title: Obstructive sleep apnea-hypopnea results in significant variations in cerebral hemodynamics detected by diffuse optical spectroscopies.
abstract: The objective of this study was to adapt a novel near-infrared diffuse correlation spectroscopy (DCS) flow-oximeter for simultaneous and continuous monitoring of relative changes in cerebral blood flow (rCBF) and cerebral oxygenation (i.e. oxygenated/deoxygenated/total hemoglobin concentration: Δ[HbO2]/Δ[Hb]/ΔTHC) during overnight nocturnal polysomnography (NPSG) diagnostic test for obstructive sleep apnea-hypopnea (OSAH). A fiber-optic probe was fixed on subject's frontal head and connected to the DCS flow-oximeter through a custom-designed fiber-optic connector, which allowed us to easily connect/detach the optical probe from the device when the subject went to bathroom. To minimize the disturbance to the subject, the DCS flow-oximeter was remotely operated by a desktop located in the control room. The results showed that apneic events caused significant variations in rCBF and ΔTHC. Moreover, the degrees of variations in all measured cerebral variables were significantly correlated with the severity of OSAH as determined by the apnea-hypopnea index (AHI), demonstrating the OSAH influence on both CBF and cerebral oxygenation. Large variations in arterial blood oxygen saturation (SaO2) were also found during OSAH. Since frequent variations/disturbances in cerebral hemodynamics may adversely impact brain function, future study will investigate the correlations between these cerebral variations and functional impairments for better understanding of OSAH pathophysiology.
authors.affiliation: Department of Biomedical Engineering, University of Kentucky, Lexington, KY 40506, USA. College of Science, Shenyang Ligong University, Shenyang, Liaoning 110159, People's Republic of China.
authors.forename: Yajun
authors.initials: Y
authors.lastname: Hou
authors.forename: Yu
authors.initials: Y
authors.lastname: Shang
authors.forename: Ran
authors.initials: R
authors.lastname: Cheng
authors.forename: Youquan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Yanli
authors.initials: Y
authors.lastname: Qin
authors.forename: Richard
authors.initials: R
authors.lastname: Kryscio
authors.forename: Abner
authors.initials: A
authors.lastname: Rayapati
authors.forename: Don
authors.initials: D
authors.lastname: Hayes
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yu
mesh_terms: D000328:Adult; D000368:Aged; D002560:Cerebrovascular Circulation; D005260:Female; D006439:Hemodynamics; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D010108:Oxyhemoglobins / Q000378:metabolism; D012890:Sleep; D020181:Sleep Apnea, Obstructive / Q000378:metabolism / Q000503:physiopathology*; D019265:Spectroscopy, Near-Infrared
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin