Executive dysfunction in children and adolescents with temporal lobe epilepsy: is the Wisconsin Card Sorting Test enough?

Cognitive flexibility impairment in temporal lobe epilepsy: The impact of epileptic foci lateralization on executive functions

INTRODUCTION

Temporal Lobe Epilepsy (TLE) has been associated with memory impairments, which are typically linked to hippocampal and mesial temporal cortex lesions. Considering the presence of extensive bidirectional frontotemporal connections, it can be hypothesized that executive dysfunction in TLE is modulated by the lateralization of the epileptic foci.

MATERIAL AND METHODS

A comprehensive neuropsychological executive functions protocol was administered to 63 participants, including 42 individuals with temporal lobe epilepsy (20 with right-TLE and 22 with left-TLE) and 21 healthy controls aged 20-49.

RESULTS

The results indicate that TLE patients exhibit poorer executive performance compared to healthy controls in working memory (F(2,60) = 4.18, p <.01), planning (F(2,60) = 4.71, p <.05), set shifting (F(2,60) = 10.1, p <.001), phonetic verbal fluency (F(2,60) = 11.71, p <.01) and semantic verbal fluency (F(2,60) = 9.61, p <.001. No significant differences were found in cognitive inhibition. Furthermore, right-TLE patients showed lower performance than left-TLE in set shifting (F(1,61) = 6.45, p <.05), while no significant differences were observed in working memory, planning, inhibition, and verbal fluency.

CONCLUSIONS

This research emphasize the importance of considering the lateralization of the temporal lobe focus to achieve a more accurate neuropsychological characterization. The cognitive differences between left and right TLE patients highlight the need for individualized approaches in their treatment and care.

Impairment of cognitive functions in children and adolescents with focal epilepsy

Introduction

Frontal Lobe Epilepsy (FLE) and Temporal Lobe Epilepsy (TLE) are the two most frequent types of focal epilepsies and they are connected with difficulties in cognitive functioning. Despite multiple trials to systematize profile of cognitive functioning among children with epilepsy by researchers, the available data are ambiguous. The aim of our study was to compare the cognitive function of children upon diagnosis of TLE and FLE and during follow-up and to compare with a control group of healthy children.

Material and methods

Study included 39 patients with newly diagnosed TLE, 24 patients with FLE whose first epileptic seizure occurred between their 6th and 12th year of life and 24 healthy children matched by age, sex and IQ level. Neuropsychological examination was performed the moment of diagnosis and 2-3 years later using diagnostic tools validated and standardized to the patient's age. Intergroup comparison was conducted in both stages of study. Also, correlation between localization of epileptic focus and cognitive difficulties was analysed.

Results

Children with FLE and TLE accomplished worse results in most of the cognitive tasks compared to the control group already in the initial examination. Patients with FLE presented difficulties in memorizing verbal and visual material, attention and in learning new information. Patients with TLE had difficulties in tasks engaging verbal and non-verbal memory and attention. In the follow-up, patients with FLE presented more severe cognitive impairment compared with the other groups. Despite similar tendencies among children with TLE significantly worse results in tasks engaging verbal memory and attention were observed among patients with FLE. It is noteworthy that patients suffering from FLE and TLE present deficits in many aspects of cognitive functioning already at the time of diagnosis.

Conclusion

Children and adolescents suffering from epilepsy are at risk of psychosocial difficulties, emotional disorders and mental illnesses. Thus, full assessment of cognitive function is essential in this patient group not only at the moment of diagnosis but also during follow-up in order to quickly introduce an individual support system.

An inventory of basic research in temporal lobe epilepsy

Temporal lobe epilepsy is a severe neurological disease, characterized by seizure occurrence and invalidating cognitive co-morbidities, which affects up to 1% of the adults. Roughly one third of the patients are resistant to any conventional pharmacological treatments. The last option in that case is the surgical removal of the epileptic focus, with no guarantee for clinical symptom alleviation. This state of affairs requests the identification of cellular or molecular targets for novel therapeutic approaches with limited side effects. Here we review some generalities about the disease as well as some of the most recent discoveries about the cellular and molecular mechanisms of TLE, and the latest perspectives for novel treatments.

