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Reddy P, Izzetoglu K, Shewokis PA, Sangobowale M, Diaz-Arrastia R. Differences in time-frequency characteristics between healthy controls and TBI patients during hypercapnia assessed via fNIRS. Neuroimage Clin 2023; 40:103504. [PMID: 37734166 PMCID: PMC10518610 DOI: 10.1016/j.nicl.2023.103504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 07/24/2023] [Accepted: 09/01/2023] [Indexed: 09/23/2023]
Abstract
Damage to the cerebrovascular network is a universal feature of traumatic brain injury (TBI). This damage is present during different phases of the injury and can be non-invasively assessed using functional near infrared spectroscopy (fNIRS). fNIRS signals are influenced by partial arterial carbon dioxide (PaCO2), neurogenic, Mayer waves, respiratory and cardiac oscillations, whose characteristics vary in time and frequency and may differ in the presence of TBI. Therefore, this study aims to investigate differences in time-frequency characteristics of these fNIRS signal components between healthy controls and TBI patients and characterize the changes in their characteristics across phases of the injury. Data from 11 healthy controls and 21 TBI patients were collected during the hypercapnic protocol. Results demonstrated significant differences in low-frequency oscillations between healthy controls and TBI patients, with the largest differences observed in Mayer wave band (0.06 to 0.15 Hz), followed by the PaCO2 band (0.012 to 0.02 Hz). The effects within these bands were opposite, with (i) Mayer wave activity being lower in TBI patients during acute phase of the injury (d = 0.37 [0.16, 0.57]) and decreasing further during subacute (d = 0.66 [0.44, 0.87]) and postacute (d = 0.75 [0.50, 0.99]) phases; (ii) PaCO2 activity being lower in TBI patients only during acute phase of the injury (d = 0.36 [0.15, 0.56]) and stabilizing to healthy levels by the subacute phase. These findings demonstrate that TBI patients have impairments in low frequency oscillations related to different mechanisms and that these impairments evolve differently over the course of injury.
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Affiliation(s)
- Pratusha Reddy
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA.
| | - Kurtulus Izzetoglu
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA.
| | - Patricia A Shewokis
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, USA; Nutrition Sciences Department, Health Sciences Division of College of Nursing and Health Professions, Drexel University, Philadelphia, PA 19104, USA
| | - Michael Sangobowale
- Clinical TBI Research Center and Department of Neurology at University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ramon Diaz-Arrastia
- Clinical TBI Research Center and Department of Neurology at University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
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Bjerkan J, Lancaster G, Meglič B, Kobal J, Crawford TJ, McClintock PVE, Stefanovska A. Aging affects the phase coherence between spontaneous oscillations in brain oxygenation and neural activity. Brain Res Bull 2023; 201:110704. [PMID: 37451471 DOI: 10.1016/j.brainresbull.2023.110704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 07/03/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
The risk of neurodegenerative disorders increases with age, due to reduced vascular nutrition and impaired neural function. However, the interactions between cardiovascular dynamics and neural activity, and how these interactions evolve in healthy aging, are not well understood. Here, the interactions are studied by assessment of the phase coherence between spontaneous oscillations in cerebral oxygenation measured by fNIRS, the electrical activity of the brain measured by EEG, and cardiovascular functions extracted from ECG and respiration effort, all simultaneously recorded. Signals measured at rest in 21 younger participants (31.1 ± 6.9 years) and 24 older participants (64.9 ± 6.9 years) were analysed by wavelet transform, wavelet phase coherence and ridge extraction for frequencies between 0.007 and 4 Hz. Coherence between the neural and oxygenation oscillations at ∼ 0.1 Hz is significantly reduced in the older adults in 46/176 fNIRS-EEG probe combinations. This reduction in coherence cannot be accounted for in terms of reduced power, thus indicating that neurovascular interactions change with age. The approach presented promises a noninvasive means of evaluating the efficiency of the neurovascular unit in aging and disease.
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Affiliation(s)
- Juliane Bjerkan
- Lancaster University, Department of Physics, LA1 4YB, Lancaster, United Kingdom
| | - Gemma Lancaster
- Lancaster University, Department of Physics, LA1 4YB, Lancaster, United Kingdom
| | - Bernard Meglič
- University of Ljubljana Medical Centre, Department of Neurology, 1525, Ljubljana, Slovenia
| | - Jan Kobal
- University of Ljubljana Medical Centre, Department of Neurology, 1525, Ljubljana, Slovenia
| | - Trevor J Crawford
- Lancaster University, Department of Psychology, LA1 4YF, Lancaster, United Kingdom
| | | | - Aneta Stefanovska
- Lancaster University, Department of Physics, LA1 4YB, Lancaster, United Kingdom.
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Han C, Gao TX, Zhang HD, Ma W, Li Y, Li B, Shen XX, Wang XP, Fu HG, Duan L, Yu XG. Wavelet Analysis of Cerebral Oxygenation Signal Measured by Near-Infrared Spectroscopy in Moyamoya Disease. World Neurosurg 2023; 172:e12-e18. [PMID: 36280048 DOI: 10.1016/j.wneu.2022.10.074] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 11/05/2022]
Abstract
BACKGROUND Spontaneous low-frequency oscillations (LFOs) have been widely studied in cerebrovascular disease, but little is known about their role in moyamoya disease (MMD). The objective of this study was to assess the value of spontaneous LFOs in MMD based on wavelet analysis of near-infrared spectroscopy signals. METHODS Sixty-four consecutive idiopathic adult patients were prospectively enrolled. The regional tissue oxygenation index (TOI) obtained from continuous near-infrared spectroscopy signals. Five frequency intervals of spontaneous LFOs (I, 0.0095-0.02 Hz; II, 0.02-0.06 Hz; III, 0.06-0.15 Hz; IV, 0.15-0.40 Hz; and V, 0.40-2.00 Hz) were extracted based on wavelet analysis. The data were compared between the patients and healthy control groups. Clinical features, cognitive function, and disease progression of MMD were analyzed using TOI and frequency interval data. RESULTS Compared with the healthy control group, patients with MMD had a higher cerebral TOI in both hemispheres. Based on wavelet analysis, the spontaneous LFO of TOI was found to be significantly lower for patients with MMD in frequency intervals II to IV than that for the controls. The spontaneous LFO of TOI is also related to the Suzuki stages in intervals II to IV, stroke in interval III, and cognitive impairment in intervals III to Ⅳ. CONCLUSIONS There were significant differences in spontaneous LFO between patients with MMD and healthy controls. The change in spontaneous LFO in MMD is related to Suzuki stage, cerebral infarction, and cognitive impairment. This might be an effective method for evaluating the severity and monitoring the progression of MMD.
