Characterising Arm Recovery in People with Severe Stroke (CARPSS): protocol for a 12-month observational study of clinical, neuroimaging and neurophysiological biomarkers

Introduction: In individuals with early (indexed ≤7 days poststroke) and severe upper limb paresis (shoulder abduction and finger extension score of <5 out of 10), our objectives are to: (1) determine if biomarkers of brain structure and function collected at <1 month poststroke explain who will experience clinically important recovery over the first 12 months poststroke; (2) compare stroke survivors' perceptions of personally meaningful recovery to clinically important recovery; and (3) characterise the trajectory of change in measures of motor function, brain structure and function.

Methods and analysis: Prospective observational study with an inception cohort of 78 first-time stroke survivors. Participants will be recruited from a single, large tertiary stroke referral centre. Clinical and biomarker assessments will be completed at four follow-up time points: 2 to 4 weeks and 3, 6 and 12 months poststroke. Our primary outcome is achievement of clinically important improvement on two out of three measures that span impairment (Fugl-Meyer Upper Limb, change ≥10 points), activity (Motor Assessment Scale item 6, change ≥1 point) and participation (Rating of Everyday Arm-use in the Community and Home, change ≥1 point). Brain biomarkers of structure and function will be indexed using transcranial magnetic stimulation and MRI. Multilevel modelling will be performed to examine the relationship between clinically important recovery achieved (yes/no) and a priori defined brain biomarkers related to the corticospinal tract and corpus callosum. Secondary analyses will compare stroke survivor's perception of recovery, as well as real-world arm use via accelerometry, to the proposed metric of clinically meaningful recovery; and model trajectory of recovery across clinical, a priori defined biomarkers and exploratory variables related to functional connectivity.

Ethics and dissemination: Approved by the hospital and university ethics review boards. Results will be disseminated through peer-reviewed publications and conference presentations.

Trial registration number: NCT02464085.