Cognitive functioning in idiopathic generalised epilepsies: A systematic review and meta-analysis

Abstract

Cognitive function in idiopathic generalised epilepsies (IGE) is of increasing research attention. Current research seeks to understand phenotypic traits associated with this most common group of inherited epilepsies and evaluate educational and occupational trajectories. A specific deficit in executive function in a subgroup of IGE, juvenile myoclonic epilepsy (JME) has been a particular focus of recent research. This systematic review provides a quantitative synthesis of cognitive function outcomes in 26 peer-reviewed, case-control studies published since 1989. Univariate random-effects meta-analyses were conducted on seven cognitive factor-domains and separately on executive function. Patients with IGE demonstrated significantly lower scores on tests across all cognitive factor-domains except visual-spatial abilities. Effect sizes ranged from 0.42 to 0.88 pooled standard deviation units. The average reduction of scores on tests of executive function in IGE compared to controls was 0.72 standard deviation units. Contrary to current thinking, there was no specific deficit in executive function in JME samples, nor in other IGE syndromes. Of more concern, people with IGE are at risk of pervasive cognitive impairment.

Brain Morphology in Patients with Genetic Generalized Epilepsy: Its Heterogeneity among Subsyndromes

“…These widespread alterations of cortical thickness and volumes beyond the frontal cortex may underlie the neurocognitive deficits in patients with GGE. Loughman et al [15] recently conducted a meta-analysis of neuropsychological tests in patients with GGE. The authors found that the patients with GGE had significantly lower scores on cognitive processing speed, crystallized and fluid intelligence, short-term/working memory, long-term memory retrieval, and overarching generalized cognitive ability, compared to the healthy controls.…”

Attention and executive functions in the early course of pediatric epilepsy

“…This contradicts those studies that demonstrated that patients with symptomatic or structural-metabolic etiology have an increased risk of developing neurocognitive deficits. Nevertheless, several authors reported a heightened prevalence of cognitive deficits in genetic epilepsy or idiopathic generalized epilepsy with a strong genetic component as well [35]. The fact that only an unknown etiology contributed significantly to the prediction of EF status prior to AED treatment in the multivariate analysis points to several problems associated with new-onset pediatric epilepsy.…”

Impaired Executive Function by Interictal Epileptiform Discharges in Patients with Idiopathic Generalized Epilepsy

“…Epileptiform discharges are abnormal neuronal discharges seen on Electroencephalogram (EEG) as a result of transient synchronous depolarisation of neurons [1]. Findings from published work suggest that these discharges are not mere biomarkers of epilepsy but have important behavioural and cognitive consequences [2][3][4]. Niemann et al established an independent relationship between cognitive impairment and the percentage of epileptiform discharges for a large number of factors such as the duration of epilepsy and the aetiology [5].…”

“…A meta-analysis found that IGE patients demonstrated significantly lower scores on tests across all cognitive factor-domains except visual-spatial abilities [3] and increasing seizure frequency was significantly associated with worse outcomes [19]. Epilepsy is not understood as a disorder affecting one discrete brain region but as a disorder of widespread brain networks [20].…”