title: Cerebral and systemic hemodynamics changes during upright tilt in chronic fatigue syndrome.
abstract: OBJECTIVE
  During head-up tilt (HUT), patients with chronic fatigue syndrome (CFS) have higher rates of neurally mediated hypotension (NMH) and postural tachycardia syndrome (POTS) than healthy controls. The authors studied whether patients with CFS were also more likely to have abnormal cerebral blood flow velocity (CBFV) compared with controls in response to orthostatic stress.
  
  
  METHODS
  Transcranial Doppler monitoring of middle cerebral artery (MCA) CBFV was performed during 3-stage HUT prospectively in 26 patients with CFS and 23 healthy controls. At the same time, continuous monitoring of arterial blood pressure (BP), heart rate (HR), endtidal CO2 (ET-CO2) were performed. Results are reported as mean +/- SD.
  
  
  RESULTS
  NMH developed in 21 patients with CFS and in 14 controls (P = .22). POTS was present in 9 CFS patients and 7 controls (P = .76). Supine HR was higher in CFS patients, but all other hemodynamics and CBFV measures were similar at baseline. The median time to hypotension did not differ, but the median time to onset of orthostatic symptoms was shorter in those with CFS (P < .001). The CBFV did not differ between groups in the supine posture, at 1 or 5 minutes after upright tilt, at 5 or 1 minute before the end of the test, or at termination of the test. Mean CBFV fell at termination of tilt testing in those with CFS and controls. ET-CO2 was lower at termination of the test in those with CFS versus controls (P = .002).
  
  
  CONCLUSIONS
  The results of this study are not consistent with the hypothesis that patients with CFS have a distinctive pattern of MCA CBFV changes in response to orthostatic stress.
authors.affiliation: Departments of Anesthesiology/Critical Care Medicine, Neurology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA. arazumov@surgicalmonitoring.net
authors.forename: Alexander Y
authors.initials: AY
authors.lastname: Razumovsky
authors.forename: Karen
authors.initials: K
authors.lastname: DeBusk
authors.forename: Hugh
authors.initials: H
authors.lastname: Calkins
authors.forename: Sally
authors.initials: S
authors.lastname: Snader
authors.forename: Katherine E
authors.initials: KE
authors.lastname: Lucas
authors.forename: Pranav
authors.initials: P
authors.lastname: Vyas
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Hanley
authors.forename: Peter C
authors.initials: PC
authors.lastname: Rowe
mesh_terms: D000328:Adult; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000098:blood supply*; D015673:Fatigue Syndrome, Chronic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D018475:Head-Down Tilt / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000502:physiology; D012039:Regional Blood Flow; D018709:Statistics, Nonparametric; D017585:Ultrasonography, Doppler, Transcranial