control survey for individuals with ASD without clinical or subclinical seizures or abnormal electroencephalograms. Survey responders rated the perceived effect of traditional antiepileptic drug (AED), non-AED seizure treatments and non-traditional ASD treatments on seizures and other clinical factors (sleep, communication, behavior, attention and mood), and listed up to three treatment side effects.

RESULTS

Responses were obtained concerning 733 children with seizures and 290 controls. In general, AEDs were perceived to improve seizures but worsened other clinical factors for children with clinical seizure. Valproic acid, lamotrigine, levetiracetam and ethosuximide were perceived to improve seizures the most and worsen other clinical factors the least out of all AEDs in children with clinical seizures. Traditional non-AED seizure and non-traditional treatments, as a group, were perceived to improve other clinical factors and seizures but the perceived improvement in seizures was significantly less than that reported for AEDs. Certain traditional non-AED treatments, particularly the ketogenic diet, were perceived to improve both seizures and other clinical factors.For ASD individuals with reported subclinical seizures, other clinical factors were reported to be worsened by AEDs and improved by non-AED traditional seizure and non-traditional treatments. The rate of side effects was reportedly higher for AEDs compared to traditional non-AED treatments.

CONCLUSION

Although this survey-based method only provides information regarding parental perceptions of effectiveness, this information may be helpful for selecting seizure treatments in individuals with ASD.

Surgery of children with frontal lobe lesional epilepsy: neuropsychological study

AIM OF THE STUDY

was to provide new data about the evolution of neuropsychological findings in patients with lesional frontal lobe epilepsy (FLE) operated on with lesion excision.

PATIENTS AND METHODS

Twelve patients with lesional FLE underwent full clinical examination including neurological, neuropsychological and developmental assessments, high-resolution magnetic resonance imaging (MRI), ictal and interictal prolonged EEG monitoring and evaluation of seizure semeiology before and after surgery. The mean follow-up duration was 2 years and 10 months (range=14 months-7 years). Another group of lesional temporal lobe epilepsy, matched for the age at surgery and side of surgery, was likewise studied in order to compare neuropsychological patterns and to try to find out specific features in frontal lobe epilepsy evolution.

RESULTS

All patients resulted seizure free at outcome except one belonging to Engel's class II. Before surgery general intelligence was similar in FLE as well as in TLE group. Executive functions and motor coordination were frequently affected in FLE whereas patients with TLE often presented with deficits in naming, visual memory and visuo-spatial attention. After surgery there was a frequent decline of IQ in FLE group together with a slight deterioration, especially of executive functions in some patients. An improvement of behaviour was often observed in both groups.

CONCLUSIONS

As already reported in literature, neuropsychological pre-surgical data confirms the involvement of attention and executive functions in lesional FLE. No significant neuropsychological improvement was produced by surgery that determined in some cases a slight decline of general intelligence and specific frontal abilities. Yet, generally behaviour improved and seizures were controlled.

Changes in extrafrontal integrity and cognition in frontal lobe epilepsy: a diffusion tensor imaging study

We used diffusion tensor imaging to characterize microstructural changes and their associations with cognition in Chinese patients with frontal lobe epilepsy (FLE). We examined 18 adult patients with FLE and 20 healthy controls. Compared with normal controls, patients with FLE had increased mean diffusivity (MD) in the right frontal lobe and decreased fractional anisotropy (FA) in both thalami. Patients with FLE also had decreased FA in the right frontal lobe that correlated with patient age at seizure onset and increased MD in the left thalamus that correlated with duration of epilepsy. Patients with FLE performed significantly worse on nearly all cognitive tasks, and there was a positive correlation between Mini-Mental Status Examination scores and FA in the left frontal lobe and the left thalamus. Our results suggest that the thalamus might be an important extrafrontal structure involved in FLE and that a longer duration of epilepsy might result in more abnormalities in the thalamus. Our results also support the hypothesis that the left frontal lobe white matter and the thalamus contribute to cognitive impairment in patients with FLE.