Ichiro Miyai

Morinomiya University of Medical Sciences, Ōsaka, Ōsaka, Japan

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Publications (76)203.78 Total impact

  • Kae Kokubo · Kyoko Suzuki · Noriaki Hattori · Ichiro Miyai · Etsuro Mori ·
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    ABSTRACT: The frontal-subcortical circuits link the specific areas of the frontal cortex to the striatum, basal ganglia, and thalamus. Disruption of the frontal-subcortical circuits may lead to cognitive impairment with frontal lobe features. The putamen is a central component of frontal-subcortical circuits. Although putaminal lesions presumably lead to cognitive and behavioral changes, studies on frontal lobe dysfunctions after putaminal stroke are scarce. There are no previous studies that systematically examined frontal lobe functions with a focal putaminal lesion. The objective of this study is to demonstrate whether putaminal hemorrhage causes frontal lobe dysfunction. Cognitive functions, including various aspects of frontal lobe functions, were systematically assessed in 15 patients with left- or right-sided putaminal hemorrhage 2 months after the onset and compared with healthy controls. Patients did not have signs of aphasia, apraxia, or spatial neglect. They performed significantly worse on tests of frontal lobe function, including Letter-Number Sequencing (U = 22, P < .001), lexical fluency (U = 30, P < .001), and motor series subtest (U = 45, P = .004) of the Frontal Assessment Battery. On the Wisconsin Card Sorting Test, patients performed significantly worse for "categories achieved" (U = 29.5, P < .001), "perseverative errors" (U = 25, P < .001), and "set loss" (U = 49, P = .008). None showed behavioral impairment. Isolated putaminal hemorrhage causes modest frontal lobe dysfunction without behavioral symptoms. Our findings indicate that isolated putaminal hemorrhage disrupts the dorsolateral-striato-pallido-thalamic circuits and causes executive dysfunction. Copyright © 2015 National Stroke Association. Published by Elsevier Inc. All rights reserved.
    Journal of stroke and cerebrovascular diseases: the official journal of National Stroke Association 07/2015; 24(9). DOI:10.1016/j.jstrokecerebrovasdis.2015.04.047 · 1.67 Impact Factor
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    I Miyai · A D Blau · M J Reding · B T Volpe ·

  • Ichiro Miyai ·
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    ABSTRACT: It remains to be elucidated whether there is a use- or dose-dependent effect of rehabilitative intervention on impairment and disability of spinocerebellar degeneration since the disease progressively damages cerebellar structure that plays a crucial role in motor learning. Moreover there is a trade-off between functional improvement after rehabilitation and functional deterioration due to disease progression. Recent clinical trials from Germany and Japan have demonstrated that comprehensive intensive rehabilitation focusing on balance function have immediate and lasting effect up to 1 year on ataxia and gait disorder in patients with spinocerebellar degeneration. For sustained gain after the intensive rehabilitation, customized attempts to boost patients' daily activities according to their ability appears to be important.
    12/2013; 53(11):931-3. DOI:10.5692/clinicalneurol.53.931
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    ABSTRACT: Treatment of motor symptoms of degenerative cerebellar ataxia remains difficult. Yet there are recent developments that are likely to lead to significant improvements in the future. Most desirable would be a causative treatment of the underlying cerebellar disease. This is currently available only for a very small subset of cerebellar ataxias with known metabolic dysfunction. However, increasing knowledge of the pathophysiology of hereditary ataxia should lead to an increasing number of medically sensible drug trials. In this paper, data from recent drug trials in patients with recessive and dominant cerebellar ataxias will be summarized. There is consensus that up to date, no medication has been proven effective. Aminopyridines and acetazolamide are the only exception, which are beneficial in patients with episodic ataxia type 2. Aminopyridines are also effective in a subset of patients presenting with downbeat nystagmus. As such, all authors agreed that the mainstays of treatment of degenerative cerebellar ataxia are currently physiotherapy, occupational therapy, and speech therapy. For many years, well-controlled rehabilitation studies in patients with cerebellar ataxia were lacking. Data of recently published studies show that coordinative training improves motor function in both adult and juvenile patients with cerebellar degeneration. Given the well-known contribution of the cerebellum to motor learning, possible mechanisms underlying improvement will be outlined. There is consensus that evidence-based guidelines for the physiotherapy of degenerative cerebellar ataxia need to be developed. Future developments in physiotherapeutical interventions will be discussed including application of non-invasive brain stimulation.
    The Cerebellum 11/2013; 13(2). DOI:10.1007/s12311-013-0531-6 · 2.72 Impact Factor

