Purpose: Diffusion tensor imaging (DTI) studies indicate the structural integrity of the ipsilesional corticospinal tract (CST) and the transcallosal motor tract, which are closely linked to stroke recovery. However, the individual contribution of these 2 fibers on different levels of outcomes remains unclear. Here, we used DTI tractography to investigate whether structural changes of the ipsilesional CST and the transcallosal motor tracts associate with motor and functional recovery after stroke rehabilitation.
Methods: Ten participants with post-acute stroke underwent the Fugl-Meyer Assessment (FMA), the Wolf Motor Function Test (WMFT), the Functional Independence Measure (FIM), and DTI before and after bilateral robotic training.
Results: All participants had marked improvements in motor performance, functional use of the affected arm, and independence in daily activities. Increased fractional anisotropy (FA) in the ipsilesional CST and the transcallosal motor tracts was noted from pre-treatment to the end of treatment. Participants with higher pre-to-post differences in FA values of the transcallosal motor tracts had greater gains in the WMFT and the FIM scores. A greater improvement on the FMA was coupled with increased FA changes along the ipsilesional CST.
Conclusions: These findings suggest 2 different structural indicators for post-stroke recovery separately at the impairment-based and function-based levels.
Keywords: Diffusion tensor imaging; corticospinal tract; motor recovery; rehabilitation; stroke; transcallosal motor tracts.