Tokyo Bay Rehabilitation Hospital

Narashino, Japan

Tokyo Bay Rehabilitation Hospital

Narashino, Japan
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Aihara T.,ATR Computational Neuroscience Laboratories | Takeda Y.,ATR Neural Information Analysis Laboratories | Takeda K.,ATR Computational Neuroscience Laboratories | Takeda K.,National Hospital Organization Murayama Medical Center | And 10 more authors.
NeuroImage | Year: 2012

Previous simulation and experimental studies have demonstrated that the application of Variational Bayesian Multimodal EncephaloGraphy (VBMEG) to magnetoencephalography (MEG) data can be used to estimate cortical currents with high spatio-temporal resolution, by incorporating functional magnetic resonance imaging (fMRI) activity as a hierarchical prior. However, the use of combined MEG and fMRI is restricted by the high costs involved, a lack of portability and high sensitivity to body-motion artifacts. One possible solution for overcoming these limitations is to use a combination of electroencephalography (EEG) and near-infrared spectroscopy (NIRS). This study therefore aimed to extend the possible applications of VBMEG to include EEG data with NIRS activity as a hierarchical prior. Using computer simulations and real experimental data, we evaluated the performance of VBMEG applied to EEG data under different conditions, including different numbers of EEG sensors and different prior information. The results suggest that VBMEG with NIRS prior performs well, even with as few as 19 EEG sensors. These findings indicate the potential value of clinically applying VBMEG using a combination of EEG and NIRS. © 2011 Elsevier Inc..

Sato T.,Nagaoka University of Technology | Sato T.,ATR Brain Information Communication Research Laboratory Group | Nambu I.,Nagaoka University of Technology | Takeda K.,ATR Brain Information Communication Research Laboratory Group | And 12 more authors.
NeuroImage | Year: 2016

Functional near-infrared spectroscopy (fNIRS) is used to measure cerebral activity because it is simple and portable. However, scalp-hemodynamics often contaminates fNIRS signals, leading to detection of cortical activity in regions that are actually inactive. Methods for removing these artifacts using standard source–detector distance channels (Long-channel) tend to over-estimate the artifacts, while methods using additional short source–detector distance channels (Short-channel) require numerous probes to cover broad cortical areas, which leads to a high cost and prolonged experimental time. Here, we propose a new method that effectively combines the existing techniques, preserving the accuracy of estimating cerebral activity and avoiding the disadvantages inherent when applying the techniques individually. Our new method accomplishes this by estimating a global scalp-hemodynamic component from a small number of Short-channels, and removing its influence from the Long-channels using a general linear model (GLM). To demonstrate the feasibility of this method, we collected fNIRS and functional magnetic resonance imaging (fMRI) measurements during a motor task. First, we measured changes in oxygenated hemoglobin concentration (∆ Oxy-Hb) from 18 Short-channels placed over motor-related areas, and confirmed that the majority of scalp-hemodynamics was globally consistent and could be estimated from as few as four Short-channels using principal component analysis. We then measured ∆ Oxy-Hb from 4 Short- and 43 Long-channels. The GLM identified cerebral activity comparable to that measured separately by fMRI, even when scalp-hemodynamics exhibited substantial task-related modulation. These results suggest that combining measurements from four Short-channels with a GLM provides robust estimation of cerebral activity at a low cost. © 2016 The Authors

Murakami R.,Tokyo Bay Rehabilitation Hospital | Otaka Y.,Tokyo Bay Rehabilitation Hospital | Otaka Y.,Keio University
Journal of Physical Therapy Science | Year: 2017

[Purpose] The ratio of step length to cadence (walk ratio) is invariant over a wide range of speeds. However, no studies have investigated details of the change in the walk ratio at slow speeds. It is necessary to explore how walking behavior changes at a low speed to understand the slow walking observed in various conditions such as aging and pathological conditions. In this study, changes in the walk ratio at slow speeds were investigated, and a lower boundary was estimated at which the walk ratio constancy is broken. [Subjects and Methods] Twenty-one healthy adults were instructed to walk along a flat, straight walkway at five different speeds (fast, preferred, slightly slow, slow, and very slow). The walk ratio was calculated from the step length and cadence. [Results] As the walking speed decreased, the walk ratio and variance began to increase abruptly. The initial break in the walk ratio constancy was at approximately 62 m/min. In addition, the boundary of cadence was approximately 98 m/steps/min. [Conclusions] The study successfully determined a lower boundary at which the walk ratio constancy was broken, suggesting that different control strategies are used when walking at less than the gait speed at which constancy is broken in healthy adults. The finding provides valuable information for understanding slow walking observed in individuals with various pathological conditions. © 2017 The Society of Physical Therapy Science. Published by IPEC Inc.

