Mario Minor Murakami1, Carl Trolle2, Diana Tran1, Brittany Seipp1, Nguyen Nguyen3, Ricardo Battaglino3, Leslie Morse3, Clas Linnman1
1Spaulding Rehabilitation Hospital, 2Uppsala University, 3University of Minnesota
Objective:
To investigate the alterations in structural connectivity within and between brain networks among individuals with spinal cord injury (SCI).
Background:
SCI is characterized by the disruption of neural pathways in the spinal cord, resulting in sensory, motor, and autonomic deficits. While the primary injury occurs within the spinal cord, there is growing recognition that the impact of SCI extends beyond the injury site, affecting brain regions and their connections.
Design/Methods:
59 persons with spinal cord injury and 27 healthy controls from two sites underwent clinical, brain magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) on 3T scanners. We created brain surface regions of interest (ROIs) using FreeSurfer from MRI. Extracted diffusion tensor imaging (DTI) and performed preprocessing using MRtrix3 and FSL. And performed probabilistic tractography analysis using TRACULA and TBSS. We used R and Python for group comparison and tested correlations using Pearson’s coefficient.
Results:
Using DTI, the SCI group showed reduced fractional anisotropy (FA) in various white matter regions (pFWE<0.05) with TBSS from FSL and threshold-free cluster enhancement (TFCE). And probabilistic tractography from the SCI group using TRACULA showed decreased FA (pFWE<0.05) in seven white matter tracts (body, genu and rostrum from the corpus callosum, superior longitudinal fasciculus (SLF) 1 and 2 from the left hemisphere and fornix and SLF1 from the right hemisphere). Increased radial diffusivity in nine white matter tracts (body, rostrum from the corpus callosum, acoustic radiation, extreme capsule, and fornix from the left hemisphere and cortical spinal tract, fornix and SLF1 and 2 from the right hemisphere) was observed.
Conclusions:
Individuals with SCI exhibit alterations in the structural connectivity within their brain networks evident from the decreased FA in multiple white matter tracts. These findings may broadly describe the neural impacts of SCI beyond the injury site and neural adaptations due to paralysis.