Cerebral blood flow asymmetry in motor-related regions is associated with 30-day upper-limb motor recovery after acute ischemic stroke

Background Upper-limb motor impairment is a leading cause of long-term disability after acute ischemic stroke (AIS), yet early prognostication relies mainly on clinical scales. Cerebral blood flow (CBF) asymmetry measured by arterial spin labeling (ASL) perfusion MRI may indicate recovery potential. We investigated whether acute-phase CBF asymmetry indices (AIs) in six motor-related regions are associated with 30-day upper-limb motor recovery. Methods Sixty patients with AIS underwent pseudo-continuous ASL MRI within 72 h of onset and completed the 30-day Fugl-Meyer Assessment of the Upper Extremity (FMA-UE). Patients were classified into good ( n = 30, ΔFMA-UE ≥ 10) and poor ( n = 30, ΔFMA-UE ≤ 4) recovery groups; both thresholds lie outside the published minimal clinically important difference range, and no patient fell between them. Mean CBF was extracted bilaterally from the precentral and postcentral gyri, supplementary motor area, putamen, pallidum, and thalamus, and AIs were calculated. Regional AI–ΔFMA-UE associations were assessed with Spearman correlation, partial correlation, analysis of covariance, and linear regression. Results Precentral and postcentral gyrus AIs each correlated positively with ΔFMA-UE (both Spearman r = 0.30, p = 0.020; false-discovery-rate q = 0.020), persisting after adjustment for cognitive status, baseline FMA-UE, and lesion volume (partial r up to 0.326; all p < 0.05); other regional AIs showed negligible correlations (| r | < 0.09). In analysis of covariance (follow-up FMA-UE as outcome, baseline FMA-UE as covariate), precentral gyrus AI remained associated with the outcome (β = 0.13, 95% CI 0.01–0.25, p = 0.037; after cognitive adjustment, p = 0.045). A model combining the six AIs with age and cognitive status explained 29.7% of variance in ΔFMA-UE ( F (8,51) = 2.69, p = 0.015), but adding the AIs to clinical variables alone did not significantly improve explanatory performance (ΔR 2 = 0.048, p = 0.170); this R 2 reflects the combined imaging–clinical model rather than ASL alone. Conclusion Sensorimotor-cortex CBF asymmetry within 72 h of onset was associated with 30-day upper-limb motor recovery after AIS, robust to adjustment for clinical variables. Acute-phase ASL may serve as a noninvasive imaging indicator for recovery-oriented rehabilitation stratification, a hypothesis requiring further validation.