No Impact of Stochastic Galvanic Vestibular Stimulation on Arterial Pressure and Heart Rate Variability in the Elderly Population.

OBJECTIVE: Noisy galvanic vestibular stimulation (nGVS) is often used to improve postural stability in disorders, such as neurorehabilitation montage. For the safe use of nGVS, we investigated whether arterial pressure (AP) and heart rate vary during static supine and slow whole-body tilt with random nGVS (0.4 mA, 0.1-640 Hz, gaussian distribution) in a healthy elderly population. METHODS: This study was conducted with a double-blind, sham-controlled, cross-over design. Seventeen healthy older adults were recruited. They were asked to maintain a static supine position on a bed for 10 min, and the bed was tilted up (TU) to 70 degrees within 30 s. After maintaining this position for 3 min, the bed was passively tilted down (TD) within 30 s. Real-nGVS or sham-nGVS was applied from 4 to 15 min. The time course of mean arterial pressure (MAP) and RR interval variability (RRIV) were analyzed to estimate the autonomic nervous activity. RESULT: nGVS and/or time, including pre-/post-event (nGVS-start, TU, and TD), had no impact on MAP and RRIV-related parameters. Further, there was no evidence supporting the argument that nGVS induces pain, vertigo/dizziness, and uncomfortable feeling. CONCLUSION: nGVS may not affect the AP and RRIV during static position and whole-body tilting or cause pain, vertigo/dizziness, and discomfort in the elderly.

Cardiac Autonomic Nervous System Activity during Slow Breathing in Supine Position.

The purpose of this study is to clarify cardiac autonomic nervous system activity during slow breathing exercises in a supine position. Eighteen healthy young males were participated. Heart rate variability was measured for 5 minutes at rest, 5 minutes at slow breathing, and then 5 minutes at rest. As a result, the LF/HF ratio increased with slow breathing, but HF value did not change. We suggest that the increased LF/HF ratio may be due to increased airway resistance. Cardiac autonomic nervous system activity during slow breathing in the supine position was revealed.

Effectiveness of Moderate Intensity Interval Training as an Index of Autonomic Nervous Activity.

The purpose of this study was to examine the effects of moderate intensity interval training from the change of the autonomic nervous activity. Ten male volunteers aged 21-22 years were studied. After 10-minute rest in a seated position, the subjects were asked to perform the strength of moderate cycling exercise in ergometer. Cycling rate was done in 50 times/min. Load resistance of the ergometer was set to 2.0 kgm. Subjects paused the exercise when the heart rate becomes 120 beats/min. Subjects have resumed the exercise when the heart rate returns to the value at rest. This trial was repeated twice. The experiment was ended when the heart rate of the subjects has returned to resting level. When the heart rate during exercise is maintained to less than 120 beats/min, sympathetic nerve activity during exercise did not work actively compared to the baseline. Vagus nerve activity after exercise cessation exceeds the baseline. It is clarified that the exercise as well as activating the vagus nerve activity stimulates the total autonomic nervous activity. It has revealed that at the time of interval training at moderate load the vagus nerve activity can be carried out.

Effect of a cognitive task during obstacle crossing in hemiparetic stroke patients.

Stroke patients are at a higher risk of falling than the community-dwelling elderly, and many falls are due to contact with an obstacle. This study compared the effects of the simultaneous addition of a cognitive task during obstacle crossing between stroke patients and community-dwelling older adults (control subjects). Participants comprised 20 stroke patients who could walk with or without supervision and 20 control subjects matched for age and height with the stroke patients. Participants were asked to cross a 4-cm-high obstacle while walking at a self-selected speed. The number of failures and the spatial and temporal parameters were compared between a single-task condition (i.e., crossing task only) and a dual-task condition (i.e., verbal fluency task: listing vegetables or animals). Under the dual-task condition, six stroke patients (30%) and three community-dwelling elderly individuals (15%) failed to complete the motor task. Task failure was only due to heel-obstacle contact after toe clearance. In both groups, obstacle-heel distance after clearance was reduced, and the time from heel contact to toe clearance and stride time were significantly increased under dual-task condition versus single-task condition. In addition, group-task interaction for the time from heel contact to toe clearance of the obstacle was significant; this increase in time was significantly greater under dual-task condition in stroke patients than in control subjects. Obstacle crossing in stroke patients involved an increase in crossing performance time and a risk of heel-obstacle contact after crossing. These tendencies appeared stronger under the dual-task condition.