Language measurement in childhood epilepsy: A review

The psychosocial well-being of children and adolescents with epilepsy is affected by comorbid language deficits. Little is known about the focus of current research in language and epilepsy. A systematic review of research was conducted to identify gaps in knowledge regarding language and epilepsy. In total, 83 published articles were eligible for inclusion. More studies included samples presenting with focal seizures (k = 39) compared to generalized seizures (k = 10), few included measures of morphology (k = 4). Most studies (k = 66) included samples of participants across a wide age range. Our review indicated t-hat future research should include a greater focus on participants with more diversity in epilepsy etiology (e.g., symptomatic epilepsy), and seizure type (e.g., generalized seizures), assessment of additional areas of language (e.g., morphology), increased focus on early childhood, focused examination of specific developmental stages, and greater use of comparison groups with an alternate epilepsy diagnosis.

Mechanisms of cognitive impairment in temporal lobe epilepsy: A systematic review of resting-state functional connectivity studies

Temporal lobe epilepsy is the most common form of focal epilepsy and related cognitive dysfunction impacts significantly on quality of life in patients. Identifying the mechanisms of such impairment would assist in the management and treatment of patients. The study of perturbations in resting-state networks could shed light on this subject. The aim of this systematic review was to synthesize findings on the relationship between aberrant resting-state functional connectivity and cognitive performance in patients with TLE. Literature searches were conducted on Scopus and PubMed electronic databases and 17 relevant articles were extracted, all of which studied the association between resting-state functional connectivity (RSFC) and cognition in adults with TLE. Study findings were synthesized according to methods used to analyze resting-state data, cognitive domains tested, and neuropsychology tasks administered. Results show that increased RSFC in the primary epileptogenic hippocampus, and reduced intra-hemispheric RSFC, are associated with weaker memory performance. In left TLE, memory impairment may be compensated for by bilateral hippocampal connectivity, which is also predictive of better postoperative memory outcomes. In right TLE, memory loss may be compensated for by increased connectivity between the contralateral hippocampus and inferior frontal gyrus. There is also tentative evidence that working memory dysfunction is related to reduced RSFC between the medial frontal-insular parietal network and the medial temporal network, executive dysfunction is related to reduced RSFC between frontal and parietal lobes, and between the frontal lobe and subcortical regions and that language dysfunction is related to reduced RSFC within the left fronto-temporal language network. Multicenter studies could refute or support these findings by enrolling large samples of patients and employing multivariate regression analysis to control for the effects of anatomical disruption, interictal discharges, seizure frequency, medication, and mood. Systematic review registration: PROSPERO: 191323.

The bridge between cognition and behavior in acquired brain injury: A graph theoretical approach

BACKGROUND

The assumption is that executive dysfunctions (EF), associated with frontal lobe injury, are responsible for behavioral disturbances. Some studies do not find a relationship between EF and behavior following frontal lobe lesions. Our main goal of this study was to use a novel statistical method, graph theory, to analyze this relationship in different brain injury groups; frontal lobe damage, non-frontal lobe damage, and controls. Within the frontal group, we expect to find a pattern of executive nodes that are highly interconnected.

METHODS

For each group, we modeled the relationship between executive functions and behavior as a network of interdependent variables. The cognitive tests and the behavioral questionnaire are the "nodes" in the network, while the relationships between the nodes were modeled as the correlations between two nodes corrected for the correlation with all other nodes in the network. Sparse networks were estimated within each group using graphical LASSO. We analyzed the relative importance of the nodes within a network (centrality) and the clustering (modularity) of the different nodes.

RESULTS

Network analysis showed distinct patterns of relationships between EF and behavior in the three subgroups. The performance on the verbal learning test is the most central node in all the networks. In the frontal group, verbal memory forms a community with working memory and fluency. The behavioral nodes do not differentiate between groups or form clusters with cognitive nodes. No other communities were found for cognitive and behavioral nodes.

CONCLUSION

The cognitive phenotype of the frontal lobe damaged group, with its stability and proportion, might be theoretically interpreted as a potential "buffer" for possible cognitive executive deficits. This might explain some of the ambiguity found in the literature. This alternative approach on cognitive test scores provides a different and possibly complimentary perspective of the neuropsychology of brain-injured patients.

