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ObjectiveTo study the brain network during balance control tasks in older adults. MethodsFrom January to April, 2022, 22 healthy young adults and 20 healthy older adults were recruited from the Fifth Affiliated Hospital of Guangzhou Medical University and communities. They were asked to finish standing tasks on the plantar pressure plate with eyes opening and closing, while the functional connectivities (FC) of prefrontal cortex (PFC) and primary motor cortex (PMC) were measured with functional near-infrared spectroscopy. ResultsCompared with the young adults, the area of the ellipse (Z = -2.884, P < 0.01) and the maximum swing (Z = -2.481, P < 0.05) increased in the older adults as eyes closing. During the standing task, the intra-FC of left (t = 2.978, P < 0.01) and right (Z = -3.123, P < 0.01) PFC decreased in the older adults, and the inter-FC of right PMC to left PFC (t = 2.087, P < 0.05) and right PFC to left PFC (t = 3.471, P < 0.001) decreased, too. ConclusionThe FC of PFC decreased in healthy older adults during balance control tasks, which may be a indicator for aging brain.
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ObjectiveTo explore the current status and frontier hotspots of functional near-infrared spectroscopy (fNIRS) in the field of stroke. MethodsRelevant literature on stroke and fNIRS from the Web of Science Core Collection (WoSCC) database was searched from its inception to July, 2023. VOSviewer, CiteSpace and Scimago were utilized for analysis of publication output, countries (regions) and institutions, international collaboration, co-cited references, co-occurring keywords and burst keywords. ResultsA total of 379 articles were included. The research activity in this field showed an overall upward trend with slight fluctuations in the early stage. Among the top five institutions by publication output, four were from China. Co-occurrence analysis revealed that Beihang University and Boston Children's Hospital were central in collaboration networks. This study involved 1 787 authors, with 120 core authors, in which the top five most cited authors were Li Zengyong, Li Wenhao, Huo Congcong, Dou Zulin and Song Ying. The publications in this field were primarily concentrated in disciplines such as neurology, psychiatry, ophthalmology and clinical medicine. Overlay visualization of journal co-citation networks demonstrated associations between medical, clinical, and neurology disciplines with psychology, education, and sociology. Co-occurrence and clustering analysis of keywords indicated research emphasis on stroke rehabilitation, integration of multiple technical modalities, and exploration of innovative training strategies and brain activation connectivity. The research evolution of fNIRS in the stroke domain revealed initial use of photodiode devices for cerebral ischemia reperfusion monitoring. Subsequent studies refined cortical activation through improved laser sources, avalanche photodiodes, single-task experimental designs and transcranial direct current stimulation. Later, research extended to whole-brain detection, multimodal stimulation and the combination of virtual reality technology with audiovisual stimulation, resulting in significantly enhanced brain activation. The application of brain-computer interface technology further facilitated direct restoration of motor function. ConclusionResearches in the field of stroke using fNIRS technology overall demonstrat a continuous upward trend. The researches focuse on post-stroke rehabilitation, integrating multimodal fusion, brain-computer interfaces, virtual reality, and sensory stimulation for real-time monitoring and personalized neurorehabilitation training strategies. It emphasizes interdisciplinary collaboration, expanding innovative research and the application of new technologies.
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ObjectiveTo study the effect of upper limb robot-assisted therapy on upper limb function and cerebral cortex activation in stroke patients using functional near-infrared spectroscopy (fNIRS). MethodsFrom January, 2022 to January, 2023, 32 stroke patients in Zhejiang Rehabilitation Medical Center were randomly divided into control group (n = 16) and experimental group (n = 16). Both groups received routine neurological medication and routine rehabilitation. The control group received routine upper limb exercises, the experimental group received upper limb robot-assisted therapy. They were assessed with Fugl-Meyer Assessment-Upper Extremities (FMA-UE) and fNIRS (oxyhemoglobin, deoxyhemoglobin, and total hemoglobin) before and four weeks after treatment. NIRS_SPM was used for activation analysis, Homer2 was used for blood oxygen concentration analysis. ResultsAfter treatment, the score of FMA-UE increased in both groups (|t| > 5.910, P < 0.001), and was higher in the experimental group than in the control group (t = -2.348, P < 0.05). fNIRS activation results showed that, the activation increased in the experimental group after treatment in channel 17 (F = 9.354, P < 0.01), and it was more than that in the control group (F = 5.217, P < 0.05). fNIRS blood oxygen concentration results showed that, the blood oxygen concentration increased in the experimental group after treatment in channel 17 (F = 12.179, P < 0.01), and it was more than that in the control group (F = 4.883, P < 0.05). ConclusionThe upper limb robot-assisted therapy can improve the upper limb motor function and cerebral cortex activation of stroke patients.
