Gait performance in cerebral small vessel disease: associations with cognitive and oculomotor function and exploratory mediation analyses.

Abstract

Background: Gait impairment in cerebral small vessel disease (CSVD) is heterogeneous and may not be fully explained by conventional structural MRI markers. We investigated the associations of neuroimaging burden, cognitive function, and oculomotor function with gait performance in CSVD and explored potential indirect associations between CSVD burden and gait impairment.

Methods: We included 65 individuals with CSVD and 35 control participants. All participants underwent quantitative gait assessment, standardized neuropsychological evaluation, and oculomotor recording. Patients with and without gait disorder were compared after adjustment for the total CSVD load score. Correlation analyses assessed associations among neuroimaging markers, cognitive and oculomotor measures, and gait parameters. Exploratory mediation analyses examined cognitive and oculomotor measures as potential statistical indirect pathways between total CSVD load and gait performance.

Results: Compared with control participants, patients with CSVD had poorer gait, cognitive, and oculomotor performance (P < 0.05). Despite comparable total CSVD load, patients with gait disorder showed worse executive function and visuospatial ability, prolonged saccade latency, reduced fixation stability, and lower anti-saccade accuracy (FDR-adjusted P < 0.05). Total CSVD load and perivascular spaces (PVS) burden were associated with cognitive, gait, and oculomotor measures. In the exploratory mediation analyses, Trail Making Test-B performance showed a significant indirect association between total CSVD load and gait impairment, with no significant residual direct association. Trail Making Test-A performance, fixation stability, and saccade latency, also showed significant indirect association, while the corresponding direct associations remained significant.

Conclusions: Executive and oculomotor dysfunction were associated with gait impairment in CSVD and may partly account for the association between total CSVD burden and gait performance. These exploratory findings require confirmation in larger longitudinal studies.