What is the prevalence and distribution of upper limb weakness early post-stroke?

ABSTRACT

Background: A growing body of international research suggests the prevalence of upper limb weakness early after stroke is currently lower (40-57%) than widely cited values of 70-80% from two decades ago. Recent work also indicates the distribution of upper limb weakness may be bimodal, with a higher proportion of people with severe or little/no weakness as compared to mild/moderate weakness. Aim: To describe the prevalence and distribution of upper limb weakness early post-stroke. Methods: Patients admitted to a tertiary acute stroke unit with a suspected stroke were screened between November 2018 to February 2020 (interrupted by COVID-19) and April to November 2021. Upper limb weakness was captured via Shoulder Abduction and Finger Extension (SAFE) score (0-10), which was prospectively assessed at first contact by the unit therapist. Data on stroke type, acute medical intervention received, and National Institute of Health Stroke Scale (NIHSS) were also extracted. Results: A total of 662 individuals with confirmed stroke (median NIHSS score 6, IQR 2-13) were administered SAFE a median 1 (IQR 1,2) day after unit admission. Only 46.2% had upper limb weakness (SAFE score ≤9). Three most common SAFE scores were 10 (53.8%), 8 (11.5%) and 0 (9.4%). The subgroup severity distribution was 59.2% little to no impairment (SAFE 9-10), 24.1% mild to moderate impairment (SAFE 5-8), and 16.7% severe impairment (SAFE 0-4). Approximately one third (29.8%) received ≥1 acute interventions (e.g., thrombolysis, thrombectomy). Data collection remains ongoing, and a larger total sample will be presented. Conclusion: The prevalence of upper limb weakness at this single tertiary centre aligns with recent international data. A better understanding of the upper limb weakness profile will help inform service delivery e.g., shifting resources to subgroups which are more common. Furthermore, it can guide researchers in target population selection in trials, which can enhance generalisability of findings.