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Affiliation(s)
- Cong Han
- Medical School of Chinese PLA, Beijing, China; Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China
| | - Tian-Xin Gao
- School of Life Science, Beijing Institute of Technology, Beijing, China; Key Laboratory of Convergence Medical Engineering System and Healthcare Technology, The Ministry of Industry and Information Technology, Beijing Institute of Technology, Beijing, China
| | - Hou-Di Zhang
- Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China
| | - Wei Ma
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Yue Li
- School of Medicine, Tsinghua University, Beijing, China
| | - Bin Li
- Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China
| | - Xu-Xuan Shen
- 307 Clinical College of Anhui Medical University, Beijing, China
| | - Xiao-Peng Wang
- 307 Clinical College of Anhui Medical University, Beijing, China
| | - He-Guan Fu
- 307 Clinical College of Anhui Medical University, Beijing, China
| | - Lian Duan
- Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China
| | - Xin-Guang Yu
- Medical School of Chinese PLA, Beijing, China; Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China.
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Sappia MS, Hakimi N, Colier WNJM, Horschig JM. Signal quality index: an algorithm for quantitative assessment of functional near infrared spectroscopy signal quality. BIOMEDICAL OPTICS EXPRESS 2020; 11:6732-6754. [PMID: 33282521 PMCID: PMC7687963 DOI: 10.1364/boe.409317] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/14/2020] [Accepted: 10/19/2020] [Indexed: 05/23/2023]
Abstract
We propose the signal quality index (SQI) algorithm as a novel tool for quantitatively assessing the functional near infrared spectroscopy (fNIRS) signal quality in a numeric scale from 1 (very low quality) to 5 (very high quality). The algorithm comprises two preprocessing steps followed by three consecutive rating stages. The results on a dataset annotated by independent fNIRS experts showed SQI performed significantly better (p<0.05) than PHOEBE (placing headgear optodes efficiently before experimentation) and SCI (scalp coupling index), two existing algorithms, in both quantitatively rating and binary classifying the fNIRS signal quality. Employment of the proposed algorithm to estimate the signal quality before processing the fNIRS signals increases certainty in the interpretations.
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Affiliation(s)
- M. Sofía Sappia
- Artinis Medical Systems, B.V., Einsteinweg 17, 6662 PW Elst, The Netherlands
- Radboud University Nijmegen, Donders Institute for Brain, Behaviour and Cognition, 6525 EN Nijmegen, The Netherlands
- These authors contributed equally to this work
| | - Naser Hakimi
- Artinis Medical Systems, B.V., Einsteinweg 17, 6662 PW Elst, The Netherlands
- Department of Neonatology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Lundlaan 6, Utrecht 3584 EA, The Netherlands
- These authors contributed equally to this work
| | | | - Jörn M. Horschig
- Artinis Medical Systems, B.V., Einsteinweg 17, 6662 PW Elst, The Netherlands
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Blaney G, Sassaroli A, Pham T, Fernandez C, Fantini S. Phase dual-slopes in frequency-domain near-infrared spectroscopy for enhanced sensitivity to brain tissue: First applications to human subjects. JOURNAL OF BIOPHOTONICS 2020; 13:e201960018. [PMID: 31479582 PMCID: PMC9219023 DOI: 10.1002/jbio.201960018] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/14/2019] [Accepted: 08/29/2019] [Indexed: 05/05/2023]
Abstract
We present a first in vivo application of phase dual-slopes (DSϕ), measured with frequency-domain near-infrared spectroscopy on four healthy human subjects, to demonstrate their enhanced sensitivity to cerebral hemodynamics. During arterial blood pressure oscillations elicited at a frequency of 0.1 Hz, we compare three different ways to analyze either intensity (I) or phase (ϕ) data collected on the subject's forehead at multiple source-detector distances: Single-distance, single-slope and DS. Theoretical calculations based on diffusion theory show that the method with the deepest maximal sensitivity (at about 11 mm) is DSϕ. The in vivo results indicate a qualitative difference of phase data (especially DSϕ) and intensity data (especially single-distance intensity [SDI]), which we assign to stronger contributions from scalp hemodynamics to SDI and from cortical hemodynamics to DSϕ. Our findings suggest that scalp hemodynamic oscillations may be dominated by blood volume dynamics, whereas cortical hemodynamics may be dominated by blood flow velocity dynamics.
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Affiliation(s)
- Giles Blaney
- Department of Biomedical Engineering Tufts University, Medford MA, USA
| | - Angelo Sassaroli
- Department of Biomedical Engineering Tufts University, Medford MA, USA
| | - Thao Pham
- Department of Biomedical Engineering Tufts University, Medford MA, USA
| | | | - Sergio Fantini
- Department of Biomedical Engineering Tufts University, Medford MA, USA
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Andersen AV, Simonsen SA, Schytz HW, Iversen HK. Assessing low-frequency oscillations in cerebrovascular diseases and related conditions with near-infrared spectroscopy: a plausible method for evaluating cerebral autoregulation? NEUROPHOTONICS 2018; 5:030901. [PMID: 30689678 PMCID: PMC6156398 DOI: 10.1117/1.nph.5.3.030901] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 08/02/2018] [Indexed: 05/08/2023]
Abstract
BACKGROUND Cerebral autoregulation (CA) is the brain's ability to always maintain an adequate and relatively constant blood supply, which is often impaired in cerebrovascular diseases. Near-infrared spectroscopy (NIRS) examines oxygenated hemoglobin (OxyHb) in the cerebral cortex. Low- and very low-frequency oscillations ( LFOs ≈ 0.1 Hz and VLFOs ≈ 0.05 to 0.01 Hz) in OxyHb have been proposed to reflect CA. AIM To systematically review published results on OxyHb LFOs and VLFOs in cerebrovascular diseases and related conditions measured with NIRS. APPROACH A systematic search was performed in the MEDLINE database, which generated 36 studies relevant for inclusion. RESULTS Healthy people have relatively stable LFOs. LFO amplitude seems to reflect myogenic CA being decreased by vasomotor paralysis in stroke, by smooth muscle damage or as compensatory action in other conditions but can also be influenced by the sympathetic tone. VLFO amplitude is believed to reflect neurogenic and metabolic CA and is lower in stroke, atherosclerosis, and with aging. Both LFO and VLFO synchronizations appear disturbed in stroke, while the former is also altered in internal carotid stenosis and hypertension. CONCLUSION We conclude that amplitudes of LFOs and VLFOs are relatively robust measures for evaluating mechanisms of CA and synchronization analyses can show temporal disruption of CA. Further research and more coherent methodologies are needed.
