Objective To examine if mixed martial arts (MMA) participation is associated with impaired neurologic function.

Design Prospective observational study.

Setting Sports science laboratory.

Participants Seventeen amateur and professional MMA fighters (14 men, 3 women; 27.5 ± 3.7 yr) and seventeen matched healthy control subjects (14 men, 3 women; 27.3 ± 3.5 yr).

Interventions (or Assessment of Risk Factors) All participants completed a baseline evaluation. Ten MMA participants completed three post-fight evaluations (3.8 ± 1.3, 11.5 ± 2.6 and 29.7 ± 4.6 days following a competition, which occurred 76.9 ± 100.5 days after baseline). All control participants completed follow-up evaluations 32.7 ± 3.0, 41.4 ± 4.3 and 57.1 ± 5.7 days after baseline.

Outcome Measures Participants were evaluated for eye movement speed and accuracy (King-Devick test; KD), near point of convergence (Vestibular/Ocular-Motor Screening; NC), hand-eye reaction time (FITLIGHT Trainer; RT), visuomotor ability (FITLIGHT Trainer, VM), multiple-object tracking speed (NeuroTracker, MOT), static balance (Wii Balance Board; SB) and dynamic balance (Y Balance Test; DB).

Main Results Baseline measures of KD (P < 0.001), NC (P = 0.013), RT (P < 0.008), VM (P < 0.017) and SB (P < 0.001 – 0.033) were significantly higher, while MOT (P < 0.001) was significantly lower in MMA participants. Furthermore, MMA participants had less improvements in KD and RT over time (P < 0.013 and P = 0.003–0.024, respectively).

Conclusions MMA fighters had deficits in several assessments of neurologic function at baseline and in serial measurements after competition, compared to age- and sex-matched control participants.