Saito K.,Tokyo Bay Rehabilitation Hospital | Saito K.,Kanagawa University of Human Services | Yamaguchi T.,Keio University | Yamaguchi T.,Japan Society for the Promotion of Science | And 5 more authors.
Experimental Brain Research | Year: 2013

Although motor imagery enhances the excitability of the corticospinal tract, there are no peripheral afferent inputs during motor imagery. In contrast, peripheral nerve electrical stimulation (ES) can induce peripheral afferent inputs; thus, a combination of motor imagery and ES may enhance the excitability of the corticospinal tract compared with motor imagery alone. Moreover, the level of stimulation intensity may also be related to the modulation of the excitability of the corticospinal tract during motor imagery. Here, we evaluated whether a combination of motor imagery and peripheral nerve ES influences the excitability of the corticospinal tract and measured the effect of ES intensity on the excitability induced during motor imagery. The imagined task was a movement that involved touching the thumb to the little finger, whereas ES involved simultaneous stimulation of the ulnar and median nerves at the wrist. Two different ES intensities were used, one above the motor threshold and another above the sensory threshold. Further, we evaluated whether actual movement with afferent input induced by ES modulates the excitability of the corticospinal tract as well as motor imagery. We found that a combination of motor imagery and ES enhanced the excitability of the motor cortex in the thenar muscle compared with the other condition. Furthermore, we established that the modulation of the corticospinal tract was related to ES intensity. However, we found that the excitability of the corticospinal tract induced by actual movement was enhanced by peripheral nerve ES above the sensory threshold. © 2013 Springer-Verlag Berlin Heidelberg.

Fujimoto S.,Tokyo Bay Rehabilitation Hospital | Fujimoto S.,Hamamatsu University School of Medicine | Fujimoto S.,Kyoto University | Fujimoto S.,Medley Inc. | And 10 more authors.
Frontiers in Neuroscience | Year: 2016

In healthy subjects, dual hemisphere transcranial direct current stimulation (tDCS) over the primary (S1) and secondary somatosensory cortices (S2) has been found to transiently enhance tactile performance. However, the effect of dual hemisphere tDCS on tactile performance in stroke patients with sensory deficits remains unknown. The purpose of this study was to investigate whether dual hemisphere tDCS over S1 and S2 could enhance tactile discrimination in stroke patients. We employed a double-blind, crossover, sham-controlled experimental design. Eight chronic stroke patients with sensory deficits participated in this study. We used a grating orientation task (GOT) to measure the tactile discriminative threshold of the affected and non-affected index fingers before, during, and 10 min after four tDCS conditions. For both the S1 and S2 conditions, we placed an anodal electrode over the lesioned hemisphere and a cathodal electrode over the opposite hemisphere. We applied tDCS at an intensity of 2 mA for 15 min in both S1 and S2 conditions. We included two sham conditions in which the positions of the electrodes and the current intensity were identical to that in the S1 and S2 conditions except that current was delivered for the initial 15 s only. We found that GOT thresholds for the affected index finger during and 10 min after the S1 and S2 conditions were significantly lower compared with each sham condition. GOT thresholds were not significantly different between the S1 and S2 conditions at any time point. We concluded that dual-hemisphere tDCS over S1 and S2 can transiently enhance tactile discriminative task performance in chronic stroke patients with sensory dysfunction. © 2016 Fujimoto, Kon, Otaka, Yamaguchi, Nakayama, Kondo, Ragert and Tanaka.

Tanaka S.,National Institute for Physiological science | Tanaka S.,Tokyo Bay Rehabilitation Hospital | Tanaka S.,National Institute of Neuroscience | Takeda K.,ATR Computational Neuroscience Laboratories | And 12 more authors.
Neurorehabilitation and Neural Repair | Year: 2011

Background. Transcranial direct current stimulation (tDCS) of the motor cortex can enhance the performance of a paretic upper extremity after stroke. Reported effects on lower limb (LL) function are sparse. Objective. The authors examined whether tDCS can increase the force production of the paretic quadriceps. Methods. In this double-blind, crossover, sham-controlled experimental design, 8 participants with chronic subcortical stroke performed knee extension using their hemiparetic leg before, during, and after anodal or sham tDCS of the LL motor cortex representation in the affected hemisphere. Affected hand-grip force was also recorded. Results. The maximal knee-extension force increased by 21 N (13.2%, P <.01) during anodal tDCS compared with baseline and sham stimulation. The increase persisted less than 30 minutes. Maximal hand-grip force did not change. Conclusions. Anodal tDCS transiently enhanced knee extensor strength. The modest increase was specific to the LL. Thus, tDCS might augment the rehabilitation of stroke patients when combined with lower extremity strengthening or functional training. © The Author(s) 2011.

