Publications by authors named "Tomofumi Yamaguchi"

40 Publications

The effect of a shoe lift on tensor fasciae latae length during standing with an artificial functional leg length discrepancy: An ultrasonic shear wave elastography study.

J Back Musculoskelet Rehabil 2021 Aug 20. Epub 2021 Aug 20.

Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.

Background: Shortening of tensor fasciae latae is one factor that causes a functional leg length discrepancy. A shoe lift has been used to correct the compensatory posture resulting from the discrepancy. Despite the potential therapeutic benefit of a shoe lift, the mechanism by which it exerts its effect is unclear.

Objective: To investigate the effect of a shoe lift on tensor fasciae latae length during standing with an artificial functional leg length discrepancy using ultrasonic shear wave elastography.

Methods: Twenty-two healthy individuals performed static standing under three conditions: drop of the pelvis and flexion of the leg resulting from fixing in the hip abduction position using a hip orthosis (functional leg length discrepancy condition); drop of the pelvis by the orthosis, but no flexion of the leg due to a shoe lift (shoe lift condition); and normal bilateral standing condition. The shear elastic modulus of tensor fasciae latae was calculated using ultrasonic shear wave elastography.

Results: The shear elastic modulus was significantly lower in the functional leg length discrepancy condition than in the shoe lift and normal conditions (p= 0.038).

Conclusions: Using a shoe lift for the functional leg length discrepancy can result in a functional hip position that elongates tensor fasciae latae.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3233/BMR-191755DOI Listing
August 2021

Transcranial Alternating Current Stimulation of the Primary Motor Cortex after Skill Acquisition Improves Motor Memory Retention in Humans: A Double-Blinded Sham-Controlled Study.

Cereb Cortex Commun 2020 6;1(1):tgaa047. Epub 2020 Aug 6.

Department of Neuroscience, University of Copenhagen, 2200 Copenhagen, Denmark.

Consolidation leading to retention of motor memory following motor practice involves activity-dependent plastic processes in the corticospinal system. To investigate whether beta-band transcranial alternating current stimulation (tACS) applied immediately following skill acquisition can enhance ongoing consolidation processes and thereby motor skill retention 20 adults participated in a randomized, double-blinded, sham-controlled study. Participants received tACS at peak beta-band corticomuscular coherence (CMC) frequency or sham tACS for 10 min following practice of a visuomotor ankle dorsiflexion task. Performance was measured as the average percentage time on target. Electroencephalograhy (EMG) was measured at Cz and EMG from the right tibialis anterior muscle. CMC and intramuscular coherence (IMC) were estimated during 2-min tonic dorsiflexion. Motor skill retention was tested 1 and 7 days after motor practice. From the end of motor practice to the retention tests, motor performance improved more in the tACS group compared with the sham tACS group after 1 ( = 0.05) and 7 days ( < 0.001). At both retention tests, beta-band IMC increased in the tACS group compared with post-tACS. Beta-band CMC increased in the tACS group at retention day 1 compared with post-tACS. Changes in CMC but not IMC were correlated with performance 1 and 7 days following practice. This study shows that tACS applied at beta-band CMC frequency improves consolidation following visuomotor practice and increases beta-band CMC and IMC. We propose that oscillatory beta activity in the corticospinal system may facilitate consolidation of the motor skill.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/texcom/tgaa047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8152838PMC
August 2020

Repetitive Peripheral Magnetic Stimulation of Wrist Extensors Enhances Cortical Excitability and Motor Performance in Healthy Individuals.

Front Neurosci 2021 18;15:632716. Epub 2021 Feb 18.

Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.

Repetitive peripheral magnetic stimulation (rPMS) may improve motor function following central nervous system lesions, but the optimal parameters of rPMS to induce neural plasticity and mechanisms underlying its action remain unclear. We examined the effects of rPMS over wrist extensor muscles on neural plasticity and motor performance in 26 healthy volunteers. In separate experiments, the effects of rPMS on motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI), intracortical facilitation (ICF), direct motor response (M-wave), Hoffmann-reflex, and ballistic wrist extension movements were assessed before and after rPMS. First, to examine the effects of stimulus frequency, rPMS was applied at 50, 25, and 10 Hz by setting a fixed total number of stimuli. A significant increase in MEPs of wrist extensors was observed following 50 and 25 Hz rPMS, but not 10 Hz rPMS. Next, we examined the time required to induce plasticity by increasing the number of stimuli, and found that at least 15 min of 50 and 25 Hz rPMS was required. Based on these parameters, lasting effects were evaluated following 15 min of 50 or 25 Hz rPMS. A significant increase in MEP was observed up to 60 min following 50 and 25 Hz rPMS; similarly, an attenuation of SICI and enhancement of ICF were also observed. The maximal M-wave and Hoffmann-reflex did not change, suggesting that the increase in MEP was due to plastic changes at the motor cortex. This was accompanied by increasing force and electromyograms during wrist ballistic extension movements following 50 and 25 Hz rPMS. These findings suggest that 15 min of rPMS with 25 Hz or more induces an increase in cortical excitability of the relevant area rather than altering the excitability of spinal circuits, and has the potential to improve motor output.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2021.632716DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7930341PMC
February 2021

Interindividual Variability of Lower-Limb Motor Cortical Plasticity Induced by Theta Burst Stimulation.

Front Neurosci 2020 13;14:563293. Epub 2020 Nov 13.

Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.

