Yuko Kasashima

Motor Improvement and Corticospinal Modulation Induced by Hybrid Assistive Neuromuscular Dynamic Stimulation (HANDS) Therapy in Patients With Chronic Stroke

Background and objective . We devised a therapeutic approach to facilitate the use of the hemiparetic upper extremity (UE) in daily life by combining integrated volitional control electrical stimulation with a wrist splint, called hybrid assistive neuromuscular dynamic stimulation (HANDS). Methods. Twenty patients with chronic hemiparetic stroke (median 17.5 months) had moderate to severe UE weakness. Before and immediately after completing 3 weeks of training in 40-minute sessions, 5 days per week over 3 weeks and wearing the system for 8 hours each day, clinical measures of motor impairment, spasticity, and UE functional scores, as well as neurophysiological measures including electromyography activity, reciprocal inhibition, and intracortical inhibition were assessed. A follow-up clinical assessment was performed 3 months later. Results. UE motor function, spasticity, and functional scores improved after the intervention. Neurophysiologically, the intervention induced restoration of presynaptic and long loop inhibitory connections as well as disynaptic reciprocal inhibition. Paired pulse transcranial magnetic stimulation study indicated disinhibition of the short intracortical inhibition in the affected hemisphere. The follow-up assessment showed that improved UE functions were maintained at 3 months. Conclusion. The combination of hand splint and volitional and electrically induced muscle contraction can induce corticospinal plasticity and may offer a promising option for the management of the paretic UE in patients with stroke. A larger sample size with randomized controls is needed to demonstrate effectiveness.

29. Motor improvement and corticospinal modulation induced by hybrid assistive neuromuscular dynamic stimulation (HANDS) therapy in patients with chronic stroke

Complementary interaction between the somatosensory and auditory cortices was studied by measuring the evoked magnetic fields. Fourteen normal volunteers were asked to discriminate three kinds of vibrotactile stimuli (180, 280 and 380 Hz) delivered to the right index finger under two conditions with and without the acoustic feedback of the vibratory frequencies at 1.3 s after the tactile stimuli (T and TA tasks, respectively). In the 10 subjects, the TA task was more accurately performed (the error rate of 9.6%) than the T task (31.9%), which was accompanied by induction of co-activation of the SII and supratemporal auditory cortices in a late SEF-component (140–250 ms) and the SII response to the feedback sound in a late AEF-component (130– 280 ms). Such cross-modal activities were not observed in other 4 subjects showing small changes in the error rate between the two tasks (2.5%; T–TA). In contrast, even with the feedback sound just like the TA task, oddball tasks (280 vs. either of 180 or 380 Hz-vibration) to detect the deviance of stimuli rather than the vibrotactile frequencies induced no cross-modal cortical activity. These results suggest a ’binding’ of asynchronous somatosensory and auditory inputs to complement vibrotactile frequency information processing.

52. Modulation of event related desynchronization during motor imagery with transcranial direct current stimulation (tDCS) in patients with chronic hemiparetic stroke

Electroencephalogram-based brain–computer interface (BCI) has been developed as a new neurorehabilitative tool for patients with severe hemiparesis. However, its application has been limited because of difficulty detecting stable brain signals from the affected hemisphere. It has been reported that transcranial direct current stimulation (tDCS) can modulate event-related desynchronization (ERD) in healthy persons. The objective of this study was to test the hypothesis that anodal tDCS could modulate ERD in patients with severe hemiparetic stroke. The participants were six patients with chronic hemiparetic stroke (mean age, 56.8 ± 9.5 years; mean time from the onset, 70.0 ± 19.6 months; Fugl-Meyer Assessment upper extremity motor score, 30.8 ± 16.5). We applied anodal tDCS (10 min, 1 mA) and sham stimulation over the affected primary motor cortex in a random order. ERD of the mu rhythm (mu ERD) with motor imagery of extension of the affected finger was assessed before and after anodal tDCS and sham stimulation. Mu ERD of the affected hemisphere increased significantly after anodal tDCS, whereas it did not change after sham stimulation. Our results show that anodal tDCS can increase mu ERD in patients with hemiparetic stroke, indicating that anodal tDCS could be used as a conditioning tool for BCI in stroke patients.

P15-21 The effect of handedness on the modulation of mu rhythm desynchronization during motor imagery with transcranial direct current stimulation

patients and between the right GPi and VT in the hemi-dystonia patient during extension of the unaffected right wrist movements but not during attempted extension of the affected left wrist. A ~64 68 Hz gamma coherence was found between the cortex and the contralateral GPi in CD patients and between the cortex, right GPi and VT in the hemi-dystonia patient. The cortico-basal ganglia-thalamo-cortical circuit is active during preparation and execution of voluntary movements. Attenuation of 5 18 Hz coherence in the BG thalamic circuit may be associated with voluntary movements.

P06.4 Cortical modulation of the short-term plasticity of spinal reciprocal inhibition

respectively. There was no statistically significant difference in SSRI group in HRV parameters. Conclusions: Though rTMS and SSRI are effective antidepressants, their effect on HRV are different. rTMS modulates the cardiac autonomic tone towards increasing the parasympathetic activity and decreasing the sympathetic activity whereas SSRI did not modulate the neurocardiac regulation. Further studies with large sample size, biochemical and imaging studies would throw more light into the mechanism of such modulation.