Recovery of Supraspinal Microstructural Integrity and Connectivity in Patients Undergoing Surgery for Degenerative Cervical Myelopathy

BACKGROUND: It remains unknown if the progressive loss of axonal conduction along sensorimotor tracts can be recovered after surgery in patients with degenerative cervical myelopathy (DCM) and if subsequent adaptive microstructural changes are associated with the neurological improvement. OBJECTIVE: To investigate the upstream recovery of microstructural integrity and reorganization of microstructural connectivity that occurs in patients with DCM after surgical decompression. METHODS: Preoperative and postoperative cerebral diffusion tensor imaging arid diffusion spectrum imaging data were collected for 22 patients with DCM (age = 56.9 +/- 9.1 years). Paired t-tests were used to identify significant microstructural changes within cohorts, and correlation analysis was used to identify whether those changes are associated with neurological improvement. RESULTS: Before surgery, higher structural connectivity (SC) was observed in the prefrontal/ frontal lobes, anterior cingulate, the internal and external capsules, and the anterior, posterior, and superior regions of the corona radiata fibers. Following surgery, an increased modified Japanese Orthopaedic Association score was associated with increased SC from the primary sensorimotor regions to the posterior cingulate and precuneus; increased SC between the cerebellum and the bilateral lingual gyri; and decreased SC from areas of the limbic system to the basal ganglia and the frontal lobe. In addition, increased fractional anisotropy and normalized quantitative anisotropy values along white matter fibers responsible for conveying sensory information and motor coordination and planning were associated with neurological improvement of patients with DCM after surgery. CONCLUSION: Recovery of microstructural integrity along the corticospinal tract and other sensorimotor pathways, together with supraspinal reorganization of microstructural connectivity within sensory and motor-related regions, was associated with neurological improvement after surgical decompression.