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Brain cortical mapping by simultaneous recording of functional near infrared spectroscopy and electroencephalograms from the whole brain during right median nerve stimulation.

Takeuchi M, Hori E, Takamoto K, Tran AH, Satoru K, Ishikawa A, Ono T, Endo S, Nishijo H - Brain Topogr (2009)

Bottom Line: Comparison of these two sets of data indicated that the distance between the dipoles of P22 and NIRS channels with maximum hemodynamic responses was less than 10 mm, and that the two topographical maps of hemodynamic responses and current source density of P22 were significantly correlated.This suggests that GLM analysis with onset delay could reveal the temporal ordering of neural activation in the hierarchical somatosensory pathway, consistent with the neurophysiological data.The present results suggest that simultaneous NIRS and EEG recording is useful for correlating hemodynamic responses to neural activity.

View Article: PubMed Central - PubMed

Affiliation: System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama, Japan.

ABSTRACT
To investigate relationships between hemodynamic responses and neural activities in the somatosensory cortices, hemodynamic responses by near infrared spectroscopy (NIRS) and electroencephalograms (EEGs) were recorded simultaneously while subjects received electrical stimulation in the right median nerve. The statistical significance of the hemodynamic responses was evaluated by a general linear model (GLM) with the boxcar design matrix convoluted with Gaussian function. The resulting NIRS and EEGs data were stereotaxically superimposed on the reconstructed brain of each subject. The NIRS data indicated that changes in oxy-hemoglobin concentration increased at the contralateral primary somatosensory (SI) area; responses then spread to the more posterior and ipsilateral somatosensory areas. The EEG data indicated that positive somatosensory evoked potentials peaking at 22 ms latency (P22) were recorded from the contralateral SI area. Comparison of these two sets of data indicated that the distance between the dipoles of P22 and NIRS channels with maximum hemodynamic responses was less than 10 mm, and that the two topographical maps of hemodynamic responses and current source density of P22 were significantly correlated. Furthermore, when onset of the boxcar function was delayed 5-15 s (onset delay), hemodynamic responses in the bilateral parietal association cortices posterior to the SI were more strongly correlated to electrical stimulation. This suggests that GLM analysis with onset delay could reveal the temporal ordering of neural activation in the hierarchical somatosensory pathway, consistent with the neurophysiological data. The present results suggest that simultaneous NIRS and EEG recording is useful for correlating hemodynamic responses to neural activity.

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Related in: MedlinePlus

Examples of current source density (CSD) waveforms (A) and CSD maps (B). EEG data (SEPs) shown in Fig. 2 were subjected to CSD transformation. Isolatency dotted lines (a), (b), (c) in (A) are at the approximate peaks of P22, P47, and at 100 ms latency, respectively, and latencies of the CSD maps in (B) (a), (b), (c) correspond to those in (A)
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Fig4: Examples of current source density (CSD) waveforms (A) and CSD maps (B). EEG data (SEPs) shown in Fig. 2 were subjected to CSD transformation. Isolatency dotted lines (a), (b), (c) in (A) are at the approximate peaks of P22, P47, and at 100 ms latency, respectively, and latencies of the CSD maps in (B) (a), (b), (c) correspond to those in (A)

Mentions: Current source density (CSD) was estimated in all subjects. Figure 4A shows waveforms of CSD at the same locations as the electrodes shown in Fig. 2, and Fig. 4B shows the CSD map at each indicated time. CSD increased in the contralateral (left) parietal area not only at the latency of P22 (Ba; 22 ms), but also at the latency of P47 (data not shown), and finally disappeared at 100 ms latency (Bc; 100 ms). It is noted that it also increased around the ipsilateral parietal area at P47 (Bb; 47 ms), although its intensity was much lower than that in the contralateral parietal area. These data suggest that weak synaptic activity was also elicited in the ipsilateral parietal area at a longer latency than in the contralateral parietal area.Fig. 4


Brain cortical mapping by simultaneous recording of functional near infrared spectroscopy and electroencephalograms from the whole brain during right median nerve stimulation.

