Changes in Dynamic Cerebral Autoregulation During Graded Orthostatic Stress in Humans

• SHIOZAWA Tomoki Y.

  Department of Environmental Health and Preventive Medicine, Nihon University School of Medicine

• GOMI Shintaro

  Health Administration Center, Aoyamagakuin University

• FURUHATA Hiroshi

  Medical Engineering Laboratory, Jikei University School of Medicine

• TAKADA Hiroki

  Nagoya University Graduate School of Engineering

• IWASE Satoshi

  2nd Department of Physiology, Aichi Medical University

• KAMIYA Atsunori

  Department of Cardiovascular Dynamics, Advanced Medical Engineering Center, National Cardiovascular Center Research Institute

• KAWASAKI Hitoshi

  Health Administration Center, Aoyamagakuin University

• HIRAYANAGI Kaname

  Department of Environmental Health and Preventive Medicine, Nihon University School of Medicine

• IWASAKI Kenichi

  Department of Environmental Health and Preventive Medicine, Nihon University School of Medicine

• YAMAGUCHI Nobuhisa

  Department of Environmental Health and Preventive Medicine, Nihon University School of Medicine

• YAJIMA Kazuyoshi

  Sano College

Bibliographic Information

Other Title

• 段階的受動起立時の動的脳血流自動調節作用の変容

Abstract

To investigate the influence of orthostatic stress on dynamic cerebral autoregulation (DCA), thirteen healthy subjects underwent graded head-upright til (HUT; 0,15,30,45,60, 90° (degrees)) stress. Dynamic cerebral autoregulation was evaluated by transfer function gain (TFG) and coherence function (CF) between blood pressure (BP) fluctuation (input) measured by photoplethysmography (Finapres) and cerebral blood flow (CBF) velocity fluctuation (output) in the middle cerebral artery measured by transcranial Doppler. In the very-low-frequency range (0.02∼0.07 Hz), many (33.3%) of the CF values were under 0.5 and the average CF value did not change significantly during the graded HUT stress. CF values in the low-frequency (LF: 0.07∼0.2 Hz) and high-frequency (HF: 0.2∼ 0.3Hz) ranges were always over 0.5. TFG in the LF and HF ranges decreased significantly at HUT 45° and 90° and during HUT 45∼90° simultaneously. These results suggest that HUT stress generally activates DCA, although the modes of activation differ according to the frequency range of BP and CBF fluctuations.

Journal

• Neurosonology

  Neurosonology 19 (1), 17-24, 2006

  The Japan Academy of Neurosonology

Keywords

• cerebral blood flow
• hemodynamics
• head-up tilt
• autoregulation
• ultrasonics

Details

• CRID: 1390001204420964736
• NII Article ID: 10018813915
• NII Book ID: AN10236361
• DOI: 10.2301/neurosonology.19.17
• ISSN: 18843336
• ISSN: 0917074X
• Web Site: https://search.jamas.or.jp/link/ui/2007173386
• Text Lang: ja
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed