Diffusion tensor image analysis along the perivascular space in former professional athletes with repetitive mild traumatic brain injury history

The long-term changes in the glymphatic system of former professional athletes exposed to repetitive mild traumatic brain injuries remain poorly understood. This study aimed to use diffusion tensor image analysis along the perivascular space (DTI-ALPS) to evaluate the glymphatic system activity and correlate the ALPS-index with neuropsychiatric symptoms in former professional athletes. Thirty former professional athletes and 24 age- and sex-matched controls underwent DTI with 3T magnetic resonance imaging. The ALPS-index (mean, right, and left) in the athlete group was compared with that in controls, and correlations with clinical variables were analyzed. The mean, right, and left ALPS indices in the athlete group were significantly lower than those of the control group (mean: 1.49±0.12 vs. 1.61±0.16, p<0.01; right: 1.51±0.12 vs. 1.61±0.16, p=0.01; and left: 1.47±0.15 vs. 1.60±0.20, p<0.01). The mean and right ALPS indices were positively correlated with the Wisconsin Card Sorting Test performance in the athlete group (mean: r=0.41, p=0.04; right: r=0.43, p=0.03; not significant after Bonferroni correction). In conclusion, a lower ALPS-index in former professional athletes may be associated with impairments in cognitive function, reflected in glymphatic dysfunction.