title: Wavelet coherence analysis of prefrontal tissue oxyhaemoglobin signals as measured using near-infrared spectroscopy in elderly subjects with cerebral infarction.
abstract: This study aims to assess the prefrontal functional connectivity using wavelet coherence analysis of cerebral tissue oxyhaemoglobin concentration (Delta [HbO2]) signals in elderly subjects with cerebral infarction (CI) during the resting state. Continuous recordings of near-infrared spectroscopy (NIRS) signals were obtained from the left and right prefrontal lobes in 10 subjects with CI (age: 74.4±9.0years) and 18 healthy elderly subjects (age: 69.9±7.3years) during the resting state. The coherence between left and right prefrontal Delta [HbO2] oscillations in four frequency intervals (I, 0.6-2Hz; II, 0.145-0.6Hz; III, 0.052-0.145Hz and IV, 0.021-0.052Hz) was analyzed using wavelet coherence analysis. In healthy elderly subjects, the Delta [HbO2] oscillations were significantly wavelet coherent in intervals I and III (p<0.05), wavelet phase coherent in intervals from I to IV. In elderly subjects with CI, the left and right Delta [HbO2] oscillations were significantly wavelet coherent and phase coherent in interval I (p<0.05). In elderly subjects with CI, the power and phase coherences were significantly lower in interval III (p<0.01) than in healthy subjects. The difference in wavelet coherence between the healthy elderly and elderly with CI indicates an altered brain functional connectivity in CI patients. This may be useful for assessing the effectiveness of functional recovery following a CI.
authors.affiliation: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China.
authors.forename: Qingyu
authors.initials: Q
authors.lastname: Han
authors.affiliation: Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China.
authors.forename: Wenhao
authors.initials: W
authors.lastname: Li
authors.affiliation: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China.
authors.forename: Yuanjin
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Hospital of Shandong University, Jinan 250061, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Xin
authors.affiliation: Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China. Electronic address: zyongli@sdu.edu.cn.
authors.forename: Zengyong
authors.initials: Z
authors.lastname: Li
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D002544:Cerebral Infarction / Q000097:blood / Q000175:diagnosis* / Q000503:physiopathology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D009991:Oscillometry; D010108:Oxyhemoglobins / Q000378:metabolism*; D011237:Predictive Value of Tests; D017397:Prefrontal Cortex / Q000098:blood supply*; D012039:Regional Blood Flow; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D058067:Wavelet Analysis
chemical_list: D015415:Biomarkers; D010108:Oxyhemoglobins
keywords: Cerebral infarction; Cerebral oxygenation; Elderly; Functional connectivity; Near-infrared spectroscopy; Phase coherence; Prefrontal cortex; Resting state; Spontaneous oscillations; Wavelet coherence