Risk factors for early-onset and late-onset fatigue after a stroke

BACKGROUND. Post-stroke fatigue is a predictor of adverse outcomes such as high mortality, worse functional outcome and daily living dependence. It is a heterogeneous syndrome that changes over time, as demonstrated by studies. AIM. The aim of the study was to assess dynamic changes of risk factors related to post-stroke fatigue during a year after first-ever stroke. MATERIALS AND METHODS. This study formed a section of a prospective observational study involving of a cohort of 348 patients experiencing their first-ever stroke (53.2% male, 46.8% of female, with a mean age of 66±12 years). During the acute stroke period, 75 patients completed the Fatigue Severity Scale (FSS). Additionally, 19 patients completed the FSS at both 3 and 6 months after their stroke, while 33 patients did so at 12 months post-stroke. The neurological (NIHSS, Rankin) and psychiatric (HDRS, HARS) evaluation scores, pain scores measured with visual analogue scales, cognitive test results (MMSE, TMT-B) taken at the same time point, and locus control testing were compared with these findings. Spearman coefficient was utilized. The relationship between fatigue and depression (DSM-IV), stroke location, and patients’ demographic characteristics were tested with a χ2-test to avoid partiality. RESULTS. Fatigue following a stroke during the acute stage showed an association with pain, depression, anxiety scores and complaints about cognitive dysfunction prior to the stroke. In contrast, late-onset fatigue (12 months post-stroke) demonstrated a link with medical locus of control and more severe neurological deficit. CONCLUSION. Post-stroke fatigue manifests as a heterogeneous syndrome, characterized by changes in risk factors over time. Due to its complexity, accurate assessment necessitates the use of modern technologies, such as EMA and digital phenotyping.