Hemodynamics Analysis of Patients With Mild Cognitive Impairment During Working Memory Tasks

Yoo, So-Hyeon

doi:10.1109/embc.2019.8856956

Cited by 9 publications

(14 citation statements)

References 38 publications

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“…More recently, the focus on non-invasive neuroimaging biomarkers for MCI and AD have shifted to functional connectivity. A recent systemic review including 36 articles over the past two decades suggests that patients with MCI and AD have impaired frontal and long-range connectivity in the resting state fMRI ( Yeung and Chan, 2020 ), which was also observed in a recent study ( Yoo and Hong, 2019 ). Task-related functional connectivity analysis suggests that the number and strength of prefrontal functional connections increased during a working memory task ( Yu et al, 2020 ) but left and inter-hemispheric connectivity during a verbal fluency test were lower ( Nguyen et al, 2019 ) in the patients with MCI compared to healthy controls.…”

Section: Clinical Application Of Fnirsmentioning

confidence: 59%

“…However, the accuracy, on average 60-70%, has been too low to reliably identify MCI patients (Yang et al, 2019). Moreover, fNIRS has shown inconsistent results suggesting that patients with MCI have an increased oxyhemoglobin response in regions of interest compared with the healthy control group (Yoo and Hong, 2019). Therefore, the hemodynamic response detected by fNIRS is unlikely to be sensitive and specific enough for clinical practice.…”

Section: Mild Cognitive Impairmentmentioning

confidence: 99%

See 1 more Smart Citation

Functional Near-Infrared Spectroscopy and Its Clinical Application in the Field of Neuroscience: Advances and Future Directions

et al. 2020

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Similar to functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS) detects the changes of hemoglobin species inside the brain, but via differences in optical absorption. Within the near-infrared spectrum, light can penetrate biological tissues and be absorbed by chromophores, such as oxyhemoglobin and deoxyhemoglobin. What makes fNIRS more advantageous is its portability and potential for long-term monitoring. This paper reviews the basic mechanisms of fNIRS and its current clinical applications, the limitations toward more widespread clinical usage of fNIRS, and current efforts to improve the temporal and spatial resolution of fNIRS toward robust clinical usage within subjects. Oligochannel fNIRS is adequate for estimating global cerebral function and it has become an important tool in the critical care setting for evaluating cerebral oxygenation and autoregulation in patients with stroke and traumatic brain injury. When it comes to a more sophisticated utilization, spatial and temporal resolution becomes critical. Multichannel NIRS has improved the spatial resolution of fNIRS for brain mapping in certain task modalities, such as language mapping. However, averaging and group analysis are currently required, limiting its clinical use for monitoring and real-time event detection in individual subjects. Advances in signal processing have moved fNIRS toward individual clinical use for detecting certain types of seizures, assessing autonomic function and cortical spreading depression. However, its lack of accuracy and precision has been the major obstacle toward more sophisticated clinical use of fNIRS. The use of high-density whole head optode arrays, precise sensor locations relative to the head, anatomical co-registration, short-distance channels, and multi-dimensional signal processing can be combined to improve the sensitivity of fNIRS and increase its use as a widespread clinical tool for the robust assessment of brain function.

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Section: Clinical Application Of Fnirsmentioning

confidence: 59%

Section: Mild Cognitive Impairmentmentioning

confidence: 99%

Functional Near-Infrared Spectroscopy and Its Clinical Application in the Field of Neuroscience: Advances and Future Directions

et al. 2020

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“…[21][22][23] There is evidence in the literature showing that fNIRS offers a great potential to become a valuable tool to identify individuals with a higher risk of developing dementia as changes in cortical haemodynamic obtained during a standardised cognitive test allow to discern between healthy and diseased individuals. [24][25][26][27][28][29][30][31] Young participants showed a stronger activation in the left hemisphere in the more difficult task conditions. Elderly participants showed no lateralisation and a decreased activation in the difficult task condition.…”

