Caroline Skirrow

Long-term intellectual outcome after temporal lobe surgery in childhood

Objective: Temporal lobe resection is an established treatment for medication-resistant temporal lobe epilepsy, which in recent years has increasingly been performed in children. However, little is known about the long-term outcome in these children. The aim of this study was to characterize intellectual and psychosocial functioning of children after temporal lobe resection as they progress into late adolescence and adulthood. Methods: We report the long-term follow-up of 42 children who underwent temporal lobe surgery after an average postoperative period of 9 years. Longitudinal change in IQ was documented, psychosocial outcome including quality of life was assessed, and preoperative and postoperative T1-weighted MRI brain scans were evaluated quantitatively. A well-matched nonsurgical comparison group of 11 children with similar clinical characteristics was also assessed. Results: At follow-up, 86% of the surgical group were seizure-free, and 57% were no longer taking antiepileptic medication. A significant increase in IQ was found in the surgical group after an extended follow-up period of >5 years. This IQ change was not found in the nonsurgical comparison group. IQ increases were associated with cessation of antiepileptic medication and changes in MRI-derived gray matter volume. The surgical group also reported better psychosocial outcome including quality of life, which was more strongly associated with seizure freedom rather than surgery per se. Conclusions: Surgery for temporal lobe epilepsy performed in childhood results in excellent long-term seizure control and favorable cognitive outcome along with positive effects on brain development. Classification of evidence: This study provides Class III evidence that temporal lobectomy in children with temporal lobe epilepsy is associated with improved long-term intellectual outcomes compared with those undergoing standard medical treatment.

Temporal lobe surgery in childhood and neuroanatomical predictors of long-term declarative memory outcome

See Berg (doi:10.1093/brain/awu320) for a scientific commentary on this article. In a long-term follow-up study of children who underwent temporal lobe surgery for treatment of epilepsy, Skirrow et al. identify no significant pre-to-post-surgery memory losses, but instead robust improvements in memory functions supported by the unoperated temporal lobe. The integrity of remaining temporal lobe structures places constraints on long-term memory outcomes.

Genetic associations between the symptoms of attention-deficit/hyperactivity disorder and emotional lability in child and adolescent twins

OBJECTIVEnEmotional lability is recognized as an associated feature of attention-deficit/hyperactivity disorder (ADHD). However, the degree of phenotypic and etiologic overlap between emotional lability and the ADHD dimensions of hyperactivity-impulsivity and inattention remains unclear. The present study examines these associations in a large, community twin sample.nnnMETHODnStructural equation models were fit to data from 1,920 child and adolescent twin pairs (age range, 5-18 years). Symptoms of hyperactivity-impulsivity (HI) and inattention (IA) were assessed using a modified version of the DuPaul rating scale, completed by parents. Symptoms of emotional lability (EL) were assessed using the parent-rated Conners 10-item scale.nnnRESULTSnThere were moderate to strong phenotypic correlations between HI, IA, and EL. Multivariate twin modeling revealed that a common pathway model best accounted for the covariance among these dimensions, represented by a highly heritable latent factor. Ad hoc analyses confirmed that all additive genetic influences on HI, IA, and EL were shared, and identified a significantly stronger association of EL with the latent ADHD factor in older than in younger individuals.nnnCONCLUSIONSnEmotional lability was phenotypically and genetically associated with hyperactivity-impulsivity and inattention in children and adolescents. The finding that a single, heritable, latent factor accounted for covariation among these phenotypes indicates that their co-occurrence is primarily the result of overlapping genetic effects. These data support the hypothesis that emotional lability is etiologically relevant to the core ADHD phenotype, and that it should be targeted in assessment and treatment in clinical practice.

Long-Term Cognitive Outcomes After Epilepsy Surgery in Children

Here we examine the evidence for long-term changes in cognitive functions after epilepsy surgery in studies published mostly since 2010. Specifically, we looked for evidence of developmental “catch-up” as indicated by an increase in IQ scores in comparison with preoperative values. About half of the studies report significant increase in IQ scores in the surgical group over time or in comparison with a nonsurgical control group. Better cognitive outcomes are linked to greater overall level of seizure freedom and partially to medication reduction. When taking into account the large variability in sample sizes and seizure freedom between studies, a modest correlation of improved cognitive outcomes with longer follow-up duration can be observed. Further research is urgently needed which relates preoperative cognitive changes with postoperative development and identifies clinical and educational factors which facilitate cognitive outcomes after epilepsy surgery in children.

Educational and Employment Outcomes Following Epilepsy Surgery in Childhood

Childhood-onset epilepsy is associated with educational under-attainment and underemployment. In some children, surgical intervention may be offered as treatment for medication-resistant seizures. Successful treatment may halt seizure-related cognitive and academic deterioration, providing opportunity for greater success in school and work. This chapter examines published research on four Indicators of educational and employment outcomes after epilepsy surgery in childhood (surgery age ≤ 18): (1) special educational provision (2) qualifications attained, (3) unemployment, and (4) financial independence. Few reports are available: research to date describes outcomes after temporal lobe surgery, hemispherectomy, and mixed surgical cohorts (resective and palliative surgeries). Better long-term outcomes across all four indicators are seen for patients who are seizure free postsurgically, and better outcome is associated with shorter lifetime duration of epilepsy. Long-term postsurgical employment outcomes in children are reported as superior to those of adults. Findings indicate that early surgery leading to seizure cessation may promote outcome. However, few studies compare outcomes of surgery with continued pharmacotherapy. Lack of longitudinal data makes it difficult to preclude that superior seizure and psychosocial outcomes simply reflect better presurgical function. More generally, duration of follow-up is often too brief to capture outcomes of epilepsy surgery in children, in whom these are continuing to emerge.