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Affiliation(s)
- Adam Vittrup Andersen
- Rigshospitalet, Department of Neurology, Glostrup, Denmark
- University of Copenhagen, Department of Clinical Medicine, Copenhagen, Denmark
- Address all correspondence to: Adam Vittrup Andersen, E-mail:
| | - Sofie Amalie Simonsen
- Rigshospitalet, Department of Neurology, Glostrup, Denmark
- University of Copenhagen, Department of Clinical Medicine, Copenhagen, Denmark
| | - Henrik Winther Schytz
- Rigshospitalet, Department of Neurology, Glostrup, Denmark
- University of Copenhagen, Department of Clinical Medicine, Copenhagen, Denmark
| | - Helle Klingenberg Iversen
- Rigshospitalet, Department of Neurology, Glostrup, Denmark
- University of Copenhagen, Department of Clinical Medicine, Copenhagen, Denmark
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Alterations in the coupling functions between cerebral oxyhaemoglobin and arterial blood pressure signals in post-stroke subjects. PLoS One 2018; 13:e0195936. [PMID: 29668713 PMCID: PMC5905974 DOI: 10.1371/journal.pone.0195936] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 04/03/2018] [Indexed: 11/19/2022] Open
Abstract
Cerebral autoregulation (CA) is the complex homeostatic regulatory relationship between blood pressure (BP) and cerebral blood flow (CBF). This study aimed to analyze the frequency-specific coupling function between cerebral oxyhemoglobin concentrations (delta [HbO2]) and mean arterial pressure (MAP) signals based on a model of coupled phase oscillators and dynamical Bayesian inference. Delta [HbO2] was measured by 24-channel near-infrared spectroscopy (NIRS) and arterial BP signals were obtained by simultaneous resting-state measurements in patients with stroke, that is, 9 with left hemiparesis (L–H group), 8 with right hemiparesis (R–H group), and 17 age-matched healthy individuals as control (healthy group). The coupling functions from MAP to delta [HbO2] oscillators were identified and analyzed in four frequency intervals (I, 0.6–2 Hz; II, 0.145–0.6 Hz; III, 0.052–0.145 Hz; and IV, 0.021–0.052 Hz). In L–H group, the CS from MAP to delta [HbO2] in interval III in channel 8 was significantly higher than that in healthy group (p = 0.003). Compared with the healthy controls, the coupling in MAP→delta [HbO2] showed higher amplitude in interval I and IV in patients with stroke. The increased CS and coupling amplitude may be an evidence of impairment in CA, thereby confirming the presence of impaired CA in patients with stroke. In interval III, the CS in L–H group from MAP to delta [HbO2] in channel 16 (p = 0.001) was significantly lower than that in healthy controls, which might indicate the compensatory mechanism in CA of the unaffected side in patients with stroke. No significant difference in region-wise CS between affected and unaffected sides was observed in stroke groups, indicating an evidence of globally impaired CA. These findings provide a method for the assessment of CA and will contribute to the development of therapeutic interventions in stroke patients.
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Bu L, Li J, Li F, Liu H, Li Z. Wavelet coherence analysis of cerebral oxygenation signals measured by near-infrared spectroscopy in sailors: an exploratory, experimental study. BMJ Open 2016; 6:e013357. [PMID: 27810980 PMCID: PMC5128848 DOI: 10.1136/bmjopen-2016-013357] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE The objective of this study was to assess the effects of long-term offshore work on cerebral oxygenation oscillations in sailors based on the wavelet phase coherence (WPCO) of near-infrared spectroscopy (NIRS) signals. METHODS The fatigue severity scale (FSS) was first applied to assess the fatigue level of sailors and age-matched controls. Continuous recordings of NIRS signals were then obtained from the prefrontal lobes in 30 healthy sailors and 30 age-matched controls during the resting state. WPCO between the left and right prefrontal oscillations was analysed and Pearson correlation analysis was used to study the relationship between the FSS and the wavelet amplitude (WA), and between the FSS and the WPCO level. RESULTS The periodic oscillations of Delta (HbO2) signals were identified at six frequency intervals: I (0.6-2 Hz); II (0.145-0.6 Hz); III (0.052-0.145 Hz); IV (0.021-0.052 Hz); V (0.0095-0.021 Hz); and VI (0.005-0.0095 Hz). The WA in intervals I (F=8.823, p=0.004) and III (F=4.729, p=0.034) was significantly lower in sailors than that in the controls. The WPCO values of sailor group were significantly lower in intervals III (F=4.686, p=0.039), IV (F=4.864, p=0.036) and V (F=5.195, p=0.03) than those of the control group. In the sailor group, the WA in interval I (r=-0.799, p<0.01) and in interval III (r=-0.721, p<0.01) exhibited a negative correlation with the FSS. Also, the WPCO exhibited a negative correlation with the FSS in intervals III (r=-0.839, p<0.01), IV (r=-0.765, p<0.01) and V (r=-0.775, p<0.01) in the sailor group. CONCLUSIONS The negative correlation between WA and FSS indicates that the lower oscillatory activities might contribute to the development of fatigue. The low WPCO in intervals III, IV and V represents a reduced phase synchronisation of myogenic, neurogenic and endothelial metabolic activities respectively and this may suggest a decline of cognitive function.
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Affiliation(s)
- Lingguo Bu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, Shandong, P. R. China
| | - Jianfeng Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, Shandong, P. R. China
| | - Fangyi Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, Shandong, P. R. China
| | - Heshan Liu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, Shandong, P. R. China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, Shandong, P. R. China
- Key Laboratory of Rehabilitation Aids Technology and System of the Ministry of Civil Affairs, National Research Center for Rehabilitation Technical Aids, Beijing, P. R. China
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Bok TH, Hysi E, Kolios MC. Simultaneous assessment of red blood cell aggregation and oxygen saturation under pulsatile flow using high-frequency photoacoustics. BIOMEDICAL OPTICS EXPRESS 2016; 7:2769-80. [PMID: 27446705 PMCID: PMC4948629 DOI: 10.1364/boe.7.002769] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 05/08/2023]
Abstract
We investigate the feasibility of photoacoustic (PA) imaging for assessing the correlation between red blood cell (RBC) aggregation and the oxygen saturation (sO2) in a simulated pulsatile blood flow system. For the 750 and 850 nm illuminations, the PA amplitude (PAA) increased and decreased as the mean blood flow velocity decreased and increased, respectively, at all beat rates (60, 120 and 180 bpm). The sO2 also cyclically varied, in phase with the PAA for all beat rates. However, the linear correlation between the sO2 and the PAA at 850 nm was stronger than that at 750 nm. These results suggest that the sO2 can be correlated with RBC aggregation induced by decreased mean shear rate in pulsatile flow, and that the correlation is dependent on the optical wavelength. The hemodynamic properties of blood flow assessed by PA imaging may be used to provide a new biomarker for simultaneous monitoring blood viscosity related to RBC aggregation, oxygen delivery related to the sO2 and their clinical correlation.
