Haruyasu Matsuzaki(Faculty of Health and Medical Science,Department of Medical Course,Medical Engineering Course)｜Teikyo Heisei University Researcher Information Researcher Search by Organization

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Haruyasu Matsuzaki

Faculty of Health and Medical Science,Department of Medical Course,Medical Engineering Course	Associate Professor
Graduate School of Information Sciences,Major of Information Sciences	Associate Professor

Last Updated :2025/10/07

■Researcher basic information

Degree

Doctor of Informatics, Teikyo Heisei University, Mar. 2000

Field Of Study

Life sciences, Biomedical engineering

■Research activity information

Paper

Boundary EEG Asymmetry Is Associated to Linguistic Competence in Vascular Cognitive Impairments.
Takashi Shibata; Toshimitu Musha; Yukio Kosugi; Michiya Kubo; Yukio Horie; Mieko Tanaka; Haruyasu Matsuzaki; Yohei Kobayashi; Satoshi Kuroda
Frontiers in human neuroscience, 2018
Background and Purpose: We recently noted a gradual change in the boundary electroencephalography (EEG) oscillation of 7.8 Hz between theta (θ) and alpha (α) bands in response to increased atherosclerosis levels in the elderly. The aim of this study was to investigate the role of boundary EEG oscillations of θ-α bands on cognitive functions in vascular cognitive impairments (VCI) patients. Materials and Methods: We examined 55 patients with VCI in carotid stenosis, and underwent EEG in a resting state with closed eyes for 5 min. The asymmetry index (AI) along homologous channel pairs (e.g., F7-8) was assessed using neuronal activity topography (NAT). AI referring to 10 frequency components ranging from 4 to 20 Hz and neuropsychological assessments including linguistic competence were analyzed. Results: The main findings was that the language score had a positive association with AI in 7.8 Hz at F7-8 and a negative association with AI in 6.3 Hz at C3-4 and 14.1 Hz at F3-4. Conclusion: EEG asymmetry in a boundary range might have a special role in linguistic competence, suggesting the application of neural oscillation on the cognitive function evaluation and neurorehabilition induced by a frequency-specific transcranial alternating current stimulation.
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Altered Neuronal Activity Topography Markers in the Elderly with Increased Atherosclerosis.
Takashi Shibata; Toshimitu Musha; Yukio Kosugi; Michiya Kubo; Yukio Horie; Naoya Kuwayama; Satoshi Kuroda; Karin Hayashi; Yohei Kobayashi; Mieko Tanaka; Haruyasu Matsuzaki; Kiyotaka Nemoto; Takashi Asada
Frontiers in aging neuroscience, 2017
Background: Previously, we reported on vascular cognitive impairment (VCI) templates, consisting of patients with VCI associated with carotid stenosis (>60%) using a quantitative electroencephalographic (EEG) technique called neuronal activity topography (NAT). Here using the VCI templates, we investigated the hypothesis that internal carotid artery-intima-media thickness (ICA-IMT) is associated with EEG spectrum intensity (sNAT) and spectrum steepness (vNAT). Methods: A total of 221 community-dwelling elderly subjects were recruited. Four groups were classified according to quartiles of ICA-IMT as assessed by ultrasonography: control group A, normal (≤0.9 mm); group B, mild atherosclerosis (1-1.1 mm); group C, moderate atherosclerosis (1.2-1.8 mm); and group D, severe atherosclerosis (≥1.9 mm). EEG markers of power ratio index (PRI), and the binary likelihood of being in the VCI group vs. the that of being in control group A (sL x:VCI-A , vL x:VCI-A ) were assessed, respectively. Differences in mean total scores for PRI, sL x:VCI-A , vL x:VCI-A , between control group A and the other groups were compared using Dunnett's test, respectively. Results: The mean total scores of the PRI were 3.25, 3.00, 2.77, and 2.26 for groups A, B, C, and D, respectively. There was a significant decrease in the PRI in group D compared with group A (P = 0.0066). The mean total scores of the sL x:VCI-A were -0.14, -0.11, -0.1, and -0.03 for groups A, B, C, and D, respectively. The sL x:VCI-A in group D was significantly higher compared to that in group A (P < 0.0001). The mean total scores of the vL x:VCI-A were -0.04,-0.01, 0.01, and 0.06 for group A, B, C, and D, respectively. The vL x:VCI-A in group D and group C was significantly higher compared to that in group A, respectively (P < 0.0001, P = 0.02). Conclusion: Community-dwelling elderly subjects in the increased carotid atherosclerosis of ICA-IMT (≥1.9 mm) were at greatest risk of an EEG change as assessed by NAT.
