Corticospinal Tractography and Motor Function in Patients Undergoing Intracerebral Hemorrhage Evacuation

Randomized-controlled trial evidence has demonstrated that minimally invasive intracerebral hemorrhage (ICH) evacuation can improve outcomes in properly selected patients. Yet, there remains a need to optimize patient selection, operative technique, and prognosis following ICH evacuation. Magnetic resonance diffusion tensor imaging (DTI) allows visualization and quantification of critical white matter tracts. Corticospinal tract DTI (CST-DTI) is associated with motor function, awareness of which may improve treatment and prognosis in patients undergoing ICH evacuation.

Patients who underwent ICH evacuation with perioperative DTI were retrospectively reviewed. CST metrics (fractional anisotropy, radial diffusivity, axial diffusivity, geodesic anisotropy, fiber count, and tract volume) were associated with contralateral motor function preoperatively and postoperatively via the Medical Research Council scale (hemibody maximum of 10). Pearson correlation was used to estimate relationships between exposures and clinical outcomes; changes in motor function over time were determined by Wilcox signed-rank testing.

Seventeen patients were included, 12 each with preoperative and postoperative DTI, 7 with matched preoperative and postoperative DTI. Preoperative geodesic anisotropy was significantly associated with both preoperative motor function on the contralateral hemibody (R = 0.616, P = 0.032, Pearson correlation) and at postoperative day 1 (R = 0.606, P = 0.038). Restoration of a deformed CST could be seen in several patients from the preoperative to the immediate postoperative period. Postoperative axial diffusivity was associated with immediate postoperative motor function (R = 0.700, P = 0.011) and at median follow-up of 6.3 months post-ICH (R = 0.608, P = 0.036). There was a significant increase in motor scores on the affected hemibody from postoperative day 1 to last follow-up (median, 4.0 versus 6.0; P = 0.038, Wilcox signed-rank test).

Preoperative CST-DTI metrics are associated with both preoperative and immediate postoperative motor function after minimally invasive ICH evacuation. A restored CST after ICH evacuation could be seen in a subset of patients. Furthermore, postoperative axial diffusivity may be a marker of long-term motor function after ICH evacuation.