Theta burst stimulation (TBS) has been used as a tool to induce synaptic plasticity and improve neurological disorders. However, there is high interindividual variability in the magnitude of the plastic changes observed after TBS, which hinders its clinical applications. The electric field induced by transcranial magnetic stimulation (TMS) is strongly affected by the depth of the stimulated brain region. Therefore, it is possible that the variability in the response to TBS over the lower-limb motor cortex is different for the hand area. This study investigated the variability of TBS-induced synaptic plasticity in the lower-limb motor cortex, for intermittent TBS (iTBS), continuous TBS (cTBS), and sham iTBS, in 48 healthy young participants. The motor cortical and intracortical excitability of the tibialis anterior was tested before and after TBS using TMS. The results showed that iTBS had facilitatory effects on motor cortex excitability and intracortical inhibition, whereas cTBS exerted opposite effects. Twenty-seven percent of individuals exhibited enhanced motor cortical plasticity after iTBS, whereas 63% of participants showed enhanced plasticity after cTBS. In addition, the amount of TBS-induced plasticity was correlated with the intracortical excitability and the variability of the motor evoked potential prior to TBS. Our study demonstrated the high variability of the iTBS-induced lower-limb motor cortical plasticity, which was affected by the sensitivity of intracortical interneuronal circuits. These findings provide further insights into the variation of the response to TBS according to the anatomy of the stimulated brain region and the excitability of the intracortical circuit.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2020.563293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7691321PMC
November 2020

Single-Session Cerebellar Transcranial Direct Current Stimulation Affects Postural Control Learning and Cerebellar Brain Inhibition in Healthy Individuals.

Cerebellum 2021 Apr 27;20(2):203-211. Epub 2020 Oct 27.

Department of Physical Therapy, Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan.

Cerebellar transcranial direct current stimulation (ctDCS) modulates cerebellar activity and postural control. However, the effects of ctDCS on postural control learning and the mechanisms associated with these effects remain unclear. To examine the effects of single-session ctDCS on postural control learning and cerebellar brain inhibition (CBI) of the primary motor cortex in healthy individuals. In this triple-blind, sham-controlled study, 36 participants were allocated randomly to one of three groups: (1) anodal ctDCS group, (2) cathodal ctDCS group, and (3) sham ctDCS group. ctDCS (2 mA) was applied to the cerebellar brain for 20 min prior to six blocks of standing postural control training (each block consisted of five trials of a 30-s tracking task). CBI and corticospinal excitability of the tibialis anterior muscle were assessed at baseline, immediately after, 1 day after, and 7 days after training. Skill acquisition following training was significantly reduced in both the anodal and cathodal ctDCS groups compared with the sham ctDCS group. Changes in performance measured 1 day after and 7 days after training did not differ among the groups. In the anodal ctDCS group, CBI significantly increased after training, whereas corticospinal excitability decreased. Anodal ctDCS-induced CBI changes were correlated with the learning formation of postural control (r = 0.55, P = 0.04). Single-session anodal and cathodal ctDCS could suppress the skill acquisition of postural control in healthy individuals. The CBI changes induced by anodal ctDCS may affect the learning process of postural control.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12311-020-01208-5DOI Listing
April 2021

Transcutaneous spinal direct current stimulation increases corticospinal transmission and enhances voluntary motor output in humans.

Physiol Rep 2020 08;8(16):e14531

Department of Neuroscience, University of Copenhagen, Copenhagen N, Denmark.

Optimization of motor performance is of importance in daily life, in relation to recovery following injury as well as for elite sports performance. The present study investigated whether transcutaneous spinal direct current stimulation (tsDCS) may enhance voluntary ballistic activation of ankle muscles and descending activation of spinal motor neurons in able-bodied adults. Forty-one adults (21 men; 24.0 ± 3.2 years) participated in the study. The effect of tsDCS on ballistic motor performance and plantar flexor muscle activation was assessed in a double-blinded sham-controlled cross-over experiment. In separate experiments, the underlying changes in excitability of corticospinal and spinal pathways were probed by evaluating soleus (SOL) motor evoked potentials (MEPs) following single-pulse transcranial magnetic stimulation (TMS) over the primary motor cortex, SOL H-reflexes elicited by tibial nerve stimulation and TMS-conditioning of SOL H-reflexes. Measures were obtained before and after cathodal tsDCS over the thoracic spine (T11-T12) for 10 min at 2.5 mA. We found that cathodal tsDCS transiently facilitated peak acceleration in the ballistic motor task compared to sham tsDCS. Following tsDCS, SOL MEPs were increased without changes in H-reflex amplitudes. The short-latency facilitation of the H-reflex by subthreshold TMS, which is assumed to be mediated by the fast conducting monosynaptic corticomotoneuronal pathway, was also enhanced by tsDCS. We argue that tsDCS briefly facilitates voluntary motor output by increasing descending drive from corticospinal neurones to spinal plantar flexor motor neurons. tsDCS can thus transiently promote within-session CNS function and voluntary motor output and holds potential as a technique in the rehabilitation of motor function following central nervous lesions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14814/phy2.14531DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7435034PMC
August 2020

Transcranial direct-current stimulation combined with attention increases cortical excitability and improves motor learning in healthy volunteers.

J Neuroeng Rehabil 2020 02 19;17(1):23. Epub 2020 Feb 19.

Laboratory of Psychology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka, 431-3192, Japan.

Background: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has the potential to induce motor cortical plasticity in humans. It is well known that motor cortical plasticity plays an essential role in motor learning and recovery in patients with stroke and neurodegenerative disorders. However, it remains unclear how cognitive function influences motor cortical plasticity induced by tDCS. The present study aimed to investigate whether anodal tDCS combined with attention to a target muscle could enhance motor cortical plasticity and improve motor learning in healthy individuals.

Methods: Thirty-three healthy volunteers were assigned to two experiments. In experiment 1, there were three interventional conditions: 1) anodal tDCS was applied while participants paid attention to the first dorsal interosseous (FDI) muscle, 2) anodal tDCS was applied while participants paid attention to the sound, and 3) anodal tDCS was applied without the participants paying attention to the FDI muscle or the sound. Anodal tDCS (2 mA, 10 min) was applied over the primary motor cortex (M1). Changes in motor evoked potentials (MEPs), short-interval intracortical inhibition (SICI), and intracortical facilitation (ICF) were assessed before and immediately after (0 min), and then 10 min, 30 min, and 60 min after each intervention. In experiment 2, we investigated whether the combination of anodal tDCS and attention to the abductor pollicis brevis (APB) muscle could facilitate the learning of a ballistic thumb movement.