Retrieval-Induced Forgetting in a Pentylenetetrazole-Induced Epilepsy Model in the Rat

The selective retrieval of some information may lead to the forgetting of related, but non-retrieved information. This memory phenomenon is termed retrieval-induced forgetting (RIF). Active inhibition is thought to function to resolve interference from competing information during retrieval, which results in forgetting. Epilepsy is associated with impaired inhibitory control that contributes to executive dysfunction. The purpose of this study is to investigate whether rats in a kindling model of epilepsy demonstrate normal levels of RIF. Rats were divided into two groups: saline and kindling. Pentylenetetrazole was injected intraperitoneally until the rats kindled. RIF was tested using a modified version of the spontaneous object recognition test, consisting of a sample phase, retrieval or interference phase, and a test phase. Exploration time for each object was analyzed. RIF was demonstrated in the saline group when rats subjected to the retrieval phase failed to discriminate between the familiar object and the novel object later in the test phase. Kindled rats, on the other hand, did not suffer forgetting even when they were subjected to the retrieval phase, as they spent significantly longer times exploring the novel rather than the familiar object in the test phase. Therefore, RIF was not observed in the kindling group. These findings indicate impaired retrieval-induced forgetting in kindled rats, which may be suggestive of a deficit in the inhibitory control of memory.

Neuropsychological development in school-aged children after surgery or transcatheter closure for ventricular septal defect

OBJECTIVES

We aimed to assess neuropsychological development in school-aged children with ventricular septal defect (VSD) after surgery or transcatheter closure.

METHODS

We included 31 children with VSD who underwent surgery and 35 who underwent transcatheter closure and their age- and sex-matched best friends as normal controls and parents. The Halstead-Reitan Battery was used to measure psychological and behavioral functions of children.

RESULTS

The mean finger-tapping time (left hand) was significantly lower for children with than without VSD (P < 0.05). For non-handedness tactual performance, the mean time was significantly longer for surgery than interventional therapy groups and controls (P < 0.05). The number of remembered locations was significantly lower for surgery than interventional therapy groups and controls (P < 0.05). The correct number of music rhythms was significantly lower for the surgery than control group (P < 0.05). Children with and without VSD did not differ in the correct number of first-group music rhythms. Nevertheless, for second- and third-group music rhythms, the correct number was significantly lower for the surgery than interventional therapy groups and controls (P < 0.05). The correct number of third-group music rhythms was significantly lower for only the interventional therapy than control group.

CONCLUSION

School-aged children with VSD had normal IQ levels after surgery or interventional therapy but decreased fine-motor and auditory discrimination abilities as well as visual spatial disorder. Children with and without VSD did not differ in general tasks, but abilities on more complex and difficult tasks were lower for children with VSD. Impairments were greater after surgery than interventional therapy.

Executive Dysfunction and Depression in Pediatric Temporal Lobe Epilepsy: The Contribution of Hippocampal Sclerosis and Psychosocial Factors

OBJECTIVES

Temporal lobe epilepsy (TLE) has been identified as a risk factor for increased depression features in children and adolescents; however, less is known regarding specific neurocognitive predictors of depression in this population above and beyond seizure-specific and sociodemographic factors.

METHODS

The study included 62 patients with TLE (64% male) aged 8 to 16 years (M=12.62; SD=2.26) who underwent comprehensive neuropsychological evaluation.

RESULTS

Correlation analyses revealed significant association between patient depression and WCST Total Perseverations, BRIEF Behavioral Regulation Index (BRI) and family stress. Perseverative errors on the WCST and the BRI were found to significantly predict depression features in youth with TLE. Patient performance on WCST was also found to fully mediate the significant relationship between hippocampal sclerosis (HS) and depression in pediatric TLE. Finally, logistic regression indicated HS in the presence of TLE was associated with a four-fold risk of clinically significant depression ratings.

CONCLUSIONS

The current findings offer strong support for the relationship between executive function (EF) and depression in pediatric TLE. Also, as HS is not modifiable, these findings suggest EF intervention may be a potential modality for improving health-related quality of life (HRQOL) in youth with TLE. (JINS, 2018, 24, 606-616).