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ObjectiveTo explore the neuromuscular control mechanism of training strategies based on mirror neuron system (MNS): action observation (AO), action execution (AE) and action imitation (AO+AE) using functional Near Infrared Spectroscopy (fNIRS) and surface electromyography (sEMG). MethodsFrom July, 2022 to February, 2023, 64 healthy adults were asked to finish four tasks: watching landscape video (control), watching landscape video and acting right wrist and hand extension (AE), watching right wrist and hand extension video (AO), and watching right wrist and hand extension video and acting right wrist and hand extension (AO+AE). A block design was adopted, five times a task in a block, eight cycles, random orders in videos and tasks. The activation of each channel and regions of interest (ROI, namely BA40, BA44, BA45, BA46, BA6 and BA7) in left MNS regions was detected with fNIRS synchronously, as well as the average electromyography (AEMG) of extensor digitorum and extensor carpi radialis with sEMG. ResultsCompared with the control condition, MNS activated in AO, AE and AO+AE conditions, and the intensities mildly increased in turn. Compared with the control condition, 15 channels activated in AO condition, 15 channels activated in AE condition, and all 20 channels activated in AO+AE condition; and the activation intensities of most channels were AO+AE > AE > AO. Four ROI, BA40, BA46, BA6 and BA7, activated in AO condition, all the six ROI activated in AE and AO+AE conditions, and the activation intensities of most ROI were AO+AE > AE > AO. The standardized AEMG of extensor digitorum and extensor carpi radialis were higher in AO+AE condition than in AE condition (|t| > 4.24, P < 0.001). ConclusionMNS has been activated during action observation, execution and imitation, and the ranges and intensities of activation increase in turn. The target muscles activate more during imitation than during execution. Synchronous application of fNIRS and sEMG is feasible in the study of neural mechanism of rehabilitation strategies based on mirror neuron theory.
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ObjectiveTo explore the characteristics of balance and cortical activation in older adults when performing cognition-balance dual tasks. MethodsFrom January to April, 2023, 20 healthy older adults were non-targeted recruited. They completed six tasks of close eyes & fixed platform (CF), close eyes & fixed platform & cognitive task (CFc), open eyes & sway-referenced platform (OS), open eyes & sway-referenced platform & cognitive task (OSc), close eyes & sway-referenced platform (CS), and close eyes & sway-referenced platform & cognitive task (CSc) on the Balance SD, wearing functional near-infrared spectroscopy caps. The overal stability index (OSI) was measured with Balance SD. The premotor cortex (PMC), sensorimotor cortex (SMC) and prefrontal cortex (PFC) were as regions of interest (ROIs), and the β values were calculated. ResultsThe OSI was more as CFc than as CF (Z = -2.014, P < 0.05), and was less as CSc than as CS (Z = -2.063, P < 0.05). The β values of bilateral ROIs were all more as CFc than as CF (|Z| > 2.464, |t| > 3.733, P < 0.05), and as OSc than as OS (|t| > 2.308, P < 0.05); the β value of the right SMC was more as CSc than as CS (t = -2.912, P < 0.05). The number of correct counts was less as CSc than as CFc and OSc (|Z| > 3.643, P < 0.001). ConclusionBalance has been impaired under dual tasks for older adults, while activation of cerebral cortex increases. However, for more difficult balance task, older adults would preferentially maintain postural balance under dual tasks, while cognitive performance decreases, which may be the results from no more activation of cerebral cortex under dual tasks.
