A neuropsychological model for the pre-surgical evaluation of children with focal-onset epilepsy: An integrated approach

The role of psychology and neuropsychology in pediatric epilepsy surgery evaluation

Epilepsy is one of the most common neurological problems affecting 470,000 children in the United States. While most youth will achieve seizure freedom using medication, up to a third will continue to have seizures and are therefore considered to have drug-resistant epilepsy (DRE). Children and adolescents with epilepsy are at higher risk of behavioral, cognitive, and emotional disorders. Youth with DRE are at even greater risk of behavioral and emotional problems impacting quality of life and may need to pursue surgical interventions, including resective surgery or device implantation. Due to advances in the evaluation of candidates and surgical options, epilepsy surgery is more effective and has become second-line treatment for youth with DRE. This paper highlights the importance of exploring, assessing, and treating psychological and neuropsychological factors throughout the three phases of the epilepsy surgery process and ways pediatricians can support youth and families.

Complementary auditory and Visual Naming Tests: Revised and updated for ages 16-55 years

Objective: Historically, naming has been assessed with visual object naming; however, we have found that auditory description naming significantly enhances lateralization and localization of dysfunction. We previously published auditory naming (ANT) and complementary Visual Naming Tests (VNT) for young adults, and recently developed these measures for children (ages 6-15 years) and older adults (ages 56-100 years). Here, we update the original stimuli and more rigorously norm the tests for ages 16-55, addressing prior limitations. Methods: Test stimuli were selected based on item characteristics and preliminary screening, eliminating those with less than 90% name agreement. A sample of 178 healthy individuals ages 16-55 years were administered the updated ANT and VNT, and other standardized measures, either in person (n = 114) or via telehealth (n = 64). Results: With no effect of age, yet a significant influence of education, education-based normative data are provided for accuracy, tips-of-the-tongue (i.e. delayed, accurate responses plus correct responses following phonemic cueing), and an aggregate Summary Score. Internal and test-retest reliability coefficients were reasonable (.67-.90). Conclusions: These measures provide updated and improved naming assessment for ages 16-55 years, contributing to a contiguous set of naming tests for school-aged children through elderly adults. Compared to the original ANT and VNT, these measures were designed to have stimuli longevity, and offer reduced item burden and evidence-based recommendations for performance measures with the greatest clinical sensitivity. The addition of these measures enables continuity in assessment across the age span, facilitating longitudinal assessment related to disease progression or therapeutic intervention.

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

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

Neuropsychiatric and Cognitive Comorbidities in Epilepsy

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Latent Semantic Structure of the WMS-III Verbal Paired-Associates

OBJECTIVE

To investigate the factor structure of the verbal paired-associates (VPA) subtest in the WMS-III using a theoretically driven model of semantic processing previously found to be well-fitting for the WMS-IV version of the test.

METHOD

Archival data were used from 267 heterogeneous neurosciences patients and 223 seizure disorder patients who completed the WMS-III as part of a standard neuropsychological evaluation. Confirmatory factor analysis was used to test theoretically driven models for VPA based on principles of semantic processing. Four nested models of different complexities were examined and compared for goodness-of-fit using chi-squared difference testing. Measurement invariance testing was conducted across heterogeneous neuroscience and seizure disorder samples to test generality of the factor model.

RESULTS

After removing items with limited variability (very easy or very hard; 12 of 40 items), a four-factor model was found to be best-fitting in the present patient samples. The four factors were "recreational", "functional", "material", and "symbolic", each representing semantic knowledge associated with the function of the target word referent. This model subsequently met the criteria for the strict measurement invariance, showing good overall fit when factor loadings, thresholds, and residuals were held to equality across samples.

CONCLUSIONS

The results of this study provide further evidence that "arbitrary" associations between word pairs in VPA items have an underlying semantic structure, challenging the idea that unrelated hard-pairs are semantic-free. These results suggest that a semantic-structure model may be implemented as an alternative scoring in future editions of the WMS to facilitate interpretation.

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.

Assessing risk: Characterizing language performance in pediatric patients with intractable epilepsy pre- and post-surgical resection

Neuropsychologists play an important role in assessing risk for post-surgical cognitive decline in pediatric patients with medically refractory epilepsy. Families, neurologists, and neurosurgeons are particularly concerned about the possibility for language decline for patients with a dominant, most often left, hemisphere epileptic focus and planned surgical resection. This study aims to describe language functioning in pediatric epilepsy patients following resection and evaluate the accuracy of a clinical approach of assessing risk. This study proposes a risk assessment method that considers a patient's pattern of lateralized dysfunction across cognitive domains, suspected neuroanatomical reorganization of language functions, and planned site of resection. Pediatric patients (N = 47) were dichotomized as being at minimal risk or at greater risk for post-surgical language decline based on the proposed risk assessment method. Retrospective chart review was utilized to obtain neuropsychological (Boston Naming Test and Weschler Vocabulary subtest) and clinical variables of interest. Patients in the minimal risk group demonstrated significantly improved BNT scores at post-surgery. Most patients remained stable in their Vocabulary knowledge. The proposed risk assessment method correctly classified patients 77% of the time based on BNT performance. Cluster analysis examining the individual components of the proposed method revealed three distinct patient subgroups. Clinical implications are discussed.

Verbal memory in children with temporal lobe epilepsy: Exploring task-specificity

RATIONALE

This study explored the applicability of the adult model of task-specificity of memory to children with temporal lobe epilepsy (TLE).

METHOD

Retrospective clinical audit; 38 children and adolescents (6-16 years) with lesional TLE (n = 22 mesial; n = 16 lateral) treated at tertiary pediatric hospitals completed two types of verbal memory paradigms: arbitrary associative (Verbal Paired Associates - Hard Pairs) and semantically related (Verbal Paired Associates - Easy Pairs; Stories).

RESULTS

Children with mesial TLE performed more poorly than their lateral TLE counterparts on both types of memory paradigms: arbitrary associative and semantically related (Stories only). Groups with left and right TLE performed comparably on all verbal memory measures.

CONCLUSIONS

Our findings suggest that the adult model of task-specificity may not be completely applicable to children with TLE. Consideration of the developmental context is critical in research and clinical work with pediatric populations.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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