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Wang B, Zhang M, Bu L, Xu L, Wang W, Li Z. Posture-related changes in brain functional connectivity as assessed by wavelet phase coherence of NIRS signals in elderly subjects. Behav Brain Res 2016; 312:238-45. [PMID: 27335218 DOI: 10.1016/j.bbr.2016.06.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/16/2016] [Accepted: 06/18/2016] [Indexed: 12/29/2022]
Abstract
Postural instability and falls are commonly seen because of aging and motor disabilities. This study aims to assess the posture-related changes in brain functional connectivity by wavelet phase coherence (WPCO) of oxyhemoglobin concentration change (Δ[HbO2]) signals measured through near-infrared spectroscopy (NIRS) in elderly subjects. The NIRS signals were continuously recorded from the prefrontal cortex and sensorimotor cortical areas in 39 healthy elderly subjects and 22 young healthy subjects during 20min resting and 10min standing states. Eight connection types were obtained from the recorded brain areas. The WPCO were calculated in five frequency intervals in each channel pair as follows: I, 0.6-2Hz; II, 0.145-0.6Hz; III, 0.052-0.145Hz; IV, 0.021-0.052Hz; and V, 0.0095-0.021Hz. Results show that posture change and age significantly interacts with the right prefrontal cortex (PFC) and left sensorimotor cortex (SMC) connectivity in interval V (F=5.010, p=0.028). The left and right PFC connectivity in interval I, the left and right SMC connectivity in interval IV, and the connectivity in interval V, including right PFC and right SMC connectivity, left PFC and left SMC connectivity, and right PFC and left SMC connectivity, showed a significant difference between the Group Elderly and Group Young in response to posture change (p<0.05). This study provides new insight into the mechanism of posture control, and results may be useful in assessing the risk of postural instability in aged persons.
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Affiliation(s)
- Bitan Wang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Ming Zhang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region
| | - Lingguo Bu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Liwei Xu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Wei Wang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China; National Research Center for Rehabilitation Technical Aids, Beijing 100176, PR China.
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11
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Song S, Kim D, Jang DP, Lee J, Lee H, Lee KM, Kim IY. Low-frequency oscillations in cerebrovascular and cardiovascular hemodynamics: Their interrelationships and the effect of age. Microvasc Res 2015; 102:46-53. [PMID: 26277229 DOI: 10.1016/j.mvr.2015.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 07/31/2015] [Accepted: 08/10/2015] [Indexed: 10/23/2022]
Abstract
The aim of this study was to investigate how the interrelationships between low-frequency oscillations (LFOs) in the cerebral and systemic cardiovascular hemodynamic systems change with aging and systemic hemodynamic perturbation. Seventeen young adult (28.4±3.5years) and seventeen elderly subjects (69.4±8.7years) underwent continuous measurements of arterial blood pressure (ABP), heart rate (HR), and cerebral oxygenation (oxy-hemoglobin, deoxy-hemoglobin, and total hemoglobin) using near-infrared spectroscopy. The LFOs were subdivided into three frequency intervals (FI-1: 0.01-0.02Hz, FI-2: 0.02-0.06Hz, and FI-3: 0.06-0.15Hz) via spectral analysis based on continuous wavelet transform. The amplitudes of the LFOs at these FIs were calculated to examine the effects of aging and head-up tilt (HUT) on cerebral and cardiovascular hemodynamics. Granger causality (GC) was used for analyzing the causal relationships between the LFOs observed in ABP, oxy-hemoglobin, and HR. The amplitudes of the LFOs were generally higher in young adults than in the elderly and increased significantly only in the younger subjects after HUT. GCs in FI-3 oscillations were significantly higher in young subjects compared to older participants in the HUT state. These results indicate that aging dampens systemic and cerebral hemodynamic regulatory mechanisms, and the interrelationships between systemic and cerebral hemodynamics become weaker with age.
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Affiliation(s)
- Soohwa Song
- Department of Biomedical Engineering, Hanyang University, Seoul, South Korea
| | - Dohyun Kim
- Department of Biomedical Engineering, Hanyang University, Seoul, South Korea
| | - Dong Pyo Jang
- Department of Biomedical Engineering, Hanyang University, Seoul, South Korea
| | - Jongshill Lee
- Department of Biomedical Engineering, Hanyang University, Seoul, South Korea
| | - Hyon Lee
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea
| | - Kyoung-Min Lee
- Department of Neurology, Seoul National University Hospital, Seoul, South Korea.
| | - In Young Kim
- Department of Biomedical Engineering, Hanyang University, Seoul, South Korea.
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12
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Han Q, Li Z, Gao Y, Li W, Xin Q, Tan Q, Zhang M, Zhang Y. Phase synchronization analysis of prefrontal tissue oxyhemoglobin oscillations in elderly subjects with cerebral infarction. Med Phys 2015; 41:102702. [PMID: 25281981 DOI: 10.1118/1.4896113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE This study aims to assess the phase relationship of prefrontal tissue oxyhemoglobin oscillations using wavelet phase coherence analysis of cerebral Delta [HbO₂] signals in cerebral infarction (CI) patients during the resting state. METHODS Continuous recordings of near-infrared spectroscopy signals were obtained from the left and right prefrontal lobes in 21 subjects with CI (Group CI, age: 76.6 ± 8.5 yr) and 21 healthy elderly subjects (Group Healthy, age: 69.0 ± 7.4 yr) during the resting state. The Group CI was further divide into two groups: CI with hypertension and CI without hypertension. The phase synchronization between left and right prefrontal Delta [HbO₂] oscillations in four frequency intervals (I, 0.6-2 Hz; II, 0.145-0.6 Hz; III, 0.052-0.145 Hz; and IV, 0.021-0.052 Hz) was analyzed using wavelet phase coherence method. RESULTS The phase coherences in intervals III and IV were significantly lower in CI with hypertension than in healthy elderly subjects (F = 12.974, p = 0.001 for III and F = 10.073, p = 0.004 for interval IV). The phase coherence of CI without hypertension in interval III was significantly lower than in healthy elderly subjects (F = 9.909, p = 0.004). Also, the phase coherence in interval IV was significantly lower in CI with hypertension than in CI without hypertension (F = 5.665, p = 0.028). Also, the phase agreement in interval IV showed evident difference between Group CI with hypertension and without hypertension. CONCLUSIONS The difference in phase characteristics of prefrontal tissue oxyhemoglobin oscillations between the CI patients and healthy elderly indicates altered phase synchronization. Moreover, the CI combined with hypertension would aggravate this process. This study provides new insight into the phase dynamics of cerebral oxygenation and may be useful in assessing the risk for stroke.
