Recovery and prediction of hand motor function after stroke : a longitudinal study using novel methods to quantify hand function and connectivity in brain networks

Background: Stroke is a heterogeneous disease and a leading cause of physical disability among adults, severely affecting people’s health and life worldwide. According to current figures, one in four people risk suffering a stroke during their lifetime. One of the most common and enduring symptoms of stroke is unilateral weakness of the upper extremity. A key challenge in post stroke rehabilitation and research is the highly variable degree of recovery in patients and a remaining incomplete understanding of which factors contribute to this variability. This problem contributes to less effective interventions. Today’s prediction models lack precision on the individual level. Improved prediction models could assist clinicians in giving information on an individual’s expected outcome and recovery potential, and guide selection of interventions matching the specific impairment profile of the patient. Aim: The overall aim of this longitudinal prospective study was to identify key determinants for recovery of hand function after stroke by combining fine-grained measures of sensorimotor impairment and activity together with commonly used clinical scales and a multimodal neuroimaging protocol. Method and materials: Patients admitted to a regional in-patient rehabilitation department in Stockholm, Sweden, within 2-6 weeks of onset of a first time ischemic or haemorrhagic stroke and with upper extremity hemiparesis were eligible for inclusion. Exclusion criteria were inability to understand or follow instructions, disorders other than stroke affecting hand function, a cerebellar lesion, or contraindications for Magnetic Resonance Imaging (MRI) examination. Written informed consent was obtained from all participants. The study was approved by the Regional Ethical Review Board. The four Studies of this thesis were based on data collected in a prospective observational study of one study cohort, who underwent repeated assessments at three time points: ~3 weeks, 3 months and 6 months after stroke onset. Novel sensorimotor ...