Prediction of prognosis of upper-extremity function following stroke-related paralysis using brain imaging

[Purpose] Diffusion tensor imaging (DTI) has attracted attention as a method for determining prognosis following paralysis after stroke. However, DTI can assess the degree of damage to the corticospinal tract but cannot evaluate other brain regions. In this study, we examined in detail the prognosis of upper-limb function of the paralyzed side following stroke, using DTI and voxel-based morphometry (VBM). [Subjects and Methods] We studied 17 consecutive patients diagnosed with stroke, including hemorrhagic and ischemic types, who exhibited hemiparesis and were treated in our hospital. DTI and VBM were performed 14 days after admission. Outcome measurements that assessed upper limb function were Fugl-Meyer Assessment (FMA) and Motor Activity Log (MAL), which were applied after 3 months. [Results] The fractional anisotropy ratio of the bilateral cerebral peduncles (rFA) was significantly correlated with FMA, amount of use, and quality of movement 3 months after stroke. The precentral gyrus significantly degenerated as compared with the control group for a case with notable motor paralysis, for which rFA was high. [Conclusion] We suggest it may be possible to predict recovery of upper limb function following stroke by combining DTI and VBM visualization methods.