The executive profile of children with Benign Epilepsy of Childhood with Centrotemporal Spikes and Temporal Lobe Epilepsy

RATIONALE

Benign Epilepsy of Childhood with Centrotemporal Spikes (BECTS) and temporal lobe epilepsy (TLE) represent two distinct models of focal epilepsy of childhood. In both, there is evidence of executive dysfunction. The purpose of the present study was to identify particular deficits in the executive function that would distinguish children with BECTS from children with TLE.

METHODS

We prospectively evaluated 19 consecutive children and adolescents with TLE with hippocampal sclerosis (HS) (57.9% male; mean 11.74years [SD 2.05]; mean IQ 95.21 [SD 15.09]), 19 with BECTS (36.8% male; mean 10.95years [SD 2.33]; mean IQ 107.40 [SD 16.01]), and 21 age and gender-matched controls (33.3% male; mean 11.86years [SD 2.25]; mean IQ 108.67 [15.05]). All participants underwent a neuropsychological assessment with a comprehensive battery for executive and attentional functions. We used ANOVA and chi-square to evaluate differences on demographic aspects among groups (BECTS, TLE-HS, and control groups). Group comparisons on continuous variables were complemented by MANOVA and Bonferroni posthoc comparisons.

RESULTS

Patients with BECTS had worse performance than controls in: Matching Familiar Figures Test, time (p=0.001); Matching Familiar Figures Test, time×errors index (p<0.001); Verbal Fluency for foods (p=0.038); Trail Making Test, part B time (p=0.030); Trail Making Test, part B number of errors (p=0.030); and WCST, number of categories achieved (p=0.043). Patients with BECTS had worse performance than patients with TLE-HS on Matching Familiar Figures Test, time (p=0.004), and Matching Familiar Figures Test, time×errors index (p<0.001). Patients with TLE-HS had worse performance than controls on the following tests: Verbal Fluency for foods (p=0.004); Wisconsin Card Sorting Test, the number of categories achieved (p<0.001); and Wisconsin Card Sorting Test, the number of perseverative errors (p=0.028). Patients with TLE-HS had worse performance than patients with BECTS on Digit Backward (p=0.002); and the Wisconsin Card Sorting Test, the number of perseverative errors (p<0.001).

CONCLUSIONS

Patients with TLE and BECTS present distinct cognitive profiles. Patients with TLE-HS had worse performance in mental flexibility, concept formation, and working memory compared to BECTS. Patients with BECTS had worse inhibitory control compared to children with TLE-HS. Both TLE-HS and BECTS had a higher number of errors on an inhibitory control test. However, patients with BECTS had a slower mental processing even when compared to patients with TLE-HS. Rehabilitation programs for children with epilepsy must include children with benign epilepsies and must take into account the epileptic syndrome and its particular neurocognitive phenotype.

Everyday memory impairment in patients with temporal lobe epilepsy caused by hippocampal sclerosis

OBJECTIVE

Patients with temporal lobe epilepsy caused by hippocampal sclerosis (TLE-HS) have episodic memory impairment. Memory has rarely been evaluated using an ecologic measure, even though performance on these tests is more related to patients' memory complaints. We aimed to measure everyday memory of patients with TLE-HS to age- and gender-matched controls.

METHODS

We evaluated 31 patients with TLE-HS and 34 healthy controls, without epilepsy and psychiatric disorders, using the Rivermead Behavioral Memory Test (RBMT), Visual Reproduction (WMS-III) and Logical Memory (WMS-III). We evaluated the impact of clinical variables such as the age of onset, epilepsy duration, AED use, history of status epilepticus, and seizure frequency on everyday memory. Statistical analyses were performed using MANCOVA with years of education as a confounding factor.

RESULTS

Patients showed worse performance than controls on traditional memory tests and in the overall score of RBMT. Patients had more difficulties to recall names, a hidden belonging, to deliver a message, object recognition, to remember a story full of details, a previously presented short route, and in time and space orientation. Clinical epilepsy variables were not associated with RBMT performance. Memory span and working memory were correlated with worse performance on RBMT.

