Cognitive proficiency in pediatric epilepsy

Executive functioning in children with posterior cortex epilepsy compared to temporal and frontal lobe epilepsies

OBJECTIVE

People with epilepsy are at an increased risk of experiencing executive dysfunction, particularly those with frontal lobe epilepsy (FLE). The literature has also demonstrated alterations in executive functioning (EF) in patients with temporal lobe epilepsy (TLE). However, few studies have examined the neuropsychological profile of posterior cortex epilepsy (PCE), and little attention has been given to cognitive impairments in the pediatric population with PCE. This study aims to investigate EF performance in children with drug-resistant PCE compared to patients with FLE and TLE.

METHODS

We analyzed neuropsychological data from 217 patients aged 6-18 years who underwent preoperative evaluation for epilepsy surgery. The EF of patients with PCE was compared to patients with FLE and TLE.

RESULTS

There was no significant difference in Full-Scale Intelligence Quotient (FSIQ) means between groups. However, we found a significant effect of brain region on the Coding task, in which patients with PCE and FLE performed worse than those with TLE (p = 0.034). We also observed performance differences between groups on the Stroop test (p = 0.005), with patients with PCE and FLE performing worse than the TLE group.

SIGNIFICANCE

These findings suggest that children with PCE have alterations in their EF that are similar to the deficits found in FLE compared to patients with TLE. This emphasizes the importance of understanding the neuroanatomy of executive functions and the model of neural networks extending beyond the prefrontal cortex.

Processing speed in temporal lobe epilepsy. A scoping review

BACKGROUND

Impaired processing speed (PS) can affect patients with temporal lobe epilepsy (TLE). However, it is usually considered a nonspecific clinical feature and is not measured, but this raises lexical and methodological problems. This review aims to evaluate the existing terminology and assessment methods of PS in patients with TLE.

METHODS

A scoping review was conducted based on the extended guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. The electronic literature search was conducted on Medline-PubMed, American Psychological Association-PsycINFO, Elton Bryson Stephens Company, and Google Scholar, using the keywords "temporal lobe epilepsy" and "speed" or "slowing" plus "processing," "cognitive," "psychomotor," or "mental." Peer-reviewed articles published before December 2022 were analyzed if they were in English, including patients older than 14 years and at least one neuropsychological measure, reported original research focused on PS and had the selected keywords in the title, keywords, and abstract.

RESULTS

Seven articles published between December 2004 and September 2021 were selected. The terms "processing speed," "psychomotor speed," and "information processing speed," based on similar theoretical constructs, were the most frequently used. Assessment methods included non-computerized or paper-and-pencil tests (WAIS-III Digit Symbol and Symbol Search subtests, Purdue Pegboard and Grooved Pegboard Tests, Trail Making Test and Stroop Color-Word Test) and computerized tests (Sternberg Memory Scanning Test, Pattern Comparison Processing Speed, Computerized Visual Searching). In some studies, impairment was associated with white and gray matter damage in the brain, independent of clinical and treatment variables.

CONCLUSION

Clinical research on TLE has focused inconsistently on PS. Different evaluation terms and methods have been used while referring to similar theoretical constructs. These findings highlight a gap between the clinical importance of PS and its assessment. Studies are needed to share terms and tools among clinical centers and clarify the position of PS in the TLE phenotype.

Etiology and duration of the disease in the assessment of intellectual functioning of pediatric patients with epilepsy: An observational study

Childhood epilepsy can be frequently associated with impaired cognitive functioning. Previous research has suggested an increased risk of cognitive impairment that may be related to the etiology, the electro-clinical pattern and the load of anti-seizure medications (ASMs). The aim of this study was to evaluate the impact of different clinical features on the global intellectual functioning in a cohort of children and adolescents with epilepsy. We studied eighty patients diagnosed and followed in a tertiary care center. These factors were examined: 1. Etiology of epileptic syndrome; 2. Type of seizure; 3. Number of ASMs; 4. Seizure frequency; 5. Age at seizure onset; 6. Total duration of epilepsy; and 7. Active duration of epilepsy. Multiple regression analysis showed that the etiology and the total duration of epilepsy were the best indicators of intellectual functioning. The present data indicate that children with symptomatic epilepsy (SE) have lower IQ scores (M = 63.5), while children with self-limited focal epilepsy and generalized idiopathic epilepsy, i.e. age-related epileptic syndromes (ARES), have a higher IQ (M = 100.0; p < 0.01). Children with epilepsy of unknown etiology (UEE) (M = 75.1; p < 0.05) are positioned at an intermediate level between the SE and the ARES group (p < 0.01). Increased duration of epilepsy was associated with decreased intellectual functioning. In conclusion, knowledge about the risks associated with etiologic factors and the duration of the disease may guide the definition of optimal neuropsychological rehabilitation strategies.

