Objectives Using a repeated-measures design, we investigated reported symptoms, oculomotor, and neurophysiological responses for up to 26 days following a sports-related concussion.

Methods Over 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.

Results Twenty-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.

Conclusion Concussed 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 player’s readiness to return to play.

No funding was provided for the submitted work. Outside of this work, AJP is currently a non-executive director of the Concussion Legacy Foundation Australia and is remunerated for expert advice to medico-legal practices. He has previously received partial philanthropic funding and equipment support from Sports Health Check, and partial industry funding from Australian Football League, Impact Technologies Inc., and Samsung Corporation. Other authors have no relevant financial or non-financial competing interests.

This study did not receive any funding

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

La Trobe University granted ethical approval for this study (HREC21342). This study was conducted with the ethical standards of the Helsinki Declaration (1964) and later amendments. Data management was consistent with La Trobe University data management policy.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

Data are available from the corresponding author upon reasonable request and with relevant University Human Research Ethics approval.