SIGNIFICANCE

Patients with TLE-HS demonstrated deficits in everyday memory functions. A standard neuropsychological battery, designed to assess episodic memory, would not evaluate these impairments. Impairment in recalling names, routes, stories, messages, and space/time disorientation can adversely impact social adaptation, and we must consider these ecologic measures with greater attention in the neuropsychological evaluation of patients with memory complaints.

Decision-making in patients with temporal lobe epilepsy: Delay gratification ability is not impaired in patients with hippocampal sclerosis

BACKGROUND

Decision-making abilities have rarely been examined in patients with temporal lobe epilepsy related to hippocampal sclerosis (TLE-HS). We aimed to investigate the ability to delay gratification, a decision-making subdomain, in patients with intractable TLE-HS and to verify the association of delay gratification performance and cool executive function tests.

METHODS

We evaluated 27 patients with TLE-HS (mean age: 35.46 [±13.31] years; 7 males) and their cognitive performance was compared with that of 27 age- and gender-matched healthy controls (mean age: 35.33 [±12.05] years; 7 males), without epilepsy and psychiatric disorders. Patients were assessed using the delay discounting task (DDT) and tests of attention, shifting, inhibitory control, and concept formation. Results were correlated with clinical epilepsy variables such as age of onset, epilepsy duration, AED use, history of status epilepticus, febrile seizures, and the presence of generalized seizures. Statistical analysis was performed using one-way ANCOVA with years of education as a confounding factor.

RESULTS

Patients and controls demonstrated similar performance on DDT, showing similar discount rate (p=0.935) and probability rate (p=0.585). Delay gratification was not related to cool executive function tests (Digit Span, Stroop Color Test, Trail Making Test, Wisconsin Card Sorting Test, and Connors' CPT). History of status epilepticus, presence of generalized seizures and higher seizure frequency, age at onset, and epilepsy duration had a significant impact on DDT.

CONCLUSION

Patients with intractable TLE-HS showed unimpaired delay gratification abilities, being able to accept a higher delay and a lower amount of chance for receiving a higher reward in the future. Clinical variables related to the epilepsy severity impacted the performance on delay gratification. Impairment on cool aspects of executive function was unrelated to this decision-making domain.

Neuropsychological deficits in temporal lobe epilepsy: A comprehensive review

Temporal lobe epilepsy (TLE) is the most prevalent form of complex partial seizures with temporal lobe origin of electrical abnormality. Studies have shown that recurrent seizures affect all aspects of cognitive functioning, including memory, language, praxis, executive functions, and social judgment, among several others. In this article, we will review these cognitive impairments along with their neuropathological correlates in a comprehensive manner. We will see that neuropsychological deficits are prevalent in TLE. Much of the effort has been laid on memory due to the notion that temporal lobe brain structures involved in TLE play a central role in consolidating information into memory. It seems that damage to the mesial structure of the temporal lobe, particularly the amygdale and hippocampus, has the main role in these memory difficulties and the neurobiological plausibility of the role of the temporal lobe in different aspects of memory. Here, we will cover the sub-domains of working memory and episodic memory deficits. This is we will further proceed to evaluate the evidences of executive function deficits in TLE and will see that set-shifting among other EFs is specifically affected in TLE as is social cognition. Finally, critical components of language related deficits are also found in the form of word-finding difficulties. To conclude, TLE affects several of cognitive function domains, but the etiopathogenesis of all these dysfunctions remain elusive. Further well-designed studies are needed for a better understanding of these disorders.

Clinical and neuropsychological assessment of executive function in a sample of children and adolescents with idiopathic epilepsy

Objective To compare the executive functions of children and adolescents with idiopathic epilepsy with a control group and to correlate with clinical data, intelligence and academic performance. Method Cross-sectional, descriptive and analytical study. Thirty-one cases and thirty-five controls were evaluated by the WCST (Wisconsin Card Sorting Test).The results were compared with clinical data (seizure type and frequency, disease duration and number of antiepileptic drugs used), IQ (WISC-III) and academic performance (APT). Results Patients with epilepsy had poorer executive function scores. There was no positive linear correlation between test scores and epilepsy variables. There was a positive association between academic performance and some executive function results. Conclusion Children with well controlled idiopathic epilepsy may show deficits in executive functions in spite of clinical variables. Those deficits may influence academic performance.

