Relationship Between Motor Function, DTI, and Neurophysiological Parameters in Patients with Stroke in the Recovery Rehabilitation unit.

Objective: We investigated the relationship between pyramidal tract evaluation indexes (i.e., diffusion tensor imaging, transcranial magnetic stimulation (TMS)-induced motor-evoked potential (MEP), and central motor conduction time (CMCT) on admission to the recovery rehabilitation unit) and motor functions at discharge in patients with ischemic or hemorrhagic stroke.

Methods: Seventeen patients were recruited (12 men; 57.9 ± 10.3 years). The mean fractional anisotropy (FA) values of the right and left posterior limbs of the internal capsule were estimated using a computer-automated method. We determined the ratios of FA values in the affected and unaffected hemispheres (rFA), TMS-induced MEP, and the ratios of CMCT in the affected and unaffected hemispheres (rCMCT) and examined their association with motor functions (Fugl-Meyer Assessment (FMA) and Action Research Arm Test (ARAT)) at discharge.

Results: Higher rFA values of the posterior limb of the internal capsule on admission to the recovery rehabilitation unit led to a better recovery of upper limb function (FMA: r = 0.78, p < 0.001; ARAT: r = 0.74, p = 0.001). Patients without MEP had poorer recovery of upper limb function than those with MEP (FMA: p < 0.001; ARAT: p = 0.001). The higher the rCMCT, the poorer the recovery of upper limb function (ARAT: r = -0.93, p < 0.001). However, no association was observed between the pyramidal tract evaluation indexes and recovery of lower limb motor function.

Conclusions: Evaluating the pyramidal tract is useful for predicting upper limb function prognosis, but not for lower limb function prognosis.