Model-based physiomarkers of cerebral hemodynamics in patients with mild cognitive impairment.
In our previous studies, we have introduced model-based "functional biomarkers" or "physiomarkers" of cerebral hemodynamics that hold promise for improved diagnosis of early-stage Alzheimer's disease (AD). The advocated methodology utilizes subject-specific data-based dynamic nonlinear models of cerebral hemodynamics to compute indices (serving as possible diagnostic physiomarkers) that quantify the state of cerebral blood flow autoregulation to pressure-changes (CFAP) and cerebral CO2 vasomotor reactivity (CVMR) in each subject. The model is estimated from beat-to-beat measurements of mean arterial blood pressure, mean cerebral blood flow velocity and end-tidal CO2, which can be made reliably and non-invasively under resting conditions. In a previous study, it was found that a CVMR index quantifying the impairment in CO2 vasomotor reactivity correlates with clinical indications of early AD, offering the prospect of a potentially useful diagnostic tool. In this paper, we explore the use of the same model-based indices for patients with amnestic Mild Cognitive Impairment (MCI), a preclinical stage of AD, relative to a control subjects and clinical cognitive assessments. It was found that the model-based CVMR values were lower for MCI patients relative to the control subjects.
Department of Biomedical Engineering & Biomedical Simulations Resource, University of Southern California, United States. Electronic address: vzm@usc.edu.
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Marmarelis
Department of Biomedical Engineering & Biomedical Simulations Resource, University of Southern California, United States.
D C
DC
Shin
Sonovation Imaging & Diagnostics Inc., Los Angeles, CA, United States.
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Orme
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, United States.
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Zhang
D000368:Aged; D001794:Blood Pressure; D001921:Brain / Q000098:blood supply / Q000378:metabolism / Q000503:physiopathology; D002245:Carbon Dioxide / Q000378:metabolism; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D060825:Cognitive Dysfunction / Q000378:metabolism / Q000503:physiopathology*; D005260:Female; D006339:Heart Rate; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008954:Models, Biological; D010865:Pilot Projects
D002245:Carbon Dioxide
Alzheimer's disease; Cerebral hemodynamics; Closed-loop PDM-based model; Mild cognitive impairment; Model-based physiomarkers; Modeling of cerebral autoregulation; Nonlinear modeling; Principal dynamic modes