  • Clinical Neurophysiology 08/2013; 124(8):e24. DOI:10.1016/j.clinph.2013.02.050 · 3.10 Impact Factor
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    ABSTRACT: Balance problems are a major sequelae of stroke and are implicated in poor recovery of activities of daily living. In a cross-sectional study, using 50-channel event-related functional near-infrared spectroscopy we previously reported a significant correlation between individual balance ability after stroke and postural perturbation-related cortical activation in the supplementary motor area (SMA) and the prefrontal cortex. However, the neural mechanisms underlying balance recovery after stroke remain unclear. Herein, we examined the cortical involvement in balance recovery after stroke by determining longitudinal regional cortical activation changes in patients with hemiplegic stroke. Twenty patients with subcortical stroke admitted to our hospital for post-acute inpatient rehabilitation participated in this study. Before and after intensive inpatient physical and occupational therapy rehabilitation, we evaluated cortical activation associated with external postural perturbations induced by combined brisk forward and backward movement of a platform. Postural perturbation-related cortical activation in the SMA of the affected and unaffected hemispheres was significantly increased after intensive rehabilitation. The increment of the postural-perturbation-related oxygenated hemoglobin signals in the SMA of the unaffected hemisphere was significantly correlated with the gain in balance function measured by the Berg Balance Scale. These findings support the conclusion that the SMA plays an important role in postural balance control, and suggest that the SMA is a crucial area for balance recovery after hemiplegic stroke.
    NeuroImage 05/2013; 85. DOI:10.1016/j.neuroimage.2013.05.014 · 6.36 Impact Factor
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    ABSTRACT: Background and purpose: Despite the findings that motor imagery and execution are supposed to share common neural networks, previous studies using imagery-based rehabilitation have revealed inconsistent results. In the present study, we investigated whether feedback of cortical activities (neurofeedback) using near-infrared spectroscopy could enhance the efficacy of imagery-based rehabilitation in stroke patients. Methods: Twenty hemiplegic patients with subcortical stroke received 6 sessions of mental practice with motor imagery of the distal upper limb in addition to standard rehabilitation. Subjects were randomly allocated to REAL and SHAM groups. In the REAL group, cortical hemoglobin signals detected by near-infrared spectroscopy were fed back during imagery. In the SHAM group, irrelevant randomized signals were fed back. Upper limb function was assessed using the finger and arm subscales of the Fugl-Meyer assessment and the Action Research Arm Test. Results: The hand/finger subscale of the Fugl-Meyer assessment showed greater functional gain in the REAL group, with a significant interaction between time and group (F(2,36)=15.5; P<0.001). A significant effect of neurofeedback was revealed even in severely impaired subjects. Imagery-related cortical activation in the premotor area was significantly greater in the REAL group than in the SHAM group (T(58)=2.4; P<0.05). Conclusions: Our results suggest that near-infrared spectroscopy-mediated neurofeedback may enhance the efficacy of mental practice with motor imagery and augment motor recovery in poststroke patients with severe hemiparesis.
    Stroke 02/2013; 44(4). DOI:10.1161/STROKEAHA.111.674507 · 5.72 Impact Factor
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    ABSTRACT: Recent studies of functional neuroimaging and clinical neurophysiology have implied that functional recovery after stroke is associated with use-dependent plasticity of the damaged brain. However the property of the reorganized neural network depends on site and size of the lesion, which makes it difficult to assess what the adaptive plasticity is. From clinical point of view there is accumulating randomized controlled trials for the benefit of task-oriented rehabilitative intervention including constraint-induced movement therapy, robotics, and body-weight supported treadmill training. However dose-matched control intervention is usually as effective as a specific intervention. This raises a question regarding the specificity of a task-oriented intervention. Second question is whether such intervention goes beyond the biological destiny of human. Specifically there is no known strategy enhancing recovery of severely impaired hand. To augment functional gain, several methods of neuro-modulation may bring break-through on the assumption that they induce greater adaptive plasticity. Such neuro-modulative methods include neuropharmacological modulation, brain stimulation using transcranial magnetic stimulation and direct current stimulation, peripheral nerve stimulation, neurofeedback using real-time fMRI and real-time fNIRS, and brain-machine interface. A preliminary randomized controlled trial regarding real-time feedback of premotor activities revealed promising results for recovery of paretic hand in patients with stroke.
    11/2012; 52(11):1174-7. DOI:10.5692/clinicalneurol.52.1174
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    Masahito Mihara · Ichiro Miyai ·

