title: Biomarkers and perfusion--training-induced changes after stroke (BAPTISe): protocol of an observational study accompanying a randomized controlled trial.
abstract: BACKGROUND
  Physical activity is believed to exert a beneficial effect on functional and cognitive rehabilitation of patients with stroke. Although studies have addressed the impact of physical exercise in cerebrovascular prevention and rehabilitation, the underlying mechanisms leading to improvement are poorly understood. Training-induced increase of cerebral perfusion is a possible mediating mechanism. Our exploratory study aims to investigate training-induced changes in blood biomarker levels and magnetic resonance imaging in patients with subacute ischemic stroke.
  
  
  METHODS
  This biomarker-driven study uses an observational design to examine a subgroup of patients in the randomized, controlled PHYS-STROKE trial. In PHYS-STROKE, 215 patients with subacute stroke (hemorrhagic and ischemic) receive either 4 weeks of physical training (aerobic training, 5 times a week, for 50 minutes) or 4 weeks of relaxation sessions (5 times a week, for 50 minutes). A convenience sample of 100 of these patients with ischemic stroke will be included in BAPTISe and will receive magnetic resonance imaging (MRI) scans and an additional blood draw before and after the PHYS-STROKE intervention. Imaging scans will address parameters of cerebral perfusion, vessel size imaging, and microvessel density (the Q factor) to estimate the degree of neovascularization in the brain. Blood tests will determine several parameters of immunity, inflammation, endothelial function, and lipometabolism. Primary objective of this study is to evaluate differential changes in MRI and blood-derived biomarkers between groups. Other endpoints are next cerebrovascular events and functional status of the patient after the intervention and after 3 months assessed by functional scores, in particular walking speed and Barthel index (co-primary endpoints of PHYS-STROKE). Additionally, we will assess the association between functional outcomes and biomarkers including imaging results. For all endpoints we will compare changes between patients who received physical fitness training and patients who had relaxation sessions.
  
  
  CONCLUSIONS
  This exploratory study will be the first to investigate the effects of physical fitness training in patients with ischemic stroke on MRI-based cerebral perfusion, pertinent blood biomarker levels, and functional outcome. The study may have an impact on current patient rehabilitation strategies and reveal important information about the roles of MRI and blood-derived biomarkers in ischemic stroke.
  
  
  BACKGROUND
  NCT01954797.
authors: Center for Stroke Research Berlin (CSB), Charité - Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany. alexander.nave@charite.de.
authors: Alexander H
authors: AH
authors: Nave
authors: Jan M
authors: JM
authors: Kröber
authors: Peter
authors: P
authors: Brunecker
authors: Jochen B
authors: JB
authors: Fiebach
authors: Jonathan
authors: J
authors: List
authors: Ulrike
authors: U
authors: Grittner
authors: Matthias
authors: M
authors: Endres
authors: Andreas
authors: A
authors: Meisel
authors: Agnes
authors: A
authors: Flöel
authors: Martin
authors: M
authors: Ebinger
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult; D015415:Biomarkers / Q000378:metabolism; D015444:Exercise; D005081:Exercise Therapy / Q000379:methods; D005500:Follow-Up Studies; D008279:Magnetic Resonance Imaging; D019370:Observation; D010477:Perfusion / Q000379:methods; D012680:Sensitivity and Specificity; D000071939:Stroke Rehabilitation; D013997:Time Factors; D016896:Treatment Outcome; D016032:Randomized Controlled Trials as Topic; D064887:Observational Studies as Topic
chemical_list: D015415:Biomarkers