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Affiliation(s)
- Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Wenhao Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, China
| | - Qitao Tan
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Manyu Zhang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
| | - Yixun Zhang
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, China
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Addison PS. A Review of Wavelet Transform Time-Frequency Methods for NIRS-Based Analysis of Cerebral Autoregulation. IEEE Rev Biomed Eng 2015; 8:78-85. [PMID: 26011892 DOI: 10.1109/rbme.2015.2436978] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Near-infrared spectroscopy (NIRS) has been proposed as a suitable technique for the analysis of cerebral autoregulation as it provides a simpler acquisition methodology and more artifact-free signal. A number of sophisticated wavelet transform methods have recently emerged to quantify the cerebral autoregulation mechanism using NIRS and blood pressure signals. These provide an enhanced partitioning of signal information via the time-frequency plane, which facilitates improved extraction of the components of interest. This area is reviewed, and enhancements to this form of analysis are suggested.
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Selb J, Yücel MA, Phillip D, Schytz HW, Iversen HK, Vangel M, Ashina M, Boas DA. Effect of motion artifacts and their correction on near-infrared spectroscopy oscillation data: a study in healthy subjects and stroke patients. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:56011. [PMID: 26018790 PMCID: PMC4445402 DOI: 10.1117/1.jbo.20.5.056011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 05/04/2015] [Indexed: 05/02/2023]
Abstract
Functional near-infrared spectroscopy is prone to contamination by motion artifacts (MAs). Motion correction algorithms have previously been proposed and their respective performance compared for evoked rain activation studies. We study instead the effect of MAs on "oscillation" data which is at the basis of functional connectivity and autoregulation studies. We use as our metric of interest the interhemispheric correlation (IHC), the correlation coefficient between symmetrical time series of oxyhemoglobin oscillations. We show that increased motion content results in a decreased IHC. Using a set of motion-free data on which we add real MAs, we find that the best motion correction approach consists of discarding the segments of MAs following a careful approach to minimize the contamination due to band-pass filtering of data from "bad" segments spreading into adjacent "good" segments. Finally, we compare the IHC in a stroke group and in a healthy group that we artificially contaminated with the MA content of the stroke group, in order to avoid the confounding effect of increased motion incidence in the stroke patients. After motion correction, the IHC remains lower in the stroke group in the frequency band around 0.1 and 0.04 Hz, suggesting a physiological origin for the difference. We emphasize the importance of considering MAs as a confounding factor in oscillation-based functional near-infrared spectroscopy studies.
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Affiliation(s)
- Juliette Selb
- Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, 149 13th Street, Charlestown, Massachusetts 02129, United States
- Address all correspondence to: Juliette Selb, E-mail:
| | - Meryem A. Yücel
- Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Dorte Phillip
- University of Copenhagen, Rigshospitalet, Danish Headache Center, Faculty of Health Sciences, Department of Neurology, Copenhagen, Glostrup 2600, Denmark
| | - Henrik W. Schytz
- University of Copenhagen, Rigshospitalet, Danish Headache Center, Faculty of Health Sciences, Department of Neurology, Copenhagen, Glostrup 2600, Denmark
| | - Helle K. Iversen
- University of Copenhagen, Rigshospitalet, Stroke Unit, Faculty of Health Sciences, Department of Neurology, Copenhagen, Glostrup 2600, Denmark
| | - Mark Vangel
- Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, 149 13th Street, Charlestown, Massachusetts 02129, United States
| | - Messoud Ashina
- University of Copenhagen, Rigshospitalet, Danish Headache Center, Faculty of Health Sciences, Department of Neurology, Copenhagen, Glostrup 2600, Denmark
| | - David A. Boas
- Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, 149 13th Street, Charlestown, Massachusetts 02129, United States
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Gao Y, Zhang M, Han Q, Li W, Xin Q, Wang Y, Li Z. Cerebral autoregulation in response to posture change in elderly subjects-assessment by wavelet phase coherence analysis of cerebral tissue oxyhemoglobin concentrations and arterial blood pressure signals. Behav Brain Res 2014; 278:330-6. [PMID: 25453742 DOI: 10.1016/j.bbr.2014.10.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2014] [Revised: 10/07/2014] [Accepted: 10/12/2014] [Indexed: 10/24/2022]
Abstract
This study aims to assess the dynamic cerebral autoregulation (dCA) in response to posture change using wavelet phase coherence (WPCO) of cerebral tissue oxyhemoglobin concentrations (Delta [HbO2]) and arterial blood pressure (ABP) signals in healthy elderly subjects. Continuous recordings of near-infrared spectroscopy (NIRS) and ABP signals were obtained from simultaneous measurements in 16 healthy elderly subjects (age: 68.9±7.1 years) and 19 young subjects (age: 24.9±3.2 years). The phase coherence between Delta [HbO2] and ABP oscillations in six frequency intervals (I, 0.6-2 Hz; II, 0.15-0.6 Hz; III, 0.05-0.15 Hz; IV, 0.02-0.05 Hz, V, 0.0095-0.02 Hz and VI, 0.005-0.0095 Hz) was analyzed using WPCO. The sit-to-stand posture change induces significantly lower WPCO in interval III (F=5.50 p=0.025) in the elderly subjects than in the young subjects. However, the stand-to-sit posture change induces higher WPCO in intervals II (F=5.25 p=0.028) and V (F=6.22 p=0.018) in the elderly subjects than in the young subjects. The difference of WPCO in response to posture change between the elderly and the young subjects indicates an altered CA due to aging. This study provides new insight into the dynamics of CA and may be useful in identifying the risk for dCA processes.
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Affiliation(s)
- Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Ming Zhang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Wenhao Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, PR China
| | - Yan Wang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China.
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Han Q, Zhang M, Li W, Gao Y, Xin Q, Wang Y, Li Z. Wavelet coherence analysis of prefrontal tissue oxyhaemoglobin signals as measured using near-infrared spectroscopy in elderly subjects with cerebral infarction. Microvasc Res 2014; 95:108-15. [PMID: 25117487 DOI: 10.1016/j.mvr.2014.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Revised: 07/29/2014] [Accepted: 08/03/2014] [Indexed: 10/24/2022]
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.
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Affiliation(s)
- Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Ming Zhang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Wenhao Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, PR China
| | - Yan Wang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, PR China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, PR China.