Cognitive estimations as a measure of executive dysfunction in childhood epilepsy

Children and adolescents with epilepsy are known to demonstrate executive function deficits. Despite prior work that has shown that cognitive estimation tasks are sensitive to executive dysfunction in children, such tasks have not been studied in children with epilepsy. This is particularly important given the fact that executive tasks have heretofore shown poor ecological validity, and it has been speculated that estimation tasks may show stronger ecological validity than other executive tests. One hundred and thirteen clinically referred children and adolescents with epilepsy were included. The Biber Cognitive Estimations Test was sensitive to cognitive dysfunction, with about half showing impairments on this task in comparison to age-matched normative data; the most frequently impaired subscales were quantity estimation and time estimation. Moreover, the Biber Cognitive Estimation Test showed moderate correlations with not only overall intellectual functions and academic achievement but also other commonly administered tests of executive functions, including digit span, Trailmaking, and the Tower of London but not with the contingency naming test. Cognitive estimations were also modestly correlated with age of epilepsy onset but not other epilepsy-severity variables such as number of antiepilepsy drugs (AEDs) or seizure frequency. Unfortunately, the hypothesis that the Biber Cognitive Estimation Test would show strong ecological validity was not supported, as it showed weak relations with parent-reported executive function deficits. The significance and limitations of this investigation are discussed.

Assessment of everyday executive functioning in children with frontal or temporal epilepsies

Executive functions are particularly vulnerable in case of brain disruption during childhood, when the brain is not fully mature. Some studies showed impairments of executive functions in children with epilepsy, but only a few of them investigated the impact of executive dysfunctions on daily life. The aim of this study was to understand the everyday executive functioning of children with epilepsy both at home and in school. We administered the Behavior Rating Inventory of Executive Function to parents and teachers of 53 children (7-16 years of age) with structural epilepsies or epilepsies of unknown cause of temporal lobe (n=25) or frontal lobe (n=28). The results indicated a global executive impairment in the whole group of patients, compared with normative data, with no difference between the group with temporal lobe epilepsy (TLE) and that with frontal lobe epilepsy (FLE), except for monitor domain, which seemed more frequently impaired in the group with FLE. Congruence between parent and teacher ratings was found. The frequency of seizures was not related to executive dysfunction, whereas the number of antiepileptic drugs tended to positively correlate with working memory impairment. Onset of epilepsy at a younger age was also related to more executive difficulties but only according to teacher ratings. Lastly, duration of epilepsy was strongly associated with executive deficits reported in the context of school. Our results support the executive dysfunction hypothesis in daily life of children with structural focal epilepsy or focal epilepsy of unknown cause and are consistent with the early brain vulnerability hypothesis currently prevalent in the context of child neuropsychology. The BRIEF appears to be a clinically useful tool for assessing executive function impairment in this clinical population.

Attention and executive functions in a rat model of chronic epilepsy

OBJECTIVE

Temporal lobe epilepsy is a relatively frequent, invalidating, and often refractory neurologic disorder. It is associated with cognitive impairments that affect memory and executive functions. In the rat lithium-pilocarpine temporal lobe epilepsy model, memory impairment and anxiety disorder are classically reported. Here we evaluated sustained visual attention in this model of epilepsy, a function not frequently explored.

METHODS

Thirty-five Sprague-Dawley rats were subjected to lithium-pilocarpine status epilepticus. Twenty of them received a carisbamate treatment for 7 days, starting 1 h after status epilepticus onset. Twelve controls received lithium and saline. Five months later, attention was assessed in the five-choice serial reaction time task, a task that tests visual attention and inhibitory control (impulsivity/compulsivity). Neuronal counting was performed in brain regions of interest to the functions studied (hippocampus, prefrontal cortex, nucleus basalis magnocellularis, and pedunculopontine tegmental nucleus).

