Citations

Abstract Background Cumulative head trauma, encompassing repetitive head impacts (RHI) and traumatic brain injury (TBI), has been associated with later‐life neurodegenerative disease. Studies on parkinsonism/Parkinson's disease (PD) have evaluated RHI and TBI in isolation, yielding mixed results. Cumulative head trauma may better predict PD risk. Objective To examine independent and cumulative effects of RHI through soccer participation and TBI history on PD diagnosis and age at diagnosis. Methods We used a cross‐sectional cohort design with data from the Fox Insight study. Participants completed self‐report questionnaires on PD diagnosis, TBI (no TBI, TBI with loss of consciousness [LOC], TBI without LOC), and sport participation. Multivariable logistic regressions examined the effects of soccer, TBI group, and their interaction on PD diagnosis. Cox proportional hazards examined associations with time to PD diagnosis. Covariates included age, sex, race, education, income, body mass index, heart disease/diabetes, and family PD history. Results Among 1231 participants (mean[SD] age = 66.12[10.60]), 278 played soccer (953 non–contact and collision sport [CCS] athletes). Participants reported no TBI (390[33%]), TBI without LOC (495[43%]), or TBI with LOC (258[23%]). Overall, 768(62%) reported a PD diagnosis (mean[SD] age at diagnosis = 59.02[9.86]). A significant soccer × TBI interaction indicated that soccer players with TBI with LOC had 2.6× higher odds of PD compared to non‐CCS athletes without TBI (OR [95% CI] = 2.600[1.085–6.305], P = 0.033). Former soccer players with TBI with LOC had a 15.6% higher hazard of early PD diagnosis (HR = 1.469, P = 0.027) compared to non‐CCS athletes with no TBI. Conclusion Cumulative head trauma (RHI + TBI) increased PD risk and lowered age at onset. © 2026 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Abstract INTRODUCTION Repetitive head impacts (RHI) from contact sports may cause a unique pattern of white matter hyperintensities (WMH) on T2‐weighted fluid‐attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI), termed RHI‐associated WMH (RHI‐WMH). These lesions are punctate, circular, and located at the gray–white matter boundary, an area vulnerable to trauma‐related damage. METHODS We investigated the association of RHI with these lesions in two aging cohorts: (1) former American football players versus asymptomatic unexposed men and (2) individuals with RHI from various contact sports versus non‐RHI participants. RHI‐WMH were assessed using visual ratings and a novel automated quantification pipeline. RESULTS Individuals with RHI had greater RHI‐WMH by both detection methods in both cohorts. RHI‐WMH were associated with plasma neurofilament light and p‐tau231, and flortaucipir positron emission tomography (PET) uptake. DISCUSSION RHI‐WMH may represent a new supportive biomarker for the detection of RHI‐related neuropathologies later in life.

Abstract Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disease linked to repetitive traumatic brain injury, but its prevalence and risk factors in the general population remain poorly defined. We investigated CTE neuropathological changes (CTE-NC) in an admixed, population-based clinicopathological cohort. Neuropathological evaluation was conducted on brain samples from 1151 individuals in the University of São Paulo Biobank for Aging Studies collected from 2004 to 2022. CTE-NC and aging-related tau astrogliopathy (ARTAG) were assessed across 14 963 histological slides using p-tau immunostaining. Clinical, cognitive, and neuropsychiatric data were obtained via informant interviews; information on sports exposure and traumatic brain injury history was limited. Seven cases (0.6%) met criteria for CTE-NC, mean age at death 73.4 ± 12.5 years; 1 was female. Dementia was present in 43% of CTE-NC cases; 57% exhibited neuropsychiatric symptoms. Most common co-pathologies were Alzheimer disease-type changes, ARTAG, and argyrophilic grain disease. Comprehensive exposure histories were unavailable for most cases; 2 had documented soccer involvement. These findings indicate that CTE-NC is rare in this population-based Brazilian cohort and predominantly affects males with frequent coexisting neuropathologies. Findings align with reports from high-income countries and support prioritizing primary prevention by reducing exposure to repetitive head impacts in sport and other settings.