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ObjectiveTo summarize the current situation, hot spots and frontiers of the application of functional near-infrared spectroscopy (fNIRS) in rehabilitation in recent ten years. MethodsLiterature related to the application of fNIRS in rehabilitation was retrieved from the core collection of Web of Science from January, 2003 to December, 2022, and the visualized analysis was performed by CiteSpace 6.1.R6 software. ResultsA total of 828 literatures were included. The annual publication volume was on the rise. The most prolific author was LI Zengyong. The most published country was the United States. And the most published institution was Karolinska Institute. Hot keywords included children, stroke, activation, quality of life, cerebral palsy, etc. The hot keywords of bursting intensity included early intervention, speech perception, cerebral palsy, plasticity, spinal cord injury, physical therapy, visual feedback, Parkinson's disease, etc. Cluster analysis suggested that in the past decade, the application of fNIRS in rehabilitation involved physical therapy, speech therapy, occupational therapy, pre-rehabilitation and early rehabilitation of surgery, mainly focusing on six themes: the rehabilitation of motor dysfunction after stroke, cognitive impairment, hearing and speech dysfunction, children with cerebral palsy, cardiopulmonary function monitoring in severe diseases and long-term nursing of chronic diseases. Among them, the application of fNIRS in neurological rehabilitation of stroke patients occupied a large proportion, which might be the current research hot spot and trend. ConclusionThe application of fNIRS in rehabilitation is on the rise. In the future, more attention should be paid to the application of fNIRS in the study of the injury and recovery mechanism of neurological disorders, especially the effects of various rehabilitation interventions on cortical plasticity and the etiology of neurological disorders.
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Objective:To explore the characteristics of functional connectivity (FC) and regional spontaneous brain activity in patients in a minimally-conscious state (MCS).Methods:Resting-state functional near-infrared spectroscopy (rs-fNIRS) was used. Ten minimally-conscious patients were studied along with 12 healthy counterparts as healthy controls (HC). Five minutes of rs-fNIRS data were recorded from each subject and FC and the fractional amplitude of low-frequency fluctuations (fALFFs) of 53 channels were computed using the NIRS-KIT toolbox. The results were compared between the two groups.Results:Compared with the HC group, a significant decrease was observed in the average FC strength of seventeen channel pairs after false discovery rate (FDR) correction. Most were in the right and left frontal pole, as well as the dorsolateral prefrontal lobe. Compared with the HC group, the average fALFF values of Broca′s area (channel 2), the premotor cortex and the supplementary motor cortex (channels 4, 10, and 40), the dorsolateral prefrontal lobe (channels 6, 11, 25, 39), the eye motor area of the frontal lobe (channel 12) and the frontal pole (channels 23, 27, 36) were significantly greater in the MCS group. The fluctuations of the frontal pole (channel 19) were significantly less (after FDR correction).Conclusion:In an MCS spontaneous neural activity is over-active in the prefrontal lobe and some speech- and motor-related brain regions, and coordination of the internal prefrontal functional network is disordered.
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Objective:To explore the characteristics and differences of oxygenated hemoglobin responses in different brain regions in adolescent depressive disorder patients and healthy adolescents during speech fluency task based on functional near-infrared spectroscopy imaging.Methods:From March 2021 to June 2021, twenty-nine adolescents with depression(depressed group) and 26 healthy adolescents(normal group) were enrolled. The severity of depression was assessed by Hamilton depression scale, and the speech fluency task was performed by functional near-infrared spectroscopy brain imaging, and the relative concentrations of oxyhemoglobin in the prefrontal and bilateral temporal lobes were measured.SPSS 26.0 statistical software was used for data analysis, chi-square test was used for gender count data. The t-test was used for comparison of two groups. The measurement data that did not conform to normal distribution were compared between the two groups by Mann-Whitney U test. Results:In the speech fluency task, there was no significant difference in the concentration of oxygenated hemoglobin in prefrontal and left temporal between the depressed group and the normal group (both P>0.05); the oxygenated hemoglobin concentration in the right temporal lobe(-9.179(-22.231, 4.789)) of depressed group was significantly lower than that of the normal group (12.754(-9.438, 35.008)), and the difference was statistically significant ( U=538.00, P<0.05). The oxygenated hemoglobin concentration in right temporal lobe of depressed group had no correlation with the score of Hamilton depression rating scale ( r=0.092, P>0.05). Conclusion:The right temporal lobe function of adolescent depression patients is lower than that of healthy controls during speech fluency tasks, which provides a basis for study of the relationship between depression and some cognitive sensitivity impairment and the function of right temporal lobe.