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17
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Li Z, Zhang M, Cui R, Xin Q, Liqian L, Zhou W, Han Q, Gao Y. Wavelet coherence analysis of prefrontal oxygenation signals in elderly subjects with hypertension. Physiol Meas 2014; 35:777-91. [PMID: 24670282 DOI: 10.1088/0967-3334/35/5/777] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study aims to assess the prefrontal functional connectivity in elderly subjects with hypertension during the resting state using wavelet coherence analysis of changes in prefrontal tissue oxyhaemoglobin concentrations (Δ[HbO2]) signals measured by near-infrared spectroscopy (NIRS). Continuous recordings of NIRS signals were obtained from the left and right prefrontal lobes in 24 elderly subjects with hypertension (age: 70.7 ± 8.4 years) and 26 elderly normotensive subjects (age: 70.6 ± 7.9 years) during the resting state. The coherence between the left and right prefrontal oscillations in four frequency intervals (I, 0.4 Hz to 2 Hz; II, 0.15 Hz to 0.4 Hz; III, 0.05 Hz to 0.15 Hz; and IV, 0.02 Hz to 0.05 Hz) was analyzed using wavelet coherence method. The Δ[HbO2] oscillations showed significant wavelet coherence (WCO) in intervals I and III, and significant wavelet phase coherence (WPCO) in intervals from I to IV. Remarkably, in elderly subjects with hypertension, the WCO and WPCO in interval III were significantly lower in the left and right prefrontal regions than in healthy elderly subjects (p = 0.014 for WCO, p = 0.007 for WPCO). The lower coherence in interval III indicates a decreased synchronization of neural control in the left and right prefrontal regions in elderly subjects with hypertension. This might suggest a weakened brain functional connectivity in the elderly subjects with hypertension.
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Affiliation(s)
- Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan 250061, People's Republic of China
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18
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Cui R, Zhang M, Li Z, Xin Q, Lu L, Zhou W, Han Q, Gao Y. Wavelet coherence analysis of spontaneous oscillations in cerebral tissue oxyhemoglobin concentrations and arterial blood pressure in elderly subjects. Microvasc Res 2014; 93:14-20. [PMID: 24594440 DOI: 10.1016/j.mvr.2014.02.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 02/20/2014] [Accepted: 02/20/2014] [Indexed: 11/29/2022]
Abstract
This study aims to assess the relationship between spontaneous oscillations in changes in cerebral tissue oxyhemoglobin concentrations (Delta [HbO2]) and arterial blood pressure (ABP) signals in healthy elderly subjects during the resting state using wavelet coherence analysis. Continuous recordings of near-infrared spectroscopy (NIRS) and ABP signals were obtained from simultaneous measurements in 33 healthy elderly subjects (age: 70.7±7.9 years) and 27 young subjects (age: 25.2±3.7 years) during the resting state. The coherence between Delta [HbO2] and ABP oscillations in six frequency intervals (I, 0.4-2 Hz; II, 0.15-0.4 Hz; III, 0.05-0.15 Hz; IV, 0.02-0.05 Hz, V, 0.005-0.0095 Hz and VI, 0.005-0.0095 Hz) was analyzed using wavelet coherence analysis. In elderly subjects, the Delta [HbO2] and ABP oscillations were significantly wavelet coherent in interval I, and wavelet phase coherent in intervals I, II and IV. The wavelet coherence in interval I was significantly higher (p=0.040), in elderly subjects than in young subjects whereas that in interval V significantly lower (p=0.015). In addition, the wavelet phase coherence in interval IV was significantly higher in elderly subjects than in young subjects (p=0.028). The difference in the wavelet coherence of the elderly subjects and the young subjects indicates an altered cerebral autoregulation caused by aging. This study provides new insight into the dynamics of Delta [HbO2] and ABP oscillations and may be useful in identifying the risk for dynamic cerebral autoregulation processes.
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Affiliation(s)
- Ruofei Cui
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Ming Zhang
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong Special Administrative Region P.R. China
| | - Zengyong Li
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China.
| | - Qing Xin
- Hospital of Shandong University, Jinan 250061, PR China
| | - Liqian Lu
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Weiei Zhou
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Qingyu Han
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
| | - Yuanjin Gao
- Key Laboratory of High Efficiency and Clean Mechanical Manufacture, School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China
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Scholkmann F, Kleiser S, Metz AJ, Zimmermann R, Mata Pavia J, Wolf U, Wolf M. A review on continuous wave functional near-infrared spectroscopy and imaging instrumentation and methodology. Neuroimage 2014; 85 Pt 1:6-27. [PMID: 23684868 DOI: 10.1016/j.neuroimage.2013.05.004] [Citation(s) in RCA: 1009] [Impact Index Per Article: 100.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 04/12/2013] [Accepted: 05/03/2013] [Indexed: 01/09/2023] Open
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Li Z, Zhang M, Xin Q, Luo S, Cui R, Zhou W, Lu L. Age-related changes in spontaneous oscillations assessed by wavelet transform of cerebral oxygenation and arterial blood pressure signals. J Cereb Blood Flow Metab 2013; 33:692-9. [PMID: 23361392 PMCID: PMC3652694 DOI: 10.1038/jcbfm.2013.4] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The study aims to assess the spontaneous oscillations in elderly subjects based on the wavelet transform of cerebral oxygenation (CO) and arterial blood pressure (ABP) signals. Continuous recordings of near-infrared spectroscopy (NIRS) and ABP signals were obtained from simultaneous measurements in 20 young subjects (age: 27.3 ± 7.1 years) and 15 elderly subjects (age: 70.8 ± 5.1 years) at rest. Using spectral analysis based on wavelet transform, five frequency intervals were identified (I, 0.005 to 0.02 Hz; II, 0.02 to 0.06 Hz; III, 0.06 to 0.15 Hz; IV, 0.15 to 0.40 Hz; and V, 0.40 to 2.0 Hz). The average amplitudes of the Δ[HbO2] and tissue oxygenation index in intervals I to V and the relative amplitudes in intervals IV and V were significantly lower in elderly subjects than in young subjects (P<0.05). In addition, the relative amplitudes of the ABP in interval I were significantly lower in elderly subjects than in young subjects (P=0.016). The present findings suggest the presence of a cerebrovascular degenerative process caused by aging. Spontaneous oscillations in the CO could be used as an indicator of cerebrovascular changes and could be used to identify the risk for cerebrovascular degenerative processes.
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Affiliation(s)
- Zengyong Li
- Interdisciplinary Division of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
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21
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Li Z, Zhang M, Xin Q, Luo S, Zhou W, Cui R, Lu L. Assessment of cerebral oxygenation oscillations in subjects with hypertension. Microvasc Res 2013; 88:32-41. [PMID: 23583904 DOI: 10.1016/j.mvr.2013.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/06/2013] [Accepted: 04/01/2013] [Indexed: 11/18/2022]
Abstract
PURPOSE The objective of this study was to assess the spontaneous oscillations in subjects with hypertension based on the wavelet transform of cerebral oxygenation signal measured with near-infrared spectroscopy (NIRS). METHODS Continuous recordings of NIRS and arterial blood pressure (ABP) signals were obtained from simultaneous measurements in 20 healthy subjects (age: 70.8±5.2 years) and 22 subjects with hypertension (age: 72.5±6.8 years). RESULTS Using spectral analysis based on wavelet transform, five frequency intervals were identified (I, 0.4-2 Hz; II, 0.15-0.4 Hz; III, 0.06-0.15 Hz; IV, 0.02-0.06 Hz and V, 0.005-0.02 Hz). The amplitudes of Δ[Hb] and Δ[HbO2] in intervals I, II and III were significantly higher in hypertensive patients, who have increased mean flow velocity in middle cerebral artery (MCA), compared to that in the healthy subjects (p<0.01). The amplitudes of the ABP in frequency intervals III and V were significantly higher in hypertensive patients than in the healthy subjects (p<0.01). CONCLUSIONS The present findings revealed that hypertension and increased mean flow velocity in MCA have significant effect on the cerebral oscillations. The higher cerebral oscillations might be related to the intracerebral atherosclerosis in response to systemic hypertension. In addition, the higher spontaneous oscillations in intervals III and V in ABP indicate a metabolic regulation and myogenic response to hypertension.
