title: Reduced cortical microvascular oxygenation in multiple sclerosis: a blinded, case-controlled study using a novel quantitative near-infrared spectroscopy method.
abstract: Hypoxia (low oxygen) is associated with many brain disorders as well as inflammation, but the lack of widely available technology has limited our ability to study hypoxia in human brain. Multiple sclerosis (MS) is a poorly understood neurological disease with a significant inflammatory component which may cause hypoxia. We hypothesized that if hypoxia were to occur, there should be reduced microvascular hemoglobin saturation (StO2). In this study, we aimed to determine if reduced StO2 can be detected in MS using frequency domain near-infrared spectroscopy (fdNIRS). We measured fdNIRS data in cortex and assessed disability of 3 clinical isolated syndrome (CIS), 72 MS patients and 12 controls. Control StO2 was 63.5 ± 3% (mean ± SD). In MS patients, 42% of StO2 values were more than 2 × SD lower than the control mean. There was a significant relationship between StO2 and clinical disability. A reduced microvascular StO2 is supportive (although not conclusive) that there may be hypoxic regions in MS brain. This is the first study showing how quantitative NIRS can be used to detect reduced StO2 in patients with MS, opening the door to understanding how microvascular oxygenation impacts neurological conditions.
authors.affiliation: Department of Radiology, Cumming School of Medicine, University of Calgary.|Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary.|Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary.
authors.forename: Runze
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Radiology, Cumming School of Medicine, University of Calgary.|Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary.|Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary.
authors.forename: Jeff F
authors.initials: JF
authors.lastname: Dunn
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000098:blood supply*; D004185:Disability Evaluation; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D055806:Microvessels / Q000378:metabolism*; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000378:metabolism* / Q000503:physiopathology; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D019265:Spectroscopy, Near-Infrared / Q000379:methods*; D016138:Walking
chemical_list: D006454:Hemoglobins; D010100:Oxygen