title: Cerebral Blood Flow During Treadmill Exercise Is a Marker of Physiological Postconcussion Syndrome in Female Athletes.
abstract: Some patients with postconcussion syndrome (PCS) have reduced exercise capacity that may reflect altered central cardiorespiratory control. The purpose of this study was to evaluate control of cerebral blood flow (CBF) during exercise in females with PCS.
  
  
  
  University Concussion Clinic.
  
  
  
  Nine female Division 1 collegiate team athletes with PCS (23 ± 6 years) and a reference group of 13 healthy female recreational aerobic athletes (21 ± 3 years).
  
  
  
  A prospective experimental study. All PCS athletes were compared with the reference group at the beginning of the study. Six of the PCS athletes were subsequently measured before and after a subsymptom threshold aerobic exercise treatment program.
  
  
  
  Exercise treadmill test during which blood pressure (BP), minute ventilation ((Equation is included in full-text article.)E), end-tidal CO2 (PETCO2), and CBF velocity (CBFV, by transcranial Doppler) were measured.
  
  
  
  Participants with PCS had significantly lower (Equation is included in full-text article.)E (by 18%) and greater PETCO2 (5%) and CBFV (14%) versus the reference group at similar workloads in association with appearance of symptoms and premature exercise cessation. Subthreshold exercise normalized (Equation is included in full-text article.)E, PETCO2, CBFV and exercise tolerance. Before treatment, PCS had low CO2 sensitivity that blunted their exercise ventilation. CO2 sensitivity and ventilation improved after exercise treatment.
  
  
  
  Some PCS patients have exercise intolerance due to abnormal CBF regulation that may be the result of concussion-induced altered sensitivity to CO2. Return of normal CBF control and exercise tolerance may be physiological markers of recovery from concussion.
authors.affiliation: Department of Physiology, Center for Research and Education in Special Environments, State University of New York, Buffalo (Ms Clausen and Dr Pendergast); SUNY Buffalo, Orthopaedics, University Sports Medicine, Buffalo, New York (Dr Leddy); and Department of Psychiatry, SUNY Buffalo (Dr Willer).
authors.forename: Mary
authors.initials: M
authors.lastname: Clausen
authors.forename: David R
authors.initials: DR
authors.lastname: Pendergast
authors.forename: Barry
authors.initials: B
authors.lastname: Willer
authors.forename: John
authors.initials: J
authors.lastname: Leddy
mesh_terms: D000293:Adolescent; D056352:Athletes; D001265:Athletic Injuries / Q000175:diagnosis / Q000503:physiopathology*; D001930:Brain Injuries / Q000175:diagnosis / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D038223:Post-Concussion Syndrome / Q000175:diagnosis*; D011446:Prospective Studies; D012129:Respiratory Function Tests; D055815:Young Adult