Association Between Cortical Cerebral Microinfarct and Motor Performance at One-Year Follow-Up in Patients with Cerebral Small Vessel Disease: An Exploratory Study

Background/Objectives: Cerebral small vessel disease (CSVD) is an important contributor to motor impairment. Cortical cerebral microinfarct (CCMI) is an emerging imaging marker of CSVD. Although its association with cognitive impairment has been well established, its relationship with motor function remains unclear. We explored associations of CCMI with motor performance at baseline and 1-year follow-up in this secondary analysis of data from the China Imaging-based Biobank of Cerebral Small Vessel Diseases. Methods: CCMI was assessed on baseline brain magnetic resonance imaging. Motor function was assessed at baseline and at 1-year follow-up. Outcomes were gait speed, poor balance performance (Short Physical Performance Battery balance score ≤ 2), abnormal gait (Scale for the Assessment and Rating of Ataxia gait score ≥ 2), and repeated chair-stand time. Gait speed was the primary outcome and all other motor outcomes were secondary. Multivariable linear and logistic regression models were used, with Benjamini–Hochberg correction applied to secondary outcomes. Results: The analysis included 192 patients, of whom 74 had 1-year follow-up motor data. At baseline, 55 patients (28.65%) had CCMI. Compared with patients without CCMI, those with CCMI had lower gait speed [0.92 (0.75–1.12) vs. 1.05 (0.87–1.16) m/s]. They also had higher prevalences of poor balance performance (29.09% vs. 14.60%) and abnormal gait (63.64% vs. 36.50%). However, fully adjusted analyses provided no conclusive evidence of baseline associations. At 1-year follow-up, CCMI was associated with slower gait speed after adjustment for demographic factors, baseline gait speed, and total CSVD burden (adjusted β −0.16, 95% CI −0.24 to −0.08; p < 0.001). CCMI was also nominally associated with longer repeated chair-stand time (adjusted β 2.07, 95% CI 0.39–3.75; nominal p = 0.02; adjusted p = 0.06), but this association did not survive correction for multiple comparisons. Conclusions: CCMI was associated with slower gait speed at 1-year follow-up in patients with CSVD. This finding is hypothesis-generating and requires confirmation.