Despite study after study demonstrating long term effects from mild traumatic brain injury (concussions), it is astounding that defense courtroom doctors still maintain that there are no permanent residuals from mild traumatic brain injury. A new studyImaging Correlates of Memory and Concussion History in Retired National Football League Athletes, published in JAMA Neurology once again debunks this myth that everyone gets better.

The objective of the study, according to the abstract was “to assess the relationship of hippocampal volume, memory performance, and the influence of concussion history in retired NFL athletes with and without mild cognitive impairment.” The design of the study was a retrospective cohort study assessing differences between groups, mean hippocampal volumes, and memory performance by computing age quintiles based on group-specific linear regression models corrected for multiple comparisons for both athletes and control participants. The study utilized 28 former NFL athletes who were compared with 27 control participants. The mean age was 58.1 for the former athletes and 59.0 for the control participants.

The study found that retired athletes with concussion history, but without cognitive impairment, had normal, but significantly lower, California Verbal Learning Test scores compared with control participants. However, those with a concussion history and mild cognitive impairment performed worse when compared with both control participants and athletes without memory impairment. Among the athletes, 17 had a G3 concussion and 11 did not. Older retired athletes with at least one G3 concussion had significantly smaller bilateral hippocampal volumes compared with control participants.

The authors concluded that “prior concussion that results in loss of consciousness is a risk factor for increased hippocampal atrophy and a development of mild cognitive impairment. In individuals with mild cognitive impairment, hippocampal volume loss appeared greater among those with a history of concussion.”