Depressive, inflammatory, and metabolic factors associated with cognitive impairment in patients with epilepsy

The purpose of this study was to examine the cognitive function and depressive traits most frequently associated with the clinical assessment of patients with epilepsy and if these clinical parameters are linked to glycolipid levels and inflammatory and apoptotic markers.

Patients with epilepsy (n = 32) and healthy subjects (n = 41) were recruited to participate in this study. Neuropsychological evaluation was performed in both groups through a battery of cognitive tests. Inflammatory markers, apoptotic factors, and deoxyribonucleic acid (DNA) damage were measured in blood samples. Additionally, the metabolic markers total cholesterol (CHO), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), and glucose (GLU) levels were analyzed.

Statistical analyses showed that patients with epilepsy presented decreased scores in memory, attention, language, and executive function tests compared with the control group. Analysis revealed that there was negative correlation in epilepsy for seizure duration vs. oral language (R = -0.4484, p < 0.05) and seizure duration vs. problem solving (executive functions) (R = -0.3995, p < 0.05). This was also observed when comparing depression with temporal-spatial orientation (TSO) (R = -0.39, p < 0.05). Furthermore, we observed a higher depression score in patients with epilepsy than in the healthy ones. Statistical analyses showed higher acetylcholinesterase (AChE) (p < 0.05), interleukin 1β (IL-1β, p < 0.001), and tumor necrosis factor-alpha (TNF-α) (p < 0.001) levels compared with those in the control group. Moreover, patients with epilepsy had significantly higher serum levels of caspase 3 (CASP 3) (p < 0.001) and Picogreen (p < 0.001) compared with the control subjects. Regarding the metabolic markers, higher glycolipid levels were observed in the patients with epilepsy (CHO < 0.05*, LDL < 0.0001*, TG < 0.05*, GLU p < 0.05). High-density lipoprotein levels were not significant. The patients with epilepsy had significant correlation when comparing total language with TNF-α (R = -0.4, p < 0.05), praxes with CASP 3 (R = -0.52, p < 0.01), total CHO with total language (R = -0.48, p < 0.05), TG with semantic memory (R = -0.54, p < 0.05), TG with prospective memory (R = -0.2165, p < 0.02), TG with total memory (R = -0.53, p < 0.02), and GLU with total attention (R = -0.62, p < 0.002).

This study supports the evidence of a distinct neuropsychological profile between patients with epilepsy and healthy subjects. Furthermore, our findings suggest that inflammatory pathway, glycolipid profile, and depressive factors may be associated with cognitive dysfunction in patients with epilepsy.