A DTI study of the contralateral corticospinal tract modeled through simulated intracranial space-occupying lesions in macaque brain motor areas

Recent studies found that a loss of motor function following corticospinal tract (CST) damage can, to some extent, be restored. Few studies, however, examine how space-occupying lesions in the brain motor area may affect the contralateral CTS structure and function. We performed a simulation of intracranial space-occupying lesions in the brain motor area by implanting of balloons into the brains of the two healthy macaques. Diffusion tensor imaging (DTI) was performed on the macaques’ brains four times to measure the FA values of the contralateral CST operative area. The results showed that on the day of balloon implantation, the FA values had no obvious effect, but with time the effect increased, becoming increasingly apparent one week after removing the balloons. Experimental results demonstrated that this model was both feasible and reliable. After the simulated space-occupying lesions occurred in the brain motor area, DTI showed a compensatory response of the contralateral CTS, which remained for a short period of time even after the lesions were removed. This result suggests that the contralateral CST may then also contribute to recovery of limb function.

Keywords
Macaque; Simulation model of intracranial space-occupying lesions; Corticospinal tract; Diffusion tensor imaging