The brain, seizures and epilepsy throughout life: understanding a moving target

Mental health and neurodevelopmental patient-reported outcome measures (PROMs) for children and young people with epilepsy: A systematic review

Children and young people with epilepsy are at higher risk of mental health disorders and atypical neurodevelopmental outcomes compared to the general population. It is essential to detect such comorbidities early in children with epilepsy and provide appropriate interventions, to improve clinical outcomes. We aimed to identify and evaluate the measurement properties of Patient-Reported Outcome Measures (PROMs) that have been validated specifically to measure mental health and neurodevelopmental outcomes in children and/or young people with epilepsy. We searched Embase, Medline, and PsycINFO in May 2023 for relevant studies. Mental health was defined as psychological symptoms (e.g., anxiety, depression, psychosis) and/or behavioural difficulties (e.g., conduct disorders). Neurodevelopmental outcomes included neurodevelopmental disorder traits such as attention-deficit hyperactivity disorder (ADHD) and autistic spectrum disorders. We assessed methodological quality using Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) guidance. Twelve papers were identified that psychometrically evaluated 13 relevant PROMs (two epilepsy-specific, eleven generic). The appraisal of the PROMs was limited by the availability of only one or two published articles for each, and incomplete psychometric evaluations in some cases. The tool demonstrating the strongest evidence was The Neurological Disorders Depression Inventory-Epilepsy for Youth. The ADHD Rating Scale-IV and The Paediatric Symptom Checklist -17 demonstrated good evidence in favour of at least two measurement properties. This review identified only a small number of mental health and neurodevelopmental PROMs evaluated specifically in paediatric epilepsy. There is a need for further validation of mental health and neurodevelopmental PROMs in children with epilepsy.

Unveiling the neuroprotective potential of dietary polysaccharides: a systematic review

Central nervous system (CNS) disorders present a growing and costly global health challenge, accounting for over 11% of the diseases burden in high-income countries. Despite current treatments, patients often experience persistent symptoms that significantly affect their quality of life. Dietary polysaccharides have garnered attention for their potential as interventions for CNS disorders due to their diverse mechanisms of action, including antioxidant, anti-inflammatory, and neuroprotective effects. Through an analysis of research articles published between January 5, 2013 and August 30, 2023, encompassing the intervention effects of dietary polysaccharides on Alzheimer's disease, Parkinson's disease, depression, anxiety disorders, autism spectrum disorder, epilepsy, and stroke, we have conducted a comprehensive review with the aim of elucidating the role and mechanisms of dietary polysaccharides in various CNS diseases, spanning neurodegenerative, psychiatric, neurodevelopmental disorders, and neurological dysfunctions. At least four categories of mechanistic bases are included in the dietary polysaccharides' intervention against CNS disease, which involves oxidative stress reduction, neuronal production, metabolic regulation, and gut barrier integrity. Notably, the ability of dietary polysaccharides to resist oxidation and modulate gut microbiota not only helps to curb the development of these diseases at an early stage, but also holds promise for the development of novel therapeutic agents for CNS diseases. In conclusion, this comprehensive review strives to advance therapeutic strategies for CNS disorders by elucidating the potential of dietary polysaccharides and advocating interdisciplinary collaboration to propel further research in this realm.

Can Old Animals Reveal New Targets? The Aging and Degenerating Brain as a New Precision Medicine Opportunity for Epilepsy

