Table 2.
Characteristics of studies reporting resting-state near-infrared spectroscopy date for dementia and MCI.
| Author | Title | Regions of interest | Results indicators | Behavioral performance | fNIRS findings | Classification results |
|---|---|---|---|---|---|---|
| Ho, Thi Kieu Khanh et al. 2022 (26) | Deep learning-based multilevel classification of Alzheimer’s disease using non-invasive functional near-infrared spectroscopy | Prefrontal | Hermodynamics | Significant differences in performance were observed between the subject groups on the N-back task. | When at rest, no differences in HbO were observed between the four subject groups. Patients with pAD exhibited lower HbO values than both HC and aAD patients. | |
| Keles, Hasan Onur et al. 2022 (25) | Screening for Alzheimer’s disease using prefrontal resting-state functional near-infrared spectroscopy | Prefrontal | Hermodynamics | N/A | The bilateral activation of PFC was found to be significantly diminished in patients with AD in comparison to the HC group. | The input of changes in oxygenated haemoglobin concentration as features into a support vector machine (SVM) resulted in a significantly higher level of accuracy than chance in predicting the presence and severity of AD. |
| Marmarelis, Vasilis Z. et al. 2017 (15) | Comparison of model-based indices of cerebral autoregulation and vasomotor reactivity using transcranial doppler versus near-infrared spectroscopy in patients with amnestic mild cognitive impairment | Frontal | Tissue oxygenation index | N/A | The response of PFC tissue oxygenation to alterations in CO2 pulses was observed to be diminished in aMCI patients when compared to HC controls. | |
| Tarumi, Takashi et al. 2014 (16) | Dynamic cerebral autoregulation and tissue oxygenation in amnestic mild cognitive impairment | Frontal | Tissue oxygenation index | The patient group (aMCI) exhibited lower scores on delayed recall and higher scores on TMT relative to the HC group. | aMCI patients had lower TOI, but the other measurements did not differ between the two groups. | |
| Li, Wenhao et al. 2022 (13) | Identifying cognitive impairment in elderly using coupling functions between cerebral oxyhemoglobin and arterial blood pressure | Prefrontal | Tissue oxygenation index, Neurovascular coupling | The patient group (MCI and CI) scored significantly lower on the MoCA than the HC group | The TOI was markedly diminished in the right and left PFC in both the MCI and CI groups in comparison to the HC group. | |
| Liu, Jie et al. 2014 (14) | Global brain hypoperfusion and oxygenation in amnestic mild cognitive impairment | Not mentioned | Tissue oxygenation index, Neurovascular coupling | The patient group (aMCI) scored significantly lower on the LM than the HC group | The aMCI and HC groups had different brain blood flow, vascular resistance and metabolic rates. | |
| Viola, S. et al. 2013 (17) | Tissue oxygen saturation and pulsatility index as markers for amnestic mild cognitive impairment: NIRS and TCD study | Temporoparietal, Parietal | Tissue oxygenation index | N/A | The aMCI group exhibited a markedly diminished TOI in the temporoparietal cortex bilaterally in comparison to the HC group. | |
| Yoo and Hong 2019 (61) | Hemodynamics analysis of patients with mild cognitive impairment during working memory tasks | Prefrontal | Functional connectivity | N/A | The interchannel correlations were observed to be higher in the HC group in comparison to the MCI patient group. | Classification was conducted using both LDA and SVM, with the former achieving a classification accuracy of 73.08% and the latter a classification accuracy of 71.15%. |
| Niu, Haijing et al. 2019 (22) | Abnormal dynamic functional connectivity and brain states in Alzheimer’s diseases: Functional near-infrared spectroscopy study | Entire cortex | Functional connectivity | The patient group (aMCI and AD) scored significantly lower on the MMSE, MoCA, and AVLT than the HC group | aMCI and AD patients have increased dynamics of functional brain connectivity and an abnormal frequency of specific brain connectivity states. | |
| Zhang, Shen et al. 2022 (23) | Early screening model for mild cognitive impairment based on resting-state functional connectivity: A functional near-infrared spectroscopy study | Prefrontal, Temporal, Parietal, Occipital | Functional connectivity | The patient group (aMCI) scored significantly lower on the MMSE and MoCA than the HC group | The aMCI group had weaker functional connectivity than the HC group. | RPF-LO was the best in ROI-based classification and had the same AUC values. CH15-CH59 did well for channel-based classification. |
| Bu, Lingguo et al. 2019 (18) | Effective connectivity in subjects with mild cognitive impairment as assessed using functional near-infrared spectroscopy | Prefrontal, Motor, Occipital | Functional connectivity | N/A | The MCI group had lower CS levels than the HC group between relevant brain regions. MMSE and MoCA scores were linked to CS levels between relevant brain regions. | |
| Nguyen, Thien et al. 2019 (21) | Investigation of brain functional connectivity in patients with mild cognitive impairment: A functional near‐infrared spectroscopy (fNIRS) study | Frontal | Functional connectivity | The patient group (MCI) demonstrated a significantly reduced number of words produced in the VFT task in comparison to the HC group. | Right hemispheric and interhemispheric connectivity (measured by HbO) was significantly higher in the MCI group than in the HC group at rest. | |
| Chiarelli, Antonio M. et al. 2021 (19) | Evidence of neurovascular un-coupling in mild Alzheimer’s disease through multimodal EEG-fNIRS and multivariate analysis of resting-state data | Frontal, Prefrontal | Neurovascular coupling | The patient group (AD) scored significantly lower on the MMSE than the HC group | Decoupling between signals from EEG and functional near-infrared spectroscopy in AD patients. | |
| Li, Xuanyu et al. 2018 (28) | Decreased resting-state brain signal complexity in patients with mild cognitive impairment and Alzheimer’s disease: A multi-scale entropy analysis | Frontal, Temporal, Parietal, Occipital | Multiscale entropy | The patient group (aMCI and AD) scored significantly lower on the MMSE, MoCA, and AVLT than the HC group | AD patients had less complex brain signals in several networks. For two of these, the signals were linked to better cognitive performance. | |
| Zeller, Julia B. M. et al. 2019 (27) | Reduced spontaneous low frequency oscillations as measured with functional near-infrared spectroscopy in mild cognitive impairment | Frontal, Temporal | Low-frequency oscillator | The patient group (MCI) scored significantly lower on the DemTect than the HC group | The number of LFOs observed in the parietal cortex of the MCI group was found to be significantly lower in comparison to the HC group. |
TOI, tissue oxygenation index; CBFV, cerebral blood flow velocity; CVRI, cerebral vascular response index; BMI, body mass index; BP, blood pressure.