Alteration of brain regional homogeneity of monkeys with spinal cord injury: A longitudinal resting-state functional magnetic resonance imaging study.

Purpose: To investigate the longitudinal brain regional homogeneity (ReHo) changes in nonhuman primate after spinal cord injury (SCI) by resting-state functional magnetic resonance imaging (fMRI).

Methods: Three adult female rhesus monkeys underwent unilateral thoracic cord injury. A resting-state fMRI examination was performed in the healthy stage and 4, 8, and 12 weeks after the injury. The ReHo value of each voxel in the monkey brain was calculated and compared between pre- and post-SCI monkeys with paired t test. The regions of interest (ROIs) in the significantly changed ReHo regions were set. The correlations between the ReHo change and the time after injury were also determined.

Results: Compared with those in healthy period, the ReHo values of the left premotor cortex and the anterior cingulate cortex (ACC) in post-SCI rhesus monkeys significantly increased in 4-week follow-up examinations. The ReHo values of posterior cingulate cortex, left precuneus, left temporal parietooccipital area, and bilateral superior parietal lobules decreased at 8-week follow-up examinations. In 12-week follow-up examinations, the ReHo values of the left postcentral gyrus, right caudate nucleus, and superior temporal gyrus increased. Correlation analysis showed positive correlations between left ACC and the postoperative time.

Conclusion: SCI can change the regional synchronism of brain activity in sensorimotor system and the default mode network. These findings may help us to understand the potential pathophysiological changes in the central nervous system after SCI.