Results: Anodal tDCS increased cortical excitability in all conditions immediately after the stimulation. Significant increases in MEPs and significant decreases in SICI were observed for at least 60 min after anodal tDCS, but only when participants paid attention to the FDI muscle. In contrast, no significant changes in ICF were observed in any condition. In experiment 2, the combination of tDCS and attention to the APB muscle significantly enhanced the acquisition of a ballistic thumb movement. The higher performance was still observed 7 days after the stimulation.

Conclusions: This study shows that anodal tDCS over M1 in conjunction with attention to the target muscle enhances motor cortex plasticity and improves motor learning in healthy adults. These findings suggest that a combination of attention and tDCS may be an effective strategy to promote rehabilitation training in patients with stroke and neurodegenerative disorders.

Trial Registration: Retrospectively registered (UMIN000036848).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s12984-020-00665-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7031972PMC
February 2020

Does the balance strategy during walking in elderly persons show an association with fall risk assessment?

J Biomech 2020 04 24;103:109657. Epub 2020 Jan 24.

Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-city, Yamagata 990-2212, Japan.

The primary objective of this study was to clarify whether balance evaluation during walking in elderly people was related to fall risk assessment; the second objective was to clarify the difference in balance strategy between young and elderly people based on the balance evaluation through a gait cycle. Thirty healthy young adults and 25 healthy elderly adults participated. All participants performed walking at their preferred speed and at a fast speed. Based on the margin of stability (MoS), balance during a gait cycle was divided into medial/lateral and anterior/posterior direction (ML/AP-MoS). Positive/negative integral values of ML-MoS were defined as ML-MoS/ML-MoS, and the average of AP-MoS over the gait cycle was defined as AP-MoS. The fast/preferred ratio of AP-MoS/ML-MoS (AP-MoS (Fast/Preferred)/ML-MoS (Fast/Preferred)) and the fast-preferred difference of ML-MoS (ML-MoS (Fast-Preferred)) were compared between groups. ML/AP-MoS at the preferred/fast gait was also compared between 12 gait events and groups. The Japanese version of the Mini-Balance Evaluation Systems Test (J-Mini-BESTest), the Japanese version of the Activities-specific Balance Confidence Scale (J-ABC scale), and the number of falls in the past year were obtained from all subjects. ML-MoS (Fast/Preferred), ML-MoS (Fast-Preferred), and AP-MoS (Fast/Preferred) were significantly correlated with J-Mini-BESTest. Gait balance evaluation based on MoS may reflect an individual's balance function. In fast gait, ML-MoS at foot flat and toe off and AP-MoS at just before heel strike were highly likely to be gait events to identify elderly adults with balance disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jbiomech.2020.109657DOI Listing
April 2020

Skillful Cycling Training Induces Cortical Plasticity in the Lower Extremity Motor Cortex Area in Healthy Persons.

Front Neurosci 2019 3;13:927. Epub 2019 Sep 3.

Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan.

Cycling exercise is commonly used in rehabilitation to improve lower extremity (LE) motor function and gait performance after stroke. Motor learning is important for regaining motor skills, suggesting that training of motor skills influences cortical plasticity. However, the effects of motor skill learning in dynamic alternating movements of both legs on cortical plasticity remain unclear. Here, we examined the effects of skillful cycling training on cortical plasticity of the LE motor area in healthy adults. Eleven healthy volunteers participated in the following three sessions on different days: skillful cycling training, constant-speed cycling training, and rest condition. Skillful cycling training required the navigation of a marker up and down curves by controlling the rotation speed of the pedals. Participants were instructed to fit the marker to the target curves as accurately as possible. Amplitudes of motor evoked potentials (MEPs) and short-interval intracortical inhibition (SICI) evoked using transcranial magnetic stimulation (TMS) were assessed at baseline, after every 10 min of the task (a total of 30 min), and 30 min after the third and final trial. A decrease in tracking errors was representative of the formation of motor learning following skillful cycling training. Compared to baseline, SICI was significantly decreased after skillful cycling training in the tibialis anterior (TA) muscle. The task-induced alterations of SICI were more prominent and lasted longer with skillful cycling training than with the other conditions. The changes in SICI were negatively correlated with a change in tracking error ratio at 20 min the task. MEP amplitudes were not significantly altered with any condition. In conclusion, skillful cycling training induced long-lasting plastic changes of intracortical inhibition, which corresponded to the learning process in the LE motor cortex. These findings suggest that skillful cycling training would be an effective LE rehabilitation method after stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2019.00927DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6733988PMC
September 2019

Effects of Leg Motor Imagery Combined With Electrical Stimulation on Plasticity of Corticospinal Excitability and Spinal Reciprocal Inhibition.

Front Neurosci 2019 21;13:149. Epub 2019 Feb 21.

Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.

Motor imagery (MI) combined with electrical stimulation (ES) enhances upper-limb corticospinal excitability. However, its after-effects on both lower limb corticospinal excitability and spinal reciprocal inhibition remain unknown. We aimed to investigate the effects of MI combined with peripheral nerve ES (MI + ES) on the plasticity of lower limb corticospinal excitability and spinal reciprocal inhibition. Seventeen healthy individuals performed the following three tasks on different days, in a random order: (1) MI alone; (2) ES alone; and (3) MI + ES. The MI task consisted of repetitive right ankle dorsiflexion for 20 min. ES was percutaneously applied to the common peroneal nerve at a frequency of 100 Hz and intensity of 120% of the sensory threshold of the tibialis anterior (TA) muscle. We examined changes in motor-evoked potential (MEP) of the TA (task-related muscle) and soleus muscle (SOL; task-unrelated muscle). We also examined disynaptic reciprocal inhibition before, immediately after, and 10, 20, and 30 min after the task. MI + ES significantly increased TA MEPs immediately and 10 min after the task compared with baseline, but did not change the task-unrelated muscle (SOL) MEPs. MI + ES resulted in a significant increase in the magnitude of reciprocal inhibition immediately and 10 min after the task compared with baseline. MI and ES alone did not affect TA MEPs or reciprocal inhibition. MI combined with ES is effective in inducing plastic changes in lower limb corticospinal excitability and reciprocal Ia inhibition.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2019.00149DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6393385PMC
February 2019

Time course of changes in corticospinal excitability induced by motor imagery during action observation combined with peripheral nerve electrical stimulation.

