Functional Magnetic Resonance Imaging of Language in Epilepsy

Functional magnetic resonance imaging (fMRI) has revolutionized our understanding of functional networks and cerebral organization in both normal and pathological brains. In the present review, we describe the use of fMRI for mapping language in epilepsy patients prior to surgical intervention including a discussion of methodological issues and task design, comparisons between fMRI and the intracarotid sodium amobarbital test, fMRI studies of language reorganization, and the use of fMRI laterality indexes to predict outcome after anterior temporal lobectomy.     

Sensitivity of the Wisconsin Card Sorting Test (64-Card Version) versus the Tower of London (Drexel Version) for detecting executive dysfunction in children with epilepsy

Executive function deficits are common in children and adolescents with epilepsy. Though the Wisconsin Card Sorting Task (WCST) is often considered the “gold standard” for executive function assessment, its sensitivity—particularly in the case of the 64-card version (WCST-64)—is insufficiently established in pediatric samples, including children and adolescents with epilepsy. The present investigation assesses the sensitivity of the WCST-64 in children and adolescents with epilepsy in comparison to another measure: the Tower of London – Drexel Version (TOL-DX). A total of 88 consecutively referred children and adolescents with epilepsy were administered both the WCST-64 and TOL-DX as part of a comprehensive neuropsychological evaluation. The sensitivity of WCST-64 and TOL-DX variables were established and relations with epilepsy severity measures and other executive function measures were assessed. Of the WCST-64 variables, Perseverative Responses is the most sensitive, but detected executive function impairment in only 19% of this clinically referred sample; in contrast, the TOL-DX Rule Violations detected executive function impairment in half of the sample. Further, TOL-DX performances are more strongly related to epilepsy severity variables and other executive function measures in comparison to the WCST-64. Despite its popularity amongst clinicians, the WCST-64 is not as sensitive to executive dysfunction in comparison to other measures of comparable administration time, such as the TOL-DX.     

The Never Land – loss of an idealized pre-birth place and the gain of a thinking mind

This paper describes the main themes in the psychotherapy of a severely epileptic girl, over a period of eleven years, aged 16 at the time of writing. For most of the therapy the girl lacked an ability to differentiate between herself and others, and therefore there was little development of rudimentary Oedipal conflicts. Her severe physical and mental impairments were inextricably linked to this fundamental problem in the process of separating: the physical problems compounding the emotional, and the emotional compounding the physical. Her mother's illnesses were significant factors. Throughout the girl's life she was subject to extreme medical interventions. The paper draws upon psychoanalytic models of mind and body integration, including notions of the 'biopsychosocial dysregulation' model of illness. The clinical material describes the girl's use of the dolls to populate a Peter Pan Never Land, with its many static perspectives, denying growth and the difference between the generations, although therein was the beginning of the use of symbolization. As the child's awareness of her physical impairments grew, so did her despair at her own and her mother's hopeless physical condition. However, she became more able to express her outrage, but with the life-saving awareness of a therapist who was not also ill. This led to the girl's increased ability to acknowledge differentiation between self and other, further painful awareness of her disabilities, losses and possible death, as well as those of her ill mother and, gradually, an ability to acknowledge the passing of time and an appreciation therein of a healthy separate thinking part of her that could use symbolization and allow for some separateness and some emotional growth.     

Assessing Effort During Neuropsychological Evaluation with the TOMM in Children and Adolescents with Epilepsy

Effort assessment is of particular importance in pediatric epilepsy where neuropsychological findings may influence treatment decisions, especially if surgical interventions are being considered. The present investigation examines the Test of Memory Malingering (TOMM) in 60 children and adolescents with epilepsy. The overall pass rate for the sample was 90%. TOMM scores were unrelated to age, though there was a significant correlation between TOMM Trial 2 scores and intelligence estimates. Overall, the TOMM appears to be a valid measure of effort in young epilepsy patients, though caution should be used when interpreting scores for those with very low IQ, especially if behavioral problems are also evident. Caution should also be exercised in interpreting scores in children with ongoing interictal epileptiform activity that may disrupt attention.     

Neuropsychological Features of Lesion-related Epilepsy in Adults: An Overview

Lesional epilepsy is thought to be a direct consequence of focal brain lesions of dysgenetic, neoplastic, vascular, or traumatic origin. It has been estimated that at least half of all epilepsies are the result of such lesions. The current discussion includes an overview of the cognitive and behavioral presentations in adults with epilepsy secondary to focal pathology. The neuropsychological presentation in this population is influenced by many factors, including the location and nature of the underlying lesion, seizure characteristics, the effects of treatment, and patient variables. Few studies attempt to disentangle the specific contributions of these variables to cognitive performance. However, where available studies examining the separable effects of seizure-related variables on cognitive functioning in individuals with lesional epilepsy are also reviewed. This overview includes a discussion of focal malformations of cortical and vascular development and select foreign tissue and acquired lesions.     