Older people represent the fastest growing group with epilepsy diagnosis. For example, cerebrovascular disease may underlie roughly 30-50% of epilepsy in older adults and seizures are also an underrecognized comorbidity of Alzheimer's disease (AD). As a result, up to 10% of nursing home residents may take antiseizure medicines (ASMs). Despite the greater incidence of epilepsy in older individuals and increased risk of comorbid seizures in people with AD, aged animals with seizures are strikingly underrepresented in epilepsy drug discovery practice. Increased integration of aged animals into preclinical epilepsy drug discovery could better inform the potential tolerability and pharmacokinetic interactions in aged individuals as the global population becomes increasingly older. Quite simply, the ASMs on the market today were brought forth based on efficacy in young adult, neurologically intact rodents; preclinical information concerning the efficacy and safety of promising ASMs is not routinely evaluated in aged animals. Integrating aged animals more often into basic epilepsy research may also uncover novel treatments for hyperexcitability. For example, cannabidiol and fenfluramine demonstrated clear efficacy in syndrome-specific pediatric models that led to a paradigm shift in the perceived value of pediatric models for ASM discovery practice; aged rodents with seizures or rodents with aging-related neuropathology represent an untapped resource that could similarly change epilepsy drug discovery. This review, therefore, summarizes how aged rodent models have thus far been used for epilepsy research, what studies have been conducted to assess ASM efficacy in aged rodent seizure and epilepsy models, and lastly to identify remaining gaps to engage aging-related neurological disease models for ASM discovery, which may simultaneously reveal novel mechanisms associated with epilepsy.

Accelerated Cognitive Ageing in epilepsy: exploring the effective connectivity between resting-state networks and its relation to cognitive decline

Objective

This study aims at understanding the dynamic functional brain organization in Accelerated Cognitive Ageing (ACA) in epilepsy. We also assess to which extend the (abnormal) effective connectivity between brain networks correlates with the (estimated) decline in IQ scores observed in the ACA patients.

Material and methods

Two multi-echo resting-state fMRI scans of 10 ACA patients and 14 age- and education-matched healthy controls were acquired. A task-based fMRI was acquired in-between those two scans, for possible cognitive fatigue effects on reserve capacity. Granger causality (GC), a measure of effective connectivity between brain regions, was applied on 7 major cognitive networks, and group-wise compared, using permutation testing statistics. This was performed on each of the resting-state sessions independently. We assessed the correlation between the cognitive deterioration scores (representing cognitive decline), and the paired-networks granger causality values.

Results

The cingulate cortex appeared to be more engaged in ACA patients. Its dynamics towards the right fronto-parietal cortex, salience network, and the dorsal attention networks (DAN) was stronger than in controls, only in the first resting-state scan session. The Granger causality from the DAN to the default mode network (DMN) and from the ventral attention network (VAN) to the left fronto-parietal network (FPL) was also stronger in ACA patients and again only in the first scans. In the second resting-state scans, only the DMN was more strongly connected with the cingulate cortex in ACA patients. A weaker GC from DMN to FPL, and stronger GC from the salience network to cingulate cortex were associated with more decline in the Full-scale IQ and more GC from DMN to VAN would lead to more decline in the Perceptual Reasoning Index in ACA.

Conclusion

The results are in line with the hypothesis of over-recruitment at low cognitive load, and exhaustion at higher cognitive load, as shown by the compensation-related utilization of neural circuits hypothesis (CRUNCH) model for ageing. Moreover, the DMN to VAN directed connectivity strongly correlates with the (estimated) decline in the Perceptual Reasoning Index, which is also in line with a recent study on ageing with mild cognitive impairment in elderly, and the posterior-anterior shift in aging (PASA) model. This study therefore supports the idea that the cognitive decline in our patients resembles the decline observed in healthy ageing, but in an accelerated mode. This study also sheds light on the directions of the impaired connectivity between the main networks involved in the deterioration process, which can be helpful for future development of treatment solutions.

Children with epilepsy demonstrate macro- and microstructural changes in the thalamus, putamen, and amygdala

PURPOSE

Despite evidence for macrostructural alteration in epilepsy patients later in life, little is known about the underlying pathological or compensatory mechanisms at younger ages causing these alterations. The aim of this work was to investigate the impact of pediatric epilepsy on the central nervous system, including gray matter volume, cerebral blood flow, and water diffusion, compared with neurologically normal children.