Exp Brain Res 2019 Mar 8;237(3):637-645. Epub 2018 Dec 8.

Tokyo Bay Rehabilitation Hospital, 4-1-1 Yatsu, Narashino-shi, Chiba, 275-0026, Japan.

While previous studies assessed corticospinal excitability changes during and after motor imagery (MI) or action observation (AO) combined with peripheral nerve electrical stimulation (ES), we examined, for the first time, the time course of corticospinal excitability changes for MI during AO combined with ES (AO-MI + ES) using transcranial magnetic stimulation to measure motor evoked potentials (MEPs) in healthy individuals. Fourteen healthy volunteers participated in the following three sessions on different days: AO-MI alone, ES alone, and AO-MI + ES. In the AO-MI task, participants imagined squeezing and relaxing a ball, along with the respective actions shown in a movie, while passively holding the ball. We applied ES (intensity, 90% of the motor threshold) to the ulnar nerve at the wrist, which innervates the first dorsal interosseous (FDI) muscle. We assessed the FDI muscle MEPs at baseline and after every 5 min of the task for a total of 20 min. Additionally, participants completed the Vividness of Movement Imagery Questionnaire-2 (VMIQ-2) at the beginning of the experiment. Compared to baseline, AO-MI + ES significantly increased corticospinal excitability after 10 min, while AO-MI or ES alone had no effect on corticospinal excitability after 20 min. Moreover, the AO-MI + ES-induced cortical excitability changes were correlated with the VMIQ-2 scores for visual and kinaesthetic imagery. Collectively, our findings indicate that AO-MI + ES induces cortical plasticity earlier than does AO-MI or ES alone and that an individual's imagery ability plays an important role in inducing cortical excitability changes following AO-MI + ES.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00221-018-5454-5DOI Listing
March 2019

Effect of the combination of motor imagery and electrical stimulation on upper extremity motor function in patients with chronic stroke: preliminary results.

Ther Adv Neurol Disord 2018 9;11:1756286418804785. Epub 2018 Oct 9.

Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.

Background: The combination of motor imagery (MI) and afferent input with electrical stimulation (ES) enhances the excitability of the corticospinal tract compared with motor imagery alone or electrical stimulation alone. However, its therapeutic effect is unknown in patients with hemiparetic stroke. We performed a preliminary examination of the therapeutic effects of MI + ES on upper extremity (UE) motor function in patients with chronic stroke.

Methods: A total of 10 patients with chronic stroke demonstrating severe hemiparesis participated. The imagined task was extension of the affected finger. Peripheral nerve electrical stimulation was applied to the radial nerve at the spiral groove. MI + ES intervention was conducted for 10 days. UE motor function as assessed with the Fugl-Meyer assessment UE motor score (FMA-UE), the amount of the affected UE use in daily life as assessed with a Motor Activity Log (MAL-AOU), and the degree of hypertonia in flexor muscles as assessed with the Modified Ashworth Scale (MAS) were evaluated before and after intervention. To assess the change in spinal neural circuits, reciprocal inhibition between forearm extensor and flexor muscles with the H reflex conditioning-test paradigm at interstimulus intervals (ISIs) of 0, 20, and 100 ms were measured before and after intervention.

Results: UE motor function, the amount of the affected UE use, and muscle hypertonia in flexor muscles were significantly improved after MI + ES intervention (FMA-UE: < 0.01, MAL-AOU: < 0.01, MAS: = 0.02). Neurophysiologically, the intervention induced restoration of reciprocal inhibition from the forearm extensor to the flexor muscles (ISI at 0 ms: = 0.03, ISI at 20 ms: = 0.03, ISI at 100 ms: = 0.01).

Conclusion: MI + ES intervention was effective for improving UE motor function in patients with severe paralysis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1756286418804785DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6178123PMC
October 2018

Priming With Intermittent Theta Burst Transcranial Magnetic Stimulation Promotes Spinal Plasticity Induced by Peripheral Patterned Electrical Stimulation.

Front Neurosci 2018 24;12:508. Epub 2018 Jul 24.

Neuroscience Research Center and Department of Neurology, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan.

This study explored the effect of corticospinal activity on spinal plasticity by examining the interactions between intermittent theta burst transcranial magnetic stimulation (iTBS) of the motor cortex and peripheral patterned electrical stimulation (PES) of the common peroneal nerve (CPN). Healthy volunteers ( = 10) received iTBS to the tibialis anterior (TA) muscle zone of the motor cortex and PES of the CPN in three separate sessions: (1) iTBS-before-PES, (2) iTBS-after-PES, and (3) sham iTBS-before-PES. The PES protocol used 10 100-Hz pulses every 2 s for 20 min. Reciprocal inhibition (RI) from the TA to soleus muscle and motor cortical excitability of the TA and soleus muscles were assessed at baseline, before PES, and 0, 15, 30, and 45 min after PES. When compared to the other protocols, iTBS-before-PES significantly increased changes in disynaptic RI for 15 min and altered long-loop presynaptic inhibition immediately after PES. Moreover, the iTBS-induced cortical excitability changes in the TA before PES were correlated with the enhancement of disynaptic RI immediately after PES. These results demonstrate that spinal plasticity can be modified by altering cortical excitability. This study provides insight into the interactions between modulation of corticospinal excitability and spinal RI, which may help in developing new rehabilitation strategies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2018.00508DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6066516PMC
July 2018

Spasticity in adults with cerebral palsy and multiple sclerosis measured by objective clinically applicable technique.

