Subcortical Volumes Associated With Post-Stroke Motor Performance Vary Across Impairment Severity, Time Since Stroke, And Lesion Laterality: An Enigma Stroke Recovery Analysis

Associations between subcortical gray matter volume and motor performance post-stroke are unclear, partly because many stroke MRI studies are underpowered. Potential influences of the severity of motor impairment, lesion laterality, and time since stroke on these associations is also unknown. Here, we addressed these questions using a large dataset (n=629) from the ENIGMA Stroke Recovery working group (http://enigma.usc.edu). Regression analyses examined brain volumes as predictors of motor scores. ENIGMA FreeSurfer protocols extracted volumes from 16 subcortical regions on T1-weighted MRIs; segmentations were manually quality controlled. Motor scores were calculated as a percentage of the maximum possible score (100% = no impairment). Covariates (e.g., age, sex, intracranial volume) were modeled. Statistical significance was assessed nonparametrically by permutation. Separate analyses were performed, stratifying by motor severity and time since stroke. Each analysis was also subdivided by lesioned hemisp...