Citation

Churchill NW, Hutchison MG, Graham SJ, Schweizer TA. Neurology 2019; ePub(ePub): ePub.

Affiliation

From the Keenan Research Centre of the Li Ka Shing Knowledge Institute (N.W.C., M.G.H., T.A.S.) and Neuroscience Research Program (N.W.C., T.A.S.), St. Michael's Hospital; Faculty of Kinesiology and Physical Education (M.G.H.), Department of Medical Biophysics (S.J.G.), Faculty of Medicine (Neurosurgery) (T.A.S.), and Institute of Biomaterials & Biomedical Engineering (T.A.S.), University of Toronto; and Physical Sciences Platform (S.J.G.), Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, ON, Canada. SchweizerT@smh.ca.

Copyright

(Copyright © 2019, Lippincott Williams and Wilkins)

DOI

10.1212/WNL.0000000000008523

PMID

31619480

Abstract

OBJECTIVE: To test the hypothesis that concussion-related brain alterations seen at symptomatic injury and medical clearance to return to play (RTP) will have dissipated by 1 year after RTP.

METHODS: For this observational study, 24 athletes with concussion were scanned longitudinally within 1 week after injury, at RTP, and 1 year after RTP. A large control cohort of 122 athletes were also scanned before the season. Each imaging session assessed global functional connectivity (Gconn) and cerebral blood flow (CBF), along with white matter fractional anisotropy (FA) and mean diffusivity (MD). The main effects of concussion on MRI parameters were evaluated at each postinjury time point. In addition, covariation was assessed between MRI parameters and clinical measures of acute symptom severity and time to RTP.

RESULTS: Different aspects of brain physiology showed different patterns of recovery over time. Both Gconn and FA displayed no significant effects at 1 year after RTP, whereas CBF and MD exhibited persistent long-term effects. The effects of concussion on MRI parameters were also dependent on acute symptom severity and time to RTP for all postinjury time points.

CONCLUSION: This study provides the first longitudinal evaluation of concussion focused on time of RTP and 1 year after medical clearance, using multiple different MRI measures to assess brain structure and function. These findings significantly enhance our understanding of the natural course of brain recovery after a concussion.

© 2019 American Academy of Neurology.

Language: en