Clin Neurophysiol 2018 09 24;129(9):2010-2021. Epub 2018 Jul 24.

Institute of Neuroscience, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark; Department of Nutrition, Exercise and Sports and Elsass Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark. Electronic address:

Objective: The present study evaluated ankle stiffness in adults with and without neurological disorders and investigated the accuracy and reproducibility of a clinically applicable method using a dynamometer.

Methods: Measurements were obtained from 8 healthy subjects (age 39.3), 9 subjects with spastic cerebral palsy (CP) (age 39.8) and 8 subjects with multiple sclerosis (MS) (age 49.9). Slow and fast dorsiflexion stretches of the ankle joint were performed to evaluate passive muscle-tendon-joint stiffness, reflex mediated stiffness and range of movement (ROM), respectively. Intra/inter-rater reliability for passive and reflex mediated ankle muscle stiffness was assessed for all groups.

Results: Subjects with CP and MS showed significantly larger values of passive stiffness in the triceps surae muscle tendon complex and smaller ROM compared to healthy individuals, while no significant difference in reflex mediated stiffness. Measurements of passive muscle-tendon-joint stiffness and reflex mediated stiffness showed good to excellent inter- and intra-rater reliability (ICC: 0.62-0.91) in all groups.

Conclusion: Increased stiffness was found in subjects with CP and MS with a clinically applicable method that provides valid and reproducible measurement of passive ankle muscle-tendon-joint stiffness and reflex mediated stiffness.

Significance: The present technique may provide important supplementary information for the clinician.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clinph.2018.07.004DOI Listing
September 2018

Development of a toileting performance assessment test for patients in the early stroke phase.

Disabil Rehabil 2019 11 29;41(23):2826-2831. Epub 2018 Jun 29.

Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.

The study aimed to develop a toileting performance assessment test to measure the toileting performance ability of patients in the early phase after stroke. In this study, 214 stroke patients were enrolled. Cronbach's , Spearman's rank correlations ( values) with the toileting-related items of the functional independence measure and Barthel Index, interrater reliability (weighted ), and responsiveness (standardized response mean) were evaluated. Receiver operating characteristic and the area under the curves were utilized to determine the cutoff scores for the significance of the independence of toilet ability with the functional independence measure and Barthel Index. Cronbach's was ≥0.90. The values between toileting performance assessment test and Barthel Index and between toileting performance assessment test and functional independence measure were 0.88 and 0.86, respectively. The weighted for each item was ≥0.61. The standardized response means were 0.81 for the functional independence measure, 0.70 for the Barthel Index, and 0.93 for the toileting performance assessment test. Cutoff scores of the toileting performance assessment test were 18 points. The toileting performance assessment test has acceptable psychometric properties and proved useful in assessing toileting performance ability of patients in the early phase after stroke.Implications for rehabilitationToileting performance assessment test demonstrated acceptable psychometric properties, and it can be useful for assessing the toileting ability of patients in the early phase after stroke.Toileting performance assessment test should provide information that leads to lowered risk of falls while toileting, and the information gathered can assist patients in achieving early toileting independence after stroke.As the development of toileting performance assessment test excluded patients with cognitive disabilities, the item for cognitive function should be developed as well.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/09638288.2018.1479455DOI Listing
November 2019

Intestinal microbiota composition is altered according to nutritional biorhythms in the leopard coral grouper (Plectropomus leopardus).

PLoS One 2018 1;13(6):e0197256. Epub 2018 Jun 1.

RIKEN Center for Sustainable Resource Science, Tsurumi-ku, Yokohama, Kanagawa, Japan.

Aquaculture is currently a major source of fish and has the potential to become a major source of protein in the future. These demands require efficient aquaculture. The intestinal microbiota plays an integral role that benefits the host, providing nutrition and modulating the immune system. Although our understanding of microbiota in fish gut has increased, comprehensive studies examining fish microbiota and host metabolism remain limited. Here, we investigated the microbiota and host metabolism in the coral leopard grouper, which is traded in Asian markets as a superior fish and has begun to be produced via aquaculture. We initially examined the structural changes of the gut microbiota using next-generation sequencing and found that the composition of microbiota changed between fasting and feeding conditions. The dominant phyla were Proteobacteria in fasting and Firmicutes in feeding; interchanging the dominant bacteria required 12 hours. Moreover, microbiota diversity was higher under feeding conditions than under fasting conditions. Multivariate analysis revealed that Proteobacteria are the key bacteria in fasting and Firmicutes and Fusobacteria are the key bacteria in feeding. Subsequently, we estimated microbiota functional capacity. Microbiota functional structure was relatively stable throughout the experiment; however, individual function activity changed according to feeding conditions. Taken together, these findings indicate that the gut microbiota could be a key factor to understanding fish feeding conditions and play a role in interactions with host metabolism. In addition, the composition of microbiota in ambient seawater directly affects the fish; therefore, it is important to monitor the microbiota in rearing tanks and seawater circulating systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0197256PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5983564PMC
November 2018

Unilateral Arm Crank Exercise Test for Assessing Cardiorespiratory Fitness in Individuals with Hemiparetic Stroke.

Biomed Res Int 2017 31;2017:6862041. Epub 2017 Dec 31.

Department of Physical Therapy, School of Health Sciences, Shinshu University, 3-1-1 Asahi, Matsumoto-shi, Nagano 390-8621, Japan.