Inflated scaled scores on the digital WISC-V coding subtest in a Canadian sample

This study examined performance differences in the traditional paper-and-pencil and new digital versions of the Coding subtest from the Wechsler Intelligence Scale for Children-Fifth Edition (WISC-V) using a cross-sectional sample. A total of 212 school-aged children between 6 and 14 years old were included in the sample, with 116 completing the paper version and 96 completing the digital version administered on a tablet in 2017-2018. One-way ANOVA revealed a significant difference with large effect size between mean scaled scores, with the digital version resulting in higher scaled scores than the paper version, F (1, 210) = 67.57, p < 0.001, d = 1.14, η_p² = 0.24. That is, normed digital scores appear inflated as compared to paper scores. No difference in raw scores was observed when controlling for age, F (1, 209) = 0.54, p > 0.05. Post-hoc analyses were performed to account for potential confounds in demographic differences and to maximize group equivalence, with the same pattern of results. Findings have important implications for clinical interpretation of Coding scores when administering the digital version of the task. Clinicians, including psychologists and neuropsychologists, should be aware of the limitations of the new digital version of this subtest, including differences in standardized performance and task requirements. Future studies using random assignment and/or repeated-measures design are needed to replicate these findings.

Examining the Cognitive Proficiency Index in rehabilitation patients

This study examined the Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) Cognitive Proficiency Index (CPI) in relation to other WAIS-IV indices, overall test battery mean (OTBM), and impairment (IMP) in an outpatient rehabilitation setting. Participants (N = 329) were 35% female and 88% Caucasian with average age and education of 42.9 (SD = 13.5) and 13.6 (SD = 2.4) years, respectively. Participants were grouped by diagnosis and validity: traumatic brain injury (TBI; n = 176; 39% mild), cerebrovascular accident (CVA; n = 52), other neurologic and psychiatric conditions (OTH; n = 49), and questionable performance validity (QPV; n = 52). OTBM was calculated from non-WAIS-IV tests; IMP was dichotomously defined as four or more non-WAIS-IV scores below cutoff (≤35 T). Significant group differences were observed on CPI, WAIS-IV indices, OTBM, and IMP. CPI significantly contributed (β = .51) to a linear regression model predicting OTBM (R² = .63) with education and GAI as covariates. A logistic regression model with IMP as the outcome and education, GAI, and CPI as predictors correctly classified 80% of cases with area under the curve of .86. A previously identified cutoff (CPI < 84) correctly classified 65-78% of clinical groups categorized by IMP. A novel cutoff (CPI ≤ 80) differentiated clinical participants with history of mild TBI from the QPV group with sensitivity of 44.2% and specificity of 89.7%. CPI showed incremental validity in predicting OTBM and IMP and warrants further study as a useful clinical addition to other WAIS-IV indices.

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).

Considerations for ADHD in the child with epilepsy and the child with migraine

INTRODUCTION

Attention Deficit Hyperactivity Disorder (ADHD) is a common comorbid condition in children with epilepsy and migraine. Treatment of ADHD in children with epilepsy or migraine is essential but clinicians may overlook symptoms of ADHD and avoid appropriate use of medications that may reduce symptoms of ADHD without compromising treatment of epilepsy or migraine. Areas covered: PubMed was searched for articles on ADHD and epilepsy or migraine. Key papers were reviewed for additional articles. Areas of interest were: epidemiology, etiological factors, and treatment with emphasis on therapy. Expert commentary: Stimulant medication, especially methylphenidate, appears to be safe and effective in the treatment of ADHD in children with epilepsy or migraine. Unfortunately, data is limited with very few controlled trials of methylphenidate and very limited information on the use of amphetamines or non-stimulant drugs.