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Noninvasive prediction of shunt operation outcome in idiopathic normal pressure hydrocephalus.
Yasunori Aoki; Hiroaki Kazui; Toshihisa Tanaka; Ryouhei Ishii; Tamiki Wada; Shunichiro Ikeda; Masahiro Hata; Leonides Canuet; Themistoklis Katsimichas; Toshimitsu Musha; Haruyasu Matsuzaki; Kaoru Imajo; Hideki Kanemoto; Tetsuhiko Yoshida; Keiko Nomura; Kenji Yoshiyama; Masao Iwase; Masatoshi Takeda
Scientific reports, 14 Jan. 2015
Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome characterized by gait disturbance, cognitive deterioration and urinary incontinence in elderly individuals. These symptoms can be improved by shunt operation in some but not all patients. Therefore, discovering predictive factors for the surgical outcome is of great clinical importance. We used normalized power variance (NPV) of electroencephalography (EEG) waves, a sensitive measure of the instability of cortical electrical activity, and found significantly higher NPV in beta frequency band at the right fronto-temporo-occipital electrodes (Fp2, T4 and O2) in shunt responders compared to non-responders. By utilizing these differences, we were able to correctly identify responders and non-responders to shunt operation with a positive predictive value of 80% and a negative predictive value of 88%. Our findings indicate that NPV can be useful in noninvasively predicting the clinical outcome of shunt operation in patients with iNPH.
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Detection of EEG-resting state independent networks by eLORETA-ICA method.
Yasunori Aoki; Ryouhei Ishii; Roberto D Pascual-Marqui; Leonides Canuet; Shunichiro Ikeda; Masahiro Hata; Kaoru Imajo; Haruyasu Matsuzaki; Toshimitsu Musha; Takashi Asada; Masao Iwase; Masatoshi Takeda
Frontiers in human neuroscience, 2015
Recent functional magnetic resonance imaging (fMRI) studies have shown that functional networks can be extracted even from resting state data, the so called "Resting State independent Networks" (RS-independent-Ns) by applying independent component analysis (ICA). However, compared to fMRI, electroencephalography (EEG) and magnetoencephalography (MEG) have much higher temporal resolution and provide a direct estimation of cortical activity. To date, MEG studies have applied ICA for separate frequency bands only, disregarding cross-frequency couplings. In this study, we aimed to detect EEG-RS-independent-Ns and their interactions in all frequency bands. We applied exact low resolution brain electromagnetic tomography-ICA (eLORETA-ICA) to resting-state EEG data in 80 healthy subjects using five frequency bands (delta, theta, alpha, beta and gamma band) and found five RS-independent-Ns in alpha, beta and gamma frequency bands. Next, taking into account previous neuroimaging findings, five RS-independent-Ns were identified: (1) the visual network in alpha frequency band, (2) dual-process of visual perception network, characterized by a negative correlation between the right ventral visual pathway (VVP) in alpha and beta frequency bands and left posterior dorsal visual pathway (DVP) in alpha frequency band, (3) self-referential processing network, characterized by a negative correlation between the medial prefrontal cortex (mPFC) in beta frequency band and right temporoparietal junction (TPJ) in alpha frequency band, (4) dual-process of memory perception network, functionally related to a negative correlation between the left VVP and the precuneus in alpha frequency band; and (5) sensorimotor network in beta and gamma frequency bands. We selected eLORETA-ICA which has many advantages over the other network visualization methods and overall findings indicate that eLORETA-ICA with EEG data can identify five RS-independent-Ns in their intrinsic frequency bands, and correct correlations within RS-independent-Ns.
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Neuronal activity topography parameters as a marker for differentiating vascular cognitive impairment in carotid stenosis.
Takashi Shibata; Toshimitu Musha; Michiya Kubo; Yukio Horie; Takashi Asahi; Naoya Kuwayama; Satoshi Kuroda; Karin Hayashi; Yohei Kobayashi; Mieko Tanaka; Haruyasu Matsuzaki; Takashi Asada
Journal of stroke and cerebrovascular diseases : the official journal of National Stroke Association, Oct. 2014
