Lesion-based structural and functional networks in patients with step length asymmetry after stroke.

Objective The aim of this study was to determine common structural and functional networks associated with asymmetric step length after unilateral ischemic stroke. Methods Thirty-nine chronic stroke patients were divided into two groups, based on the presence or absence of asymmetric step length. In each group, each lesion was mapped onto a brain magnetic resonance image. The structural and functional networks of brain regions connected to each lesion were identified using a public diffusion tensor and resting state function magnetic resonance image dataset. To identify brain regions associated with asymmetric step length, we conducted voxel-wise independent sample t-tests for structural and function lesion network maps. Results At least 85% of lesions showed functional network overlap in the bilateral frontal lobe. Functional connectivity of the dorsolateral prefrontal cortex in the contralesional hemisphere was significantly decreased in group 1 compared to that in group 2. Conclusions The dorsolateral prefrontal cortex may have an important role in compensating for an asymmetric step length after a unilateral stroke.