Enhancement of STroke REhabilitation with Levodopa (ESTREL): Rationale and design of a randomized placebo-controlled, double blind superiority trial

Rationale: Novel therapeutic approaches are needed in stroke recovery. Whether pharmacological therapies are beneficial for enhancing stroke recovery is unclear. Dopamine is a neurotransmitter involved in motor learning, reward, and brain plasticity. Its prodrug levodopa is a promising agent for stroke recovery. Aim and hypothesis: To investigate the hypothesis that levodopa, in addition to standardized rehabilitation therapy based on active task training, results in an enhancement of functional recovery in acute ischemic or hemorrhagic stroke patients compared to placebo. Design: ESTREL (Enhancement of Stroke REhabilitation with Levodopa) is a randomized (ratio 1:1), multicenter, placebo-controlled, double-blind, parallel-group superiority trial. Participants: 610 participants (according to sample size calculation) with a clinically meaningful hemiparesis will be enrolled ⩽7 days after stroke onset. Key eligibility criteria include (i) in-hospital-rehabilitation required, (ii) capability to participate in rehabilitation, (iii) previous independence in daily living. Intervention: Levodopa 100 mg/carbidopa 25 mg three times daily, administered for 5 weeks in addition to standardized rehabilitation. The study intervention will be initiated within 7 days after stroke onset. Comparison: Matching placebo plus standardized rehabilitation. Outcomes: The primary outcome is the between-group difference of the Fugl-Meyer-Motor Assessment (FMMA) total score measured 3 months after randomization. Secondary outcomes include patient-reported health and wellbeing (PROMIS 10 and 29), patient-reported assessment of improvement, Rivermead Mobility Index, modified Rankin Scale, National Institutes of Health Stroke Scale (NIHSS), and as measures of harm: mortality, recurrent stroke, and serious adverse events. Conclusion: The ESTREL trial will provide evidence of whether the use of Levodopa in addition to standardized rehabilitation in stroke patients leads to better functional recovery compared to rehabilitation alone.