Effect of Salivation by Facial Somatosensory Stimuli of Facial Massage and Vibrotactile Apparatus

We studied the effects of salivary promotion of fluid secretion after hand massage, and the apparatus of vibrotactile stimulation (89 Hz frequency, 15 min) in normal humans. Personal massage cannot be performed on handicap and stroke patients, and then giving hand massage to them for 5 min massage gives a tired feeling. So, we focused 3 min stranger massage. Salivary glands can discharge the accumulated saliva by extrusion from the acinus glands’ massages as described in the recent Japanese textbook. We think that this method may not produce realistic recovery. Our aim ideas are to relieve stress and increase temperature with lightly touch massage of the skin and for a 1 cycle of 1 s. We recorded RR interval of ECG, total salivation, facial skin temperature, OxyHb of fNIRS on the frontal cortex, and amylase activity for the autonomic changes. In increased 2°C of the facial skin temperature, the hand massage had a need for 3 min and the vibrotactile stimulation for 15 min. Increase from 700 to 1000 ms of RR intervals had a need for 3 min in the hand massage and had 15 min in the vibrotactile stimulation. Although vibrotactile stimulation needs long time of 4–7 years as effective recovery, hand massage may have more effect with a repetition of day after day

Salivary Effects of Facial Vibrotactile Stimulation in Patients with Sjogren’s Syndrome and Poor Salivation

We examined the effect of vibrotactile apparatus in patients with Sjögren’s syndrome and others with reduced salivation in comparison to normal subjects. The most effective salivation in normal subjects was produced by 89 Hz vibrotactile stimulation with 9.8 μm amplitude on the parotid or submandibular glands vibrotactile stimuli. First, we examined by measuring the weight of dental cotton rolls positioned at the opening of the secretory duct for total salivation 3 min during resting, and then after 5-min intervals, the weights were measured every 3 min of vibrotactile stimulation on salivary glands. Furthermore, we measured facial temperature around vibrators after 2 min of vibration. We investigated 10 poor salivation patients with Sjögren’s syndrome (8 patients) defined by examinations (contrast study or scintigraphic test) and others (2 patients). About 50% of patients with poor salivation gained recognition for good results, although they had periods of short-term (3 months) and long-term effects (6–7 years) during recuperation. Furthermore, facial skin temperatures on both sides of parotid glands were decreased in Sjogren’s syndrome after vibration, although their temperatures were increased following recovery. Although the mechanism is not clear, we think that vibrotactile stimulation gives activation to salivary glands under the rising facial temperature

A Machine Learning-Based Screening Test for Sarcopenic Dysphagia Using Image Recognition

Background: Sarcopenic dysphagia, a swallowing disorder caused by sarcopenia, is prevalent in older patients and can cause malnutrition and aspiration pneumonia. This study aimed to develop a simple screening test using image recognition with a low risk of droplet transmission for sarcopenic dysphagia. Methods: Older patients admitted to a post-acute care hospital were enrolled in this cross-sectional study. As a main variable for the development of a screening test, we photographed the anterior neck to analyze the image features of sarcopenic dysphagia. The studied image features included the pixel values and the number of feature points. We constructed screening models using the image features, age, sex, and body mass index. The prediction performance of each model was investigated. Results: A total of 308 patients participated, including 175 (56.82%) patients without dysphagia and 133 (43.18%) with sarcopenic dysphagia. The area under the receiver operating characteristic curve (ROC-AUC), sensitivity, specificity, positive predictive value, negative predictive value, and area under the precision-recall curve (PR-AUC) values of the best model were 0.877, 87.50%, 76.67%, 66.67%, 92.00%, and 0.838, respectively. The model with image features alone showed an ROC-AUC of 0.814 and PR-AUC of 0.726. Conclusions: The screening test for sarcopenic dysphagia using image recognition of neck appearance had high prediction performance

Association of Oral Function and Dysphagia with Frailty and Sarcopenia in Community-Dwelling Older Adults: A Systematic Review and Meta-Analysis

Studies investigating the associations of oral function and dysphagia with frailty and sarcopenia in community-dwelling older adults are increasing; however, they have not been systematically summarized. We conducted a systematic review to investigate these associations. We searched electronic databases and synthesized relevant data using conventional (frequentist-style) and Bayesian meta-analyses. Twenty-four studies were found to be eligible for our review, including 20 cross-sectional and four prospective cohort studies. Older adults with frailty or sarcopenia had lower tongue pressure, according to the results of conventional meta-analysis (mean difference [95% confidence interval or credible interval]: −6.80 kPa [−10.22 to −3.38] for frailty and −5.40 kPa [−6.62 to −4.17] for sarcopenia) and Bayesian meta-analysis (−6.90 kPa [−9.0 to −4.8] for frailty, −5.35 kPa [−6.78 to −3.89] for sarcopenia). People with frailty had a higher odds ratio (OR) for dysphagia according to the results of conventional meta-analysis (3.99 [2.17 to 7.32]) and Bayesian meta-analysis (1.38 [0.77 to 1.98]). However, the results were inconclusive for people with sarcopenia. A prospective association could not be determined because of the lack of information and the limited number of studies. Decreased oral function and dysphagia can be important characteristics of frailty and sarcopenia in community-dwelling older adults

Facial Vibrotactile Stimulation Activates the Parasympathetic Nervous System: Study of Salivary Secretion, Heart Rate, Pupillary Reflex, and Functional Near-Infrared Spectroscopy Activity

We previously found that the greatest salivation response in healthy human subjects is produced by facial vibrotactile stimulation of 89 Hz frequency with 1.9 μm amplitude (89 Hz-S), as reported by Hiraba et al. (2012, 20011, and 2008). We assessed relationships between the blood flow to brain via functional near-infrared spectroscopy (fNIRS) in the frontal cortex and autonomic parameters. We used the heart rate (HRV: heart rate variability analysis in RR intervals), pupil reflex, and salivation as parameters, but the interrelation between each parameter and fNIRS measures remains unknown. We were to investigate the relationship in response to established paradigms using simultaneously each parameter-fNIRS recording in healthy human subjects. Analysis of fNIRS was examined by a comparison of various values between before and after various stimuli (89 Hz-S, 114 Hz-S, listen to classic music, and “Ahh” vocalization). We confirmed that vibrotactile stimulation (89 Hz) of the parotid glands led to the greatest salivation, greatest increase in heart rate variability, and the most constricted pupils. Furthermore, there were almost no detectable differences between fNIRS during 89 Hz-S and fNIRS during listening to classical music of fans. Thus, vibrotactile stimulation of 89 Hz seems to evoke parasympathetic activity