METHODS

Inter-ictal magnetic resonance imaging data was obtained from 30 children with epilepsy ages 1-16 (73% F, 27% M). An atlas-based approach was used to determine values for volume, cerebral blood flow, and apparent diffusion coefficient in the cerebral cortex, hippocampus, thalamus, caudate, putamen, globus pallidus, amygdala, and nucleus accumbens. These values were then compared with previously published values from 100 neurologically normal children using a MANCOVA analysis.

RESULTS

Most brain volumes of children with epilepsy followed a pattern similar to typically developing children, except for significantly larger putamen and amygdala. Cerebral blood flow was also comparable between the groups, except for the putamen, which demonstrated decreased blood flow in children with epilepsy. Diffusion (apparent diffusion coefficient) showed a trend towards higher values in children with epilepsy, with significantly elevated diffusion within the thalamus in children with epilepsy compared with neurologically normal children.

CONCLUSION

Children with epilepsy show statistically significant differences in volume, diffusion, and cerebral blood flow within their thalamus, putamen, and amygdala, suggesting that epilepsy is associated with structural changes of the central nervous system influencing brain development and potentially leading to poorer neurocognitive outcomes.

Physical activity and sedentary levels among people living with epilepsy: A systematic review and meta-analysis

How physically active and sedentary people with epilepsy are is unclear. We conducted a meta-analysis to investigate physical activity and sedentary behavior levels compared with the general population in people with epilepsy across the lifespan. Embase, PubMed, PsycARTICLES, and CINAHL Plus were searched from inception until 1/3/2019. A random effects meta-analysis was conducted. Adults with epilepsy (mean age range = 30-47 years) were significantly less likely to comply with physical activity recommendations [odds ratio (OR) = 0.68; 95% confidence interval (CI) = 0.53-0.87; P < 0.001; N analyses = 10; n epilepsy = 1599; n controls = 137,800] and more likely to be inactive (as defined by individual study criteria) (OR = 1.57; 95% CI = 1.34-1.84; P < 0.001; N analyses = 6; n epilepsy = 6032; n controls = 928,184). Data in children (mean age range = 10-12 years) were limited (N = 4; n = 170) and inconsistent while there were no data available for middle-aged and old age (>65 years) people with epilepsy. Our data demonstrate that adults with epilepsy are less physically active than the general population. Public health campaigns specifically targeting the prevention of physical inactivity in adults with epilepsy are warranted. More research on physical activity and sedentary levels in children, adolescents, middle-aged, and old age but also adult people with epilepsy is needed before specific recommendations can be formulated.

Physical activity correlates across the lifespan in people with epilepsy: a systematic review

PURPOSE

Understanding barriers and facilitators of physical activity (PA) participation in people with epilepsy is an essential first step to enable development of targeted and effective interventions. This systematic review examined that PA correlates in people with epilepsy across the lifespan.

MATERIAL AND METHODS

Major electronic databases were searched from inception until 1 April 2019. Keywords included "physical activity" or "exercise" and "epilepsy".

RESULTS

Out of 31 correlates from 10 studies (n = 495, 5-72 years) no consistent (i.e., reported in four or more studies) correlates were identified. In children and adolescents, membership of a sports club was a facilitator for being physically active (confirmed in one study: 1/1), while lower maternal educational level was a barrier (1/1). In adults, the most reported barrier was the presence of depression (3/3), followed by trait anxiety (2/3), state anxiety (1/1), side effects of medication (1/1), and perceived stigma (1/1). No studies focusing on middle-aged and old age people with epilepsy were available.

CONCLUSIONS

The current review found that quantitative research about PA barriers and facilitators in people with epilepsy is still in its infancy, but PA participation is associated with a range of biological, social, and psychological factors which should be considered in rehabilitation programs.Implications for rehabilitationMany people living with epilepsy do not engage in physical activity on a regular basis.Children with epilepsy who are member of a sports club are more physically active.Depression, anxiety, and perceived stigma are important barriers for being active in adults with epilepsy.Side-effects of antiepilepstic drugs are a barrier for being active in adults with epilepsy.

