Acute and chronic changes in diffusivity measures after sports concussion.

Area of Science:

• Neuroscience
• Sports Medicine
• Radiology

Background:

• Concussive impacts cause brain acceleration/deceleration, leading to metabolic and electrophysiological changes.
• These alterations may stem from biomechanical strain affecting white matter, despite negative conventional neuroimaging findings.
• Diffusion Tensor Imaging (DTI) offers advanced insights into white matter microstructure.

Purpose of the Study:

• To investigate the effects of sports concussion on white matter integrity.
• To compare DTI measures (FA, MD, AD) between concussed and non-concussed athletes.
• To assess white matter changes in both acute and chronic post-injury phases.

Main Methods:

• Employed Diffusion Tensor Imaging (DTI) with fractional anisotropy (FA), mean diffusivity (MD), and axial diffusivity (AD) measures.
• Utilized a voxel-based approach (VBA) to compare 18 concussed athletes with 10 non-concussed athletes.
• Conducted MRI scans acutely (1-6 days post-concussion) and 6 months later, analyzing data with repeated-measures ANOVAs.

Main Results:

• Increased FA observed in corticospinal tracts (CST) and corpus callosum of concussed athletes.
• Elevated axial diffusivity (AD) noted in the right CST of concussed athletes.
• Decreased mean diffusivity (MD) found in the CST and corpus callosum of concussed athletes at both time points.

Conclusions:

• Sports concussions induce significant white matter diffusivity changes in the corpus callosum and CST.
• These DTI-detected alterations are not visible with conventional neuroimaging techniques.
• The findings highlight DTI's utility in identifying subtle, persistent white matter damage after concussion.