Lack of association of informant-reported traumatic brain injury and chronic traumatic encephalopathy.

Repetitive head impacts (RHIs) from football are associated with the neurodegenerative tauopathy chronic traumatic encephalopathy (CTE). It is unclear if a history of traumatic brain injury (TBI) is sufficient to precipitate CTE neuropathology. We examined the association between TBI and CTE neuropathology in 580 deceased individuals exposed to RHIs from football. TBI was assessed using a modified version of the Ohio State University TBI Identification Method Short Form administered to informants. 22 donors had no TBI, 213 had at least one TBI without LOC, 345 had TBI with LOC, and, of those with a history of TBI with LOC, 36 had at least one msTBI (LOC >30 minutes). CTE neuropathology was diagnosed in 405. There was no association between CTE neuropathology status or severity and TBI with LOC (OR=0.95, 95% CI=0.64-1.41; OR=1.22, 95% CI=0.71-2.09) or msTBI (OR=0.70, 95% CI=0.33-1.50; OR=1.01, 95% CI=0.30-3.41). There were no associations with other neurodegenerative or cerebrovascular pathologies examined. TBI with LOC and msTBI were not associated with CTE neuropathology in this sample of brain donors exposed to RHIs from American football.