Accelerated Cognitive Ageing in Epilepsy: A Neuropsychological Evaluation of Cognitive Deterioration

OBJECTIVE

Shed light on cognitive deterioration in Accelerated Cognitive Ageing (ACA) in epilepsy from a neuropsychological point of view in order to improve clinical diagnostics.

METHODS

We compared the IQ-profile including GAI, OPIE IV-premorbid IQ and deterioration-scores of 21 epilepsy patients with ACA with 21 matched epilepsy patients without ACA (Epilepsy Controls) and 16 age- and education-matched Healthy Controls. Memory was also evaluated.

RESULTS

Premorbid IQs were equal in all groups. Deterioration was apparent in the ACA-group in the WAIS-IV FSIQ and PRI, whereas no deterioration was found in the two control groups. PSI was impaired in both epilepsy groups, though with more impairment seen in the ACA-group. The VCI remained unimpaired. The FSIQ-GAI discrepancy was equal in both patient groups and significantly larger than in the Healthy Controls. WMS-IV memory indices were of average level in all groups. Memory impairment in ACA was not statistically different from the Epilepsy Controls. 85.7% of ACA-patients could be correctly classified through factors DET_FSIQ and PSI.

CONCLUSIONS

Cognitive deterioration in ACA is characterized by an average drop of 19 IQ-points in FSIQ and PRI. Verbal abilities remain unimpaired. Impairments in fluid functions compromise cognitive abilities in epilepsy, but only partially contribute to cognitive deterioration in ACA. PSI proved to have some diagnostic value in differentiating epilepsy patients from healthy controls, but fails to differentiate between ACA and Epilepsy Controls. A comparison made between OPIE-IV equations and obtained IQs leads to a significant better detection of cognitive deterioration in epilepsy than the use of GAI-FSIQ discrepancies alone.

Molecular Mechanism Involved in the Pathogenesis of Early-Onset Epileptic Encephalopathy

Recent studies have shown that neurologic inflammation may both precipitate and sustain seizures, suggesting that inflammation may be involved not only in epileptogenesis but also in determining the drug-resistant profile. Extensive literature data during these last years have identified a number of inflammatory markers involved in these processes of “neuroimmunoinflammation” in epilepsy, with key roles for pro-inflammatory cytokines such as: IL-6, IL-17 and IL-17 Receptor (IL-17R) axis, Tumor-Necrosis-Factor Alpha (TNF-α) and Transforming-Growth-Factor Beta (TGF-β), all responsible for the induction of processes of blood-brain barrier (BBB) disruption and inflammation of the Central Nervous System (CNS) itself. Nevertheless, many of these inflammatory biomarkers have also been implicated in the pathophysiologic process of other neurological diseases. Future studies will be needed to identify the disease-specific biomarkers in order to distinguish epilepsies from other neurological diseases, as well as recognize different epileptic semiology. In this context, biological markers of BBB disruption, as well as those reflecting its integrity, can be useful tools to determine the pathological process of a variety of neurological diseases. However; how these molecules may help in the diagnosis and prognostication of epileptic disorders remains yet to be determined. Herein, authors present an extensive literature review on the involvement of both, systemic and neuronal immune systems, in the early onset of epileptic encephalopathy.

