Peripheral inflammatory markers and metabolic profiles in temporal lobe epilepsy and functional dissociative seizures

Temporal lobe epilepsy (TLE) and functional dissociative seizures (FDS) are distinct conditions that share overlapping clinical, neuropsychiatric, and biological features, including depressive symptoms, obesity-related metabolic dysregulation, and alterations in systemic inflammatory markers. Understanding the interplay among these factors may provide insight into their shared biological burden.

This study aimed to investigate the relationships among systemic inflammatory markers, adipokines, obesity, seizure frequency, and depressive symptom burden in patients with drug-resistant TLE, drug-responsive TLE, and FDS.

Seventy-four patients were enrolled and divided into three groups: drug-resistant TLE (n = 24), drug-responsive TLE (n = 25), and FDS (n = 25). Demographic and clinical data, physical activity levels, and depression scores were collected. Serum levels of IL-1β, IL-6, TNF-α, BDNF, leptin, and adiponectin were measured using ELISA. Group comparisons were initially performed using One-Way ANOVA or Kruskal-Wallis tests. Multiple linear regression models were subsequently constructed to adjust for potential confounders, including age, sex, and body mass index (BMI). Adjusted p values < 0.05 were considered statistically significant.

In crude analyses, IL-1β, leptin, and adiponectin levels differed significantly across groups. However, after adjustment for age, sex, and BMI, only leptin (adjusted p = 0.014) and adiponectin (adjusted p = 0.005) remained significantly associated with the diagnostic group. The difference in IL-1β levels did not retain statistical significance after adjustment (adjusted p = 0.067). IL-6, TNF-α, and BDNF levels did not differ significantly between groups in either crude or adjusted analyses. Beck Depression Inventory scores were numerically higher in the FDS and drug-resistant TLE groups, but the difference did not reach statistical significance. No significant differences were observed in BMI or physical activity levels, and the majority of participants were classified as overweight or having stage 1 obesity.

After controlling for age, sex, and BMI, metabolic markers-particularly leptin and adiponectin-remained independently associated with diagnostic group, whereas inflammatory cytokines did not demonstrate robust independent differences. These findings suggest that metabolic dysregulation may represent a more prominent differentiating factor than systemic inflammation among patients with TLE and FDS.