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. 2019 Nov 19;93(21):e1980-e1992.
doi: 10.1212/WNL.0000000000008523. Epub 2019 Oct 16.

Mapping brain recovery after concussion: From acute injury to 1 year after medical clearance

Nathan W Churchill  1 , Michael G Hutchison  1 , Simon J Graham  1 , Tom A Schweizer  2
Affiliations

Mapping brain recovery after concussion: From acute injury to 1 year after medical clearance

Nathan W Churchill et al. Neurology. .

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.

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Figures

Figure 1
Figure 1. Brain areas showing significant effects of concussion at SYM, medical clearance to RTP, and 1 year after RTP
Parameters include global functional connectivity (Gconn), cerebral blood flow (CBF), fractional anisotropy (FA), and mean diffusivity (MD). Slices are shown as maximum-intensity projections in axial and sagittal planes (Montreal Neurological Institute coordinates: x = −4, z = +14). RTP = return to play; SYM =early symptomatic injury.
Figure 2
Figure 2. Brain areas where severity of concussion effects is significantly associated with both acute symptom severity and time to RTP, shown for SYM, medical clearance to RTP, and 1 year after RTP
Parameters include global functional connectivity (Gconn), cerebral blood flow (CBF), fractional anisotropy (FA), and mean diffusivity (MD). Slices are shown as maximum-intensity projections in axial and sagittal planes (Montreal Neurological Institute coordinates: x = −4, z = +14). RTP = return to play; SYM = early symptomatic injury.
See this image and copyright information in PMC

References

    1. McCrory P, Meeuwisse W, Dvorak J, et al. . Consensus statement on concussion in sport: the 5th International Conference on Concussion in Sport held in Berlin, October 2016. Br J Sports Med 2017;51:838–847. - PubMed
    1. Manley G, Gardner AJ, Schneider KJ, et al. . A systematic review of potential long-term effects of sport-related concussion. Br J Sports Med 2017;51:969–977. - PMC - PubMed
    1. Murugavel M, Cubon V, Putukian M, et al. . A longitudinal diffusion tensor imaging study assessing white matter fiber tracts after sports-related concussion. J Neurotrauma 2014;31:1860–1871. - PMC - PubMed
    1. Henry LC, Tremblay J, Tremblay S, et al. . Acute and chronic changes in diffusivity measures after sports concussion. J Neurotrauma 2011;28:2049–2059. - PubMed
    1. Zhu DC, Covassin T, Nogle S, et al. . A potential biomarker in sports-related concussion: brain functional connectivity alteration of the default-mode network measured with longitudinal resting-state fMRI over thirty days. J Neurotrauma 2015;32:327–341. - PubMed

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