A Screen for Synaptic Growth Mutants Reveals Mechanisms That Stabilize Synaptic Strength

Synapses grow, prune, and remodel throughout development, experience, and disease. This structural plasticity can destabilize information transfer in the nervous system. However, neural activity remains stable throughout life, implying that adaptive countermeasures exist that maintain neurotransmission within proper physiological ranges. Aberrant synaptic structure and function have been associated with a variety of neural diseases, including Fragile X syndrome, autism, and intellectual disability. We have screened 300 mutants in Drosophila larvae of both sexes for defects in synaptic growth at the neuromuscular junction, identifying 12 mutants with severe reductions or enhancements in synaptic growth. Remarkably, electrophysiological recordings revealed that synaptic strength was unchanged in all but one of these mutants compared with WT. We used a combination of genetic, anatomical, and electrophysiological analyses to illuminate three mechanisms that stabilize synaptic strength despite major disparities in synaptic growth. These include compensatory changes in (1) postsynaptic neurotransmitter receptor abundance, (2) presynaptic morphology, and (3) active zone structure. Together, this characterization identifies new mutants with defects in synaptic growth and the adaptive strategies used by synapses to homeostatically stabilize neurotransmission in response.SIGNIFICANCE STATEMENT This study reveals compensatory mechanisms used by synapses to ensure stable functionality during severe alterations in synaptic growth using the neuromuscular junction of Drosophila melanogaster as a model system. Through a forward genetic screen, we identify mutants that exhibit dramatic undergrown or overgrown synapses yet express stable levels of synaptic strength, with three specific compensatory mechanisms discovered. Thus, this study reveals novel insights into the adaptive strategies that constrain neurotransmission within narrow physiological ranges while allowing considerable flexibility in overall synapse number. More broadly, these findings provide insights into how stable synaptic function may be maintained in the nervous system during periods of intensive synaptic growth, pruning, and remodeling.

Electroconvulsive therapy and subsequent epilepsy in patients with affective disorders: A register-based Danish cohort study

OBJECTIVE

It has been suggested that Electroconvulsive Therapy (ECT) might increase the risk of epilepsy but the few patient studies with retrospective data from medical records do not support the hypothesis. The aim of this study was to examine the relationship between ECT and subsequent incident epilepsy in patients with affective disorder. We also explored whether any association varied with number of ECTs and time since last treatment.

METHODS

All 169,457 patients with first hospital contact for an affective disorder between January 2005 and December 2015 were identified in the Danish National Patient Registry and followed for incident epilepsy from January 2005 until November 2016. The association between ECT and epilepsy was examined using Cox proportional hazard regression with adjustment for gender, age, educational level, comorbid schizophrenia, previous stroke and antidepressant and antipsychotic medication use.

RESULTS

A total of 5875 patients had at least one ECT and 1873 patients developed epilepsy (Incidence rate: 213 pr. 100,000 person years) during the follow-up of mean 5 years. In patients below age 40 years, ECT was associated with a higher rate of epilepsy after adjustment for covariables (Hazard Ratio (HR) = 1.84; 95% Confidence Intervals (CI) = [1.24-2.74]). In patients aged 41-60 years ECT was not associated with epilepsy, while for those above 60 treated with ECT the rate was lower (HR = 0.57; (95% CI = [0.37-0.89]).

CONCLUSION

In patients with affective disorders, we found a weak positive association between ECT and subsequent diagnosis of epilepsy in those younger than 40 years, and a weak negative association in patients older than 60 years. The associations might be subject to residual confounding from risk factors related to ECT.

Susceptibility to hippocampal kindling seizures is increased in aging C57 black mice

The incidence of seizures increases with old age. Stroke, dementia and brain tumors are recognized risk factors for new-onset seizures in the aging populations and the incidence of these conditions also increased with age. Whether aging is associated with higher seizure susceptibility in the absence of the above pathologies remains unclear. We used classic kindling to explore this issue as the kindling model is highly reproducible and allows close monitoring of electrographic and motor seizure activities in individual animals. We kindled male young and aging mice (C57BL/6 strain, 2-3 and 18-22 months of age) via daily hippocampal CA3 stimulation and monitored seizure activity via video and electroencephalographic recordings. The aging mice needed fewer stimuli to evoke stage-5 motor seizures and exhibited longer hippocampal afterdischarges and more frequent hippocampal spikes relative to the young mice, but afterdischarge thresholds and cumulative afterdischarge durations to stage 5 motor seizures were not different between the two age groups. While hippocampal injury and structural alterations at cellular and micro-circuitry levels remain to be examined in the kindled mice, our present observations suggest that susceptibility to hippocampal CA3 kindling seizures is increased with aging in male C57 black mice.

