Minimally invasive procedures reduced the damages to motor function in patients with thalamic hematoma: observed by motor evoked potential and diffusion tensor imaging.

BACKGROUND: The purpose of this study was to observe changes in motor function using diffusion tensor imaging (DTI) and motor-evoked potential (MEP) in patients with thalamic hematoma treated by minimally invasive procedures.

METHODS: Forty-three patients with thalamic hematoma were randomized to either a minimally invasive group (MI group) or a medical treatment group (MT group). The patients in the MI group underwent whole-brain DTI and MEP measurements both before and 2 weeks after the thalamic hematoma was evacuated by minimally invasive procedures. The fractional anisotropy (FA) values of the corticospinal tract (CST) in the internal capsule and MEP ipsilateral to the hematoma side and the contralateral side were determined and then compared with the MT group.

RESULTS: DTI showed that fibers in the internal capsule ipsilateral to the hematoma decreased either in number or were interrupted because of hematoma-induced damages, and in both groups, the CST FA values on admission were significantly lower (0.428 ± 0.032 and 0.415 ± 0.048 for the MI and MT groups, respectively) than the control values. Two weeks after the hematoma was evacuated, the number of fibers and the FA values of the CST in the internal capsule had both increased significantly relative to the values on admission. MEP was recorded simultaneously in all patients who were treated with minimally invasive procedures, and the latency of MEP decreased compared with the MT group. As FA values of the CST in internal capsule increased and MEP appeared with its latency decreased, the modified National Institutes of Health Stroke Scale score decreased after the surgery.

CONCLUSIONS: Minimally invasive procedures for thalamic hematoma evacuation could effectively reduce the degree of injury to the function as observed by a combination of DTI and MEP measurements.