PROFILE OF BLOOD SYSTEMIC INFLAMMATORY MARKERS AND TIME-BASED CHARACTERISTICS OF POSTSTROKE FATIGUE

Abstract

Post-stroke fatigue (PSF) is very common after stroke and is strongly related to poor quality of life, independent of depression and disability. PSF is heterogeneous phenomenon. During acute stroke period PSF is associated predominantly with biological factors, while at chronic stroke period PSF is connected, as rule, with emotional and behavioral factors. In recent years, among biological risk factors for PSF occurrence is being considered post-ischemic inflammatory response.Aim: to study the dynamic patterns of blood systemic inflammatory markers depending on the time of PSF onset and PSF clinical course. Object and methods. We recruited in the study 49 patients with ischemic acute cerebrovascular events (ACE) – strokes and transient ischemic attacks. PSF was diagnosed by use of questionnaire – Fatigue Assessment Scale. On the ground of the time-based PSF characteristics we conditionally divided all PSF cases as early PSF (that manifested within the first month after ACE onset with subsequent self-resolution not later than at 3 months time-point observation), persistent PSF (that manifested within the first post-stroke month and was still present at 3 months timepoint observation) and late PSF (that manifested at 3 months after ACE onset or later). It was included 15 patients with early PSF, 15 patients with persistent PSF and 9 patients with late PSF. Control group consisted of 10 patients without PSF. Diagnosis of PSF presence/absence and simultaneous measurement of systemic inflammatory markers (C-reactive protein (CRP), interleukin (IL)-1 ?, IL-6) in blood serum by ELISA method was carried out at the certain time points after ACE onset. Variables were expressed as mediana (Me) and interquartile (25%-75%) range (Q1- Q3). Data were evaluated using non-parametric comparisons (Mann-Whitney, Friedman, Wilcoxon, Newman-Keuls tests). A p-value less than 0,05 was considered statistically significant. Results and discussion. Within the first 3 days after ACE onset, regardless of presence (absence) of PSF, all patients had much less identical elevated mean CRP level (within the range of 27,8 (25,3-29,2) mg/l to 29,0 (26,8-30,3) mg/l). However, in the next months, dynamics of changes in mean CRP concentration were significantly different, depending on PSF presence and on PSF duration. In the non-PSF patients, mean CRP level was significantly lowered already at 1 month after ACE onset (to 14,6 (5,4-23,0) mg/l) compared to baseline values. In the patients with early PSF, at 3 months time-point observation, on the background of self-resolved PSF, mean CRP level was significantly reduced (to 15,5 (12,7-22,9) mg/l) compared to the previous two measurements (at the first 3 days and at 1 month after PSF onset) and compared with mean value of CRP concentration in the patients with persistent PSF at 3 months after ACE onset (28,3 (24,8-32,4) mg/l). In the patients with persistent PSF, mean CRP level was significantly reduced only at 6 months time-point observation (to 13,3 (7,3-23,0) mg/l), compared with the all three previous measurements. In the patients with late PSF, mean CRP level was relatively low (12,3 (4,8-21,8) mg/l) and practically didn’t differ from mean CRP serum value in the non-PSF patients at 1 month after the ACE onset. Mean L-1? levels were stable during the whole observation period with the exception for the patients with persistent PSF who had significant serum IL-1? elevation at 1 month time-point observation (to 24,0 (20,5-25,5) pg/l), compared with the first 3 days mean value (18,0 (17,0-20,0) pg/l), followed by decreasing to baseline mean value at 3 months time-point observation (to 18,0 (16,5-22,0) pg/l). Serum mean levels of IL-6 were unchanged during the whole observation period regardless of PSF presence (absence) and regardless of PSF clinical course as well. Conclusions 1. In PSF patients the time patterns of CRP reduction during the first months after ACE onset are much less synchronized with PSF duration. 2. In PSF patients, an increase of IL-1? level during acute ACE period is associated with prolongation of PSF duration at least till recovery ACE period. 3. PSF that first appeared during recovery ACE period is not associated with an increase in the blood level of any systemic inflammatory marker

Keywords

• stroke
• fatigue
• intensity
• interleukin
• C-reactive protein.