Cognitive deterioration in adult epilepsy: clinical characteristics of "Accelerated Cognitive Ageing"

OBJECTIVES

"Epileptic dementia" is reported in adults with childhood-onset refractory epilepsy. Cognitive deterioration can also occur in a "second-hit model".

MATERIALS AND METHODS

We studied the clinical and neuropsychological characteristics of patients with cognitive deterioration (≥1 SD discrepancy between current IQ and premorbid IQ). Memory function, reaction time and processing speed were also evaluated. Analyses were performed to investigate which clinical characteristics correlated with cognitive deterioration.

RESULTS

Twenty-seven patients were included with a mean age of 55.7 years old, an average age at epilepsy onset of 33.9 years and a mean duration of 21.8 years. Over 40% had experienced at least one status epilepticus. About 77.8% had at least one comorbid disease (most of (cardio)vascular origin). Cognitive deterioration scores were significant for both Performance IQ and Full Scale IQ, but not for Verbal IQ. Impairments in fluid functions primarily affected the IQ-scores. Memory was not impaired. Epilepsy factors explained 7% of the variance in deterioration, whereas 38% was explained by relatively low premorbid IQ and educational level, high age at seizure onset and older age.

CONCLUSIONS

A subgroup of patients with localization-related epilepsy exhibits cognitive decline characterized by deterioration in PIQ and FSIQ, but with preserved higher order functions (VIQ and memory). Patients typically have epilepsia tarda, comorbid pathology, relatively low educational level and older age. These are factors known to increase the vulnerability of the brain by diminishing cognitive reserve. Cognitive deterioration may develop according to a stepwise "second-hit model", affecting and accelerating the cognitive ageing process.

Cognitive deterioration in adult epilepsy: Does accelerated cognitive ageing exist?

A long-standing concern has been whether epilepsy contributes to cognitive decline or so-called 'epileptic dementia'. Although global cognitive decline is generally reported in the context of chronic refractory epilepsy, it is largely unknown what percentage of patients is at risk for decline. This review is focused on the identification of risk factors and characterization of aberrant cognitive trajectories in epilepsy. Evidence is found that the cognitive trajectory of patients with epilepsy over time differs from processes of cognitive ageing in healthy people, especially in adulthood-onset epilepsy. Cognitive deterioration in these patients seems to develop in a 'second hit model' and occurs when epilepsy hits on a brain that is already vulnerable or vice versa when comorbid problems develop in a person with epilepsy. Processes of ageing may be accelerated due to loss of brain plasticity and cognitive reserve capacity for which we coin the term 'accelerated cognitive ageing'. We believe that the concept of accelerated cognitive ageing can be helpful in providing a framework understanding global cognitive deterioration in epilepsy.

Rapid, Coordinate Inflammatory Responses after Experimental Febrile Status Epilepticus: Implications for Epileptogenesis

Epilepsy is a common neurological disorder with many causes. For temporal lobe epilepsy, antecedent insults are typically found. These risk factors include trauma or history of long fever-associated seizures (febrile status epilepticus) in childhood. Whereas the mechanisms by which such insults promote temporal lobe epilepsy are unknown, an extensive body of work has implicated inflammation and inflammatory mediators in both human and animal models of the disorder. However, direct evidence for an epileptogenic role for inflammation is lacking. Here we capitalized on a model where only a subgroup of insult-experiencing rodents develops epilepsy. We reasoned that if inflammation was important for generating epilepsy, then early inflammation should be more prominent in individuals destined to become epileptic compared with those that will not become epileptic. In addition, the molecular and temporal profile of inflammatory mediators would provide insights into which inflammatory pathways might be involved in the disease process. We examined inflammatory profiles in hippocampus and amygdala of individual rats and correlated them with a concurrent noninvasive, amygdalar magnetic resonance imaging epilepsy-predictive marker. We found significant individual variability in the expression of several important inflammatory mediators, but not in others. Of interest, a higher expression of a subset of hippocampal and amygdalar inflammatory markers within the first few hours following an insult correlated with the epilepsy-predictive signal. These findings suggest that some components of the inflammatory gene network might contribute to the process by which insults promote the development of temporal lobe epilepsy.

