title: Effect of valsalva maneuver-induced hemodynamic changes on brain near-infrared spectroscopy measurements.
abstract: Near-infrared spectroscopy (NIRS) is widely used to measure human brain activation on the basis of cerebral hemodynamic response. However, a limitation of NIRS is that systemic changes influence the measured signals. The purpose of this study was to clarify the relationship between NIRS signals and blood pressure during the Valsalva maneuver. Nine healthy volunteers performed a 20-s Valsalva maneuver to change their blood pressure. Changes in oxyhemoglobin (O2Hb) concentration were measured with 34 channels with an inter-optode distance of 30 mm for deep-penetration measurements (deepO2Hb) and 9 channels with an inter-optode distance of 15 mm for shallow-penetration measurements (shallowO2Hb). The difference value (diffO2Hb) between deepO2Hb and shallowO2Hb was calculated. Mean arterial pressure (MAP) was recorded by volume clamping the finger pulse, and skin blood flow changes were measured at the forehead. Pearson's correlation coefficients between deepO2Hb and MAP, shallowO2Hb and MAP, and diffO2Hb and MAP were 0.893 (P < 0.01), 0.963 (P < 0.01), and 0.831 (P < 0.01), respectively. The results suggest that regional and systemic changes in the cardiovascular state strongly influence NIRS signals.
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan. tsubaki@nuhw.ac.jp.|Department of Physical Therapy, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan. tsubaki@nuhw.ac.jp.
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Tsubaki
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.|Graduate School of Health and Welfare, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Kojima
authors.affiliation: Department of Physical Therapy, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Adriane Akemi
authors.initials: AA
authors.lastname: Furusawa
authors.affiliation: Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.|Department of Physical Therapy, Niigata University of Health and Welfare, 1398 Shimami-cho, Kita-ku, Niigata-shi, Niigata, 950-3198, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Onishi
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology; D001921:Brain / Q000098:blood supply* / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D010100:Oxygen / Q000097:blood / Q000378:metabolism; D010108:Oxyhemoglobins / Q000378:metabolism; D012039:Regional Blood Flow / Q000502:physiology; D019265:Spectroscopy, Near-Infrared / Q000379:methods; D014636:Valsalva Maneuver / Q000502:physiology*; D055815:Young Adult
chemical_list: D010108:Oxyhemoglobins; D010100:Oxygen