title: Myelin Water Fraction Is Transiently Reduced after a Single Mild Traumatic Brain Injury--A Prospective Cohort Study in Collegiate Hockey Players.
abstract: Impact-related mild traumatic brain injuries (mTBI) are a major public health concern, and remain as one of the most poorly understood injuries in the field of neuroscience. Currently, the diagnosis and management of such injuries are based largely on patient-reported symptoms. An improved understanding of the underlying pathophysiology of mTBI is urgently needed in order to develop better diagnostic and management protocols. Specifically, dynamic post-injury changes to the myelin sheath in the human brain have not been examined, despite 'compromised white matter integrity' often being described as a consequence of mTBI. In this preliminary cohort study, myelin water imaging was used to prospectively evaluate changes in myelin water fraction, derived from the T2 decay signal, in two varsity hockey teams (45 players) over one season of athletic competition. 11 players sustained a concussion during competition, and were scanned at 72 hours, 2 weeks, and 2 months post-injury. Results demonstrated a reduction in myelin water fraction at 2 weeks post-injury in several brain areas relative to preseason scans, including the splenium of the corpus callosum, right posterior thalamic radiation, left superior corona radiata, left superior longitudinal fasciculus, and left posterior limb of the internal capsule. Myelin water fraction recovered to pre-season values by 2 months post-injury. These results may indicate transient myelin disruption following a single mTBI, with subsequent remyelination of affected neurons. Myelin disruption was not apparent in the athletes who did not experience a concussion, despite exposure to repetitive subconcussive trauma over a season of collegiate hockey. These findings may help to explain many of the metabolic and neurological deficits observed clinically following mTBI.
authors.affiliation: MD/PhD Program, University of British Columbia, Vancouver, Canada.|Southern Medical Program, University of British Columbia Okanagan, Kelowna, Canada.|Department of Experimental Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Wright
authors.affiliation: UBC MRI Research Centre, University of British Columbia, Vancouver, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Jarrett
authors.affiliation: UBC MRI Research Centre, University of British Columbia, Vancouver, Canada.
authors.forename: Irene
authors.initials: I
authors.lastname: Vavasour
authors.affiliation: UBC MRI Research Centre, University of British Columbia, Vancouver, Canada.
authors.forename: Elham
authors.initials: E
authors.lastname: Shahinfard
authors.affiliation: Faculty of Medicine, Division of Neurology, University of British Columbia, Vancouver, Canada.
authors.forename: Shannon
authors.initials: S
authors.lastname: Kolind
authors.affiliation: School of Health and Exercise Sciences, University of British Columbia Okanagan, Kelowna, Canada.
authors.forename: Paul
authors.initials: P
authors.lastname: van Donkelaar
authors.affiliation: Faculty of Medicine, Division of Sports Medicine, University of British Columbia, Vancouver, Canada.
authors.forename: Jack
authors.initials: J
authors.lastname: Taunton
authors.affiliation: Faculty of Medicine, Department of Radiology, University of British Columbia, Vancouver, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Li
authors.affiliation: UBC MRI Research Centre, University of British Columbia, Vancouver, Canada.|Department of Pediatrics, Division of Neurology, University of British Columbia, Vancouver, Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rauscher
mesh_terms: D000328:Adult; D056352:Athletes; D001265:Athletic Injuries / Q000175:diagnosis / Q000503:physiopathology*; D001924:Brain Concussion / Q000175:diagnosis / Q000503:physiopathology*; D015331:Cohort Studies; D003337:Corpus Callosum / Q000503:physiopathology; D005260:Female; D006688:Hockey / Q000293:injuries*; D006801:Humans; D020772:Internal Capsule / Q000503:physiopathology; D008297:Male; D009186:Myelin Sheath / Q000473:pathology*; D064926:Neurophysiological Monitoring / Q000379:methods; D011446:Prospective Studies; D013334:Students; D014495:Universities; D014867:Water / Q000032:analysis; D055815:Young Adult
chemical_list: D014867:Water