Differential regulation of gene expression pathways with dexamethasone and ACTH after early life seizures

Early-life seizures (ELS) are associated with persistent cognitive deficits such as ADHD and memory impairment. These co-morbidities have a dramatic negative impact on the quality of life of patients. Therapies that improve cognitive outcomes have enormous potential to improve patients' quality of life. Our previous work in a rat flurothyl-induction model showed that administration of adrenocorticotropic hormone (ACTH) at time of seizure induction led to improved learning and memory in the animals despite no effect on seizure latency or duration. Administration of dexamethasone (Dex), a corticosteroid, did not have the same positive effect on learning and memory and has even been shown to exacerbate injury in a rat model of temporal lobe epilepsy. We hypothesized that ACTH exerted positive effects on cognitive outcomes through beneficial changes to gene expression and proposed that administration of ACTH at seizure induction would return gene-expression in the brain towards the normal pattern of expression in the Control animals whereas Dex would not. Twenty-six Sprague-Dawley rats were randomized into vehicle- Control, and ACTH-, Dex-, and vehicle- ELS. Rat pups were subjected to 60 flurothyl seizures from P5 to P14. After seizure induction, brains were removed and the hippocampus and PFC were dissected, RNA was extracted and sequenced, and differential expression analysis was performed using generalized estimating equations. Differential expression analysis showed that ACTH pushes gene expression in the brain back to a more normal state of expression through enrichment of pathways involved in supporting homeostatic balance and down-regulating pathways that might contribute to excitotoxic cell-damage post-ELS.

Behavioral aspects of executive functions in young adults with well-controlled epilepsy

Executive function (EF) skills involve higher-level cognitive functions, such as planning, goal formation, goal-directed behavior, and effective performance. Previous research has shown that these aspects of EF are essential for successful functioning in everyday life. This study aimed to examine differences in the behavioral aspects of EF between young adults with epilepsy and healthy controls. The study involved 62 young adults, aged 18 to 30 years, divided into two groups: a study group of young adults with well-controlled epilepsy and a control group of healthy young adults. The groups were matched according to basic sociodemographic characteristics. The Behavior Rating Inventory of Executive Function - Adult version was used to assess the behavioral aspects of executive functions. A significant difference between groups was only observed on the Organization of Materials scale, where the group with epilepsy achieved better performance. Our findings suggest that self-assessed behavioral control of EF is almost the same in healthy young adults and young adults with epilepsy who have no comorbidities and have good control of the disease as well as preserved intellectual ability and functionality in everyday activities.

The impact of processing speed on cognition in temporal lobe epilepsy

PURPOSE

To characterize the impact of slowed processing speed on the efficiency of broader cognitive function in temporal lobe epilepsy (TLE).

METHODS

Participants included 100 patients with TLE and 89 healthy controls (mean ages 36.8 and 33.6, respectively) administered a neuropsychological battery consisting of 15 cognitive metrics. Confirmatory factor analysis using structural equation modeling (SEM) latent variable modeling demonstrated a cognitive structure representing the domains of verbal intelligence, immediate memory, delayed memory, executive function, working memory, and processing speed. Furthermore, the latent variable measurement model determined the direct and indirect relationships of verbal intelligence and processing speed with immediate memory, delayed memory, executive function, and working memory.

RESULTS

Following SEM of hypothesized structural models, the results demonstrated that, among controls, intelligence had a direct and unmediated (by processing speed) relationship with all identified cognitive domains. In contrast, among participants with TLE, processing speed mediated the relationship between verbal intelligence and performance across all cognitive domains.

CONCLUSION

Slowing of cognitive/psychomotor processing speed appears to play a critical mediating role in the broader cognitive status of participants with TLE and may serve as a target through which to attempt to exert a broad positive impact on neuropsychological status.

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.

