Racial differences in adult-onset MRI-negative temporal lobe epilepsy

Disparities in Epilepsy Diagnosis and Management in High-Income Countries: A Review of the Literature

Purpose of Review

Currently, an estimated 3.4 million people in the United States live with epilepsy. Previous studies have identified health disparities associated with race/ethnicity, socioeconomic status (SES), sex, insurance status, and age in this population. However, there has been a dearth of research addressing these disparities. We performed a literature review of articles published between 2010 and 2020 pertaining to health disparities in people with epilepsy (PWE), identified key factors that contribute to gaps in their care, and discussed possible solutions.

Recent Findings

Health disparities in prevalence, treatment access, time to diagnosis, health care delivery and engagement, and clinical outcomes were identified among individuals who were either of low SES, rural-based, uninsured/underinsured, older patients, patients of color, or female sex.

Summary

Disparities in care for PWE continue to persist. Greater priority should be placed on addressing these gaps intricately tied to sociodemographic factors. Reforms to mitigate health disparities in PWE are necessary for timely diagnosis, effective treatment, and positive long-term outcomes.

Network, clinical and sociodemographic features of cognitive phenotypes in temporal lobe epilepsy

This study explored the taxonomy of cognitive impairment within temporal lobe epilepsy and characterized the sociodemographic, clinical and neurobiological correlates of identified cognitive phenotypes. 111 temporal lobe epilepsy patients and 83 controls (mean ages 33 and 39, 57% and 61% female, respectively) from the Epilepsy Connectome Project underwent neuropsychological assessment, clinical interview, and high resolution 3T structural and resting-state functional MRI. A comprehensive neuropsychological test battery was reduced to core cognitive domains (language, memory, executive, visuospatial, motor speed) which were then subjected to cluster analysis. The resulting cognitive subgroups were compared in regard to sociodemographic and clinical epilepsy characteristics as well as variations in brain structure and functional connectivity. Three cognitive subgroups were identified (intact, language/memory/executive function impairment, generalized impairment) which differed significantly, in a systematic fashion, across multiple features. The generalized impairment group was characterized by an earlier age at medication initiation (P < 0.05), fewer patient (P < 0.001) and parental years of education (P < 0.05), greater racial diversity (P < 0.05), and greater number of lifetime generalized seizures (P < 0.001). The three groups also differed in an orderly manner across total intracranial (P < 0.001) and bilateral cerebellar cortex volumes (P < 0.01), and rate of bilateral hippocampal atrophy (P < 0.014), but minimally in regional measures of cortical volume or thickness. In contrast, large-scale patterns of cortical-subcortical covariance networks revealed significant differences across groups in global and local measures of community structure and distribution of hubs. Resting-state fMRI revealed stepwise anomalies as a function of cluster membership, with the most abnormal patterns of connectivity evident in the generalized impairment group and no significant differences from controls in the cognitively intact group. Overall, the distinct underlying cognitive phenotypes of temporal lobe epilepsy harbor systematic relationships with clinical, sociodemographic and neuroimaging correlates. Cognitive phenotype variations in patient and familial education and ethnicity, with linked variations in total intracranial volume, raise the question of an early and persisting socioeconomic-status related neurodevelopmental impact, with additional contributions of clinical epilepsy factors (e.g., lifetime generalized seizures). The neuroimaging features of cognitive phenotype membership are most notable for disrupted large scale cortical-subcortical networks and patterns of functional connectivity with bilateral hippocampal and cerebellar atrophy. The cognitive taxonomy of temporal lobe epilepsy appears influenced by features that reflect the combined influence of socioeconomic, neurodevelopmental and neurobiological risk factors.