title: Parasympathetic baroreflexes and heart rate variability during acute stage of sport concussion recovery.
abstract: To assess and compare the parasympathetic state of individuals in healthy vs concussion groups, by measuring cardiovascular metrics under resting and baroreflex conditions using a squat-stand manoeuvre.
  
  
  
  This was a retrospective mixed-method study, with participants who sustained a medically diagnosed sport concussion (n = 12), being tested within 72-hours post-injury.
  
  
  
  Participant's heart rate (Electrocardiogram, ECG) and blood pressure (finger plethysmography) data was collected during rest and during 10-second squat-stands (10SS, 0.05 Hz). Blood pressure and heart rate standard deviation data was analysed in the 0-5 seconds and 6-10 seconds periods of squatting and standing. Resting and baroreflex ECG data were analysed via Fourier Transformations for %Low Frequency and %High Frequency (%LF and %HF).
  
  
  
  The control group alleviated more pressure and had a significantly higher standard deviation of heart rate during the 6-10 seconds of squatting (p < 0.05). Overall heart rate standard deviation in the concussion group was significantly lower than healthy controls when standing (p < 0.05). There were no differences in %LF and % HF between groups or between rest and 10SS.
  
  
  
  This study provides preliminary evidence that autonomic function is dysregulated following mTBI within the initial 72 hours of injury.
authors.affiliation: a Faculty of Kinesiology and Health Studies , University of Regina , Regina , Saskatchewan , Canada.
authors.forename: Scott
authors.initials: S
authors.lastname: Bishop
authors.affiliation: a Faculty of Kinesiology and Health Studies , University of Regina , Regina , Saskatchewan , Canada.
authors.forename: Ryan
authors.initials: R
authors.lastname: Dech
authors.affiliation: a Faculty of Kinesiology and Health Studies , University of Regina , Regina , Saskatchewan , Canada.
authors.forename: Taylor
authors.initials: T
authors.lastname: Baker
authors.affiliation: b College of Medicine , University of Saskatchewan , Saskatoon , Saskatchewan , Canada.
authors.forename: Matthew
authors.initials: M
authors.lastname: Butz
authors.affiliation: a Faculty of Kinesiology and Health Studies , University of Regina , Regina , Saskatchewan , Canada.
authors.forename: Kaishan
authors.initials: K
authors.lastname: Aravinthan
authors.affiliation: a Faculty of Kinesiology and Health Studies , University of Regina , Regina , Saskatchewan , Canada.
authors.forename: J Patrick
authors.initials: JP
authors.lastname: Neary
mesh_terms: D000293:Adolescent; D001265:Athletic Injuries / Q000503:physiopathology*; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D001924:Brain Concussion / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D010275:Parasympathetic Nervous System / Q000503:physiopathology*; D012189:Retrospective Studies; D055815:Young Adult
keywords: Concussion; autonomic nervous system; baroreflexes; heart rate variability