Pre-Surgical Language Mapping with Functional Magnetic Resonance Imaging

Patients with lesions in or near eloquent cortex typically undergo one of several invasive techniques to prevent loss of function following surgery. One of the most promising potential clinical applications of functional magnetic resonance imaging (fMRI) is to map these functions as part of the pre-surgical work-up to identify patients at-risk, guide the surgical entry, or tailor the surgical procedure to prevent deficits. While motor and sensory mapping are relatively straightforward, language mapping is far more complex. The language system is variable in location across individuals and in many cases may reorganize partially or completely to the contralateral hemisphere. In addition, multiple regions of the brain contribute to language functioning including essential regions that must not be removed in surgery, and contributory regions that may result in transient or insignificant impairments post-surgery. Despite these challenges, an increasing number of studies have supported the use of fMRI for pre-surgical language mapping in a variety of disorders. This article reviews the literature from three disorders for which patients benefit from preoperative language mapping: epilepsy, brain tumors, and arteriovenous malformations. Each disorder presents unique challenges to language mapping. Specific case studies are presented highlighting the both the potential benefits of preclinical fMRI for language mapping as well as the potential risks and pitfalls.     

Identification of abnormal movements with 3D accelerometer sensors for seizure recognition

Human-activity recognition and seizure-detection techniques have gathered pace with the widespread availability of wearable devices. A study of the literature shows various studies for 3D accelerometer-based seizure detection that describe the selection of acceleration variables and controlled transformations, while discarding the remaining input variable contributions. The aim of this research is to evaluate feature extraction based on different techniques and with the advantage of an overview of all information on the problem. Three feature extraction techniques – namely, Locally Linear Embedding, Principal Component Analysis (PCA) and a Distance-Based PCA – are analyzed and their outcomes compared against K-Nearest Neighbor and Decision Trees. A realistic experimentation simulating epileptic mioclonic convulsions was performed. The PCA-based methods were found to produce solutions that managed the problem perfectly well, either learning specific models for each individual or learning generalized models.     

Everyday executive function in focal onset pediatric epilepsy on the parent-report BRIEF2

Executive function (EF) difficulties are a core neuropsychological feature of pediatric epilepsy, and parent-report measures of EF concerns are an important complement to task-based EF measures. The Behavior Rating Inventory of Executive Function (BRIEF) has shown sensitivity to parent-reported EF concerns in epilepsy and other pediatric populations. We compared profiles of parent-reported EF concerns using the BRIEF and its revision, the BRIEF2, in 117 pediatric patients with focal onset epilepsy to examine the clinical utility of the revised scale. We then compared BRIEF2 profiles between patients and age- and gender-matched healthy controls. Among patients, profiles on the BRIEF did not globally differ from the BRIEF2, and agreement was very good across scales. Patients and controls differed significantly on the BRIEF2, with patients showing higher EF difficulties reported by parents across most scales. High rates of clinical elevation among patients emerged on the Task Monitor, Plan/Organize, Working Memory, and Shift scales. Younger age of epilepsy onset, chronic epilepsy, and right hemisphere seizure focus were associated with higher parent-reported EF concerns. Findings suggest that the BRIEF2 demonstrates similar performance to the BRIEF among pediatric patients with focal onset epilepsy who are most at risk in the areas of task monitoring, working memory, planning and organization, and flexibility. These findings are informative when comparing literature across versions and provide additional insight into the nature of parent-reported EF difficulties among children with focal onset epilepsy.     

Differences in memory functioning between children with attention-deficit/hyperactivity disorder and/or focal epilepsy

Prior research has shown that attention-deficit/hyperactivity disorder (ADHD) and epilepsy are frequently comorbid and that both disorders are associated with various attention and memory problems. Nonetheless, limited research has been conducted comparing the two disorders in one sample to determine unique versus shared deficits. Hence, we investigated differences in working memory (WM) and short-term and delayed recall between children with ADHD, focal epilepsy of mixed foci, comorbid ADHD/epilepsy and controls. Participants were compared on the Core subtests and the Picture Locations subtest of the Children’s Memory Scale (CMS). Results indicated that children with ADHD displayed intact verbal WM and long-term memory (LTM), as well as intact performance on most aspects of short-term memory (STM). They performed worse than controls on Numbers Forward and Picture Locations, suggesting problems with focused attention and simple span for visual-spatial material. Conversely, children with epilepsy displayed poor focused attention and STM regardless of the modality assessed, which affected encoding into LTM. The only loss over time was found for passages (Stories). WM was intact. Children with comorbid ADHD/epilepsy displayed focused attention and STM/LTM problems consistent with both disorders, having the lowest scores across the four groups. Hence, focused attention and visual-spatial span appear to be affected in both disorders, whereas additional STM/encoding problems are specific to epilepsy. Children with comorbid ADHD/epilepsy have deficits consistent with both disorders, with slight additive effects. This study suggests that attention and memory testing should be a regular part of the evaluation of children with epilepsy and ADHD.