    Infrared Spectroscopy - Life and Biomedical Sciences, 04/2012; , ISBN: 978-953-51-0538-1
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    ABSTRACT: Despite its remarkable effect on the activities of daily living, the precise mechanism underlying balance control after stroke remains to be elucidated. In this study, we investigated the cortical activation induced by postural perturbation in 20 patients with stroke using a 50-channel event-related functional near-infrared spectroscopy. A combination of brisk forward and backward movements of a platform without any prior cue was used as an external postural perturbation. Multi-participant analysis of oxygenated hemoglobin signals showed postural perturbation-related cortical activation in the prefrontal cortical areas in both hemispheres as well as the premotor and parietal association cortical areas in the unaffected hemisphere. Regression analysis using the individual Berg Balance Scale as the regressor showed a significant positive correlation between balance ability and the postural perturbation-related changes in oxygenated hemoglobin signals in the supplementary motor areas and prefrontal cortical areas in both hemispheres. Consistent with the previous findings in healthy participants, these findings suggest that the broad cortical network, including the prefrontal, premotor, supplementary motor, and parietal cortical areas in both hemispheres, was essential for balance control even in poststroke patients.
    Neuroreport 03/2012; 23(5):314-9. DOI:10.1097/WNR.0b013e328351757b · 1.52 Impact Factor
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    ABSTRACT: Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practices in the form of motor imagery have been implemented in rehabilitation regimes of stroke patients with favorable results. Because direct monitoring of motor imagery is difficult, feedback of cortical activities related to motor imagery (neurofeedback) could help to enhance efficacy of mental practice with motor imagery. To determine the feasibility and efficacy of a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS), two separate experiments were performed. Experiment 1 was used in five subjects to evaluate whether real-time cortical oxygenated hemoglobin signal feedback during a motor execution task correlated with reference hemoglobin signals computed off-line. Results demonstrated that the NIRS-mediated neurofeedback system reliably detected oxygenated hemoglobin signal changes in real-time. In Experiment 2, 21 subjects performed motor imagery of finger movements with feedback from relevant cortical signals and irrelevant sham signals. Real neurofeedback induced significantly greater activation of the contralateral premotor cortex and greater self-assessment scores for kinesthetic motor imagery compared with sham feedback. These findings suggested the feasibility and potential effectiveness of a NIRS-mediated real-time neurofeedback system on performance of kinesthetic motor imagery. However, these results warrant further clinical trials to determine whether this system could enhance the effects of mental practice in stroke patients.
    PLoS ONE 03/2012; 7(3):e32234. DOI:10.1371/journal.pone.0032234 · 3.23 Impact Factor
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    ABSTRACT: To investigate short- and long-term effects of intensive rehabilitation on ataxia, gait, and activities of daily living (ADLs) in patients with degenerative cerebellar disease. A total of 42 patients with pure cerebellar degeneration were randomly assigned to the immediate group or the delayed-entry control group. The immediate group received 2 hours of inpatient physical and occupational therapy, focusing on coordination, balance, and ADLs, on weekdays and 1 hour on weekends for 4 weeks. The control group received the same intervention after a 4-week delay. Short-term outcome was compared between the immediate and control groups. Long-term evaluation was done in both groups at 4, 12, and 24 weeks after the intervention. Outcome measures included the assessment and rating of ataxia, Functional Independence Measure, gait speed, cadence, functional ambulation category, and number of falls. The immediate group showed significantly greater functional gains in ataxia, gait speed, and ADLs than the control group. Improvement of truncal ataxia was more prominent than limb ataxia. The gains in ataxia and gait were sustained at 12 weeks and 24 weeks, respectively. At least 1 measure was better than at baseline at 24 weeks in 22 patients. Short-term benefit of intensive rehabilitation was evident in patients with degenerative cerebellar diseases. Although functional status tended to decline to the baseline level within 24 weeks, gains were maintained in more than half of the participants.
    Neurorehabilitation and neural repair 12/2011; 26(5):515-22. DOI:10.1177/1545968311425918 · 3.98 Impact Factor
  • Ichiro Miyai ·
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    ABSTRACT: Cerebellar Ataxia Rehabilitation trial tested if intensive rehabilitation improved ataxia, gait, and activities of daily living (ADLs) in 42 patients with degenerative cerebellar diseases. They were randomly assigned to the immediate intervention group or the delayed-entry control group. The immediate group received 1 h physical and 1 h occupational therapy for 4 weeks and delayed-entry control group received the same intervention after 4-week delay. The immediate group showed significantly greater functional gains in ataxia, gait speed, and ADLs than control. The improvements in ataxia and gait speed were sustained at 12 and 24 weeks after the intervention, respectively. Further strategies inducing meaningful gains for a longer period should be investigated.
    The Cerebellum 11/2011; 11(2):436-7. DOI:10.1007/s12311-011-0327-5 · 2.72 Impact Factor
  • Ichiro Miyai ·