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Parkinson disease (PD) is a common neurodegenerative disease with motor and non-motor symptoms that seriously affect the quality of life and social function of patients. The current non-invasive techniques in PD brain function studies mainly include functional magnetic resonance imaging and electroencephalography, which made it difficult to assess brain function under motor state or magnetoelectric treatment. As an emerging functional neuroimaging technique, functional near-infrared spectroscopy (fNIRS) can monitor the real movement-related cortical responses of PD patients in real time, providing a safe and non-invasive method with high ecological validity for direct monitoring of brain activity. This article presented a review of recent advances in the application of fNIRS technology in PD research, intending to provide new ideas for functional neuroimaging studies in PD. The results suggested that PD gait and balance deficits were closely associated with abnormal activation of the cerebral cortex, particularly the prefrontal cortex, involving a compensatory strategy of cortical cognitive resources for basal ganglia dysfunction. Drugs, deep brain stimulation, and other interventions could be applied to fNIRS techniques to evaluate neurorehabilitation effects and reveal the neural basis of intervention effects. This area of research is currently in its infancy, but the evidence provided supports for the translation of fNIRS into clinical practice. Future research should develop multimodal imaging techniques and in-depth studies of broad areas of the cerebral cortex to obtain more valuable findings for clinical practice.
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Functional near infrared spectroscopy (fNIRS) is an emerging neuroimaging technology, which has such advantages as non-invasiveness, portability, robustness to motion and no noise over other neuroimaging tools.Therefore, it has important values in the research of children language development.fNIRS has been currently applied to the study of neonatal word recognition, infant speech perception, language functional lateralization, bilingual cognitive mechanism, language related neurodevelopmental disorders, etc.It has a bright future of applications in the field of children language development.
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ObjectiveTo compare the functional connectivity of brain networks in stroke patients with upper limb motor dysfunction during unilateral or bilateral upper limb movement using functional near-infrared spectroscopy (fNIRS). MethodsFrom April to June, 2021, 40 stroke patients with upper limb motor dysfunction in Department of Rehabilitation Medicine, Huashan Hospital, finished unilateral (affected) and bilateral upper limb movement. Eight-minute fNIRS data were collected before and after movement, and the functional activities and connectivity of prefrontal cortex (PFC), upper limb and hand functional area (H), primary sensory cortex (S1) were analyzed based on oxygenated hemoglobin. ResultsFunctional activities increased in affected H after unilateral task (t = -3.135, P < 0.05), while the functional connectivity increased between affected H and affected S1, affected H and unaffected S1, and affected S1 and unaffected S1 (|t| > 3.218, P < 0.05). There was no significant difference in the functional activities and connectivity of all the areas after bilateral upper limb task (|t| < 2.385, P > 0.05). The improvement of affected H was more after unilateral task than after bilateral upper limb task (t = 2.026, P < 0.05). ConclusionUnilateral affected upper limb training is more effective on functional activities and connectivity for corresponding brain regions than bilateral task.
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@#Objective To investigate the resting brain functional connectivity in patients with post-stroke cognitive impairment (PSCI).Methods From January, 2020 to January, 2021, 24 PSCI patients were divided into mild group (n=12) and moderate group (n=12) according to Mini-Mental State Examination and Montreal Cognitive Assessment scores; and other ten healthy controls (control group) were included. All the subjects were scanned with 64-channel functional near-infrared spectroscopy in resting for six minutes. The data were analyzed with NirSpark 1.6.12 and SPSS 26.0.Results Using deoxyhemoglobin, the functional connectivity between bilateral hemispheres reduced in the moderate group compared with those in the control group (t=-2.763, P=0.024), especially for the functional connectivity between sensorimotor cortexes (F=12.674, P=0.031).Conclusion Functional connectivity between hemispheres decreases in PSCI patients, especially between sensorimotor cortexes.
