Relationship between diffusion-tensor fractional anisotropy and long-term outcome in patients with hemiparesis after intracerebral hemorrhage

We assessed the relationship between fractional anisotropy (FA) values of magnetic resonance-diffusion tensor imaging (DTI) and long-term outcome (3-7 months after onset) in patients with hemiparesis after intracerebral hemorrhage (N = 12). DTI data were obtained on days 14-18. FA values within the cerebral peduncle were analyzed using a computer-automated method. Motor outcome of hemiparesis was evaluated using Brunnstrom stage (six-point scale: severe to normal) for separate shoulder/elbow/forearm, wrist/hand, and lower extremity functions when patients were discharged from a long-term rehabilitation facility 3-7 months after onset. In addition, the motor component of the functional independence measure (FIM-motor) was scored. The ratio of FA values in the affected hemisphere to those in the unaffected hemisphere (rFA) was assessed in relation to the clinical data (Spearman's rank correlation test, P < 0.05). Analysis revealed a statistically significant relationship between rFA and upper extremity function (R = 0.863 for shoulder/elbow/forearm; 0.834 for wrist/hand). Although statistically significant, the relationship between rFA and lower extremity function was less evident (R = 0.609). In contrast, analysis of rFA and FIM-motor scores did not reveal statistical significance. FA values within the cerebral peduncle are tightly associated with long-term outcomes of upper extremity function.