New method finds undetected brain impairments in ice hockey players with and without diagnosed concussions
A hockey concussion study tracking the brain function of 47 Junior A male ice hockey players using a new brainwave monitoring method called "brain vital signs", has found that this more sensitive measure detected neurophysiological impairments, such as attention and cognitive processing deficits, in players who had been diagnosed with concussions and were cleared for return-to-play. Surprisingly, the team also found significant delays in cognitive processing for players who were not diagnosed with concussions at any time during the season (sub-concussive effects).
The new method is easy and quick to use, taking less than 10 minutes and being easily and fully deployable within a variety of sporting settings.
New technique confirms persistent brain changes after concussion
A brain imaging study of 52 female athletes from a women's varsity rugby team, including 21 who suffered a concussion, has used a technique that combines multiple imaging measures to produce a much more sensitive and complete picture of concussion injury.
The study identified three unique signatures — one that shows acute brain changes after an athlete has suffered a concussion, another that can identify persistent brain changes six months after the concussion, and a third that shows evidence of concussion history.
Confirming growing evidence of persistent changes in the brain that last well beyond clinical recovery and clearance to return to play, the study showed clear brain changes in both structure and function that persisted six-months after injury.
Lasting impact of concussions on young adults seen in brainwaves & cognitive control
A study involving 21 young adults (18-24) with a history of two or more concussions and 21 age- and gender-matched controls has revealed that those in the concussion group performed significantly worse on a task-switching activity. This was accompanied by greater desynchronization of brainwaves in relevant brain areas. It’s suggested that a change in neural communication occurs and persists after concussion.
All concussions were at least a month earlier.
Sub-concussive impacts in one football season not linked to cognitive harm
A prospective study following 112 youth football players age 9-18 found that sub-concussive impacts were not correlated with worsening performance in neurocognitive function.
The pre- and post-season assessments used to measure outcomes included:
- Neuropsychological testing
- Symptoms assessment
- Vestibular and ocular-motor screening
- Balance testing
- Parent-reported ADHD symptoms
- Self-reported behavioral adjustment
Sensors placed in the helmets recorded sub-concussive head impacts during practices and games.
Concussions loosen insulation around brain cells
Detailed scans of concussed university hockey players found that myelin (the protective fatty tissue surrounding brain cell fibers) was loosened two weeks after the injury — even though the athletes felt fine and were deemed ready to return to the ice.
Myelin speeds the transmission of electrical signals between brain cells, and previous animal research has shown that this loosened myelin can completely deteriorate with subsequent blows. This is the first evidence in humans.
Conventional brain scans do not reveal myelin loosening.
Happily, the myelin had returned to normal after two months, but the findings provide more evidence that more time is needed before concussed athletes return to play.
Paper available at https://www.frontiersin.org/articles/10.3389/fneur.2018.00575/full
Manning, K.Y. et al. 2019. Linked MRI signatures of the brain's acute and persistent response to concussion in female varsity rugby players. NeuroImage: Clinical, 21, 101627.
(2018). Investigation of the changes in oscillatory power during task switching after mild traumatic brain injury.
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Rose SC, Yeates KO, Fuerst DR, Ercole PM, Nguyen JT, Pizzimenti NM. 2018. Head impact burden and change in neurocognitive function during a season of youth football. The Journal of Head Trauma Rehabilitation. [Epub ahead of print.]
Weber, A.M.et al. 2018. Pathological Insights From Quantitative Susceptibility Mapping and Diffusion Tensor Imaging in Ice Hockey Players Pre and Post-concussion. Frontiers in Neurology, 9, 575.