Functional and structural effects of the early initiation of gait training with Hybrid Assistive Limb in addition to the conventional physical therapy on patients with acute stroke

Background: There are still limited reports about functional and structural effects of therapeutic interventions like robot-assisted training in addition to the conventional physical therapy (CPT) in the early periods after stroke onset.
Purpose: The aims were to examine walking independency and microstructural changes of white matter by diffusion tensor imaging (DTI) using a 3-Tesla MRI scanner associated with gait training with Hybrid Assistive Limb (HAL) in addition to CPT in patients with acute stroke.
Methods: Patients with first-ever stroke, who required a walking aid and were able to start gait training within 1 week of stroke onset were included. Patients were assigned to either the CPT group or gait training using HAL. Functional measurements were examined at baseline, the 2nd (2-6 weeks), and 3rd (3–5 months) assessments. DTI was examined at baseline and 3rd assessment. Patients in the HAL group underwent gait training using HAL until the 2nd assessment. Voxel-based statistical analyses of fractional anisotropy (FA) images were performed using diffusion metric voxel-wise analyses. Volume of interest (VOI)-based analyses were used to assess changes in FA (ΔFA).
Results: Thirty-seven patients (19 from CPT and 18 from HAL, median age=69 years) were enrolled. At the 2nd assessment, total Functional Independence Measure (FIM) score was higher in the HAL group than in the CP group (90.1 vs. 79.0, p=0.042); however, this difference disappeared at the 3rd assessment. Twenty-seven patients (17 from CPT and 10 from HAL) completed the DTI study. Compared to baseline, there were decreases in FA in the ipsi-lesional cerebral peduncle in the CPT group (p < .001) and increases in the contra-lesional rostrum of the corpus callosum in the HAL group (p < .001) at the 3rd assessment, consistent with the mean ΔFA in each group from VOI analysis (CPT/HAL: cerebral peduncle, −0.066/−0.027, p = .027; corpus callosum, 0.002/0.042, p < .001). Conclusion: Significant improvement of FIM in the HAL group was identified at the 2nd assessment. Early initiation of gait training with HAL after stroke onset facilitated the prevented the progression of Wallerian degeneration of the affected pyramidal tract and recovery of inter-hemispheric communication.