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Objective To investigate the efficacy of acupuncture and rehabilitation therapy on lower limb motor function, and to explore a cortical mechanism using functional near infrared spectroscopy (fNIRS). Methods From December, 2020 to July, 2021, 24 stroke patients with lower limb motor dysfunction in our hospital were randomly divided into rehabilitation group (n = 12) and acupuncture-rehabilitation group (n = 12), and received routine rehabilitation training and acupuncture-rehabilitation intervention for four weeks, respectively. The control group included ten healthy subjects matched the patients. Before and after intervention, the lower limb motor function of the patients was assessed with Fugl-Meyer Assessment-Lower Extremities (FMA-LE), and all the subjects accepted fNIRS examination. The functional intensity and lateralization index (LI) of supplementary motor area (SMA), premotor cortex (PMC) and sensory motor cortex (SMC) were calculated based on oxygenated hemoglobin (HbO2). Results There was no significant difference in FMA-LE score between the rehabilitation group and the acupuncture-rehabilitation group before the intervention (P > 0.05). After four weeks of intervention, FMA-LE scores improved in both groups (t > 3.770, P 0.05). After intervention, the average functional connection increased in both groups (t > 2.178, P < 0.05), and the functional connection of the affected PMC of acupuncture-rehabilitation group increased (P < 0.05). The LI in SMC increased in the acupuncture-rehabilitation group (P < 0.05). There was a significant positive correlation between the change of functional connection of the affected PMC and the change of FMA-LE scores in the acupuncture-rehabilitation group (r = 0.579, P < 0.05). Conclusion Acupuncture with rehabilitation therapy can significantly improve the lower limb motor function and asymmetrical activation of SMC in stroke patients. The recovery of lower limb motor function may be related to the enhanced activation of affected PMC.
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Working memory is an important foundation for advanced cognitive function. The paper combines the spatiotemporal advantages of electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) to explore the neurovascular coupling mechanism of working memory. In the data analysis, the convolution matrix of time series of different trials in EEG data and hemodynamic response function (HRF) and the blood oxygen change matrix of fNIRS are extracted as the coupling characteristics. Then, canonical correlation analysis (CCA) is used to calculate the cross correlation between the two modal features. The results show that CCA algorithm can extract the similar change trend of related components between trials, and fNIRS activation of frontal pole region and dorsolateral prefrontal lobe are correlated with the delta, theta, and alpha rhythms of EEG data. This study reveals the mechanism of neurovascular coupling of working memory, and provides a new method for fusion of EEG data and fNIRS data.
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Electroencephalography/methods , Memory, Short-Term , Neurovascular Coupling/physiology , Prefrontal Cortex , Spectroscopy, Near-Infrared/methodsABSTRACT
Objective:To explore the characteristics of cortical activation during the stimulation-assisted walking of hemiplegic stroke survivors using functional near-infrared spectroscopy (fNIRS).Methods:Eight stroke survivors with right hemiplegia (average age 44.4±7.2 years) in a self-controlled study each walked at 2km/h on a treadmill, alone and assisted by functional electronic stimulation (FES). Real-time near-infrared spectroscopic images were recorded. The Matlab NIRS-SPM toolkit was employed to calculate the changes in oxyhemoglobin concentration in different cortical regions. A general linear model was evaluated which integrated the task effects, and version 20.0 of the SPSS statistical software was used to perform single sample or paired sample t-tests of the beta values so as to produce activation hot maps of the significant differences.Results:During unassisted walking channels 8, 10, 11, 13-20, 23-28, 30 and 32-37 were significantly activated. During FES-assisted walking it was the same channels plus channels 9 and 22, 31. The results suggest that in walking the cortical regions activated are mainly located in M1 of the unaffected hemisphere, supplemented by M1 and SMA, PMC and S1 in the affected hemisphere. There were significant differences in the activation of channels 9, 24, 27, 32, 33 between the two walking tasks. FES-assistance enhances S1 activation on the unaffected side, as well as the SMA and PMC of the affected side more significantly.Conclusions:Bilateral asymmetrical activation is found mostly in M1 during walking with or without FES assistance. FES assistance significantly strengthens the compensatory activation of the PMC and SMA of the affected hemisphere while walking for those with hemiplegia.
