title: Cerebral oxygenation monitoring for detecting critical cerebral hypoperfusion in patients with multiple system atrophy during the head-up tilt test.
abstract: OBJECTIVE
  Near infrared spectroscopy (NIRS) is a non-invasive optical technique to monitor cerebral tissue oxygen saturation (ScO(2)). The purpose of this study was to reveal the usefulness of ScO(2) monitoring in evaluating cerebral circulation in patients with autonomic failure.
  
  
  METHODS
  Nineteen patients with multiple system atrophy (MSA), who had autonomic failure, and 10 age-matched normal control subjects participated. In addition to blood pressure monitoring, ScO(2) was recorded by a near-infrared spectroscopy instrument during head-up tilt (HUT) test.
  
  
  RESULTS
  HUT tests induced postural symptoms in 9 MSA patients (presyncopal group), but not in 10 MSA patients (non-presyncopal group) or in any of the controls. ScO(2), which decreased slightly in the controls and MSA patients, did not differ significantly between the MSA and control groups. With regard to MSA subgroups, the ScO(2) reduction in the presyncopal group (-3.1+/-1.7%) was significantly larger than in the non-presyncopal group (-0.9+/-0.5%, P<0.005) and controls (-1.1+/-1.0%, P<0.05). The systolic blood pressure decreases during HUT in the non-presyncopal (-35.2+/-16.1 mmHg, P<0.01) and presyncopal (-54.3+/-27.5 mmHg, P<0.0005) groups were significantly greater than that in the control group (4.0+/-10.7 mmHg), but the difference between presyncopal and non-presyncopal groups was not significant.
  
  
  CONCLUSIONS
  In our study, ScO(2) reduction seemed to be associated with presyncopal symptoms. ScO(2) monitoring may be useful to detect cerebral hypoperfusion in MSA patients with autonomic failure.
authors.affiliation: Department of Neurology, Chiba University Graduate School of Medicine.
authors.forename: Koji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Masato
authors.initials: M
authors.lastname: Asahina
authors.forename: Atsuya
authors.initials: A
authors.lastname: Suzuki
authors.forename: Takamichi
authors.initials: T
authors.lastname: Hattori
mesh_terms: D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000378:metabolism / Q000503:physiopathology; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D005260:Female; D006706:Homeostasis; D006801:Humans; D007024:Hypotension, Orthostatic / Q000503:physiopathology; D020925:Hypoxia-Ischemia, Brain / Q000175:diagnosis* / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D019578:Multiple System Atrophy / Q000378:metabolism* / Q000503:physiopathology; D010100:Oxygen / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared; D013575:Syncope / Q000503:physiopathology; D018667:Tilt-Table Test
chemical_list: D010100:Oxygen