Cardiorespiratory fitness assessment with leg cycle exercise testing may be influenced by motor impairments in the paretic lower extremity. Hence, this study examined the usefulness of a unilateral arm crank exercise test to assess cardiorespiratory fitness in individuals with stroke, including sixteen individuals with hemiparetic stroke (mean ± SD age, 56.4 ± 7.5 years) and 12 age- and sex-matched healthy controls. Participants performed the unilateral arm crank and leg cycle exercise tests to measure oxygen consumption ([Formula: see text]O) and heart rate at peak exercise. The [Formula: see text]O at peak exercise during the unilateral arm crank exercise test was significantly lower in the stroke group than in the control group ( < 0.001). In the stroke group, the heart rate at peak exercise during the unilateral arm crank exercise test did not significantly correlate with the Brunnstrom recovery stages of the lower extremity ( = 0.137), whereas there was a significant correlation during the leg cycle exercise test (rho = 0.775, < 0.001). The unilateral arm crank exercise test can detect the deterioration of cardiorespiratory fitness independently of lower extremity motor impairment severity in individuals with hemiparetic stroke. This study is registered with UMIN000014733.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2017/6862041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5804117PMC
August 2018

Voluntary contraction enhances spinal reciprocal inhibition induced by patterned electrical stimulation in patients with stroke.

Restor Neurol Neurosci 2018 ;36(1):99-105

Department of Rehabilitation Medicine, Keio University School of Medicine, Tokyo, Japan.

Background: Reciprocal inhibition (RI) may be important for recovering locomotion after stroke. Patterned electrical stimulation (PES) can modulate RI in a manner that could be enhanced by voluntary muscle contraction (VC).

Objective: To investigate whether VC enhances the PES-induced spinal RI in patients with stroke.

Methods: Twelve patients with chronic stroke underwent three 20 min tasks, each on different days: (1) PES (10 pulses, 100 Hz every 2 s) applied to the common peroneal nerve; (2) VC consisting of isometric contraction of the affected-side tibialis anterior muscle; (3) PES combined with VC (PES + VC). RI from the tibialis anterior to the soleus muscle was assessed before, immediately after, and 10, 20, and 30 min after the task.

Results: Compared to the baseline, PES + VC significantly increased the changes in reciprocal inhibition at immediately after and 10 min after the task. PES alone significantly increased this change immediately after the task, while VC alone showed no significant increase.

Conclusion: VC enhanced the PES-induced plastic changes in RI in patients with stroke. This effect can potentially increase the success rate of newer neurorehabilitative approaches in achieving functional recovery after stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3233/RNN-170759DOI Listing
October 2018

The Effect of Dual-Hemisphere Transcranial Direct Current Stimulation Over the Parietal Operculum on Tactile Orientation Discrimination.

Front Behav Neurosci 2017 20;11:173. Epub 2017 Sep 20.

Division of Psychology, School of Social Sciences (SSS), College of Humanities, Arts, & Social Sciences, Nanyang Technological UniversitySingapore, Singapore.

The parietal operculum (PO) often shows ipsilateral activation during tactile object perception in neuroimaging experiments. However, the relative contribution of the PO to tactile judgment remains unclear. Here, we examined the effect of transcranial direct current stimulation (tDCS) over bilateral PO to test the relative contributions of the ipsilateral PO to tactile object processing. Ten healthy adults participated in this study, which had a double-blind, sham-controlled, cross-over design. Participants discriminated grating orientation during three tDCS and sham conditions. In the dual-hemisphere tDCS conditions, anodal and cathodal electrodes were placed over the left and right PO. In the uni-hemisphere tDCS condition, anodal and cathodal electrodes were applied over the left PO and contralateral orbit, respectively. In the tDCS and sham conditions, we applied 2 mA for 15 min and for 15 s, respectively. Computational models of electric fields (EFs) during tDCS indicated that the strongest electric fields were located in regions in and around the PO. Compared with the sham condition, dual-hemisphere tDCS improved the discrimination threshold of the index finger contralateral to the anodal electrode. Importantly, dual-hemisphere tDCS with the anodal electrode over the left PO yielded a decreased threshold in the right finger compared with the uni-hemisphere tDCS condition. These results suggest that the ipsilateral PO inhibits tactile processing of grating orientation, indicating interhemispheric inhibition (IHI) of the PO.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnbeh.2017.00173DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5611440PMC
September 2017

Trans-omics approaches used to characterise fish nutritional biorhythms in leopard coral grouper (Plectropomus leopardus).

Sci Rep 2017 08 24;7(1):9372. Epub 2017 Aug 24.

RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.

Aquaculture is now a major supplier of fish, and has the potential to be a major source of protein in the future. Leopard coral groupers are traded in Asian markets as superior fish, and production via aquaculture has commenced. As feeding efficiency is of great concern in aquaculture, we sought to examine the metabolism of leopard coral groupers using trans-omics approaches. Metabolic mechanisms were comprehensively analysed using transcriptomic and metabolomic techniques. This study focused on the dynamics of muscular metabolites and gene expression. The omics data were discussed in light of circadian rhythms and fasting/feeding. The obtained data suggest that branched-chain amino acids played a role in energy generation in the fish muscle tissues during fasting. Moreover, glycolysis, TCA cycles, and purine metabolic substances exhibited circadian patterns, and gene expression also varied. This study is the first step to understanding the metabolic mechanisms of the leopard coral grouper.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-017-09531-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5570933PMC
August 2017

Real-time changes in corticospinal excitability related to motor imagery of a force control task.

Behav Brain Res 2017 09 18;335:185-190. Epub 2017 Aug 18.

School of Rehabilitation, Faculty of Health and Social Services, Kanagawa University of Human Services, 1-10-1 Heisei-cho, Yokosuka, Kanagawa, 238-8522, Japan. Electronic address:

Objective: To investigate real-time excitability changes in corticospinal pathways related to motor imagery in a changing force control task, using transcranial magnetic stimulation (TMS).

Methods: Ten healthy volunteers learnt to control the contractile force of isometric right wrist dorsiflexion in order to track an on-screen sine wave form. Participants performed the trained task 40 times with actual muscle contraction in order to construct the motor image. They were then instructed to execute the task without actual muscle contraction, but by imagining contraction of the right wrist in dorsiflexion. Motor evoked potentials (MEPs), induced by TMS in the right extensor carpi radialis muscle (ECR) and flexor carpi radialis muscle (FCR), were measured during motor imagery. MEPs were induced at five time points: prior to imagery, during the gradual generation of the imaged wrist dorsiflexion (Increasing phase), the peak value of the sine wave, during the gradual reduction (Decreasing phase), and after completion of the task. The MEP ratio, as the ratio of imaged MEPs to resting-state, was compared between pre- and post-training at each time point.

