Ichiro Miyai

Morinomiya University of Medical Sciences, Ōsaka, Ōsaka, Japan

Are you Ichiro Miyai?

Claim your profile

Publications (70)188.74 Total impact

  • Source
    [Show abstract] [Hide abstract]
    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; · 2.60 Impact Factor
  • [Show abstract] [Hide abstract]
    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; · 6.25 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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; · 6.16 Impact Factor
  • Ichiro Miyai
    [Show abstract] [Hide abstract]
    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.
    Rinshō shinkeigaku = Clinical neurology. 01/2013; 53(11):931-3.
  • Source
    Masahito Mihara, Ichiro Miyai
    04/2012; , ISBN: 978-953-51-0538-1
  • [Show abstract] [Hide abstract]
    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. · 1.40 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    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 01/2012; 7(3):e32234. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    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.
    Rinshō shinkeigaku = Clinical neurology. 01/2012; 52(11):1174-7.
  • [Show abstract] [Hide abstract]
    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. · 4.28 Impact Factor
  • Ichiro Miyai
    [Show abstract] [Hide abstract]
    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. · 2.60 Impact Factor
  • Ichiro Miyai
    Rinshō shinkeigaku = Clinical neurology. 11/2011; 51(11):1129.
  • Ichiro Miyai
    Rinshō shinkeigaku = Clinical neurology. 11/2011; 51(11):1058.
  • [Show abstract] [Hide abstract]
    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. · 4.28 Impact Factor
  • [Show abstract] [Hide abstract]
    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. · 4.28 Impact Factor
  • Neuroscience Research - NEUROSCI RES. 01/2011; 71.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Functional near-infrared spectroscopy (fNIRS) is an effective tool to non-invasively investigate cerebral oxygenation and hemodynamics. fNIRS as well as other functional neuroimaging techniques including functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) have been used for investigating the neural mechanisms of functional recovery after a stroke or a traumatic brain injury. fNIRS has several advantages over other neuroimaging techniques in terms of clinical application in the field of rehabilitation medicine. In addition to its portability and low equipment cost, fNIRS does not require strict motion restriction during measurement, unlike other functional imaging techniques. Therefore, this technique enables the examination of cortical activation during physically dynamic activities, like gait or balance perturbation. Studies using fNIRS have revealed several implications for gait recovery after stroke. These studies have shown that the medial sensorimotor cortex (SMC) and the supplementary motor area (SMA) are mainly involved in steadying gait and that the prefrontal cortex (PFC) is involved in the adjustment of walking speed. In hemiparetic patients, lateralization of SMC activation during gait is reduced, and additional cortical activations in the premotor cortex and PFC during gait became evident after focused rehabilitation for several months. The cortical activation pattern may be modified after different types of rehabilitative interventions. These results imply that fNIRS data is a potential biomarker for functional recovery and the response to rehabilitative interventions. Although further studies are required, fNIRS might provide useful information for customizing rehabilitation programs in order to enhance functional recovery.
    Brain and nerve = Shinkei kenkyū no shinpo 02/2010; 62(2):125-32.
  • Clinical Neurophysiology - CLIN NEUROPHYSIOL. 01/2010; 121.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Rehabilitation for upper limbs is important for the elderly people, the stroked patients and so on. In recent years, the needs for rehabilitation support systems are increasing, which use robot technology, virtual reality technology and neuroscience. In this paper we present about a development of evaluation system of the motor function for upper limbs using 3-D rehabilitation Robot ldquoEMULrdquo and brain function imaging method ldquoNIRSrdquo.
    Rehabilitation Robotics, 2009. ICORR 2009. IEEE International Conference on; 07/2009
  • NeuroImage 01/2009; 47. · 6.25 Impact Factor
  • The Japanese Journal of Rehabilitation Medicine 01/2009; 46(12):787-792.

Publication Stats

1k Citations
188.74 Total Impact Points

Institutions

  • 2007–2013
    • Morinomiya University of Medical Sciences
      Ōsaka, Ōsaka, Japan
  • 2008
    • Nihon Fukushi University
      Manda, Aichi, Japan
  • 2001–2008
    • Tsukuba Memorial Hospital
      Tsukuba, Ibaraki, Japan
    • Weill Cornell Medical College
      New York City, New York, United States
  • 1998–2001
    • Toneyama National Hospital - Toyonaka
      Toyonaka, Ōsaka, Japan
  • 1997
    • Cornell University
      Ithaca, New York, United States