Psychometric validation of the Pediatric Symptom Checklist-17 in a pediatric population with epilepsy: A methods study

OBJECTIVE

The purpose of this study was to address critical gaps in behavioral health care of youth with epilepsy by examining the utility of a brief, well-validated screening instrument, the PSC-17, in a pediatric population with epilepsy.

METHOD

One hundred eighty-seven caregivers of youth with epilepsy ages 2-17years completed the PSC-17 for their child/adolescent during a routine epilepsy visit. Demographic and seizure information was abstracted from electronic medical record review.

RESULTS

Confirmatory factor analyses for the PSC-17 revealed an acceptable fit with the 3-factor model, χ(2) (116 [N=187]=204.54, p<0.001, CFI=0.90, TLI=0.88, RMSEA=0.064, SRMSR=0.078). Scale level reliabilities were excellent (0.72-0.85). Interscale correlations were moderate (0.48-0.69). Approximately 1/5th of the sample met clinical cut-offs for the total score of behavioral health concerns. However, an additional 20% of the sample had at least one elevated subscale score despite the total score being in the normative/nonclinical range.

SIGNIFICANCE

The PSC-17 is a brief, free behavioral health screening tool with adequate to strong validity, reliability, and clinical utility for pediatric populations with epilepsy. Clinicians should consider using the 3 PSC-17 subscale scores instead of the total score to guide referrals for further evaluation as the subscales may provide a more accurate picture of functioning in particular domains.

Symptomatic neonatal seizures followed by febrile status epilepticus: the two-hit hypothesis for the subsequent development of epilepsy

Neonatal seizures have been associated with the later development of postneonatal epilepsy, mainly beginning within the first year of life. Mechanisms of epileptogenesis in the immature brain still need to be fully elucidated but a two-hit hypothesis, showing that an early insult heightens later susceptibility to seizure-induced brain damage, has been demonstrated in animal models. We describe 2 cases of preterm babies sustaining recurrent neonatal seizures in the context of a severe perinatal brain damage who presented with symptomatic epilepsy only after the occurrence of an episode of febrile status epilepticus. In the context of preexisting perinatal brain damage, febrile status epilepticus acted as a second hit for developing epilepsy, confirming animal evidence.

Neurodevelopmental and mental health comorbidities in children and adolescents with epilepsy and migraine: a response to identified research gaps

AIM

To determine the distribution and risk characteristics of comorbid neurodevelopmental and mental health comorbidities among children and adolescents (6-18y) with epilepsy or migraine (i.e. a neurological condition with shared features and potential etiology) compared with lower extremity fracture (LEF).

METHOD

This case-control study involved a subset analysis of surveillance data in South Carolina, USA. Hospital admission, outpatient, and emergency department visits for individuals with an International Classification of Disease, 9th revision Clinical Modification diagnosis of epilepsy (n=6730; 54.5% females, 45.5% males; mean age [SD] 14y 2mo [4y 5mo]); migraine (n=10 495; 74.5% females, 25.5% males; 15y 6mo [2y 6mo]), or LEF (n=15 305; 40.3% females, 59.7% males; 13y 11mo [2y 11mo]) from January 1 2000 to December 31 2011 were identified. The association of epilepsy, migraine, or LEF with any mental health comorbidity was evaluated with univariate and multivariate polytomous logistic regression.

