Published papers

While previous studies have assessed changes in corticospinal excitability following voluntary contraction coupled with electrical stimulation (ES), we sought to examine, for the first time in the field, real-time changes in corticospinal excitability. We monitored motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation and recorded the MEPs using a mechanomyogram, which is less susceptible to electrical artifacts. We assessed the MEPs at each level of muscle contraction of wrist flexion (0%, 5%, or 20% of maximum voluntary contraction) during voluntary wrist flexion (flexor carpi radialis (FCR) voluntary contraction), either with or without simultaneous low-frequency (10 Hz) ES of the median nerve that innervates the FCR. The stimulus intensity corresponded to 1.2× perception threshold. In the FCR, voluntary contraction with median nerve stimulation significantly increased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.01). In addition, corticospinal excitability was significantly modulated by the level of FCR voluntary contraction. In contrast, in the extensor carpi radialis (ECR), FCR voluntary contraction with median nerve stimulation significantly decreased corticospinal excitability compared with FCR voluntary contraction without median nerve stimulation (p<0.05). Thus, median nerve stimulation during FCR voluntary contraction induces reciprocal changes in cortical excitability in agonist and antagonist muscles. Finally we also showed that even mental imagery of FCR voluntary contraction with median nerve stimulation induced the same reciprocal changes in cortical excitability in agonist and antagonist muscles. Our results support the use of voluntary contraction coupled with ES in neurorehabilitation therapy for patients. © 2012 Yamaguchi et al.

Objective: For the recovery of hemiparetic hand function, a therapy was developed called contralateral homonymous muscle activity stimulated electrical stimulation (CHASE), which combines electrical stimulation and bilateral movements, and its feasibility was studued in three chronic stroke patients with severe hand hemiparesis. Methods: Patients with a subcortical lesion were asked to extend their wrist and fingers bilaterally while an electromyogram (EMG) was recorded from the extensor carpi radialis (ECR) muscle in the unaffected hand. Electric stimulation was applied to the homonymous wrist and finger extensors of the affected side. The intensity of the electrical stimulation was computed based on the EMG and scaled so that the movements of the paretic hand looked similar to those of the unaffected side. The patients received 30-minutes of therapy per day for 2 weeks. Results: Improvement in the active range of motion of wrist extension was observed for all patients. There was a decrease in the scores of modified Ashworth scale in the flexors. Fugl-Meyer assessment scores of motor function of the upper extremities improved in two of the patients. Conclusions: The results suggest a positive outcome can be obtained using the CHASE system for upper extremity rehabilitation of patients with severe hemiplegia. © 2012 Informa UK Ltd.

Objective: Research to examine the immediate effects of electrical stimulation combined with passive locomotion-like movement on gait velocity and spasticity.Design: A single-masked, randomized controlled trial design.Subjects: Twenty-seven stroke inpatients in subacute phase (ischemic n=16, hemorrhagic n=11).Interventions: A novel approach using electrical stimulation combined with passive locomotion-like movement.Main measures: We assessed the maximum gait speed and modified Ashworth scale before and 20 minutes after the interventions.Results: The gait velocity of the electrical stimulation combined with passive locomotion-like movement group showed the increase form 0.68±0.28 (mean±SD, unit: m) to 0.76±0.32 after the intervention. Both the electrical stimulation group and passive locomotion-like movement group also showed increases after the interventions (from 0.76±0.37 to 0.79±0.40, from 0.74±0.35 to 0.77±0.36, respectively). The gait velocity of the electrical stimulation combined with passive locomotion-like movement group differed significantly from those of the other groups (electrical stimulation combined with passive locomotion-like movement versus electrical stimulation: P=0.049, electrical stimulation combined with passive locomotion-like movement versus passive locomotion-like movement: P=0.025). Although there was no statistically significant difference in the modified Ashworth scale among the three groups, six of the nine subjects (66.6%) in the electrical stimulation combined with passive locomotion-like movement group showed improvement in the modified Ashworth scale score, while only three of the nine subjects (33.3%) in the electrical stimulation group and two of the nine subjects (22.2%) improved in the passive locomotion-like movement group.Conclusion: These findings suggest electrical stimulation combined with passive locomotion-like movement could improve gait velocity in stroke patients. © The Author(s) 2011.