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Affiliation(s)
- Zengyong Li
- School of Mechanical Engineering, Shandong University, Jinan, 250061 PR China.
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Phillip D, Schytz HW, Selb J, Payne S, Iversen HK, Skovgaard LT, Boas DA, Ashina M. Low frequency oscillations in cephalic vessels assessed by near infrared spectroscopy. Eur J Clin Invest 2012; 42:1180-8. [PMID: 22897146 PMCID: PMC3730271 DOI: 10.1111/j.1365-2362.2012.02704.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND METHODS Low frequency oscillations (LFO) of cerebral vessels are believed to reflect cerebral autoregulation. We investigated day-to-day and hemispheric variations in 0.1 Hz LFO with near infrared spectroscopy (NIRS) and transcranial Doppler (TCD) to determine phase shift and gain of oxygenated haemoglobin (oxyHb) and the velocity of the middle cerebral artery (Vmca) to the arterial blood pressure (ABP). The direct left-right phase shifts of oxyHb and Vmca were also assessed. We examined 44 healthy volunteers by simultaneous recordings of ABP, oxyHb and Vmca during spontaneous and paced breathing at 6 breaths per minute on two separate days. RESULTS The variation between hemispheres had a prediction interval (PI) of ± 39° for ABP-oxyHb phase shift and ± 69% for gain. ABP-Vmca showed ± 57° PI phase shift and ± 158% PI for gain. The variation from day to day showed ± 61° PI for ABP-oxyHb phase shift and ± 297% PI for gain. ABP-Vmca showed ± 45° PI phase shift and ± 166% PI for gain. We found a linear relation between phase shift of oxyHb and Vmca at paced breathing (P=0.0005), but not at rest (P=0.235). CONCLUSION Our results show that LFO phase shift ABP-oxyHb may be used as a robust measurement of differences in autoregulation between hemispheres and over time. In addition, we found a strong relation between oxyHb and Vmca during paced breathing. Gain showed too large variation for clinical use, as the SD was up to 100-fold of mean values.
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Affiliation(s)
- Dorte Phillip
- Danish Headache Center, Glostrup Hospital, University of Copenhagen, Copenhagen, Denmark
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Pierro ML, Sassaroli A, Bergethon PR, Ehrenberg BL, Fantini S. Phase-amplitude investigation of spontaneous low-frequency oscillations of cerebral hemodynamics with near-infrared spectroscopy: a sleep study in human subjects. Neuroimage 2012; 63:1571-84. [PMID: 22820416 DOI: 10.1016/j.neuroimage.2012.07.015] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 05/24/2012] [Accepted: 07/10/2012] [Indexed: 11/25/2022] Open
Abstract
We have investigated the amplitude and phase of spontaneous low-frequency oscillations (LFOs) of the cerebral deoxy- and oxy-hemoglobin concentrations ([Hb] and [HbO]) in a human sleep study using near-infrared spectroscopy (NIRS). Amplitude and phase analysis was based on the analytic signal method, and phasor algebra was used to decompose measured [Hb] and [HbO] oscillations into cerebral blood volume (CBV) and flow velocity (CBFV) oscillations. We have found a greater phase lead of [Hb] vs. [HbO] LFOs during non-REM sleep with respect to the awake and REM sleep states (maximum increase in [Hb] phase lead: ~π/2). Furthermore, during non-REM sleep, the amplitudes of [Hb] and [HbO] LFOs are suppressed with respect to the awake and REM sleep states (maximum amplitude decrease: 87%). The associated cerebral blood volume and flow velocity oscillations are found to maintain their relative phase difference during sleep, whereas their amplitudes are attenuated during non-REM sleep. These results show the potential of phase-amplitude analysis of [Hb] and [HbO] oscillations measured by NIRS in the investigation of hemodynamics associated with cerebral physiology, activation, and pathological conditions.
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Affiliation(s)
- Michele L Pierro
- Department of Biomedical Engineering, Tufts University, Medford, MA, USA.
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Dommer L, Jäger N, Scholkmann F, Wolf M, Holper L. Between-brain coherence during joint n-back task performance: a two-person functional near-infrared spectroscopy study. Behav Brain Res 2012; 234:212-22. [PMID: 22750679 DOI: 10.1016/j.bbr.2012.06.024] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 06/15/2012] [Accepted: 06/20/2012] [Indexed: 10/28/2022]
Abstract
The present study aimed to step into two-person neuroscience by investigating the hemodynamic correlates of between-brain connectivity during joint task performance. To test this approach, wireless functional near-infrared spectroscopy (fNIRS) was used to record brain signals during performance of a dual n-back task simultaneously in paired players as compared to single players. Evaluating functional connectivity between the paired players' brains using wavelet transform coherence (WTC) analysis revealed (1) a significant increase in between-brain coherence during joint task performance as compared to baseline condition. These patterns were observed in two frequency bands, i.e. in the heart rate (HR) frequency and in low-frequency oscillations (LFOs). (2) Averaged hemodynamic responses revealed larger responses in total hemoglobin concentration changes [tHb] for the paired players as compared to the single players; in addition, within the paired players groups joint task performance revealed larger changes in [tHb] as compared to a rest period and to a baseline condition. (3) No increase in behavioral performance was found in the paired players as compared to the single players. Our findings designate fNIRS as suitable tool for monitoring interpersonal performances between two subjects. The results show that two-person performance leads to relevant and significant effects, which are detectable using between-brain connectivity analysis. Using this approach can provide additional insight into interpersonal activation patterns not detectable using typical one-person experiments. Our study demonstrates the potential of simultaneously assessing cerebral hemodynamic responses for various two-person experimental paradigms and research areas where interpersonal performances are involved.
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Affiliation(s)
- Lukas Dommer
- Biomedical Optics Research Laboratory, Division of Neonatology, University Hospital Zurich, Frauenklinikstrasse 10, 8091 Zurich, Switzerland.
