For older, but not younger, ex-American football players, the earlier in life that they were exposed to the sport was correlated with a higher likelihood of developing white matter hyperintensities (WMH). Greater WMH in ex-football players was linked to diminished cognitive abilities, including worse verbal memory and executive function. White matter hyperintensities (WMH) are not well understood in terms of their clinical manifestation, risk factors, or underlying causes in patients who have experienced repeated head injuries. Researchers looked at the prevalence and location of WMH in retired American football players and their relationship to playing time, age at initial exposure, and clinical performance. Fluid-attenuated inversion recovery magnetic resonance imaging, cognitive testing, and self-report neuropsychiatric assessments were completed by 149 ex-football players and 53 asymptomatic unexposed volunteers (all men, 45-74 years old). WMH was calculated using the Lesion Segmentation Toolbox. The full sample was analyzed, and the results were broken down by age bracket starting at 60. Previous football players showed higher total, frontal, temporal, and parietal log-WMH than asymptomatic unexposed individuals, but only in older subjects. There was a correlation between log-WMH and age of first exposure to football and poorer executive function in older but not younger ex-football players. WMH may have different symptoms, risk factors, and causes in elderly ex-football players.