Published papers

Because recovery of upper extremity (UE) functions to a practical level has been considered difficult in many patients with stroke, compensatory approaches have been emphasised. Recently, based on basic and clinical research indicating a greater potential for plastic changes in the brain, approaches directed toward functional restoration are becoming increasingly popular. Meta-analysis has indicated the effectiveness of constraint-induced movement therapy, electromyography biofeedback, electrostimulation, mental practice, and robot exercise to improve UE functions, but not hand functions. Therefore, we devised two new interventions to improve the paretic hand. One is hybrid assistive neuromuscular dynamic stimulation therapy, designed to facilitate daily use of the hemiparetic UE by combining electromyography (EMG)-triggered electrical stimulation with a wrist splint. We demonstrated improvement of motor function, spasticity, functional scores, and neurophysiologic parameters in chronic hemiparetic stroke. With a randomised controlled trial, we also demonstrated its effectiveness in subacute stroke. The other is brain-machine interface neurofeedback training, which provides real-time feedback based on analysis of volitionally decreased amplitudes of sensory motor rhythm during motor imagery involving extension of the affected fingers. This elicited new voluntary EMG activities, and improved finger functions and neurophysiological parameters. These interventions may offer powerful neurorehabilitative tools for improving hemiparetic UE function after stroke. © 2012 Hong Kong Physiotherapy Association Ltd.

Lower limb lymphedema is difficult to prevent and diagnose early because its natural history is unclear. Therefore, the aim of this study was to clarify its pathogenesis and to identify risk factors that may lead to early diagnosis. In 29 patients, aged 25 to 74 years with cervical, uterine, or ovarian cancer who underwent pelvic lymphadenectomy, indocyanine green fluorescence lymphangiography was performed with an infrared camera system, and lymph pumping pressure was measured indirectly preoperatively, and one, two, three, and six months postoperatively. Of these 29 patients, 22 (75.9%) completed the examinations. In the non-lymphedema group, the average lymph pumping pressure did not change significantly at postoperative follow-up compared with preoperative values. On the other hand, lymph pumping pressure increased at various time points in five patients who developed early lymphatic changes with dermal diffusion at the level of the proximal femur. An increase in lymph flow path resistance due to pelvic lymphadenectomy resulted in an initial increase in lymph pumping pressure, followed by a subsequent decrease, in the early lymphatic changes group. This trend in the pressure change signifies that the lymph vessels became dysfunctional as they were overwhelmed by the overload condition and this feature may be a clinically useful signal for the early diagnosis of developing lymphedema.

It is known that weak transcranial direct current stimulation (tDCS) induces persistent excitability changes in the cerebral cortex. There are, however, few studies that compare the after-effects of anodal versus cathodal tDCS in patients with stroke. This study assessed the after-effects of tDCS over the motor cortex in patients with hemiparetic stroke and healthy volunteers. Seven stroke patients and nine healthy volunteers were recruited. Ten minutes of anodal and cathodal tDCS (1 mA) and sham stimulation were applied to the affected primary motor cortex (M1) on different days. In healthy subjects, tDCS was applied to the right M1. Before and after tDCS, motor-evoked potentials (MEPs) in the first dorsal interosseous (FDI) muscle and silent period were measured. Anodal tDCS increased the MEPs of the affected FDI in patients with stroke as well as in healthy subjects. Cathodal tDCS increased the MEPs of the affected FDI in patients with stroke. In healthy subjects, however, cathodal tDCS decreased the MEPs. We found no significant change in the duration of the silent period after anodal or cathodal tDCS. We found that both anodal and cathodal tDCS increased the affected M1 excitability in patients with stroke. It is thought that the after-effects of tDCS are different in patients with stroke compared with healthy subjects. © 2012 Informa Healthcare USA, Inc.

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. © Springer-Verlag 2012.