Cognitive function in Nigerian children with newly diagnosed epilepsy: a preliminary report

Introduction

Epilepsy has long been associated with cognitive dysfunction and educational underachievement. The purpose of the study was to describe the baseline findings from a larger prospective study.

Methods

New cases of epilepsy aged 6-16 years seen at a paediatric neurology clinic in Ibadan, Nigeria were evaluated for any evidence of cognitive impairment. Intelligence quotient (IQ) of the participants was measured using the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). Scores on cognitive subtests and Full Scale IQ (FSIQ) were computed and association between the subsets scores and seizure variables were calculated.

Results

40 children, 24 males and 16 females were studied and their ages ranged from 6 to 16 years with a mean of 10.8 (SD=3.0) years. Global intellectual functioning as measured by the WISC-IV was in the normal range (FSIQ scores <85) for 52.5% (n = 21) of the participants and the remaining participants (47.5%) scored between the borderline and severe category for intellectual disability. The strongest correlation was between ‘caregiver's assessment of school performance’ and FSIQ, (r = 0.70; p< 0.001). Age at onset of epilepsy and seizure type had no significant association with scores on the WISC-IV composite scores.

Conclusion

There is a high prevalence of significant cognitive dysfunction in Nigerian children with epilepsy, even in the absence of any known brain insult. All children with epilepsy should have routine IQ assessment following diagnosis, in order to allow for early intervention when indicated, and thus, improved outcomes.

Cognitive and neurodevelopmental comorbidities in paediatric epilepsy

Cognitive and behavioural comorbidities are often seen in children with epilepsy, and are more common and severe in refractory epilepsy. These comorbidities are associated with worse quality of life, increased behavioural and language problems and worse social skills, all of which adversely affect long-term psychosocial functioning. To enable early intervention and therapy, children and teens with epilepsy should be periodically screened for cognitive comorbidities. The location of the epileptic focus can, to a certain degree, predict the type(s) of comorbidity; however, the spectrum of disability is often broad, presumably because focal perturbations can cause network dysfunction. Comorbidities often result from underlying structural or functional pathology that has led to seizures. In selected cases, therapy targeting the underlying cause, such as the ketogenic diet for GLUT1 deficiency syndromes, may be remarkably effective in ameliorating both seizures and cognitive concerns. In many cases, however, cognitive impairment persists despite seizure control. In epileptic encephalopathies, frequent seizures and/or interictal epileptiform abnormalities exacerbate neurocognitive dysfunction, owing to synaptic reorganization or impaired neurogenesis, or to other effects on developing neural circuits, and prompt initiation of effective antiepileptic therapy is essential to limit cognitive comorbidities.

Utility of the General Ability Index (GAI) and Cognitive Proficiency Index (CPI) with survivors of pediatric brain tumors: Comparison to Full Scale IQ and premorbid IQ estimates

INTRODUCTION

Pediatric brain tumor survivors are at risk for working memory and processing speed impairment. The General Ability Index (GAI) provides an estimate of intellectual functioning that is less influenced by working memory and processing speed than a Full Scale IQ (FSIQ). The Cognitive Proficiency Index (CPI) provides a measure of efficient information processing derived from working memory and processing speed tasks. We examined the utility of the GAI and CPI to quantify neurocognitive outcomes in a sample of pediatric brain tumor survivors.

METHOD

GAI, CPI, and FSIQ scores from the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) were examined for 57 pediatric brain tumor survivors (ages 6-16 years) treated with cranial radiation therapy (RT).

RESULTS

GAI scores were higher than FSIQ and CPI scores, both p < .001. Lower CPI scores were associated with history of craniospinal irradiation and time since RT. Lower FSIQ and GAI scores were associated with higher RT dose and time since RT. The rate of clinically significant GAI-FSIQ discrepancies in our sample was greater than that observed in the WISC-IV standardization sample, p < .001. Estimated premorbid IQ scores were higher than GAI, p < .01, and FSIQ scores, p < .001.