Kojima S.,Niigata University of Health and Welfare | Kojima S.,Tokyo Bay Rehabilitation Hospital | Onishi H.,Niigata University of Health and Welfare | Miyaguchi S.,Niigata University of Health and Welfare | And 4 more authors.
NeuroReport | Year: 2015

The aim of this study was to investigate the effects of cathodal transcranial direct current stimulation (tDCS) applied over the primary somatosensory cortex (S1) on short-interval afferent inhibition (SAI). Thirteen healthy individuals participated in this study. Cathodal tDCS was applied for 15 min at 1mA over the left S1. Motor-evoked potentials (MEPs) were measured from the right first dorsal interosseous muscle in response to transcranial magnetic stimulation (TMS) of the left motor cortex before tDCS (pre), immediately after tDCS (immediately), and 15 min after tDCS (post-15 min). SAI was evaluated by measuring MEPs in response to TMS pulses applied 40 ms after peripheral electrical stimulation of the index finger. For each measurement period (pre, immediately, and post-15 min), MEP amplitude was significantly smaller when TMS followed index finger stimulation (SAI condition) than when TMS was delivered alone (single TMS) (P<0.01), indicating expression of SAI. The MEP ratio (MEP of SAI/MEP of single TMS) at post-15 min was significantly larger than that of pre (P<0.05), indicating suppression of SAI. However, no significant difference was observed between pre and immediately, and immediately and post-15 min. These results suggest that cathodal tDCS applied over the S1 causes a decrease in S1 excitability following peripheral electrical stimulation and cathodal tDCS applied over the S1 decreased the inhibitory effects of SAI. Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

Takahashi M.,Terumo Corporation | Takeda K.,ATR Computational Neuroscience Laboratories | Takeda K.,National Hospital Organization | Otaka Y.,ATR Computational Neuroscience Laboratories | And 5 more authors.
Journal of NeuroEngineering and Rehabilitation | Year: 2012

Background: We developed an electroencephalogram-based brain computer interface system to modulate functional electrical stimulation (FES) to the affected tibialis anterior muscle in a stroke patient. The intensity of FES current increased in a stepwise manner when the event-related desynchronization (ERD) reflecting motor intent was continuously detected from the primary cortical motor area. Methods: We tested the feasibility of the ERD-modulated FES system in comparison with FES without ERD modulation. The stroke patient who presented with severe hemiparesis attempted to perform dorsiflexion of the paralyzed ankle during which FES was applied either with or without ERD modulation. Results: After 20 minutes of training, the range of movement at the ankle joint and the electromyography amplitude of the affected tibialis anterior muscle were significantly increased following the ERD-modulated FES compared with the FES alone. Conclusions: The proposed rehabilitation technique using ERD-modulated FES for stroke patients was feasible. The system holds potentials to improve the limb function and to benefit stroke patients. © 2012 Takahashi et al.; licensee BioMed Central Ltd.

Fujimoto S.,Tokyo Bay Rehabilitation Hospital | Yamaguchi T.,Tokyo Bay Rehabilitation Hospital | Yamaguchi T.,Keio University | Otaka Y.,Tokyo Bay Rehabilitation Hospital | And 3 more authors.
Clinical Neurophysiology | Year: 2014

Objective: The aim of this study was to test the hypothesis that dual-hemisphere transcranial direct current stimulation (tDCS) over the primary somatosensory cortex (S1) could improve performance in a tactile spatial discriminative task, compared with uni-hemisphere or sham tDCS. Methods: Nine healthy adults participated in this double-blind, sham-controlled, and cross-over design study. The performance in a grating orientation task (GOT) in the right index finger was evaluated before, during, immediately after and 30. min after the dual-hemisphere, uni-hemisphere (1. mA, 20. min), or sham tDCS (1. mA, 30. s) over S1. In the dual-hemisphere and sham conditions, anodal tDCS was applied over the left S1, and cathodal tDCS was applied over the right S1. In the uni-hemisphere condition, anodal tDCS was applied over the left S1, and cathodal tDCS was applied over the contralateral supraorbital front. Results: The percentage of correct responses on the GOT during dual-hemisphere tDCS was significantly higher than that in the uni-hemisphere or sham tDCS conditions when the grating width was set to 0.75. mm (all p<. 0.05). Conclusions: Dual-hemisphere tDCS over S1 improved performance in a tactile spatial discrimination task in healthy volunteers. Significance: Dual-hemisphere tDCS may be a useful strategy to improve sensory function in patients with sensory dysfunctions. © 2013 International Federation of Clinical Neurophysiology.

Otaka Y.,Tokyo Bay Rehabilitation Hospital
Clinical calcium | Year: 2010

Fall-related fracture in elderly is one of the big issues in our aging society. A major cause of fractures in elderly is fall. Therefore, the prevention of falls is essential for the prevention of fractures in elderly. Various risk factors of falls such as physical fragility, cognitive decline and visual problem have been reported. The effective way for prevention of falls is the modification of the risk factors for falls. Especially, exercise has been known effective. In addition to prevention of falls, we should explore the appropriate approach to modify fall direction, defensive reaction, local shock absorption, which are closely related to fall-related fracture risk.

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