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.