Glymphatic system impairment in nonathlete older male adults who played contact sports in their youth associated with cognitive decline: A diffusion tensor image analysis along the perivascular space study

Abstract

Background and purposeExposure to contact sports in youth causes brain health problems later in life. For instance, the repetitive head impacts in contact sports might contribute to glymphatic clearance impairment and cognitive decline. This study aimed to assess the effect of contact sports participation in youth on glymphatic function in old age and the relationship between glymphatic function and cognitive status using the analysis along the perivascular space (ALPS) index.Materials and methodsA total of 52 Japanese older male subjects were included in the study, including 12 who played heavy-contact sports (mean age, 71.2 years), 15 who played semicontact sports (mean age, 73.1 years), and 25 who played noncontact sports (mean age, 71.3 years) in their youth. All brain diffusion-weighted images (DWIs) of the subjects were acquired using a 3T MRI scanner. The ALPS indices were calculated using a validated semiautomated pipeline. The ALPS indices from the left and right hemispheres were compared between groups using a general linear model, including age and years of education. Furthermore, partial Spearman's rank correlation tests were performed to assess the correlation between the ALPS indices and cognitive scores (Mini-Mental State Examination and the Japanese version of the Montreal Cognitive Assessment [MoCA-J]) after adjusting for age years of education and HbA1c.ResultsThe left ALPS index was significantly lower in the heavy-contact and semicontact groups than that in the noncontact group. Although no significant differences were observed in the left ALPS index between the heavy-contact and semicontact groups and in the right ALPS index among groups, a trend toward lower was found in the right ALPS index in individuals with semicontact and heavy-contact compared to the noncontact group. Both sides' ALPS indices were significantly positively correlated with the MoCA-J scores.ConclusionThe findings indicated the potential adverse effect of contact sports experience in youth on the glymphatic system function in old age associated with cognitive decline.

Diffusion Tensor Image Analysis ALong the Perivascular Space (DTI-ALPS): Revisiting the Meaning and Significance of the Method

“…There is also a paper that examines the ALPS-index calculated for the right hemisphere and the ALPS-index calculated for the left hemisphere separately. 16 , 19 , 69 , 165 , 166…”

“…There is also a paper that examines the ALPS-index calculated for the right hemisphere and the ALPS-index calculated for the left hemisphere separately. 16,19,69,165,166 Some studies employ atlas based placement. 56,147 Yokota et al coregistered diffusion maps to the DTI-81 atlas of the International Consortium for Brain Mapping (ICBM) and established ROIs for projection and association fiber regions.…”

Noninvasive Magnetic Resonance Imaging Measures of Glymphatic System Activity

“…behavior disorder, 27 obstructive sleep apnea, 28 and metabolic syndrome, 29 and in participants playing contact sports 30 and patients with AD and PD. Furthermore, some lifestyle activities, including sleep, 31,32 could have significant associations with the glymphatic system.…”

“…Moreover, it has been reported that impairments in the waste clearance system are related to CSF absorption and ISF bulk‐flow (i.e., glymphatic system; Fig. 1) in patients with idiopathic intracranial hypertension, 26 isolated rapid eye movement (REM) sleep behavior disorder, 27 obstructive sleep apnea, 28 and metabolic syndrome, 29 and in participants playing contact sports 30 and patients with AD and PD. Furthermore, some lifestyle activities, including sleep, 31,32 could have significant associations with the glymphatic system.…”

“…This result suggested that the impairment of the glymphatic system causes Aβ accumulation in the brain. Additionally, studies have reported a significant decline of the ALPS index in patients with isolated REM sleep behavior disorder, 27 PD, 23 obstructive sleep apnea, 28 and metabolic syndrome 29 and participants with contact sports 30 compared with healthy controls. As described, the association between the glymphatic system and the ALPS index in multiple diseases, including AD, has been reported.…”