The relationship between body sway patterns and motor and attentional functions in early childhood.

[Purpose] We focused on the relationship between body sway patterns and motor and attentional functions in early childhood, and classified diagrams of body sway into four patterns. Furthermore, the relationship between physical fitness tests and Interactive Metronome (IM) tasks was used to determine whether the body sway patterns are indicators of motor and attentional functions in early childhood. [Participants and Methods] Participants were 24 male and 26 female children with a mean age of 2,148.1 ± 103.7 days. Participants were evaluated using physical fitness tests, body sway measures, baseline scores on the IM task (the "task average"), and the percentage of perfect hits ("Super Right On") on the IM task (the "Super Right On" score, or SRO%). [Results] The association between the body sway pattern and motor and attentional functions was examined, and results revealed that the body sway pattern was only slightly associated with motor functions. However, participants with an anterior-posterior pattern of body sway had worse timing and attentional functions than participants with other patterns, as indicated by a lower task average and SRO% on the IM task. [Conclusion] These results suggested that anterior-posterior sway may reflect attentional functions when body sway is measured in children such as 6 year-olds.

Comparison of the effective intensity of transcutaneous electrical nerve stimulation contralateral to a pain site for analgesia.

[Purpose] This study aimed to compare the effectiveness of transcutaneous electrical nerve stimulation contralateral to the pain site for analgesia to identify the effective stimulation intensity. [Participants and Methods] Ten healthy adult females were recruited for the study. The same heat stimulation was applied to the left wrist joint of each participant to induce pain, serving as the control. Transcutaneous electrical nerve stimulation was then randomly administered to the right wrist, corresponding to the same dermatome contralateral to the painful site, at the intensities of comfortable stimulation, pain threshold, and maximum pain. The effect of transcutaneous electrical nerve stimulation was assessed using a Visual Analogue Scale and by analysis of heart rate variability. [Results] The Visual Analogue Scale score was significantly lower after stimulation with the maximum pain intensity than that for control, and there were no significant differences among the intensities of comfortable stimulation, pain threshold, and maximum pain. No significant differences were found among the groups in terms of high and low-to-high frequency components. [Conclusion] Transcutaneous electrical nerve stimulation at the maximum pain intensity to the dermatome area contralateral to that of the dorsal pain site of the left wrist was considered effective.

Comparison of the pain-relieving effects of transcutaneous electrical nerve stimulation applied at the same dermatome levels as the site of pain in the wrist joint.

[Purpose] The purpose of this study was to develop a proposal for an effective interventional option for therapeutic stimulation sites by comparing the pain-relieving effect of transcutaneous electrical nerve stimulation (TENS) applied to the same dermatome level of the contralateral sites of the dorsal wrist joint with the pain or the neck, or both sites simultaneously. [Subjects and Methods] A control was first established by triggering pain in the left dorsal wrist joints of adult females by using heat stimulation. Three interventions were then performed, comprising the TENS to the contralateral wrist joint (CW) and to the neck (N) at the same dermatome level as the site of pain, and the TENS to both CW and N simultaneously (CWN). Levels of pain and cerebral blood flow were also measured. [Results] The pain levels of three interventions were found to be significantly decreased compared with the control; however, no significant differences in the levels of pain were seen between any combinations of three interventions. Furthermore, no significant differences were seen between any interventions in terms of cerebral blood flow. [Conclusion] The results suggest that in order for TENS to be effective, it is necessary to make effective use of the dermatome.

Central neural mechanisms of interindividual difference in discomfort during sensorimotor incongruence in healthy volunteers: an experimental study.

OBJECTIVES: It has been reported that disturbance in sensory and motor function may induce sensorimotor incongruence and produce pain, discomfort and other sensations in healthy volunteers. One study suggested that sensorimotor incongruent information to healthy subjects results in increased neuronal activity in the posterior parietal cortex (PPC) and dorsolateral prefrontal cortex; however, this study did not take into consideration the discomfort induced by sensorimotor incongruence. The present study attempted to characterize intracortical electrical activities for sensorimotor incongruence in the frequency domain. In our study, electroencephalogram (EEG) cortical sources were compared between sensorimotor congruence and sensorimotor incongruence. In addition, high and no discomfort subgroups were compared during sensorimotor incongruence. METHODS: Eighteen healthy female subjects participated in this study. Subjects were then asked to flex/extend both arms in a congruent/incongruent manner while viewing a whiteboard/mirror. EEG was performed to determine the cortical activation during sensorimotor congruence and incongruence. RESULTS: Alpha band activity in the right posterior parietal cortex during sensorimotor incongruence was significantly lower than that of sensorimotor congruence. The source activities induced in the anterior cingulate cortex (ACC) beta band activity and the posterior cingulate cortex (PCC) alpha band activity significantly decreased in the high-discomfort vs the no-discomfort subgroup. CONCLUSION: The present findings suggest that the ACC and PCC are more activated in the high-discomfort subgroup than in the no-discomfort subgroup during sensorimotor incongruence. This method may evaluate the effectiveness of new medication therapy and/or rehabilitation by assessing the difference in the neuronal activity of chronic patients before and after treatment.

Associations of testosterone and cortisol concentrations with sleep quality in Japanese male workers.

Low testosterone concentrations are associated with disrupted sleep, and high levels of cortisol, which is elevated in response to stress, lead to insomnia. This study aimed to investigate the associations of testosterone and cortisol concentrations with sleep quality and to examine potential interactions between them in Japanese working men. This study was a cross-sectional design, and testosterone and cortisol concentrations in blood were the exposure variables and sleep parameters were the outcome variables. The Japanese version of the Pittsburgh Sleep Quality Index was used to measure sleep quality, and it included the total duration of sleep, time in bed (TIB), and sleep efficacy. We included 178 men (mean age = 49.1 years, standard deviation = 9.0) who completed all components in the questionnaire related to sleep and provided blood samples. Testosterone and cortisol concentrations were negatively associated with TIB (standardized beta = -0.15 and -0.24, p < 0.05, respectively), while only testosterone concentrations were positively associated with sleep efficacy (standardized beta = 0.15, p < 0.05). An interaction effect of testosterone and cortisol was significant for TIB and sleep efficacy (standardized beta for interaction term = 0.40, p < 0.001 and -0.22, p = 0.012, respectively). When stratified by cortisol concentrations, the associations between testosterone concentrations and sleep parameters were modified. Our findings suggest that associations between testosterone concentrations and sleep parameters are stronger at low cortisol concentrations, but not at high cortisol concentrations. High cortisol concentrations may diminish associations between low testosterone concentrations and diminished sleep efficacy.