title: Motor system alterations in retired former athletes: the role of aging and concussion history.
abstract: BACKGROUND
  Retired athletes with a history of sports concussions experience cognitive and motor declines with aging, and the risk of severe neurodegenerative conditions is magnified in this population. The present study investigated the effects of aging on motor system metabolism and function in former university-level athletes who sustained their last concussion several decades prior to testing.
  
  
  METHODS
  To test the hypothesis that age and remote concussions induce functional as well as metabolic alterations of the motor system, we used proton magnetic resonance spectroscopy to detect metabolic abnormalities in the primary motor cortex and the serial reaction time task (SRTT) to evaluate motor learning.
  
  
  RESULTS
  Our results indicate that motor learning is significantly reduced in former concussed athletes relative to controls. In addition, glutamate/H2O ratio in M1 was disproportionately reduced in concussed athletes with advancing age and was found to strongly correlate with motor learning impairments.
  
  
  CONCLUSIONS
  Findings from this study provide evidence that the acquisition of a repeated motor sequence is compromised in the aging concussed brain and that its physiological underpinnings could implicate disproportionate reductions of M1 glutamate concentrations with advancing age.
authors: Centre de recherche en neuropsychologie et cognition (CERNEC), Université de Montréal, Montréal, Canada. hugo.theoret@umontreal.ca.
authors: Louis
authors: L
authors: De Beaumont
authors: Sébastien
authors: S
authors: Tremblay
authors: Luke C
authors: LC
authors: Henry
authors: Judes
authors: J
authors: Poirier
authors: Maryse
authors: M
authors: Lassonde
authors: Hugo
authors: H
authors: Théoret
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging; D000704:Analysis of Variance; D001057:Apolipoproteins E / Q000235:genetics; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology*; D001924:Brain Concussion / Q000473:pathology* / Q000503:physiopathology*; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008875:Middle Aged; D009043:Motor Activity / Q000235:genetics / Q000502:physiology*; D009044:Motor Cortex / Q000378:metabolism*; D009483:Neuropsychological Tests; D010775:Photic Stimulation; D011522:Protons; D011930:Reaction Time / Q000502:physiology; D012044:Regression Analysis; D011795:Surveys and Questionnaires
chemical_list: D001057:Apolipoproteins E; D011522:Protons; D001224:Aspartic Acid; D018698:Glutamic Acid; C000179:N-acetylaspartate
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