Previously, we reported on the differentiation between patients with Alzheimer disease and normal controls using a quantitative electroencephalographic technique called neuronal activity topography (NAT). In this technique, cerebral neuronal activities are characterized by the signal intensity and coherence (sNAT and vNAT, respectively). In the present study, we examined 47 patients with vascular cognitive impairment in carotid stenosis and 52 normal controls. All subjects underwent electroencephalography in a resting state with closed eyes for 5 minutes. Electroencephalographic markers of the differential likelihood, that is, the sensitivity-versus-specificity characteristics, sL(x:VCI-NLc) and vL(x:VCI-NLc), were assessed with neuronal activity topography and were compared between the 2 groups. sL(x:VCI-NLc) and vL(x:VCI-NLc) crossed each other at a cutoff value of the differential likelihood. Separation of the patients and controls was made with a sensitivity of 92% and 88%, as well as a false-positive rate of 8% and 12% for sL(x:VCI-NLc) and vL(x:VCI-NLc), respectively. Using sNAT, we accurately differentiated 92% patients with vascular cognitive impairment. We recommend that sNAT, rather than vNAT, should be used in detecting vascular cognitive impaired patients.
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EEG markers for characterizing anomalous activities of cerebral neurons in NAT (neuronal activity topography) method.
Toshimitsu Musha; Haruyasu Matsuzaki; Yohei Kobayashi; Yoshiwo Okamoto; Mieko Tanaka; Takashi Asada
IEEE transactions on bio-medical engineering, Aug. 2013
A pair of markers, sNAT and vNAT, is derived from the electroencephalogram (EEG) power spectra (PS) recorded for 5 min with 21 electrodes (4-20 Hz) arranged according to the 10-20 standard. These markers form a new diagnosis tool "NAT" aiming at characterizing various brain disorders. Each signal sequence is divided into segments of 0.64 s and its discrete PS consists of eleven frequency components from 4.68 (3 × 1.56) Hz through 20.34 (13 × 1.56) Hz. PS is normalized to its mean and the bias of PS components on each frequency component across the 21 signal channels is reset to zero. The marker sNAT consists of ten frequency components on 21 channels, characterizing neuronal hyperactivity or hypoactivity as compared with NLc (normal controls). The marker vNAT consists of ten ratios between adjacent PS components denoting the over- or undersynchrony of collective neuronal activities as compared with NLc. The likelihood of a test subject to a specified brain disease is defined in terms of the normalized distance to the template NAT state of the disease in the NAT space. Separation of MCI-AD patients (developing AD in 12-18 months) from NLc is made with a false alarm rate of 15%. Locations with neuronal hypoactivity and undersynchrony of AD patients agree with locations of rCBF reduction measured by SPECT. The 2-D diagram composed of the binary likelihoods between ADc and NLc in the two representations of sNAT and vNAT enables tracing the NAT state of a test subject approaching the AD area, and the follow-up of the treatment effects.
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Normalized power variance change between pre-ictal and ictal phase of an epilepsy patient using NAT analysis: a case study.
Yasunori Aoki; Ryouhei Ishii; Masao Iwase; Shunichiro Ikeda; Masahiro Hata; Leonides Canuet; Kaoru Imajo; Mieko Tanaka; Haruyasu Matsuzaki; Toshimitsu Musha; Masatoshi Takeda
Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual International Conference, 2013
Variance of state variables shifts due to phase-instability and may serve as an early-warning signal of phase transition of complex systems such as an epileptic seizure of brain cortical activity. Neuronal Activity Topology (NAT) analysis calculates a normalized-power-variance (NPV) of electroencephalogram (EEG) data in each frequency band to obtain relative values comparable among different power states.
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EEG and Neuronal Activity Topography analysis can predict effectiveness of shunt operation in idiopathic normal pressure hydrocephalus patients.
Yasunori Aoki; Hiroaki Kazui; Toshihisa Tanaka; Ryouhei Ishii; Tamiki Wada; Shunichiro Ikeda; Masahiro Hata; Leonides Canuet; Toshimitsu Musha; Haruyasu Matsuzaki; Kaoru Imajo; Kenji Yoshiyama; Tetsuhiko Yoshida; Yoshiro Shimizu; Keiko Nomura; Masao Iwase; Masatoshi Takeda
NeuroImage. Clinical, 2013