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Objective:To detect the abnormalities within the functional connectivity (FC) of the prefrontal cortex (PFC) in patients with overactive bladder (OAB) and to explore its central pathogenesis.Methods:Seven OAB patients (OAB group, 6 females, mean age 47.6±16.0 years) and 13 healthy controls [HC] (HC group, 10 females, mean age 49.9±9.2 years) were prospectively enrolled from August to December 2020. All subjects underwent rs-fNIRS scanning synchronized with urodynamic monitoring, and two rs-fNIRS scans were performed when the bladder was empty and when the desire to void was strong/urodynamic monitoring indicated detrusor hyperactivity (DO). The Pearson's correlation coefficients (r value, i. e., FC value) between time series of the 22 channels were calculated, and a 22×22 FC matrix for each subject was obtained. A paired-sample t-test ( P<0.05, FDR corrected) was used to compare the difference in FC values between the HC group and the OAB group when the bladder was empty and the desire to void was strong. A two-sample t-test ( P<0.05, FDR corrected) was used to compare the group differences in FC values between OAB and HC groups. Results:In this study, 7 patients were included in the OAB group, including 1 male and 6 female. The mean age was (47.6±16.0) years old. In HC group, 13 healthy subjects were included, including 3 males and 10 females. The mean age was (49.9±9.2) years. There was no significant difference in baseline data between the two groups, including age, sex composition, years of education, handedness and urgency score at the second scan ( P>0.05). Residual urine volume in both groups was less than 10 ml. The OABSS score, 3-day urine diary parameters (frequency of urination/24 h, frequency of urinary incontinence/24 h, frequency of urgency/24 h) and maximum detrusor pressure during urine storage in OAB group were significantly higher than those in HC group, with statistical significance ( P<0.01). The average urination volume/time, bladder capacity at first sensation and maximum bladder capacity in OAB group were significantly lower than those in HC group, and the differences were statistically significant ( P<0.01). In the process of bladder filling to strong desire to void, the detrusor pressure in HC group was stable without DO, and 6 cases in OAB group had DO. Compared to empty bladder state, healthy subjects with strong desire to void showed significantly increased FC within PFC in 5 Brodmann area (BA9, BA10, BA44, BA45, BA46)and 13 edges, such as the BA9(left dorsolateral prefrontal cortex [DLPFC]: ch 4, 5, 7 and right DLPFC: ch 3), BA10(left frontopolar area: ch 12, 21 and right frontopolar area: ch 10, 18), BA44(left pars opercularis Broca's area: ch 15), BA45(left pars triangularis: ch 22), BA46(left DLPFC: ch 6, 14); significantly decreased FC in 3 brain regions (BA9, BA10 and BA46) and 2 edges, such as the BA9(left DLPFC: ch 7), BA10(left frontopolar area: ch21 and right frontopolar area: ch 17), BA46(right DLPFC: ch 9). There was no significant difference in FC within PFC between OAB and HC groups with empty bladder. However, during the strong desire to void state, the FC within PFC in OAB patients was significantly abnormal when compared with HC. OAB patients showed significantly increased FC within PFC in 4 brain regions (BA9, BA10, BA45 and BA46) and 4 edges, such as the BA9(right DLPFC: ch 1 and left DLPFC: ch 7), BA10(right frontopolar area: ch 17), BA45(left pars triangularis: ch 22), BA46(right DLPFC: ch 9, 16); significantly decreased FC in 3 brain regions (BA9, BA10 and BA46) and 4 edges, such as the BA9 (right DLPFC: ch 3 and left DLPFC: ch 4), BA10(left frontopolar area: ch 12, 21), BA46(left DLPFC: ch 14) Conclusion:Compared with HC group, the PFC in OAB group showed significant abnormalities, which may lead to "dyssynergia" of PFC internal functions, result in frontal lobe dysfunction, involving sensory integration, motivation drive, emotional control and decision whether to urinate or not, etc., leading to urinary control dysfunction, which manifested as typical clinical symptoms of OAB. Our findings contribute to the understanding of the central pathogenesis of OAB and may provide a theoretical basis for the emergence of targeted brain therapy in the future.
