Cervical percutaneous interferential current stimulation improves citric acid cough tests in patients with Parkinson's disease on medication.

Aspiration pneumonia is the leading cause of death in patients with Parkinson's disease. The incidence of silent aspiration is high in such patients owing to decreased pharyngeal and laryngeal sensation; thus, interventions for this condition may help prevent pneumonia. In this single-arm, open-label study, we used a cervical percutaneous interferential current stimulation device to activate pharyngeal and laryngeal sensory nerves. We evaluated its effectiveness in patients with Hoehn-Yahr stages 2-4 Parkinson's disease. The primary endpoint was the proportion of patients with a normal cough reflex after consuming 1% citric acid at the end of the intervention compared with baseline measurements. In total, 25 patients received neck percutaneous interferential current stimulation for 20 min twice weekly for 8 weeks. Afterward, the proportion of patients with a normal cough reflex after 1% citric acid consumption increased significantly (p = 0.001), whereas other indicators, such as tongue pressure, peak expiratory flow, and penetration or aspiration during videofluoroscopic examination, remained unchanged. A longer duration of illness, higher Unified Parkinson's Disease Rating Scale total scores, and higher levodopa equivalent daily doses were significantly associated with improved cough test outcomes. Hence, cervical percutaneous interferential current stimulation significantly improved cough reflexes and may improve silent aspiration. Trial Registration: Japan Registry of Clinical Trials, jRCTs062220013, first registered 09/05/2022.

Association between motor symptoms of Parkinson's disease and swallowing disorders.

BACKGROUND: Parkinson's disease (PD) presents with motor symptoms that hinder physical activity. This study aimed to thoroughly investigate swallowing dysfunction in patients with PD using videofluoroscopy (VF) and the Movement Disorder Society (MDS)-Unified PD Rating Scale (UPDRS) sub-scores. METHODS: This study was part of an intervention project to evaluate the effectiveness of cervical percutaneous interferential current stimulation in patients with Hoehn and Yahr stages 2-4 PD. Baseline data, including swallowing-related indicators such as VF, were obtained and compared to the MDS-UPDRS sub-scores including rigidity, tremor, postural instability/gait difficulty, and limb scores. RESULTS: Twenty-seven patients were included in this study. In the VF analysis, laryngeal penetration/aspiration, oral cavity residue, epiglottic vallecular residue, and pharyngeal residue were observed with remarkable frequency. The multivariate analysis revealed that the mean rigidity score of UPDRS was an independent and significantly correlated factor with laryngeal penetration/aspiration during the ingestion of 10 mL of water (odds ratio 1.294, 95% confidence interval 1.035-1.617; p = 0.024). CONCLUSION: This study revealed a correlation between muscle rigidity and laryngeal penetration or aspiration risk. The detailed comparative analysis of various individual PD symptoms and swallowing disorders was substantial, which enabled early detection of the risk of swallowing disorder and the implementation of appropriate measures. TRIAL REGISTRATION NUMBER: jRCTs062220013.

Low tongue pressure and depression using Kihon Checklist for assessing frailty status among community-dwelling Japanese older adults: A pilot study.

BACKGROUND: Evaluation of low tongue pressure is used to diagnose oral hypofunction. The pathophysiology of oral hypofunction is hypothesized to be associated with oral dysfunction related to ageing. Depression in older adults is a major problem and is related to handgrip strength, which is related to tongue pressure. We hypothesized that low tongue pressure could indicate depression mood in community-dwelling older adults. OBJECTIVES: This study aimed to measure maximum tongue pressure and compare it to the responses to the Kihon Checklist (KCL), which is used to check mental and physical deterioration of community-dwelling older adults. METHODS: A total of 49 community-dwelling independent older adults with stable dental condition (23 men, 26 women; median age, 79 years) answered the KCL, which contained questions on frailty status, cognitive function, nutritional and sarcopenia status. Oral function was measured to assess oral hypofunction. The relationship between tongue pressure differences and frailty status, cognitive function, nutritional and sarcopenia status was analysed using logistic regression analyses after adjusting for age and sex. RESULTS: Nine participants (6 men and 3 women; median age, 81 years) had a tongue pressure <23.0 kPa, which was the lowest limit of the standard value of maximum tongue pressure in patients aged ≥70 years. Logistic regression analyses showed that only Question 21, which is related to a lack of fulfilment in daily life, was significantly associated with low tongue pressure (p = .027). CONCLUSION: Low tongue pressure may be associated with sociopsychological factors in older adults.

