Early-stage structural and biochemical changes in cervical spinal cord after sensory nerve root injury revealed by multi-parametric MRI

Motivation: We hypothesize that dorsal nerve root injury induces inflammation-associated axonal degeneration in the adjacent regions in intact spinal cord. Goal(s): Our primary objective is to comprehensively evaluate early-stage regional changes in the cervical spinal cord of non-human primates following a unilateral injury to dorsal nerve root bundles of C4 and C5 segments. Approach: Diffusion, quantitative magnetization transfer, and chemical exchange saturation transfer MRI provide specific metrics for assessing structural and biochemical changes post-injury. Results: Results show secondary damage in the adjacent dorsal root entry zone (DREZ) and altered local fiber orientations after dorsal nerve root injury. Impact: Multi-parametric MRI offers sensitive and specific metrics for assessing changes within the spinal cord after sensory nerve root injury. Our findings reveal the early-stage structural and biochemical alterations at the damaged nerve roots and the adjacent dorsal root entry zone.