Idiopathic normal pressure hydrocephalus (iNPH) is a neuropsychiatric syndrome characterized by gait disturbance, cognitive impairment and urinary incontinence that affect elderly individuals. These symptoms can potentially be reversed by cerebrospinal fluid (CSF) drainage or shunt operation. Prior to shunt operation, drainage of a small amount of CSF or "CSF tapping" is usually performed to ascertain the effect of the operation. Unfortunately, conventional neuroimaging methods such as single photon emission computed tomography (SPECT) and functional magnetic resonance imaging (fMRI), as well as electroencephalogram (EEG) power analysis seem to have failed to detect the effect of CSF tapping on brain function. In this work, we propose the use of Neuronal Activity Topography (NAT) analysis, which calculates normalized power variance (NPV) of EEG waves, to detect cortical functional changes induced by CSF tapping in iNPH. Based on clinical improvement by CSF tapping and shunt operation, we classified 24 iNPH patients into responders (N = 11) and nonresponders (N = 13), and performed both EEG power analysis and NAT analysis. We also assessed correlations between changes in NPV and changes in functional scores on gait and cognition scales before and after CSF tapping. NAT analysis showed that after CSF tapping there was a significant decrease in alpha NPV at the medial frontal cortex (FC) (Fz) in responders, while nonresponders exhibited an increase in alpha NPV at the right dorsolateral prefrontal cortex (DLPFC) (F8). Furthermore, we found correlations between cortical functional changes and clinical symptoms. In particular, delta and alpha NPV changes in the left-dorsal FC (F3) correlated with changes in gait status, while alpha and beta NPV changes in the right anterior prefrontal cortex (PFC) (Fp2) and left DLPFC (F7) as well as alpha NPV changes in the medial FC (Fz) correlated with changes in gait velocity. In addition, alpha NPV changes in the right DLPFC (F8) correlated with changes in WMS-R Mental Control scores in iNPH patients. An additional analysis combining the changes in values of alpha NPV over the left-dorsal FC (∆alpha-F3-NPV) and the medial FC (∆alpha-Fz-NPV) induced by CSF tapping (cut-off value of ∆alpha-F3-NPV + ∆alpha-Fz-NPV = 0), could correctly identified "shunt responders" and "shunt nonresponders" with a positive predictive value of 100% (10/10) and a negative predictive value of 66% (2/3). In contrast, EEG power spectral analysis showed no function related changes in cortical activity at the frontal cortex before and after CSF tapping. These results indicate that the clinical changes in gait and response suppression induced by CSF tapping in iNPH patients manifest as NPV changes, particularly in the alpha band, rather than as EEG power changes. Our findings suggest that NAT analysis can detect CSF tapping-induced functional changes in cortical activity, in a way that no other neuroimaging methods have been able to do so far, and can predict clinical response to shunt operation in patients with iNPH.
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Static gamma-motoneurones couple group Ia and II afferents of single muscle spindles in anaesthetised and decerebrate cats.
M H Gladden; H Matsuzaki
The Journal of physiology, 15 Aug. 2002
Ideas about the functions of static gamma-motoneurones are based on the responses of primary and secondary endings to electrical stimulation of single static gamma-axons, usually at high frequencies. We compared these effects with the actions of spontaneously active gamma-motoneurones. In anaesthetised cats, afferents and efferents were recorded in intramuscular nerve branches to single muscle spindles. The occurrence of gamma-spikes, identified by a spike shape recognition system, was linked to video-taped contractions of type-identified intrafusal fibres in the dissected muscle spindles. When some static gamma-motoneurones were active at low frequency (< 15 Hz) they coupled the firing of group Ia and II afferents. Activity of other static gamma-motoneurones which tensed the intrafusal fibres appeared to enhance this effect. Under these conditions the secondary ending responded at shorter latency than the primary ending. In another series of experiments on decerebrate cats, responses of primary and secondary endings of single muscle spindles to activation of gamma-motoneurones by natural stimuli were compared with their responses to electrical stimulation of single gamma-axons supplying the same spindle. Electrical stimulation mimicked the natural actions of gamma-motoneurones on either the primary or the secondary ending, but not on both together. However, gamma-activity evoked by natural stimuli coupled the firing of afferents with the muscle at constant length, and also when it was stretched. Analysis showed that the timing and tightness of this coupling determined the degree of summation of excitatory postsynaptic potentials (EPSPs) evoked by each afferent in alpha-motoneurones and interneurones contacted by terminals of both endings, and thus the degree of facilitation of reflex actions of group II afferents.