Impact of early severity of finger paresis on upper limb motor recovery and functional outcomes in people after stroke: a retrospective cohort study

Background Upper-limb hemiparesis is a frequent, disabling post-stroke complication. While initial severity is a dominant predictor of long-term recovery, performing complex motor assessments is often challenging during the unstable, very acute phase. Objectives To evaluate the association between very acute hand-finger paresis severity and subsequent subacute outcomes across multiple domains: motor impairment, motor capacity, and activities of daily living (ADL). Methods This retrospective cohort study included post-stroke individuals ( N = 473) receiving continuous rehabilitation from acute to subacute phases between 2019 and 2021. Initial hand-finger motor paresis severity was assessed using the Stroke Impairment Assessment Set Finger-Function (SIAS-FF). Outcomes at hospital discharge were evaluated using SIAS-FF, SIAS Knee-Mouth (SIAS-KM) test for proximal function, the Simple Test for Evaluating Hand Function (STEF) for motor capacity, and Functional Independence Measure (FIM) selfcare items for ADL. Multivariable regression models (ordinal logistic regression and generalized linear models) adjusting for age and length of hospital stay were implemented to test associations between the acute hand-finger paresis severity and subacute outcomes. Results Analyses included 356 participants (mean age, 66.7 years). Acute finger paresis severity (assessed at 1.7 days post-stroke) was associated with subacute outcomes (at 86.9 days) in multivariable regression models ( p < 0.01). Participants with better SIAS-FF scores in the acute phase achieved better discharge outcomes across all measures, including SIAS-FF, SIAS-KM, STEF, and FIM selfcare scores, even after controlling for age and length of hospital stay. Conclusions Severity of hand-finger paresis in the very acute phase is significantly associated with global upper-limb recovery. The SIAS-FF is a simple clinical tool that provides useful information for estimating post-stroke functional outcomes.