Results: In the ECR muscle, the MEP ratio significantly increased during the Increasing phase and at the peak force of dorsiflexion imagery after training. Moreover, the MEP ratio was significantly greater in the Increasing phase than in the Decreasing phase. In the FCR, there were no significant consistent changes.

Conclusion: Corticospinal excitability during motor imagery in an isometric contraction task was modulated in relation to the phase of force control after image construction.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bbr.2017.08.020DOI Listing
September 2017

Transcranial Direct Current Stimulation Does Not Affect Lower Extremity Muscle Strength Training in Healthy Individuals: A Triple-Blind, Sham-Controlled Study.

Front Neurosci 2017 4;11:179. Epub 2017 Apr 4.

Laboratory of Psychology, Hamamatsu University School of MedicineShizuoka, Japan.

The present study investigated the effects of anodal transcranial direct current stimulation (tDCS) on lower extremity muscle strength training in 24 healthy participants. In this triple-blind, sham-controlled study, participants were randomly allocated to the anodal tDCS plus muscle strength training (anodal tDCS) group or sham tDCS plus muscle strength training (sham tDCS) group. Anodal tDCS (2 mA) was applied to the primary motor cortex of the lower extremity during muscle strength training of the knee extensors and flexors. Training was conducted once every 3 days for 3 weeks (7 sessions). Knee extensor and flexor peak torques were evaluated before and after the 3 weeks of training. After the 3-week intervention, peak torques of knee extension and flexion changed from 155.9 to 191.1 Nm and from 81.5 to 93.1 Nm in the anodal tDCS group. Peak torques changed from 164.1 to 194.8 Nm on extension and from 78.0 to 85.6 Nm on flexion in the sham tDCS group. In both groups, peak torques of knee extension and flexion significantly increased after the intervention, with no significant difference between the anodal tDCS and sham tDCS groups. In conclusion, although the administration of eccentric training increased knee extensor and flexor peak torques, anodal tDCS did not enhance the effects of lower extremity muscle strength training in healthy individuals. The present null results have crucial implications for selecting optimal stimulation parameters for clinical trials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2017.00179DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5378798PMC
April 2017

The effects of patterned electrical stimulation combined with voluntary contraction on spinal reciprocal inhibition in healthy individuals.

Neuroreport 2017 May;28(8):434-438

aDepartment of Rehabilitation Medicine, Keio University School of Medicine bDepartment of Physical Medicine and Rehabilitation, Juntendo University Graduate School of Medicine cJSPS, Overseas Research Fellow, Tokyo dDepartment of Physical Therapy, Yamagata Prefectural University of Health Sciences, Yamagata, Japan eDepartment of Neuroscience and Pharmacology, University of Copenhagen, Copenhagen, Denmark.

The aim of this study was to examine the effects of voluntary contraction (VC) on the modulation of reciprocal inhibition induced by patterned electrical stimulation (PES) in healthy individuals. Twelve healthy volunteers participated in this study. PES was applied to the common peroneal nerve with a train of 10 pulses at 100 Hz every 2 s for 20 min. VC comprised repetitive ankle dorsiflexion at a frequency of 0.5 Hz for 20 min. All participants performed the following three tasks: (i) VC alone, (ii) PES alone, and (iii) PES combined with VC (PES+VC). Reciprocal inhibition was assessed using a soleus H-reflex conditioning-test paradigm at the time points of before, immediately after, 10 min after, 20 min after, and 30 min after the tasks. PES+VC increased the amount of reciprocal inhibition, with after-effects lasting up to 20 min. PES alone increased reciprocal inhibition and maintained the after-effects on reciprocal inhibition for 10 min, whereas VC alone increased only immediately after the task. VC could modulate the plastic changes in spinal reciprocal inhibition induced by PES in healthy individuals. PES combined with VC has a potential to modulate impaired reciprocal inhibition and it may facilitate functional recovery and improve locomotion after central nervous system lesions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/WNR.0000000000000777DOI Listing
May 2017

Validity of gait asymmetry estimation by using an accelerometer in individuals with hemiparetic stroke.

J Phys Ther Sci 2017 Feb 24;29(2):307-311. Epub 2017 Feb 24.

Department of Health Sciences, Graduate School of Medicine, Shinshu University, Japan.

[Purpose] The purpose of this study was to evaluate the validity of estimating step time and length asymmetries, using an accelerometer against force plate measurements in individuals with hemiparetic stroke. [Subjects and Methods] Twenty-four individuals who previously had experienced a stroke were asked to walk without using a cane or manual assistance on a 16-m walkway. Step time and length were measured using force plates, which is the gold standard for assessing gait asymmetry. In addition to ground reaction forces, trunk acceleration was simultaneously measured using an accelerometer. To estimate step time asymmetry using accelerometer data, the time intervals between forward acceleration peaks for each leg were calculated. To estimate step length asymmetry using accelerometer data, the integration of the positive vertical accelerations following initial contact of each leg was calculated. Asymmetry was considered the affected side value divided by the unaffected side value. [Results] Significant correlations were found between the accelerometer and the force plates for step time and length asymmetries (rho=0.83 and rho=0.64, respectively). [Conclusion] An accelerometer might be useful for assessing step time and length asymmetries in individuals with hemiparetic stroke, although improvements are needed for estimating the accuracy of step length asymmetry.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1589/jpts.29.307DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5332994PMC
February 2017

Transcranial Direct Current Stimulation Over the Primary and Secondary Somatosensory Cortices Transiently Improves Tactile Spatial Discrimination in Stroke Patients.