Detailed findings of videofluoroscopic examination among patients with Parkinson's disease on the effect of cervical percutaneous interferential current stimulation.

Introduction: Parkinson's disease (PD) leads to various types of swallowing disorders. We investigated the effect of cervical percutaneous interferential current stimulation on dysphagia. By conducting detailed qualitative and quantitative analysis of videofluoroscopic examination, we aimed to understand dysphagia in patients with PD and investigate its effects on swallowing function. Methods: Patients received cervical percutaneous interferential current stimulation for 20 min twice a week for 8 weeks. In this exploratory study, we evaluated aspiration/laryngeal penetration, oral cavity residue, vallecular residue, and pharyngeal residue. In addition, we performed temporal analysis. Results: Twenty-five patients were completely evaluated. At baseline, the proportions of laryngeal penetration/aspiration, oral cavity residue, epiglottic vallecula residue, and pharyngeal residue were 40.0, 88.0, 72.0, 60.0, and 16.0%, respectively. Conversely, pharyngeal transit time, laryngeal elevation delay time, pharyngeal delay time, and swallowing reflex delay were nearly within the normal ranges. Cervical percutaneous interferential current sensory stimulation improved only oral cavity residue at the end of the intervention, from 88.0 to 56.0%. Discussion: Patients with PD demonstrated remarkably high frequencies of residues in the oral and pharyngeal regions. The usefulness of cervical interferential current stimulation was partially demonstrated for oral cavity residue. Considering that PD exhibits diverse symptoms, further accumulation of cases and knowledge is warranted. Trial registration: jRCTs062220013.

Swallowing sound index analysis using electronic stethoscope and artificial intelligence for patients with Parkinson's disease.

BACKGROUND AND PURPOSE: Several noninvasive tools assess swallowing disorders, including electronic stethoscope artificial intelligence (AI) analysis for remote diagnosis, with the potential for telemedicine. This study investigated the swallowing sound index in patients with Parkinson's disease (PD). METHODS: This single-arm, open-label trial assessed the impact of cervical percutaneous interferential current stimulation on swallowing in patients with PD classified as Hoehn-Yahr stages 2-4. Stimulation was conducted for 8 weeks. Baseline data were used to examine the link between the swallowing sound index and indicators such as videofluoroscopy (VF). Furthermore, we examined changes in the swallowing sound index after the intervention. RESULTS: Twenty-five patients were included. The swallowing sound index in patients with PD was higher than that in those with amyotrophic lateral sclerosis but considerably lower than that in healthy controls. The number of patients with normal EAT-10 scores positively correlated with the swallowing sound index, whereas elevated C-reactive protein levels were negatively correlated with the swallowing sound index. However, the index displayed no correlation with other indicators, including the VF results. Despite the intervention, the index remained unchanged throughout the study. CONCLUSION: In patients with PD, a decrease in the swallowing sound index suggests a potential association between swallowing disorders and the risk of aspiration pneumonia. TRIAL REGISTRATION NUMBER: jRCTs062220013.

Impact of neck percutaneous interferential current sensory stimulation on swallowing function in patients with Parkinson's disease: A single-arm, open-label study protocol.

Background: Parkinson's disease (PD) can lead to swallowing dysfunction, resulting in aspiration pneumonia. Among the types of swallowing disorders, a characteristic and serious problem associated with PD is silent aspiration due to pharyngeal and laryngeal hypoesthesia. Methods: This single-arm, open-label study aims to evaluate the effectiveness of percutaneous neck interferential current sensory stimulation in enhancing swallowing function in patients with PD. The efficacy and safety of percutaneous neck interferential current sensory stimulation will be investigated for patients diagnosed with PD, based on the Movement Disorder Society criteria, of Hoehn-Yahr stages 2-4. The patients will receive neck percutaneous interferential current sensory stimulation for 20 min twice a week for 8 weeks using a Gentle Stim® (FoodCare Co., Ltd., Kanagawa, Japan) device. Once the intervention is initiated, evaluations will be performed every 4 weeks for a 16-week period. The primary endpoint to be assessed is the proportion of patients with normal cough with 1% citric acid at the end of the intervention (8 weeks after intervention initiation) compared with that at the beginning. This clinical trial will examine the usefulness of percutaneous neck interferential current sensory stimulation in patients with PD. In addition, this study will use novel instruments, such as multichannel surface electromyography and electronic stethoscope, to evaluate swallowing function. Discussion: This novel evaluation can provide insights into dysphagia in patients with PD and the usefulness of percutaneous neck interferential current stimulation. This exploratory study is limited by its single-arm, open-label design and small size. Trial registration number: jRCTs062220013; pre-results.