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Holper L, Scholkmann F, Wolf M. Between-brain connectivity during imitation measured by fNIRS. Neuroimage 2012; 63:212-22. [PMID: 22732563 DOI: 10.1016/j.neuroimage.2012.06.028] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2012] [Revised: 06/09/2012] [Accepted: 06/16/2012] [Indexed: 10/28/2022] Open
Abstract
The present study aimed to step into two-person neuroscience by investigating the hemodynamic correlates of between-brain connectivity involved in imitation and its dependency on pacing stimuli. To test this approach, we used wireless functional near-infrared spectroscopy (fNIRS) to record simultaneously during imitation performance of a paced finger-tapping task (PFT) in two subjects over premotor cortices (PMC). During the imitation (IM) condition, a model and an imitator were recorded while tapping in synchrony with auditory stimuli separated by a constant interval (stimulus-paced mode, St-P), followed by tapping without the pacing stimulus (self-paced mode, Se-P). During the control (CO) condition, each subject (single 1 and 2) performed the PFT task with the same pacing mode pattern, but alone without reference to each other. Using wavelet transform coherence (WTC) analysis evaluating functional connectivity between brains, we found (1) that IM revealed a larger coherence increase between the model and the imitator as compared to the CO condition. (2) Within the IM condition, a larger coherence increase was found during Se-P as compared to St-P mode. Using Granger-causality (G-causality) analysis evaluating effective connectivity between brains, we found (3) that IM revealed larger G-causality as compared to the CO condition and (4) that within the IM condition, the signal of the model G-caused that of the imitator to a greater extent as compared to vice versa. Our findings designate fNIRS as suitable tool for monitoring between-brain connectivity during dynamic interactions between two subjects and that those measurements might thereby provide insight into activation patterns not detectable using typical single-person experiments. Overall, the results of the present study demonstrate the potential of simultaneously assessing brain hemodynamics in interacting subjects in several research areas where social interactions are involved.
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Affiliation(s)
- Lisa Holper
- Biomedical Optics Research Laboratory, Division of Neonatology, University Hospital Zurich, Frauenklinikstrasse 10, 8091 Zurich, Switzerland.
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Li Z, Zhang M, Xin Q, Chen G, Liu F, Li J. Spectral analysis of near-infrared spectroscopy signals measured from prefrontal lobe in subjects at risk for stroke. Med Phys 2012; 39:2179-85. [DOI: 10.1118/1.3696363] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Zhang Y, Chan GSH, Tracy MB, Lee QY, Hinder M, Savkin AV, Lovell NH. Spectral analysis of systemic and cerebral cardiovascular variabilities in preterm infants: relationship with clinical risk index for babies (CRIB). Physiol Meas 2011; 32:1913-28. [PMID: 22048689 DOI: 10.1088/0967-3334/32/12/003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Frequency spectrum analysis of circulatory signals has been proposed as a potential method for clinical risk assessment of preterm infants by previous studies. In this study, we examined the relationships between various spectral measures derived from systemic and cerebral cardiovascular variabilities and the clinical risk index for babies (CRIB II). Physiological data collected from 17 early low birth weight infants within 1-3 h after birth were analysed. Spectral and cross-spectral analyses were performed on heart rate variability, blood pressure variability and cerebral near-infrared spectroscopy measures such as oxygenated and deoxygenated haemoglobins (HbO(2) and HHb) and tissue oxygenation index (TOI). In addition, indices related to cardiac baroreflex sensitivity and cerebral autoregulation were derived from the very low, low- and mid-frequency ranges (VLF, LF and MF). Moderate correlations with CRIB II were identified from mean arterial pressure (MAP) normalized MF power (r = 0.61, P = 0.009), LF MAP-HHb coherence (r = 0.64, P = 0.006), TOI VLF percentage power (r = 0.55, P = 0.023) and LF baroreflex gain (r = -0.61, P = 0.01 after logarithmic transformation), with the latter two parameters also highly correlated with gestational age (r = -0.75, P = 0.0005 and r = 0.70, P = 0.002, respectively). The relationships between CRIB II and various spectral measures of arterial baroreflex and cerebral autoregulation functions have provided further justification for these measures as possible markers of clinical risks and predictors of adverse outcome in preterm infants.
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Affiliation(s)
- Ying Zhang
- School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, NSW 2052, Australia
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Li Z, Zhang M, Xin Q, Li J, Chen G, Liu F, Li J. Correlation analysis between prefrontal oxygenation oscillations and cerebral artery hemodynamics in humans. Microvasc Res 2011; 82:304-10. [PMID: 21875605 DOI: 10.1016/j.mvr.2011.08.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 07/19/2011] [Accepted: 08/13/2011] [Indexed: 11/30/2022]
Abstract
The objective of this study is to assess the correlation between the prefrontal cerebral oxygenation oscillations measured by near-infrared spectroscopy (NIR) and cerebral artery hemodynamic parameters as measured by transcranial Doppler (TCD). A total of thirty subjects were recruited from the university to participate in this study. The cerebral oxygenation signal and TCD hemodynamic parameters were monitored on separate days. The cerebral oxygenation signal was monitored for 10 min from the left prefrontal lobe using NIRS. TCD monitoring was performed to measure the hemodynamic parameters including end diastolic, peak systolic, and mean cerebral blood flow velocities. Pulsatility index (PI) and resistance index (RI) were calculated automatically. With spectral analysis based on wavelet transform of NIR signal, five frequency intervals were identified (I, 0.005-0.02 Hz, II, 0.02-0.06 Hz, III, 0.06-0.15 Hz, IV, 0.15-0.50 Hz and V, 0.50-2.0 Hz). Significant negative correlation was found between the cerebral [Hb] and [HbO(2)] oscillations in frequency intervals from I to V and the PI or RI in left external carotid artery (ECA) (p<0.005). Also weak negative correlation was found between the cerebral [Hb] and [HbO(2)] oscillations in frequency intervals III, IV, V and the mean velocity in left middle cerebral artery (MCA) (p<0.05). The results suggested that the cerebral oscillations measured from the frontal lobe were closely related to the pulsatility of ECA and reflect partly the vessel stiffness of MCA.
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Affiliation(s)
- Zengyong Li
- School of Mechanical Engineering, Shandong University, Jinan, 250061, PR China.
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Li Z, Wang Y, Li Y, Wang Y, Li J, Zhang L. Wavelet analysis of cerebral oxygenation signal measured by near infrared spectroscopy in subjects with cerebral infarction. Microvasc Res 2010; 80:142-7. [DOI: 10.1016/j.mvr.2010.02.004] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 01/24/2010] [Accepted: 02/04/2010] [Indexed: 01/31/2023]
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Wabnitz H, Moeller M, Liebert A, Obrig H, Steinbrink J, Macdonald R. Time-Resolved Near-Infrared Spectroscopy and Imaging of the Adult Human Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 662:143-8. [DOI: 10.1007/978-1-4419-1241-1_20] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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