RESULTS

Lithium-pilocarpine rats developed motor seizures. When they were able to learn the task, they exhibited attention impairment and a tendency toward impulsivity and compulsivity. These disturbances occurred in the absence of neuronal loss in structures classically related to attentional performance, although they seemed to better correlate with neuronal loss in hippocampus. Globally, rats that received carisbamate and developed motor seizures were as impaired as untreated rats, whereas those that did not develop overt motor seizures performed like controls, despite evidence for hippocampal damage.

SIGNIFICANCE

This study shows that attention deficits reported by patients with temporal lobe epilepsy can be observed in the lithium-pilocarpine model. Carisbamate prevents the occurrence of motor seizures, attention impairment, impulsivity, and compulsivity in a subpopulation of neuroprotected rats.

Temporal lobe epilepsy in children: executive and mnestic impairments

The current definition of epilepsy emphasizes the importance of cognitive impairment for a complete understanding of the disorder. Cognitive deficits have distinct functional manifestations that differentially impact the daily life experiences of children and adolescents with epilepsy and are a particular concern as they frequently impair academic performance. In particular, memory impairment and executive dysfunction are common disabilities in adults with temporal lobe epilepsy but are less easily recognized and studied in the pediatric population. This review focuses on the consequences of early-onset temporal lobe epilepsy for the development of memory and executive function and discusses current theories to explain these deficits.

Assessment of Executive Functions in a Brazilian Sample of Bipolar Subjects

Research has demonstrated impairments in executive functions in Bipolar Mood Disorder patients. Evidence shows that this impairment is present in both periods of active symptoms of the disorder, as well as euthymic stages, and is compounded by mood episodes, especially manic phases. The purpose of this study was to compare the executive performance of a sample of Brazilian bipolar patients in depressive episodes, (44 participants), euthymia (37 participants), and in controls (43 participants). The main instrument for evaluation was the Wisconsin Card Sorting Test. Significant differences were found in performance on the Wisconsin Card Sorting Test between Bipolar subjects (Type I) (both in depression and euthymia) and the controls. No significant correlations were found between the number of manic episodes and the performance on execute measurement variables. The findings suggest that the executive dysfunctions in Bipolar Disorder may be related to both transitory and permanent deficits.

Executive functioning in children with intractable frontal lobe or temporal lobe epilepsy

The aim of the present study was to shed light on the executive functioning deficits that might differentiate children with frontal lobe epilepsy (FLE) from children with temporal lobe epilepsy (TLE). Participants included 19 youth with intractable FLE and 47 youth with intractable TLE. Participants completed the Wisconsin Card Sorting Test (WCST), verbal fluency, Trail Making Test (Trails A and B), Digit Span Forward (DSF), and Digit Span Backward (DSB). When compared to the normative sample, the FLE group performed significantly worse on DSF, DSB, Trails B, and the WCST. Similarly, the TLE group performed significantly worse on DSF and DSB compared to the normative sample. Youth with FLE had significantly greater difficulty on the WCST compared to the TLE group. Overall, the results indicated that youth with FLE had significantly greater difficulty with concept formation compared to children with TLE. No differences between groups emerged on tasks assessing attention, working memory, mental flexibility, or rapid word retrieval. Both groups performed significantly below the normative sample levels on attention and working memory tasks. As a whole, it appears that some, although not all, executive dysfunction is specific to FLE.

The cognitive impact of sexual abuse and PTSD in children: a neuropsychological study

Sexual abuse is known to have an impact on both child and adult mental health, but the neuropsychological basis of this effect is still largely unknown. This study compared neuropsychological test results from a group of 76 children, 13 of them sexual abuse victims with symptoms of post-traumatic stress disorder, 26 victims of sexual abuse who showed no symptoms post-traumatic stress disorder, and 37 controls. The groups were matched by age, sex, socioeconomic status, and educational level. Child sexual abuse was associated with reduced ability to inhibit automatic responses measured by the Stroop test regardless of post-traumatic stress disorder status. These findings indicate possible attentional inhibition difficulties in child victims of sexual abuse, which may help explain psychopathology associated with the experience.

