Lesion locations associated with gait independence in patients with stroke: a support vector regression...

Regaining independence in gait is a major goal of stroke rehabilitation. Although gait ability is significantly affected by age and motor paresis, independent walking can be achieved even in patients with advanced age and/or severe paresis. Brain imaging provides valuable prognostic information regarding gait independence. However, the characteristics of the brain lesions that contribute to the recovery of gait ability, even in cases of severe paresis, remain unclear. This study aimed to identify brain lesion areas associated with gait independence using support vector regression lesion symptom mapping (SVR-LSM), excluding the effects of age and motor paresis.

We conducted an SVR-LSM analysis in 132 patients with first-time strokes using age and Fugl-Meyer motor assessment scores for the lower extremities as covariates.

Gait independence at admission was associated with the corticospinal tract (CST), putamen, and pallidus when adjusted for age, whereas no significant association with lesion location was observed after adjusting for motor function. Gait independence at discharge was correlated with the CST, sensory tracts, putamen, pallidus, thalamus, and supplementary motor area (SMA).

These findings suggest that, at admission, strong motor impairments overshadowed the association of motor paresis with specific lesion locations when motor paresis was controlled. By the time of discharge, regions such as the CST, putamen, and SMA were highlighted even after controlling for motor impairments. This indicates that factors other than motor deficits, such as motor learning, play a significant role in achieving gait independence. Identifying lesion locations may be crucial for enhancing the skills required for independent walking despite persistent paresis.