Diffusion tensor imaging in evaluating the injury of corticospinal tract in patients with hypertensive basal ganglia hemorrhage

Abstract

Objective To investigate the value of diffusion tensor imaging (DTI) in evaluating the injury of corticospinal tract (CST), including the motor dysfunction and the integrity of CST, in patients with hypertensive intracerebral hemorrhage (HICH), and explore the relation between DTI results and the recovery of myodynamia. Methods Clinical data of 10 healthy volunteers and 35 patients with HICH, admitted to our hospital and performed evacuation of hematoma from November 2006 to May 2009, were retrospectively analyzed; DTI by using a 3.0T MR canner were chosen on them and the imaging was analyzed by Functool software. The changes of directionality and integrity of SCT were analyzed on fractional anisorropic (FA) map, color-coded directional map, and three-dimensional white matter tractography. Myodynamic examination at Brunnstrom standard 2 months after rehabilitation nursing was performed in these patients. The correlation between the injured degree of CST and the recovery of myodynamia was analyzed. Results Fiber tractography derived from DTI was consistent with known white matter fiber anatomy in 10 healthy volunteers. Three patterns of corticospinal tract involvement were identified in 35 patients: the intact one in 11 patients (the ipsilateral corticospinal tract was almost the same as contralateral corticospinal tract), the partially damaged one in 18 patients (the ipsilateral corticospinal tract was less than 2/3 but larger than 1/3 contralateral corticospinal tract) and the almost completely damaged one in 6 patients (the ipsilateral corticospinal tract was less than 1/3 contralateral corticospinal tract). Different pattern had totally different clinical outcome and the intact one had a full recovery. The ipsilateral corticospinal tract showed significantly lower Brunnstrom scores of the upper extremities than the ipsilateral one (P<0.05); the Brunnstorm scores and the value of myodynamia among the 3 patterns were statistically different (P<0.05). The recovery of motor function was negatively correlated to the injured degree of CST (r=-0.931, P=0.000). Conclusion The DTI, offering the optimal visualization of white matter tracts can detect the injured degree of the corticospinal tracts and predicate the prognosis to some extent, thus, early evaluation of corticospinal tract injury based on DTI can provide predictive value for motor functional outcome in patients with HICH. Key words: Hypertensive intracerebral hemorrhage; Diffusion tensor imaging; Magnetic resonance imaging; Corticospinal tract