The Significance of Interleukin-6 and Tumor Necrosis Factor-Alpha Levels in Cognitive Impairment among First-Ever Acute Ischaemic Stroke Patients.

BACKGROUND: Acute ischemic stroke (AIS) frequently results in the development of cognitive impairment, which quite often persists. The pathophysiological mechanisms involved in the development of cognitive impairment are only partially elucidated. The aim of this study was to evaluate the correlation between interleukin 6 (IL-6) and tumor necrosis factor-alpha (TNF-α) serum levels with cognitive impairment in AIS patients. SUBJECTS AND METHODS: This hospital-based case-control study was performed during December 2014 - May 2018. A total number of 130 randomly selected patients were prospectively recruited from the Department of Neurology, Clinical Center University of Sarajevo. The study examined 100 first-ever AIS patients, while 30 comprised the non-stroke control group of patients with discogenic lumbosacral radiculopathy. All participants were evaluated using the Mini-Mental State Examination, the Montreal Cognitive Assessment, the Frontal Assessment Battery, and the Addenbrooke's Cognitive Examination-Revised. Cognitive testing and laboratory analyses were performed within the first three days of admission in all patients while AIS patients were reassessed on the 15thday of hospitalization. RESULTS: Female stroke patients with cognitive impairment had significantly higher baseline levels of IL-6 (p<0.017), and TNF-α (p<0.017) than those without cognitive impairment. In the control measurement, a significant difference in IL-6 levels (p=0.037) in male and TNF-α levels (p=0.042) in female stroke patients with cognitive impairment was observed. CONCLUSIONS: These findings indicate that pro-inflammatory cytokines are probably implicated in the pathogenesis of cognitive decline in AIS patients.

Analysis of Serum Inflammatory Markers in Cognitive Impairment among Acute Ischaemic Stroke Patients.

BACKGROUND: Previous studies have indicated that changes in the expression of certain inflammatory biomarkers are associated with cognitive impairment (CI), but only a limited number of studies were conducted in patients with acute ischemic stroke (AIS). The present study aimed to evaluate the potential association between serum levels of several inflammatory markers and cognitive impairment in AIS patients. These markers included interleukin 6 (IL-6), C-reactive protein (CRP), plasma fibrinogen, erythrocyte sedimentation rate (ESR), and white blood cell (WBC) count. SUBJECTS AND METHODS: All participants were prospectively recruited from the Department of Neurology, Clinical Center University of Sarajevo. A total of 100 patients with first-ever AIS were included in stroke group and 30 in the non-stroke control group. Each patient underwent a comprehensive cognitive assessment and laboratory tests (IL-6, CRP, fibrinogen, ESR and WBC) within the first three days of admission. Cognitive status was assessed using cognitive instruments: the Mini-Mental State Examination, the Montreal Cognitive Assessment, the Frontal Assessment Battery, and the Addenbrooke's Cognitive Examination-Revised. RESULTS: Female stroke patients with CI had higher levels of IL-6 compared to those without CI and controls (p<0.017). AIS patients with CI had significantly higher plasma fibrinogen (p<0.001) and CRP levels (p<0.001) than controls, whereas there was no significant difference in comparison with cognitively intact patients. There were no statistical differences in ESR or WBC count between groups. CONCLUSIONS: Of the inflammatory markers, only IL-6 levels were associated with CI in AIS patients. Measuring circulating IL-6 could be used as a screening test to identify all such patients.