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BACKGROUND: The current diagnosis and study of depression lacks objective biological indicators. As an emerging non-invasive brain functional imaging technology, functional near infrared spectroscopy (fNIRS) may be a potential biomarker for the identification and diagnosis of depression. OBJECTIVE: To review the application of fNIRS technique in depression research and provide guidance for clinical research. METHODS: The keywords were “functional near-infrared spectroscopy, oxyhemoglobins, prefrontal cortex, depressive disorder.” The first author searched CNKI, WanFang, VIP, PuMed and Web of Science database from 1996 to 2020 in Chinese and English. Finally, 50 literatures were selected for review. RESULTS AND CONCLUSION: fNIRS signal may be a potential biomarker for depression. fNIRS technology is mainly used to study the cognitive dysfunction of depression based on the frontal lobe hemodynamic changes, which can be used for the differential diagnosis of depression. However, the current research on fNIRS is still in the exploratory stage, and there are still some defects in the existing research, which need to be further optimized and deepened in the future research. It can increase the study sample size and monitoring indicators, and integrate fNIRS with other technologies to improve the temporal and spatial resolution, so as to study the neural mechanism of depression systematically, comprehensively and accurately.
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OBJECTIVE@#To explore the effect of low-frequency magnetic stimulation at Shenmen (HT 7) acupoint on blood oxygen levels in the prefrontal cortex of healthy subjects.@*METHODS@#Functional near-infrared spectroscopy (fNIRS) technology was used to collect real-time data of oxygenated hemoglobin (oxy-Hb) in the prefrontal cortex of 16 healthy subjects at resting state and low-frequency magnetic stimulation of Shenmen. The mean and integral values of blood oxygen concentration were analyzed.@*RESULTS@#Compared with the resting state, the mean and integral values of blood oxygen concentration were decreased during the task period, recovery period, and the whole process in the magnetic stimulation of Shenmen acupoint (P<0.05). In particular, the difference was statistically significant in the recovery period (P<0.01).@*CONCLUSIONS@#The prefrontal cortex was widely activated and produced an immediate effect by reducing the local blood oxygen concentration at low-frequency magnetic stimulation of Shenmen acupoint, which verifies the sedative effect of Shenmen acupoint.
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Objective：We aimed to examine the effects of a transcranial direct current stimulation (tDCS) performed prior to occupational therapy and combined with an Integrated Volitional control Electrical Stimulation (IVES) therapy on the upper extremity function for patients with chronic stroke. We also aimed to detect the longitudinal changes of hemodynamic responses in the sensorimotor cortex area (SMC) following successive tDCS prior to IVES therapy.Methods：Seven subjects with moderate upper extremity (UE) paresis in chronic stroke were enrolled in this study. The patients received coupled tDCS and IVES therapy five times a week. UE function was estimated by Simple Test for Evaluating Hand Function (STEF). Functional near-infrared spectroscopy (fNIRS) was used to detect the long-term changes of hemodynamic responses in bilateral SMC during opening and closing of the affected fingers, assisted by IVES. Lastly, the SMC responses after the first tDCS were compared with those obtained after the fifth tDCS.Results：Coupled tDCS and IVES therapy was effective for improving the UE paresis. fNIRS demonstrated a significantly increased hemodynamic responses in bilateral SMC, following IVES therapy with the fifth tDCS relative to those with the first tDCS.Conclusion：The findings suggested that tDCS prior to IVES therapy might improve UE function of the patients with chronic stroke, presumably by augmenting hemodynamic responses in bilateral SMC.
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Sleep is a complex physiological process of great significance to physical and mental health, and its research scope involves multiple disciplines. At present, the quantitative analysis of sleep mainly relies on the "gold standard" of polysomnography (PSG). However, PSG has great interference to the human body and cannot reflect the hemodynamic status of the brain. Functional near infrared spectroscopy (fNIRS) is used in sleep research, which can not only meet the demand of low interference to human body, but also reflect the hemodynamics of brain. Therefore, this paper has collected and sorted out the related literatures about fNIRS used in sleep research, concluding sleep staging research, clinical sleep monitoring research, fatigue detection research, etc. This paper provides a theoretical reference for scholars who will use fNIRS for fatigue and sleep related research in the future. Moreover, this article concludes the limitation of existing studies and points out the possible development direction of fNIRS for sleep research, in the hope of providing reference for the study of sleep and cerebral hemodynamics.