CONCLUSIONS

Pediatric brain tumor survivors exhibit weaker cognitive proficiency than that expected for age, while general reasoning ability remains relatively spared. The GAI may be useful to quantify the intellectual potential of a survivor when appropriate accommodations are in place for relative cognitive proficiency weaknesses. The CPI may be a particularly sensitive outcome measure of treatment-related cognitive change in this population.

WISC-IV Intellectual Profiles in Italian Children With Specific Learning Disorder and Related Impairments in Reading, Written Expression, and Mathematics

The fifth edition of theDiagnostic and Statistical Manual of Mental Disordersgrouped specific learning disabilities in the single diagnostic category of specific learning disorder (SLD), with specifiers for impairments in reading, written expression, and mathematics. This study aimed at investigating the intellectual profile, assessed with the fourth edition of theWechsler Intelligence Scale for Children(WISC-IV), of 172 children with a diagnosis of SLD, compared to 74 clinical referral controls. WISC-IV intellectual functioning in children with SLD was characterized by a significant discrepancy between general ability and cognitive proficiency (General Ability Index [GAI] > Cognitive Proficiency Index [CPI]), and worse performances on the Similarities, Digit Span, Letter-Number Sequencing, and Coding subtests, supporting models of multiple cognitive deficits at the basis of neurodevelopmental disorders as SLD. GAI was the best and more conservative measure provided by the WISC-IV to identify intellectual functioning in children with SLD, and the intellectual discrepancy between GAI and CPI could be considered a "cognitive sign" for the presence of SLD in a single diagnostic category. Cognitive deficits differed in subtypes of impairment (reading, written expression, and mathematics), supporting their distinction for empirical, educational, and rehabilitative purposes. These findings need further replication in larger samples and in comparison to typically developing children.

Epilepsy and attention-deficit hyperactivity disorder: links, risks, and challenges

Attention-deficit hyperactivity disorder (ADHD) has a prevalence rate of 7%-9% in the general population of children. However, in children with epilepsy, ADHD has been found to be present in 20%-50% of patients. This paper provides a review of ADHD prevalence in pediatric epilepsy populations and reviews data on specific symptom presentation and attention deficits in patients with epilepsy. This paper also reviews evidence-based treatments for ADHD and specifically the treatment of ADHD as a comorbid condition in children with epilepsy.

Pediatric epilepsy and comorbid reading disorders, math disorders, or autism spectrum disorders: Impact of epilepsy on cognitive patterns

INTRODUCTION

In pediatric epilepsy, comorbidities are reported to be frequent. The present study focusedon the cognitive patterns of children with isolated epilepsy, children with isolated neurodevelopmental disorders (reading disorders, math disorders, autism spectrum disorders), and children with epilepsy and these neurodevelopmental disorders as comorbidities.

METHODS

Based on two samples of referred children, one with epilepsy, reading disorders, math disorders, or ASDs occurring in "isolation" (n=117) and one with reading disorders, math disorders, and ASDs occurring comorbid with epilepsy (n=171), cognitive patterns were compared. The patterns displayed by verbal and nonverbal abilities from the WISC series were studied with repeated measures ANOVA. Thereafter, an exploratory 2∗3∗2 factorial analysis was done to study the independent contribution of the type of comorbidity and of the presence or absence of epilepsy to the VIQ-PIQ pattern.

RESULTS

In isolated epilepsy, a VIQ>PIQ pattern was found, which was not seen in the other disorders. When epilepsy and another disorder co-occurred, patterns were altered. They resembled partly the pattern seen in isolated epilepsy and partly the pattern seen in the isolated neurodevelopmental disorder. In comorbid reading disorders, the VIQ>PIQ pattern was mitigated; in comorbid math disorders, it was exacerbated. In comorbid ASDs, no clear pattern emerged. In the presence of epilepsy, patterns characteristic of isolated disorders appeared systematically shifted toward relatively lowered performance abilities or relatively spared verbal abilities. The similar "impact" exerted by epilepsy on the patterns of the various conditions suggested shared mechanisms.

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.