Section: Strengths and Limitations Of This Studymentioning

confidence: 90%

Multimodal measurement approach to identify individuals with mild cognitive impairment: study protocol for a cross-sectional trial

et al. 2021

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IntroductionThe diagnosis of mild cognitive impairment (MCI), that is, the transitory phase between normal age-related cognitive decline and dementia, remains a challenging task. It was observed that a multimodal approach (simultaneous analysis of several complementary modalities) can improve the classification accuracy. We will combine three noninvasive measurement modalities: functional near-infrared spectroscopy (fNIRS), electroencephalography and heart rate variability via ECG. Our aim is to explore neurophysiological correlates of cognitive performance and whether our multimodal approach can aid in early identification of individuals with MCI.Methods and analysisThis study will be a cross-sectional with patients with MCI and healthy controls (HC). The neurophysiological signals will be measured during rest and while performing cognitive tasks: (1) Stroop, (2) N-back and (3) verbal fluency test (VFT). Main aims of statistical analysis are to (1) determine the differences in neurophysiological responses of HC and MCI, (2) investigate relationships between measures of cognitive performance and neurophysiological responses and (3) investigate whether the classification accuracy can be improved by using our multimodal approach. To meet these targets, statistical analysis will include machine learning approaches.This is, to the best of our knowledge, the first study that applies simultaneously these three modalities in MCI and HC. We hypothesise that the multimodal approach improves the classification accuracy between HC and MCI as compared with a unimodal approach. If our hypothesis is verified, this study paves the way for additional research on multimodal approaches for dementia research and fosters the exploration of new biomarkers for an early detection of nonphysiological age-related cognitive decline.Ethics and disseminationEthics approval was obtained from the local Ethics Committee (reference: 83/19). Data will be shared with the scientific community no more than 1 year following completion of study and data assembly.Trial registration numberClinicalTrials.gov, NCT04427436, registered on 10 June 2020, https://clinicaltrials.gov/ct2/show/study/NCT04427436.

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“…Two studies observed blunted haemodynamic responses in MCI [39], [40], with a gradation from healthy controls to MCI to AD [24], whereas three found no difference in functional response [27], [41] or connectivity [31] between MCI and controls. Interestingly, one study identified hyperactivation in MCI compared to controls [42]. Perhaps the discriminatory ability of the n-back task is more subtle: there is evidence for differential WM load modulation across disease stages.…”

Section: Discussionmentioning

confidence: 99%

“…Such subject-specific information is also necessary for creating detailed topographical maps of brain activity using High-density Diffuse Optical Tomography (HD-DOT). Whilst no studies used HD-DOT and only a few studies used high-density systems (e.g., [27], [42]), Talamonti et al [82] used DOT and Li et al [59] performed source localisation of the NIRS signal, however, neither of these used subject-specific information. Moreover, many studies only analysed the HbO signal and discarded the HbR signal, citing a higher signal-to-noise ratio of the HbO signal and greater correlation with BOLD fMRI signal [95].…”

Section: Discussionmentioning

confidence: 99%

A systematic review of near-infrared spectroscopy in dementia

Butters

Srinivasan

O’Brien

et al. 2022

Preprint

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Objectives. This review aimed to evaluate previous studies using Near-infrared spectroscopy (NIRS) in dementia by summarising the results, determining the consensus in the literature, and delineating if, and how, NIRS experimental and analysis methods may be improved for future studies in dementia. Methods. Three databases (PsychINFO, Medline, Embase) were searched for original research studies using NIRS in dementia and prodromal disease stages. We included both observational and randomised control trials, and studies published in English. Animal studies, conference abstracts, and reviews were excluded. Results. From 759 identified records, 80 studies using NIRS in dementia and prodromal populations across a range of activation tasks testing memory (28), word retrieval (22), and motor (7) and visuo-spatial function (4), as well as in the resting state (29) were evaluated. Across these cognitive domains, dementia patients generally showed a blunted haemodynamic response, often localised to frontal regions of interest, and a lack of task-appropriate frontal lateralisation. Prodromal stages, such as Mild Cognitive Impairment, revealed mixed results and were associated with either diminished responses or hyperactivity, accompanied by reduced cognitive function, the latter suggesting a possible compensatory neural response which is not present at the dementia stage. Conclusion. There is clear evidence of alterations in brain oxygenation in both dementia and prodromal stages across a range of cognitive domains and in the resting state, indicating an ability of NIRS to distinguish dementia from healthy ageing, or at-risk populations. A consensus as to the nature of these changes, however, is difficult to reach due to a lack of standardisation in optical techniques and processing methods. Further studies are required exploring more naturalistic settings and in a wider range of dementia subtypes.

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Hemodynamics Analysis of Patients With Mild Cognitive Impairment During Working Memory Tasks

Cited by 9 publications

References 38 publications

Functional Near-Infrared Spectroscopy and Its Clinical Application in the Field of Neuroscience: Advances and Future Directions

Functional Near-Infrared Spectroscopy and Its Clinical Application in the Field of Neuroscience: Advances and Future Directions

Multimodal measurement approach to identify individuals with mild cognitive impairment: study protocol for a cross-sectional trial

A systematic review of near-infrared spectroscopy in dementia

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