Associating executive dysfunction with behavioral and socioemotional problems in children with epilepsy. A systematic review

As children with epilepsy may have a number of learning and behavioral problems, it is important that insight into the underlying neurocognitive differences in these children, which may underlie these areas of challenge is gained. Executive function (EF) problems particularly are associated with specific learning abilities as well as behavioral problems. We aim to review systematically the current status of empirical studies on the association between EF problems and behavior and socioemotional problems in children with epilepsy. After search, 26 empirical studies were identified, most of them of moderate quality. Overall, attention problems were the most reported cognitive deficit in test assessment and the most reported problem by parents. In 54% of the studies, children with epilepsy scored below average compared to controls/normative samples on different aspects of EF. Most studies reported behavior problems, which ranged from mild to severe. Forty-two percent of the studies specifically reported relationships between EF deficits and behavioral problems. In the remaining studies, below average neuropsychological functioning seemed to be accompanied by above average reported behavioral problems. The association was most pronounced for cognitive control and attention in relation to externalizing behavior problems. This cognitive control is also associated with social functioning. Relevant epilepsy variables in this relationship were early age at onset and high seizure frequency.Future research should distinguish specific aspects of EF and take age into account, as this provides more insight on the association between EF and behavior in pediatric epilepsy, which makes it possible to develop appropriate and early intervention.

Language in childhood epilepsy: A systematic review and meta-analysis

The abnormal brain activity associated with childhood epilepsy can have an impact on the developmental trajectory of cognitive processes, like language, in this population. However, there is variation in how researchers study language ability in children with epilepsy and the findings that are reported (no differences vs. a significant difference). The current systematic review and meta-analysis uses data from 13 available studies to consider the magnitude of language differences in children with epilepsy compared to their typically developing peers. Seizure classification, age of onset, component of language measured, and instrument used to measure language were all considered as potential moderators of differences in language skill. The results indicate a significant large effect size for language deficits in children with epilepsy compared to their peers. Seizure classification partially, but not fully, accounts for the variability in effect size. In addition, effect sizes differ relative to component of language measured; effect sizes were greatest in magnitude for semantic language and verbal fluency, and minimal for syntax, but only when including all studies of children with epilepsy, regardless of seizure classification. These findings differ when considering language component in children with generalized or focal seizures only. The data reported here also indicate distinct differences in effect size depending on type of instrument used to measure one aspect of language, verbal fluency.

Intellectual outcome after a cortical lesion with versus without epilepsy: A life span neurodevelopmental view

In patients with cortical lesions, the structure of intelligence has never been studied as a function of age at lesion onset and presence vs absence of lesional epilepsy over the life span.

METHOD

Two thousand one hundred eighty-six cases were assembled bearing unilateral cortical lesions occurring at all ages (1301 with seizures) with postlesion verbal intelligence quotient (IQ) (VIQ) and performance IQ (PIQ).

RESULTS

Global IQ significantly and constantly decreased as a function of age at lesion onset in the cases without epilepsy, and increased in the cases with epilepsy. Beyond the lesion onset age of 12 years, VIQ was significantly higher than PIQ in the cases without epilepsy, and lower in the cases with epilepsy. The VIQ/PIQ × lesion-side interaction indicative of hemispheric specialization increased significantly linearly with age at lesion onset in the patients without epilepsy but ceased to progress at the lesion-onset age of 30 years and beyond in the cases with epilepsy.

CONCLUSION

Postlesion global IQ, the difference between VIQ and PIQ, and the laterality index all vary significantly as a function of age at lesion onset. In addition, these changes over the life span are all quite different between cases with and without epilepsy.

Tested and reported executive problems in children and youth epilepsy

OBJECTIVES

Executive problems in children and youth with epilepsy influence their ability to handle important aspects of daily life activities. The present study sought to explore factors associated with executive problems for patients with epilepsy in this age group.

METHODS

The cohort consisted of 97 consecutive patients at the National Centre for Epilepsy in Norway, aged 10-19 years, with focal or genetic generalized epilepsy. All underwent tests of executive functions (D-KEFS), the Behavior Rating Inventory for Executive Function (BRIEF), and screening for psychiatric symptoms, using the Strengths and Difficulties Questionnaire (SDQ).

RESULTS

Parent-reported cognitive executive dysfunction (BRIEF, Metacognitive Index) was the strongest independent predictor for tested executive dysfunction and vice versa. Furthermore, male gender correlated strongest with parent-reported behavioral regulation problems (BRIEF, Behavioral Regulation Index) along with borderline/pathological score on the SDQ and parent-reported cognitive executive dysfunction.

CONCLUSIONS

A strong association between parent-reported cognitive executive dysfunction and tested executive dysfunction was found. Male gender correlated strongest with parent-reported behavioral regulation problems. The latter was probably related to a higher frequency of symptoms associated with psychopathology among the boys than the girls. The frequency of executive deficits according to the different modes of measurement varied from 16% to 43%, suggesting that they capture different aspects of behavior under the executive umbrella.