Memory in children with temporal lobe epilepsy is at least partially explained by executive dysfunction

An association between memory and executive dysfunction (ED) has been demonstrated in patients with mixed neurological disorders. We aimed to investigate the impact of ED in memory tasks of children with temporal lobe epilepsy (TLE). We evaluated 36 children with TLE and 28 controls with tests for memory, learning, attention, mental flexibility, and mental tracking. Data analysis was composed of comparison between patients and controls in memory and executive function; correlation between memory and executive function tests; and comparison between patients with mild and severe ED in memory tests. Children with TLE had worse performance in focused attention, immediate and delayed recall, phonological memory, mental tracking, planning, and abstraction. Planning, abstraction, and mental tracking were correlated with visual and verbal memory. Children with severe ED had worse performance in verbal and visual memory and learning tests. This study showed that ED was related to memory performance in children with TLE.

Episodic and semantic memory in children with mesial temporal sclerosis

The aim of this study was to analyze semantic and episodic memory deficits in children with mesial temporal sclerosis (MTS) and their correlation with clinical epilepsy variables. For this purpose, 19 consecutive children and adolescents with MTS (8 to 16 years old) were evaluated and their performance on five episodic memory tests (short- and long-term memory and learning) and four semantic memory tests was compared with that of 28 healthy volunteers. Patients performed worse on tests of immediate and delayed verbal episodic memory, visual episodic memory, verbal and visual learning, mental scanning for semantic clues, object naming, word definition, and repetition of sentences. Clinical variables such as early age at seizure onset, severity of epilepsy, and polytherapy impaired distinct types of memory. These data confirm that children with MTS have episodic memory deficits and add new information on semantic memory. The data also demonstrate that clinical variables contribute differently to episodic and semantic memory performance.

Teste Wisconsin de classificação de cartas: uma revisão sistemática de 1952 a 2009

O WCST é um teste neuropsicológico de resolução de problemas. Os critérios de resolução são inicialmente desconhecidos e mutantes, exigindo do respondente uma compreensão dos princípios lógicos do problema. Diante da relevância do WCST na avaliação neuropsicológica, este trabalho descreve uma revisão bibliográfica dos artigos que fazem referência ao teste. Realizou-se uma busca bibliográfica em três bases internacionais: Medline, Science Direct, PsycINFO, usando como descritor o unitermo "WCST". Foram identificados 1.076 artigos científicos, desde 1952 até 2009, observando-se significativo aumento das publicações com WCST a partir de 1993, com proporções crescentes a cada ano. Os países que mais publicaram sobre este teste neuropsicológico foram Holanda, Estados Unidos e Reino Unido, sendo os principais descritores das revistas que publicaram sobre o WCST: Psiquiatria, Neuropsicologia, Psicologia e Cérebro. O presente trabalho demonstra, ainda, que os periódicos que publicaram 10 ou mais artigos sobre o WCST têm elevado fator de impacto (JCR).

Deficits in oculomotor performance in pediatric epilepsy

PURPOSE

Given evidence of limitations in neuropsychological performance in epilepsy, we probed the integrity of components of cognition--including speed of processing, response inhibition, and spatial working memory--supporting executive function in pediatric epilepsy patients and matched controls.

METHODS

A total of 44 pairs of controls and medically treated pediatric epilepsy patients with no known brain pathology completed cognitive oculomotor tasks, computerized neuropsychological testing, and psychiatric assessment.

KEY FINDINGS

Patients showed slower reaction time to initiate a saccadic response compared to controls but had intact saccade accuracy. Cognitively driven responses including response inhibition were impaired in the patient group. Patients had increased incidence of comorbid psychopathology, but comorbidity did not predict worse functioning compared to patients with no Attention Deficit Hyperactivity Disorder (ADHD). Epilepsy type and medication status were not predictive of outcome. More complex neuropsychological performance was impaired in tasks requiring visual memory and sequential processing, which was correlated with inhibitory control and antisaccade accuracy.

SIGNIFICANCE

Pediatric epilepsy may be associated with vulnerabilities that specifically undermine speed of processing and response inhibition but not working memory, and may underlie known neuropsychological performance limitations. This particular profile of abnormalities may be associated with seizure-mediated compromises in brain maturation early in development.