Pedaling is widely used for rehabilitation of locomotion because it induces similar muscle activity to that observed during locomotion. However, no study has examined the effects of pedaling exercise on intracortical inhibition. The aim of the present study was to investigate the effect of pedaling exercise on short-interval intracortical inhibition (SICI) in the cortical area controlling the tibialis anterior (TA) and soleus (SOL) muscles. Ten healthy adults participated in this study and were instructed to perform 7 min of active and passive pedaling. Paired pulse transcranial magnetic stimulation (TMS) was used to investigate the SICI. Using interstimulus intervals of 2-3 ms, the SICI of TA and SOL muscles was recorded at rest before and after the pedaling and repetitive ankle dorsiflexion tasks. SICI in both TA and SOL muscles decreased immediately after active pedaling. There were no significant changes in SICI after the passive pedaling and repetitive ankle dorsiflexion. A short-term, low-intensity active pedaling exercise decreases the intracortical inhibition of the leg area of the motor cortex. Our results suggest that pedaling has the potential to restore ambulation-inducing cortical reorganization among patients with central nervous system lesions. © Springer-Verlag 2012.

Objective: Inter-organizational coordination is important for rehabilitation disaster relief. The 2011 Great East Japan Earthquake and Disaster was unprecedented, being geographically widespread and multifaceted. Faced with the crisis, rehabilitation professionals established the 10 Rehabilitation- Related Organizations of Rehabilitation Support Service (10-RRO). The objectives of this paper are to provide descriptive epidemiology and assess the activities of 10- RRO. Design: Descriptive. Methods: Epidemiological data on disability were collected, mainly from official sources. Relief activities were reviewed from daily reports, and the preparedness, initial response and functioning of 10-RRO were assessed with a questionnaire directed at 36 executives of individual organizations. Results: The disaster was characterized by a very low ratio of injuries to death of 0.372, and an odds ratio of deaths among disabled persons of 2.32. 10-RRO provided relief activities at 3 shelters. The total number of dispatch days ranged from 107 to 146, and the cumulative number of professionals and evacuees served was 1,202 and 7,300, respectively. Support activities included prevention of immobilization, daily life support, environmental improvement and transition to temporary housing. The questionnaire survey revealed poor preparedness, satisfactory initial response and support activities, and problems of data collection and advocacy. Conclusion: The disaster was characterized by minimal trauma and a great need for preventing immobilization. This first collaborative endeavour was successful. © 2012 Foundation of Rehabilitation Information.

The sensorimotor cortex activity measured by scalp EEG shows coherence with electromyogram (EMG) activity within the 15- to 35-Hz frequency band (β-band) during weak to moderate intensity of isometric voluntary contraction. This coupling is known to change its frequency band to the 35- to 60-Hz band (γ-band) during strong contraction. This study aimed to examine whether such contraction level-related modulation of corticomuscular coupling differs between muscles with different muscle compositions and functions. In 11 healthy young adults, we quantified the coherence between EEG over the sensorimotor cortex and rectified EMG during tonic isometric voluntary contraction at 10-70% of maximal voluntary contraction of the tibialis anterior (TA) and soleus (SOL) muscles, respectively. In the TA, the EEG-EMG coherence shifted from the β-band to the γ-band with increasing contraction level. Indeed, the magnitude of β-band EEG-EMG coherence was significantly decreased, whereas that of γ-band coherence was significantly increased, when the contraction level was above 60% of maximal voluntary contraction. In contrast to the TA, the SOL showed no such frequency changes of EEG-EMG coherence with alterations in the contraction levels. In other words, the maximal peak of EEG-EMG coherence in the SOL existed within the β-band, irrespective of the contraction levels. These findings suggest that the central nervous system regulates the frequency of corticomuscular coupling to exert the desired levels of muscle force and, notably, that the applicable rhythmicity of the coupling for performing strong contractions differs between muscles, depending on the physiological muscle compositions and functions of the contracting muscle. Copyright © 2012 the American Physiological Society.