Correlation between interictal cerebral glucose hypometabolism and IQ in children with epilepsy

The aim of this study was to understand the relationship between IQ and glucose metabolism in brain cells in a wide variety of subjects with epilepsy. The study participants were 78 children with epilepsy and 15 healthy children for comparison. All participants were administered the Chinese Wechsler Intelligence Scale for Children (C-WISC). The verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ), and full-scale intelligence quotient (FIQ) were compared between children with epilepsy and typically developing children. Seventy-eight patients underwent interictal positron emission computed tomography (PET) using 2-deoxy-2[(18)F]fluoro-d-glucose (FDG) as the tracer for evaluating brain glucose metabolism. Verbal intelligence quotient, PIQ, and FIQ based on the C-WISC were significantly lower in children with epilepsy than those in the healthy comparison group (P<0.001, P=0.001, and P<0.001, respectively). The IQ of patients with normal metabolism, unifocal abnormal hypometabolism, and multifocal abnormal hypometabolism determined by PET differed significantly. The extent of the abnormal hypometabolism was negatively correlated with the FIQ (rs=-0.549, P<0.001). In patients with lateralized hypometabolism based on PET, the VIQ/PIQ discrepancy scores (|VIQ-PIQ|≥15 points) differed significantly between the left hemisphere abnormal hypometabolism and right hemisphere abnormal hypometabolism subgroups, with negative values in the left and positive values in the right subgroups (P=0.004). In conclusion, brain metabolic abnormalities are correlated with IQ, and performing interictal PET along with C-WISC can better assess the extent of severity of cognitive impairment and VIQ/PIQ discrepancy.

Resting state networks in temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is typically described as a neurologic disorder affecting a cerebral network comprising the hippocampus proper and several anatomically related extrahippocampal regions. A new level of complexity was recently added to the study of this disorder by the evidence that TLE also appears to chronically alter the activity of several brain-wide neural networks involved in the control of higher order brain functions and not traditionally linked to epilepsy. Recently developed brain imaging techniques such as functional magnetic resonance imaging (fMRI) analysis of resting state connectivity, have greatly contributed to these observations by allowing the precise characterization of several brain networks with distinct functional signatures in the resting brain, and therefore also known as "resting state networks." These significant advances in imaging represent an opportunity to investigate the still elusive origins of the disabling cognitive and psychiatric manifestations of TLE, and could have important implications for its pathophysiology and, perhaps, its therapy. Herein we review recent studies in this field by focusing on resting state networks that have been implicated in the pathophysiology of psychiatric disorders and cognitive impairment in patients with epilepsy: the default mode network, the attention network, and the reward/emotion network.

Intellectual functioning in children with epilepsy: frontal lobe epilepsy, childhood absence epilepsy and benign epilepsy with centro-temporal spikes

PURPOSE

The purpose of our study is to describe intellectual functioning in three common childhood epilepsy syndromes - frontal lobe epilepsy (FLE), childhood absence epilepsy (CAE) and benign epilepsy with centro-temporal spikes (BECTS). And also to determine the influence of epilepsy related variables, type of epilepsy, age at epilepsy onset, duration and frequency of epilepsy, and treatment on the scores.

METHODS

Intellectual functioning was examined in a group of 90 children with epilepsy (30 FLE, 30 CAE, 30 BECTS), aged 6-15 years, and compared with a control group (30). All subjects obtained a Full Scale IQ ≥ 70 and they were receiving no more than two antiepileptic medications. Participants completed the Wechsler Intelligence Scale for Children - Third Edition. The impact of epilepsy related variables (type of epilepsy, age at epilepsy onset, duration of epilepsy, seizure frequency and anti-epileptic drugs) on intellectual functioning was examined.

RESULTS

Children with FLE scored significantly worse than controls on WISC-III Verbal IQ, Full Scale IQ and Processing Speed Index. There was a trend for children with FLE to have lower intelligence scores than CAE and BECTS groups. Linear regression analysis showed no effect for age at onset, frequency of seizures and treatment. Type of epilepsy and duration of epilepsy were the best indicators of intellectual functioning.

CONCLUSION

It is crucial that children with FLE and those with a longer active duration of epilepsy are closely monitored to allow the early identification and evaluation of cognitive problems, in order to establish adequate and timely school intervention plans.