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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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Estimated dipoles generating cortical SEPs superimposed on a surface image created by magnetic resonance scans. Location of each dipole base is indicated by a filled circle, and direction of the dipole is indicated by projection of the line. The dipoles estimated at the latencies indicated by P22 and P47 in Fig. 2b were superimposed based on [the] X and Y coordinates of the same subject. The dotted lines (a), (b), (d) in the horizontal plane (C) correspond to the MRI slices in (A), (B), and (D), respectively. The dipolarity was 96.3% in this subject
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Fig5: Estimated dipoles generating cortical SEPs superimposed on a surface image created by magnetic resonance scans. Location of each dipole base is indicated by a filled circle, and direction of the dipole is indicated by projection of the line. The dipoles estimated at the latencies indicated by P22 and P47 in Fig. 2b were superimposed based on [the] X and Y coordinates of the same subject. The dotted lines (a), (b), (d) in the horizontal plane (C) correspond to the MRI slices in (A), (B), and (D), respectively. The dipolarity was 96.3% in this subject

Mentions: Dipoles were estimated in all 15 averages, and only equivalent dipoles in the approximate peak latency range of each SEP component with dipolarity exceeding 94% were evaluated in the contralateral hemisphere. Figure 5 shows some results of DT applied to the data shown in Fig. 2. The locations and directions of the dipoles of P22 and P47 are superimposed on MRI images of stereotaxic sections of the brain in which coronal planes in A, B, and D correspond to a, b, and d in C. The estimated dipoles in the 19–24 ms latency range, concurrent with P22, were located in the posterior central gyrus, SI area (Fig. 5A, C, D). In the 45–55 ms latency range, concurrent with P47, dipoles were located around the superior parietal lobule (SPL) (areas 5 and 7) (Fig. 5B, C, D). These current generators were observed in the other 14 subjects in the same way; it first appeared at the SI, then moved to the areas 5 and 7.Fig. 5


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)

Estimated dipoles generating cortical SEPs superimposed on a surface image created by magnetic resonance scans. Location of each dipole base is indicated by a filled circle, and direction of the dipole is indicated by projection of the line. The dipoles estimated at the latencies indicated by P22 and P47 in Fig. 2b were superimposed based on [the] X and Y coordinates of the same subject. The dotted lines (a), (b), (d) in the horizontal plane (C) correspond to the MRI slices in (A), (B), and (D), respectively. The dipolarity was 96.3% in this subject
© Copyright Policy
Related In: Results  -  Collection

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

Fig5: Estimated dipoles generating cortical SEPs superimposed on a surface image created by magnetic resonance scans. Location of each dipole base is indicated by a filled circle, and direction of the dipole is indicated by projection of the line. The dipoles estimated at the latencies indicated by P22 and P47 in Fig. 2b were superimposed based on [the] X and Y coordinates of the same subject. The dotted lines (a), (b), (d) in the horizontal plane (C) correspond to the MRI slices in (A), (B), and (D), respectively. The dipolarity was 96.3% in this subject
Mentions: Dipoles were estimated in all 15 averages, and only equivalent dipoles in the approximate peak latency range of each SEP component with dipolarity exceeding 94% were evaluated in the contralateral hemisphere. Figure 5 shows some results of DT applied to the data shown in Fig. 2. The locations and directions of the dipoles of P22 and P47 are superimposed on MRI images of stereotaxic sections of the brain in which coronal planes in A, B, and D correspond to a, b, and d in C. The estimated dipoles in the 19–24 ms latency range, concurrent with P22, were located in the posterior central gyrus, SI area (Fig. 5A, C, D). In the 45–55 ms latency range, concurrent with P47, dipoles were located around the superior parietal lobule (SPL) (areas 5 and 7) (Fig. 5B, C, D). These current generators were observed in the other 14 subjects in the same way; it first appeared at the SI, then moved to the areas 5 and 7.Fig. 5

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