RESULTS

Comorbidities were highly prevalent in children and adolescents, with epilepsy with a rate of 29.7% (95% confidence interval [CI]: 28.6-30.8) for mental health comorbidities and 30.8% (95% CI: 29.7-31.9) for neurodevelopmental comorbidities. The odds of mental health comorbidity was 2.20 (95% CI: 2.02-2.39) for children and adolescents with epilepsy and 1.60 (95% CI: 1.48-1.73) for migraine, in reference to children and adolescents with LEF after adjusting for potential confounders. Prevalence and risk for specific comorbidities are presented.

INTERPRETATION

Neuropathophysiological and psychosocial factors specific to epilepsy may provide more risk for adolescents with epilepsy compared to migraine.

Hyper-excitability and epilepsy generated by chronic early-life stress

Epilepsy is more prevalent in populations with high measures of stress, but the neurobiological mechanisms are unclear. Stress is a common precipitant of seizures in individuals with epilepsy, and may provoke seizures by several mechanisms including changes in neurotransmitter and hormone levels within the brain. Importantly, stress during sensitive periods early in life contributes to ‘brain programming’, influencing neuronal function and brain networks. However, it is unclear if early-life stress influences limbic excitability and promotes epilepsy. Here we used an established, naturalistic model of chronic early-life stress (CES), and employed chronic cortical and limbic video-EEGs combined with molecular and cellular techniques to probe the contributions of stress to age-specific epilepsies and network hyperexcitability and identify the underlying mechanisms.

In control male rats, EEGs obtained throughout development were normal and no seizures were observed. EEGs demonstrated epileptic spikes and spike series in the majority of rats experiencing CES, and 57% of CES rats developed seizures: Behavioral events resembling the human age-specific epilepsy infantile spasms occurred in 11/23 (48%), accompanied by EEG spikes and/or electrodecrements, and two additional rats (9%) developed limbic seizures that involved the amygdala. Probing for stress-dependent, endogenous convulsant molecules within amygdala, we examined the expression of the pro-convulsant neuropeptide corticotropin-releasing hormone (CRH), and found a significant increase of amygdalar--but not cortical--CRH expression in adolescent CES rats.

In conclusion, CES of limited duration has long-lasting effects on brain excitability and may promote age-specific seizures and epilepsy. Whereas the mechanisms involved require further study, these findings provide important insights into environmental contributions to early-life seizures.

Rapamycin reveals an mTOR-independent repression of Kv1.1 expression during epileptogenesis

Changes in ion channel expression are implicated in the etiology of epilepsy. However, the molecular leading to long-term aberrant expression of ion channels are not well understood. The mechanistic/mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase that mediates activity-dependent protein synthesis in neurons. mTOR is overactive in epilepsy, suggesting that excessive protein synthesis may contribute to the neuronal pathology. In contrast, we found that mTOR activity and the microRNA miR-129-5p reduce the expression of the voltage-gated potassium channel Kv1.1 in an animal model of temporal lobe epilepsy (TLE). When mTOR activity is low, Kv1.1 expression is high and the frequency of behavioral seizures is low. However, as behavioral seizure activity rises, mTOR activity increases and Kv1.1 protein levels drop. In CA1 pyramidal neurons, the reduction in Kv1.1 lowers the threshold for action potential firing. Interestingly, blocking mTOR activity with rapamycin reduces behavioral seizures and temporarily keeps Kv1.1 levels elevated. Overtime, seizure activity increases and Kv1.1 protein decreases in all animals, even those treated with rapamycin. Notably, the concentration of miR-129-5p, the negative regulator of Kv1.1 mRNA translation, increases by 21days post-status epilepticus (SE), sustaining Kv1.1 mRNA translational repression. Our results suggest that following kainic-acid induced status epilepticus there are two phases of Kv1.1 repression: (1) an initial mTOR-dependent repression of Kv1.1 that is followed by (2) a miR-129-5p persistent reduction of Kv1.1.