Table 1

Glossary of definitions, adapted from Jordan32

Chronic traumatic brain injury (TBI)	A spectrum of disorders associated with long-term consequences of single or repetitive TBI.
Chronic traumatic encephalopathy (CTE)*	Prototypic chronic TBI, long-term neurological consequences of repetitive mild TBI.
Dementia pugilistica	A subtype of CTE that is typically reserved for cases of severe end-stage dementia secondary to a long boxing career.
Chronic postconcussion syndrome*	A condition in those athletes in whom post-concussion symptoms do not appear to resolve.
Chronic neurocognitive impairment*	A rather diverse classification of chronic neurocognitive signs and symptoms secondary to head impact exposures and recurrent concussions that is theoretically distinctive from CTE.
Post-traumatic dementia†	Cases in which the athlete meets clinical criteria for dementia secondary to a single moderate-to-severe TBI.
Post-traumatic cognitive impairment†	Individuals who sustain long-term neurocognitive deficits from a single moderate-to-severe brain injury and do not meet clinical criteria for dementia, but instead mild cognitive impairment.
Post-traumatic parkinsonism	A Parkinsonian-like syndrome secondary to a single moderate-to-severe or repetitive TBI, occurring solely or as a component of CTE.