The Relationship Between Fighting Style, Cognition, and Regional Brain Volume in Professional Combatants: A Preliminary Examination Using Brief Neurocognitive Measures.

OBJECTIVE: Repetitive head impacts (RHIs) in combat sports are associated with cognitive decline and brain volume reduction. While fighting style differences between boxers, mixed martial artists (MMAs), and martial artists (MAs) have resulted in a broader spectrum of injury, the effects of RHIs on MAs relative to other fighters have not yet been explored. This study aimed to determine a differential effect of fighting style on cognition and brain. SETTING: A large outpatient medical center specializing in neurological care. PARTICIPANTS, DESIGN, AND MAIN MEASURES: In total, 40 MAs, 188 boxers, and 279 MMAs were compared on baseline measures of subcortical regional brain volumes, after controlling for total brain volumes, and cognitive performance. RESULTS: Significant differences between MAs, MMAs, and boxers were observed in subcortical brain structure volumes and cognitive measures. MMAs and MAs consistently had larger volumes and higher scores than boxers. Fighting style significantly moderated the relationship between the number of professional fights and the volumes of various subcortical brain structures and performance on a measure of processing speed at baseline. CONCLUSIONS: Differences in RHIs across fighting styles may be of clinical significance. Exploring changes over time within the MA, boxer, and MMA cohorts may provide insight into longer-term discrepancies in subcortical regional brain volumes and cognitive functioning across fighting styles.

The Relations Among Depression, Cognition, and Brain Volume in Professional Boxers: A Preliminary Examination Using Brief Clinical Measures.

OBJECTIVE: Depression, neuropathology, and cognitive decline are commonly observed with repetitive head injuries (RHIs). We examined whether in boxers (a) clinically significant depression is associated with structural brain changes and cognition; (b) minimal symptoms of depression moderate the relations among RHI and brain volumes and cognition; and (c) baseline depression is associated with longitudinal cognitive changes. SETTING: Clinical Research Center. PARTICIPANTS: A total of 205 male professional boxers. DESIGN: Cross-sectional and longitudinal (subsample: n = 45; first visit to follow-up range = 1-6 years; mean = 2.61 years). MAIN MEASURES: Patient Health Questionnaire-9 depression; CNS Vital Signs cognitive battery; brain imaging. RESULTS: Clinically significant depression was associated with smaller regional volumes in insula, cingulate, orbitofrontal cortex, thalami, and middle corpus-callosum subregions; and with poorer verbal memory and psychomotor speed performance. Depression symptoms moderated the relations between RHI and bilateral thalami, left hippocampus, left medial orbitofrontal cortex, and bilateral insula volumes; but not cognition. Baseline depression was associated with poorer psychomotor speed and reaction time longitudinally and improved verbal memory performance longitudinally. CONCLUSION: Clinical depression is associated with volumetric and cognitive changes occasioning RHI exposure, and even minimal depressive symptoms may moderate the relations between exposure and brain volumes in key regions. Longitudinally, there is preliminary evidence that depression precedes cognitive changes.

Factors Associated With Weight Intervention Participation Among People With Serious Mental Illness.

Evidence-based practices effectively reduce weight in people with serious mental illness (SMI), yet participation is limited. Positive relationships between self-efficacy (SE), readiness to change (RtC), and subsequent participation in weight loss interventions have been demonstrated in the general population. The role of SE and RtC in predicting participation in individuals with SMI is explored. A total of 82 participants recruited from a county mental health clinic and a Veterans Affairs mental health clinic were randomly assigned to a weight management intervention or usual care. RtC and SE were assessed at baseline. Intervention participation rates were gathered. SE significantly correlated with intervention participation (p < 0.02). RtC did not predict significantly over and above SE. A linear combination of all measures was significantly related to participation (p < 0.05). To improve weight intervention participation by individuals with SMI, one direction may be to improve weight loss SE.

Sex Moderates the Relationship That Number of Professional Fights Has With Cognition and Brain Volumes.

Objective: Incidence of concussions and report of symptoms are greater among women across sports. While structural brain changes and cognitive declines are associated with repetitive head impact (RHI), the role of sex is not well-understood. This study aimed to determine if there is a moderating effect of sex on the relationship the number of professional fights has with cognitive functioning and regional brain volumes in a cohort of boxers, mixed martial artists, and martial artists. Methods: A total of 55 women were matched with 55 men based on age, years of education, ethnicity, and fighting style. Cognition was assessed via the CNS Vital Signs computerized cognitive battery and supplemental measures. Structural brain scans, demographic data, and number of professional fights (NoPF) were also considered. The matched pairs were compared via analysis of covariance, accounting for total brain volume. Within-subject moderation models were utilized to assess the moderating effect of sex on the relationship between NoPF and brain volumes and cognitive performance. Results: Men were observed to have poorer performance on measures of psychomotor speed when compared to women. On a series of analyses assessing the role of sex as a moderator of the relationship between NoPF and regional brain volumes/cognitive performance, a significant moderation effect was observed across multiple measures of cognitive functioning, such that men had poorer performance. Differences in numerous regional brain volumes were also observed, such that the relationship between NoPF and brain volumes was steeper among men. Conclusion: Sex was observed to be an important moderator in the relationship between NoPF, aspects of cognitive functioning, and volumes of numerous brain regions, suggesting that sex differences in neuroanatomic and cognitive response to RHI deserve further attention.

Concussion reporting and perceived knowledge of professional fighters.

Objective: For concussions to be effectively managed in sports, they need to be correctly identified and reported. The extent to which professional athletes correctly recognize concussions, and their willingness to report symptoms, is not yet well understood. Given the risk of head injuries leading to concussions across combat sports, insight into professional fighters' knowledge and reporting of concussive symptoms is essential to improve concussion management. Methods: To investigate understanding and reporting patterns of concussions sustained while training or competing, 257 fighters completed a self-report questionnaire assessing self-perception of concussion knowledge, trust of ringside medical providers, and reported number of previous head injuries. Fighting history, including number of knockouts, was obtained from self-report (amateur) and published (professional) records. Results: Significant gaps in fighters' perceived knowledge of concussion symptoms and long-term effects of multiple concussions emerged. Approximately 40% of fighters reported returning to training or competition the same day a head injury was sustained, while 21% of fighters endorsed concealing symptoms of head injury from medical providers and coaches. Conclusions: Confusion surrounding terms used to describe head injuries amongst fighters (e.g., concussions, knockouts), coupled with limited understanding of concussive symptoms and a desire to return to competition, likely contributes to significant underreporting of symptoms.