Neuropsychological performance following a history of multiple self-reported concussions: a meta-analysis.

Debate continues about the long-term neuropsychological impact of multiple mild traumatic brain injuries (MTBI). A meta-analysis of the relevant literature was conducted to determine the impact of having a history of more than one self-reported MTBI (versus just one MTBI) across seven cognitive domains, as well as symptom complaints. The analysis was based on 8 studies, all conducted with athletes, involving 614 cases of multiple MTBI and 926 control cases of a single MTBI. The overall effect of multiple MTBI on neuropsychological functioning was minimal and not significant (d = 0.06). However, follow-up analyses revealed that multiple self-reported MTBI was associated with poorer performance on measures of delayed memory and executive functioning. The implications and limitations of these findings are discussed.