    11/2011; 51(11):1058. DOI:10.5692/clinicalneurol.51.1058
  • Ichiro Miyai ·

    11/2011; 51(11):1129. DOI:10.5692/clinicalneurol.51.1129
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    ABSTRACT: Motor learning is essential to gain skills with neurorehabilitation. To investigate whether capacity for motor learning affects rehabilitation outcome and its relevant brain activation in ataxic patients with stroke. Twelve patients presenting with ataxia admitted for inpatient rehabilitation 2 to 3 months after infratentorial stroke and 6 control subjects performed 8 repetitions of 30-second pursuit rotor (PR) task. Cortical oxygenated hemoglobin (oxyHb) signals were measured using functional near-infrared spectroscopy. Both patients and controls learned the PR skill, although the gains in PR performance were significantly lower in patients. In patients, the less learning significantly correlated with smaller rehabilitation gains assessed by the Functional Independence Measure. The Fugl-Meyer score for coordination and balance did not change. Center of task-related increase of cortical oxyHb signals shifted from the presupplementary motor area (preSMA) to the supplementary motor area (SMA) with task repetitions in controls but not in patients. Accordingly, serial changes of ratio of oxyHb increase in the preSMA to SMA (preSMA/SMA ratio) were significantly different between the groups. In patients and controls, gains in PR performance and changes of the preSMA/SMA ratio correlated. Impaired motor sequence learning by the PR task was correlated with reduced rehabilitation gains for ataxic patients with stroke.
    Neurorehabilitation and neural repair 09/2011; 26(3):293-300. DOI:10.1177/1545968311412053 · 3.98 Impact Factor