Impaired performance on advanced Theory of Mind tasks in children with epilepsy is related to poor communication and increased attention problems

Children with epilepsy (CWE) have social difficulties that can persist into adulthood, and this could be related to problems with understanding others' thoughts, feelings, and intentions. This study assessed children's ability to interpret and reason on mental and emotional states (Theory of Mind) and examined the relationships between task scores and reports of communication and behavior. Performance of 56 CWE (8-16years of age) with below average IQ (n=17) or an average IQ (n=39) was compared with that of 62 healthy controls with an average IQ (6-16years of age) on cognition, language, and two advanced Theory of Mind (ToM) tasks that required children to attribute mental or emotional states to eye regions and to reason on internal mental states in order to explain behavior. The CWE-below average group were significantly poorer in both ToM tasks compared with controls. The CWE - average group showed a significantly poorer ability to reason on mental states in order to explain behavior, a difference that remained after accounting for lower IQ and language deficits. Poor ToM skills were related to increased communication and attention problems in both CWE groups. There is a risk for atypical social understanding in CWE, even for children with average cognitive function.

Memory in children with epilepsy: a systematic review

PURPOSE

Research suggests an increased risk for cognitive impairment in childhood epilepsy with memory being one area of cognition most likely to be affected. Understanding the prevalence and predictors of memory difficulties may help improve awareness of the difficulties and allow efficacious supports to be put in place.

METHOD

A systematic review was carried out using the search terms 'memory', 'children' and 'epilepsy' in the database PUBMED. Eighty-eight studies met inclusion criteria. The review focuses on comparisons of memory scores of children with epilepsy and controls, and comparison of memory scores of children with epilepsy to normative scores. Predictors of memory impairment and the effect of surgery on memory functioning are also reviewed.

RESULTS

The majority (78%) of studies reviewed revealed that children with epilepsy scored lower than controls and normative scores on measures of memory. Post-surgery, memory scores were reported to improve in 50% of studies. Predictors of memory impairment included a greater number of AEDs used, younger age of onset, increased seizure frequency and longer duration of epilepsy.

CONCLUSION

Children with epilepsy have a high frequency of memory impairments. However, the exact prevalence of difficulties is not clear due to the lack of population-based data. Most studies have not controlled for IQ and thus it is unclear if difficulties are always related to global cognitive difficulties. There is need for future population-based studies and studies focussing on the neurobiology of memory problems in children with epilepsy.

Uncovering the neurobehavioural comorbidities of epilepsy over the lifespan

Epilepsy is a common neurological disorder that is complicated by psychiatric, cognitive, and social comorbidities that have become a major target of concern and investigation in view of their adverse effect on the course and quality of life. In this report we define the specific psychiatric, cognitive, and social comorbidities of paediatric and adult epilepsy, their epidemiology, and real life effects; examine the relation between epilepsy syndromes and the risk of neurobehavioural comorbidities; address the lifespan effect of epilepsy on brain neurodevelopment and brain ageing and the risk of neurobehavioural comorbidities; consider the overarching effect of broader brain disorders on both epilepsy and neurobehavioural comorbidities; examine directions of causality and the contribution of selected epilepsy-related characteristics; and outline clinic-friendly screening approaches for these problems and recommended pharmacological, behavioural, and educational interventions.

Starting at the beginning: the neuropsychological status of children with new-onset epilepsies

This review examines the neurodevelopmental contribution to the cognitive and behavioural complications of epilepsy. Following a brief review of the lifespan complications of childhood epilepsies, attention turns to cognitive, psychiatric and social correlates of childhood epilepsies reported in population-based and tertiary care studies. The focus then becomes the neurobehavioural status of children with new-onset epilepsy; a point in time not confounded by the effects of years of recurrent seizures, medications, and social reactions to epilepsy. Recent research shows that abnormalities in cognition, brain structure and behaviour are present at or near the time of diagnosis. Further, careful history taking indicates that neurobehavioural problems may be present in advance of the first seizure suggesting the potential influence of epileptogenesis, antecedent neurodevelopmental abnormalities, genetic and environmental susceptibilities, and other risk factors. This becomes the substrate upon which to characterise the effects of epilepsy and its treatment on subsequent neurodevelopment. The review concludes with suggestions for future clinical care and research.