Takeuchi M, Hori E, Takamoto K, Tran AH, Satoru K, Ishikawa A, Ono T, Endo S, Nishijo H - Brain Topogr (2009)

Examples of current source density (CSD) waveforms (A) and CSD maps (B). EEG data (SEPs) shown in Fig. 2 were subjected to CSD transformation. Isolatency dotted lines (a), (b), (c) in (A) are at the approximate peaks of P22, P47, and at 100 ms latency, respectively, and latencies of the CSD maps in (B) (a), (b), (c) correspond to those in (A)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2749167&req=5

Fig4: Examples of current source density (CSD) waveforms (A) and CSD maps (B). EEG data (SEPs) shown in Fig. 2 were subjected to CSD transformation. Isolatency dotted lines (a), (b), (c) in (A) are at the approximate peaks of P22, P47, and at 100 ms latency, respectively, and latencies of the CSD maps in (B) (a), (b), (c) correspond to those in (A)
Mentions: Current source density (CSD) was estimated in all subjects. Figure 4A shows waveforms of CSD at the same locations as the electrodes shown in Fig. 2, and Fig. 4B shows the CSD map at each indicated time. CSD increased in the contralateral (left) parietal area not only at the latency of P22 (Ba; 22 ms), but also at the latency of P47 (data not shown), and finally disappeared at 100 ms latency (Bc; 100 ms). It is noted that it also increased around the ipsilateral parietal area at P47 (Bb; 47 ms), although its intensity was much lower than that in the contralateral parietal area. These data suggest that weak synaptic activity was also elicited in the ipsilateral parietal area at a longer latency than in the contralateral parietal area.Fig. 4

Bottom Line: Comparison of these two sets of data indicated that the distance between the dipoles of P22 and NIRS channels with maximum hemodynamic responses was less than 10 mm, and that the two topographical maps of hemodynamic responses and current source density of P22 were significantly correlated.This suggests that GLM analysis with onset delay could reveal the temporal ordering of neural activation in the hierarchical somatosensory pathway, consistent with the neurophysiological data.The present results suggest that simultaneous NIRS and EEG recording is useful for correlating hemodynamic responses to neural activity.

View Article: PubMed Central - PubMed

Affiliation: System Emotional Science, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama, Japan.

ABSTRACT
To investigate relationships between hemodynamic responses and neural activities in the somatosensory cortices, hemodynamic responses by near infrared spectroscopy (NIRS) and electroencephalograms (EEGs) were recorded simultaneously while subjects received electrical stimulation in the right median nerve. The statistical significance of the hemodynamic responses was evaluated by a general linear model (GLM) with the boxcar design matrix convoluted with Gaussian function. The resulting NIRS and EEGs data were stereotaxically superimposed on the reconstructed brain of each subject. The NIRS data indicated that changes in oxy-hemoglobin concentration increased at the contralateral primary somatosensory (SI) area; responses then spread to the more posterior and ipsilateral somatosensory areas. The EEG data indicated that positive somatosensory evoked potentials peaking at 22 ms latency (P22) were recorded from the contralateral SI area. Comparison of these two sets of data indicated that the distance between the dipoles of P22 and NIRS channels with maximum hemodynamic responses was less than 10 mm, and that the two topographical maps of hemodynamic responses and current source density of P22 were significantly correlated. Furthermore, when onset of the boxcar function was delayed 5-15 s (onset delay), hemodynamic responses in the bilateral parietal association cortices posterior to the SI were more strongly correlated to electrical stimulation. This suggests that GLM analysis with onset delay could reveal the temporal ordering of neural activation in the hierarchical somatosensory pathway, consistent with the neurophysiological data. The present results suggest that simultaneous NIRS and EEG recording is useful for correlating hemodynamic responses to neural activity.

Show MeSH
Related in: MedlinePlus