  • Neuroscience Research 09/2011; 71. DOI:10.1016/j.neures.2011.07.356 · 1.94 Impact Factor
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    ABSTRACT: Exertional dyspnea is the primary symptom that limits exercise in patients with chronic obstructive pulmonary disease (COPD). It is unknown which activated brain area is associated with this symptom in COPD patients. To investigate the activation of cortical areas associated with dyspnea during exercise in COPD patients. COPD patients (n = 10) and age-matched controls (n = 10) performed mild-intensity constant work rate cycle exercise (40% of their symptom-limited peak work rates) for 10 min, while cerebral hemodynamics and oxygenation were measured by near-infrared spectroscopy (NIRS). Ventilatory responses (breathing pattern and pulmonary gas exchange) and Borg scale ratings of dyspnea and leg fatigue were measured during exercise. Three NIRS probes were placed over the prefrontal and temporoparietal cortical regions of the subjects' heads. Changes in cortical oxyhemoglobin (oxy-Hb), deoxyhemoglobin (deoxy-Hb), and total hemoglobin (total Hb) concentrations from baseline recordings were measured. Increased oxy-Hb (oxygenation) was assumed to reflect cortical activation. Oxy-Hb concentration was significantly increased in the prefrontal region during exercise in both groups but not in the temporoparietal regions. The change in prefrontal oxy-Hb concentration of COPD patients was not different from that of controls. Dyspnea scores were positively correlated with changes in oxy-Hb concentrations of the prefrontal regions in both groups. Multivariate analysis showed that oxy-Hb concentration in the prefrontal region was the best predictor of dyspnea in both groups. Exertional dyspnea was related to activation (oxygenation) of the prefrontal cortex in COPD patients and control subjects.
    Respiration 04/2011; 82(6):492-500. DOI:10.1159/000324571 · 2.59 Impact Factor
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    ABSTRACT: A new interdisciplinary postacute rehabilitation unit, the Kaifukuki (convalescent) rehabilitation ward (KRW), has been incorporated into the Japanese medical insurance system since 2000. More than 57 000 beds (45 beds per 100 000 population) are currently available nationwide. The maximal coverage for therapy sessions increased from 2 to 3 hours per day, 7 days a week, in 2006. To investigate how changes in policy affected rehabilitation outcomes of KRWs in a retrospective cohort study of 87 917 patients over 10 years. The mean (standard deviation) age of the patients was 73.0 (13.8) years, and 55.4% were women. Diagnoses included stroke (47.9%); orthopedic diseases, including hip fracture (35.2%); and traumatic brain and spinal cord injury (5.4 %). Onset-admission interval (OAI) was 31.5 (18.6) days, length of stay was 75.9 (46.1) days, and 69.1% were discharged home. Daily therapy time was 79.4 (34.5) minutes. Admission/discharge scores of the Barthel Index and the Functional Independence Measure were 49.3 (31.0)/70.4 (31.9) and 75.3 (31.2)/91.7 (31.8), respectively. Year-by-year comparison revealed that older age, greater initial disability, and shorter OAI were coupled with a higher dose of rehabilitative interventions and a higher rate of home discharge. Longitudinal data from a cohort of hospitals implied a small but significant dose-dependent effect of hours of therapy on rehabilitation outcome after stroke. Although the organization of KRWs is in flux as the system of hospitals grows, results over the past 8 years suggest that changes in national insurance policies are affecting the quantity and organization of rehabilitation interventions and improvement in patient outcomes.
    Neurorehabilitation and neural repair 03/2011; 25(6):540-7. DOI:10.1177/1545968311402696 · 3.98 Impact Factor

  • Neuroscience Research 10/2010; 121. DOI:10.1016/S1388-2457(10)61278-3 · 1.94 Impact Factor

Publication Stats

2k Citations
203.78 Total Impact Points


  • 2007-2013
    • Morinomiya University of Medical Sciences
      Ōsaka, Ōsaka, Japan
  • 2011
    • Osaka University
      • Division of Neurology
      Suika, Ōsaka, Japan
  • 2010
    • Japan Science and Technology Agency (JST)
      Edo, Tōkyō, Japan
  • 2006
    • Nikko Memorial Hospital
      Hidachi, Ibaraki, Japan
  • 2001
    • Osaka City University
      Ōsaka, Ōsaka, Japan
  • 1999-2001
    • Toneyama National Hospital - Toyonaka
      Toyonaka, Ōsaka, Japan
  • 1997
    • Cornell University
      Итак, New York, United States
    • White Plains Hospital
      White Plains, New York, United States