Front Neurosci 2016 31;10:128. Epub 2016 Mar 31.

Laboratory of Psychology, Hamamatsu University School of Medicine Shizuoka, Japan.

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2016.00128DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4814559PMC
April 2016

The effects of anodal transcranial direct current stimulation and patterned electrical stimulation on spinal inhibitory interneurons and motor function in patients with spinal cord injury.

Exp Brain Res 2016 06 20;234(6):1469-78. Epub 2016 Jan 20.

Department of Rehabilitation Medicine, Keio University School of Medicine, Shinjuku-ku, Tokyo, Japan.

Supraspinal excitability and sensory input may play an important role for the modulation of spinal inhibitory interneurons and functional recovery among patients with incomplete spinal cord injury (SCI). Here, we investigated the effects of anodal transcranial direct current stimulation (tDCS) combined with patterned electrical stimulation (PES) on spinal inhibitory interneurons in patients with chronic incomplete SCI and in healthy individuals. Eleven patients with incomplete SCI and ten healthy adults participated in a single-masked, sham-controlled crossover study. PES involved stimulating the common peroneal nerve with a train of ten 100 Hz pulses every 2 s for 20 min. Anodal tDCS (1 mA) was simultaneously applied to the primary motor cortex that controls the tibialis anterior muscle. We measured reciprocal inhibition and presynaptic inhibition of a soleus H-reflex by stimulating the common peroneal nerve prior to tibial nerve stimulation, which elicits the H-reflex. The inhibition was assessed before, immediately after, 10 min after and 20 min after the stimulation. Compared with baseline, simultaneous application of anodal tDCS with PES significantly increased changes in disynaptic reciprocal inhibition and long-latency presynaptic inhibition in both healthy and SCI groups for at least 20 min after the stimulation (all, p < 0.001). In patients with incomplete SCI, anodal tDCS with PES significantly increased the number of ankle movements in 10 s at 20 min after the stimulation (p = 0.004). In conclusion, anodal tDCS combined with PES could induce spinal plasticity and improve ankle movement in patients with incomplete SCI.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00221-016-4561-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4851690PMC
June 2016

After-effects of pedaling exercise on spinal excitability and spinal reciprocal inhibition in patients with chronic stroke.

Int J Neurosci 2017 Jan 15;127(1):73-79. Epub 2016 Feb 15.

a Department of Rehabilitation Medicine , Keio University School of Medicine , Tokyo , Japan.

Purpose Of The Study: To evaluate the after-effects of pedaling on spinal excitability and spinal reciprocal inhibition in patients with post-stroke spastic hemiparesis.

Materials And Methods: Twenty stroke patients with severe hemiparesis participated in this study and were instructed to perform 7 min of active pedaling and 7 min of passive pedaling with a recumbent ergometer at a comfortable speed. H reflexes and M waves of paretic soleus muscles were recorded at rest before, immediately after and 30 min after active and passive pedaling. The Hmax/Mmax ratio and H recruitment curve were measured. Reciprocal inhibition was assessed using the soleus H reflex conditioning test paradigm.

Results: The Hmax/Mmax ratio was significantly decreased after active and passive pedaling exercise. The decreased Hmax/Mmax ratio after active pedaling lasted at least for 30 min. The H recruitment curve and reciprocal inhibition did not change significantly after active or passive pedaling exercise.

Conclusions: Pedaling exercise decreased spinal excitability in patients with severe hemiparesis. Pedaling may be effective in rehabilitation following stroke.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3109/00207454.2016.1144055DOI Listing
January 2017

Increasing corticospinal excitability in the antagonist muscle during muscle relaxation with a tracking task.

Somatosens Mot Res 2015 ;32(1):39-43

Department of Rehabilitation, Yokosuka Kyosai Hospital , Yokosuka , Kanagawa , Japan .

The present study aimed to investigate corticospinal excitability changes during muscle relaxation with a tracking task. The motor-evoked potential, which was elicited from the flexor carpi radialis (agonist) and extensor carpi radialis (antagonist) muscles, was analyzed in terms of both the relaxation velocity and phase. Our results suggest that increasing corticospinal excitability in the antagonist muscle plays an important role in controlling the relaxation of the agonist muscle during gradual relaxation with a tracking task.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3109/08990220.2014.958215DOI Listing
February 2016

Use of a gyroscope/accelerometer data logger to identify alternative feeding behaviours in fish.

J Exp Biol 2014 Sep 10;217(Pt 18):3204-8. Epub 2014 Jul 10.

Institute for East China Sea Research, Nagasaki University, Taira-machi, Nagasaki 851-2213, Japan.

We examined whether we could identify the feeding behaviours of the trophic generalist fish Epinephelus ongus on different prey types (crabs and fish) using a data logger that incorporated a three-axis gyroscope and a three-axis accelerometer. Feeding behaviours and other burst behaviours, including escape responses, intraspecific interactions and routine movements, were recorded from six E. ongus individuals using data loggers sampling at 200 Hz, and were validated by simultaneously recorded video images. For each data-logger record, we extracted 5 s of data when any of the three-axis accelerations exceeded absolute 2.0 g, to capture all feeding behaviours and other burst behaviours. Each feeding behaviour was then identified using a combination of parameters that were derived from the extracted data. Using decision trees with the parameters, high true identification rates (87.5% for both feeding behaviours) with low false identification rates (5% for crab-eating and 6.3% for fish-eating) were achieved for both feeding behaviours.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1242/jeb.108001DOI Listing
September 2014

Dual-hemisphere transcranial direct current stimulation improves performance in a tactile spatial discrimination task.

Clin Neurophysiol 2014 Aug 31;125(8):1669-74. Epub 2013 Dec 31.

Nagoya Institute of Technology, Aichi, Japan. Electronic address:

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 30min after the dual-hemisphere, uni-hemisphere (1mA, 20min), or sham tDCS (1mA, 30s) 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 0.75mm (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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clinph.2013.12.100DOI Listing
August 2014
-->