Time-course responses following sports-related concussion: A multi-modality study.

ObjectivesUsing a repeated-measures design, we investigated reported symptoms, oculomotor, and neurophysiological responses for up to 26 days following a sports-related concussion. MethodsOver the course of one season, 115 athletes (mean age 26.2 {+/-} 5.4 years) from one football team (f=28, m=37) and one ice hockey team (f=21, m=29) were assessed for self-reported symptoms and severity of symptoms, cognitive testing for 10-word recall and digit backwards. Oculomotor performance was assessed using eye-pursuits. Neurophysiology was assessed using transcranial magnetic stimulation. Baseline data was tested during pre-season for all athletes and, when a concussion was identified, carried out at 48h, 12-, 19-, and 26-days post injury. ResultsTwenty-two players suffered concussion injuries (f=10, m=12). Significant increases in symptoms were reported at 48-hours (p<0.001) and 12-days (p=0.017). Severity of symptoms were significantly increased at 48-hours only (p=0.002). Significant decrements in performance for 10-word recall (p=0.003), digit backwards (p=0.011), and eye-pursuit (p=0.009) were observed at 48-hours in comparison to baseline. Transcranial magnetic stimulation revealed significantly increased cortical inhibition at 48-hours (p=0.024), 12- (p=0.009), and 19-days (p=0.028) compared to baseline. No differences were seen between females and males for any variables or timepoints. ConclusionConcussed players show acute changes in cortical inhibition, resolving by 26-days after injury, which follows a longer time-course for recovery compared to symptoms, cognitive tests, and oculomotor eye-pursuits. These results suggest that measuring the recovery of concussed athletes should incorporate a range of testing modalities in the determination of a players readiness to return to play.