Abnormalities of the first three steps of gait initiation in patients with Parkinson's disease with freezing of gait.

The purpose of this study was to investigate abnormalities of the first three steps of gait initiation in patients with Parkinson's disease (PD) with freezing of gait (FOG). Ten PD patients with FOG and 10 age-matched healthy controls performed self-generated gait initiation. The center of pressure (COP), heel contact positions, and spatiotemporal parameters were estimated from the vertical pressures on the surface of the force platform. The initial swing side of gait initiation was consistent among the trials in healthy controls but not among the trials in PD patients. The COP and the heel contact position deviated to the initial swing side during the first step, and the COP passed medial to each heel contact position during the first two steps in PD patients. Medial deviation of the COP from the first heel contact position had significant correlation with FOG questionnaire item 5. These findings indicate that weight shifting between the legs is abnormal and that medial deviation of the COP from the first heel contact position sensitively reflects the severity of FOG during the first three steps of gait initiation in PD patients with FOG.

Variable initial swing side and prolonged double limb support represent abnormalities of the first three steps of gait initiation in patients with Parkinson's disease with freezing of gait.

This study investigated abnormalities of the first three steps of gait initiation in patients with Parkinson's disease without freezing of gait (PD - FOG) and investigated which abnormalities are related to FOG. Seven PD - FOG and seven age-matched healthy controls performed self-generated or cue-triggered gait initiation. Data for PD patients with FOG (PD + FOG) were cited from a previous study using a procedure similar to that used in the present study. Gait initiation was abnormal, and external cue normalized some abnormalities in PD - FOG. The initial swing side was fairly consistent among the trials in both PD - FOG and in healthy controls, although the initial swing side was inconsistent in PD + FOG. The duration of the first double limb support (DLS) was the only parameter that depends on FOG severity and that was abnormal in PD + FOG but was not abnormal in PD - FOG. The variability of the initial swing side and prolonged first DLS are abnormalities specifically related to FOG.

Effects of ultrasound therapy on calcificated tendinitis of the shoulder.

In general, surgery is recommended for calcificated tendinitis of the shoulder if the patients have symptoms after conservative treatments, including needle aspiration and physical therapy. Many researchers agree about the need for adequate physical therapy consisting of range of motion exercise, muscle strengthening exercises and electrophysical agents. Some researchers report that ultrasound (u/s) promotes angiogenesis and calcium uptake to fibroblasts, but there are few studies about u/s effects on calcificated tendinitis of the shoulder. The purpose of this study was to evaluate the u/s therapy effect on calcification, pain during active movement, and to identify factors related to improvement in a randomized controlled fashion. We used the stratified random allocation method to assign 40 consecutive patients to experimental and control groups, so each group consisted of 20 patients. The experimental group was treated by u/s therapy and therapeutic exercises, and the control group was treated with therapeutic exercises only. All patients in both groups came to our department 3 times per week and u/s therapy was performed 3 times per week until the end of the study. First, we classified the calcifications as type I (clearly circumscribed and with dense appearance on radiography), type II (dense or clearly circumscribed appearance) and type III (translucent or cloudy appearance without clear circumscription) according to the classification of Gartner and Heyer. Radiography was performed every one month, and the main outcome measure was the change from the base-line of the calcification on radiography at the end of the treatment. The three point scale of Gartner and Heyer was used, in which a score of 1 indicates no change or a worsening of the condition, a score of 2 a decrease of at least 50 percent in the area and density of the calcification, and a score of 3 a complete resolution of the calcification. We also examined the affected shoulders for presence or absence of pain in active movement at the start and at the end of the study. The calcifications improved significantly and fewer patients had pain during active movement in the experimental group. There was a statistical significant disease duration difference from the first clinical presentation between scores 2 and 3 in the experimental group. The results of this study suggest that u/s therapy helps to resolve calcifications of shorter disease duration. Calcifications of longer disease duration tended to persist in spite of u/s therapy, but we thought treatment of 27-38 times (95% CI), until score 2 was attained, was a desirable strategy.