Quantitative analysis of high-voltage-electrical spinal cord injury using diffusion tensor imaging

Abstract

The aim of this study was to investigate the relationships between clinical outcomes and the diffusion as well as electrical conduction characteristics of the spinal cord in patients with high-voltage-electrical injury but showing no abnormal radiological findings. We recruited eight high-voltage-electrical injury patients and eight healthy subjects matched for age and sex. Diffusion tensor imaging (DTI) and central motor conduction time (CMCT) were acquired in both patient and control groups. We obtained the patient and control group DTI indices according to the spinal cord levels (from C2 to C7) and parts (anterior, lateral, and posterior). The DTI indices of fractional anisotrophy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were inter-group-compared; additionally, they were intra-group-compared in relation to spinal cord level and part. The correlations among the DTI indices, CMCT, and neurological status of spinal cord injury also were analyzed. In the patient group relative to the control group, the FA value decreased and the MD and RD values increased in all of the regions of interest (ROIs), with statistical significance (p<0.05); the AD value did not differ. Within the patient group, comparing the anterior spinal cord with the lateral and posterior spinal cords, the FA decreased in the ROIs (p<0.05). The DTI indices did not differ by level. The ASIA motor score tended to correlate with the FA of the anterior spinal cord (p=0.16) and with CMCT (p=0.12). In conclusion, DTI revealed myelopathy in patients with high-voltage-electrical injury, and corroborated high-voltage-electrical spinal cord injury’s reported pathophysiology, including myelinopathy and ascending homogeneous involvement more typically affecting the anterior spinal cord.