Proapoptotic effect of nonthermal pulsed ultrasound on prostate cancer cells in a nude mouse model.

BACKGROUND: Ultrasound (US) can induce cell injury, and we have previously reported that adjusting the pulse repetition frequency (PRF) of ultrasound output can induce prostate cancer cell destruction without causing a rise in the temperature of the irradiated area. In this study, we examined the mechanism of nonthermal ultrasound cell destruction, which was not fully clarified in our previous reports. METHODS: In vitro, we evaluated postirradiation cells immediately after treatment and examined membrane disruption by proliferation assay, LDH assay, and apoptosis assay. In vivo, we injected mice with human LNCaP and PC-3 prostate cancer cells and evaluated the therapeutic effects of US irradiation by H-E staining and immunostaining. RESULTS: Proliferation assays showed inhibition at 3 h postirradiation independently of PRF and cell line (p < 0.05). Quantitative assessment of apoptosis/necrosis by flow cytometry showed widely varying results depending on cell type. LNCaP showed an increase in late apoptosis at 0 h independent of PRF (p < 0.05), while PC-3 showed no significant difference at 0 h. The LDH assay showed an increase in LDH independent of PRF in LNCaP (p < 0.05 respectively), but no significant difference in PC-3. In vivo, tumor volume was compared and a significant reduction was observed at 10 Hz for LNCaP (p < 0.05) and 100 Hz for PC-3 (p < 0.001) at 3 weeks after the start of irradiation. The excised tumors were evaluated with Ki-67, Caspase-3, and CD-31 and showed a significant treatment effect independent of cell type and PRF (p < 0.001 respectively). CONCLUSION: Examining the mechanism behind the therapeutic effect of US irradiation revealed that the main effect was achieved by apoptosis induction rather than necrosis.

Combined Treatment with Ultrasound and Immune Checkpoint Inhibitors for Prostate Cancer.

Background: Ultrasound (US) is mostly used for diagnostic purpose but could be used for cancer treatments with a US intensity or frequency fitted to such a purpose. Prostate cancer (PC) has the highest prevalence in the urological field, but indications for immune checkpoint inhibitors (ICIs) for PC are limited to very few cases. In this study, we compared the antitumor effect of US irradiation alone with the combined use of US and ICIs in vitro and in vivo. Methods: PC cell line TRAMP-C2 cells were used in our experiments. TRAMP-C2 cells were irradiated with US with pulse repeated frequencies (PRF) of 1, 10, and 100 Hz. Cell proliferation was evaluated by MTS assay and apoptotic cells were analyzed using flow cytometry. To verify the antitumor effect of US irradiation on PC in vivo, we conducted animal experiments using mice. TRAMP-C2-bearing mice were irradiated with US with PRF of 10 and 100 Hz. Three weeks after the start of US irradiation, anti-PD-1 antibody was administered to the mice. Finally, mice were sacrificed and tumors were collected. Immunohistochemical (IHC) analyses were assessed for cleaved caspase-3 and CD3 in tumor cell extracts. Results: Cell proliferation assays showed that 1 and 10 Hz US significantly inhibited cell survival (p < 0.0001). In addition, US irradiation induced apoptosis at 1, 10, and 100 Hz (p = 0.0129, p = 0.0150, and p = 0.0017, respectively). In animal experiments, a significant tumor growth inhibitory effect was observed at 10 and 100 Hz, and 100 Hz + ICIs (p < 0.05, respectively). Hematoxylin−eosin (H−E) staining showed a significant increase in the necrotic area of the tumor at 100 Hz and 100 Hz + ICIs (p < 0.05, respectively). In addition, under IHC staining the expression level of cleaved caspase-3 and the number of CD3-positive cells increased at 100 Hz (p < 0.05, respectively). Conclusion: US irradiation induced apoptosis in cells and reduced cell viability. In vivo tumor growth was suppressed by combined treatment with US irradiation and ICIs. Further research on immune system activation will lead to less invasive and more efficient treatments for PC.

Relationship between Food Crushing and Oral Function in Older Adults Requiring Nursing Home Care: A Pilot Study.

We investigated how jelly is crushed and examined the relationship between tongue pressure and tongue food crushing ability among older adults requiring nursing home care. Seventy-two participants were instructed to freely crush the test foods soft jelly (SJ) and hard jelly (HJ). We visually evaluated the crushability of the test food and identified the intraoral tissues (active sites) used to crush the test food. The active sites were consistent for all participants for both SJ and HJ, and they included the maxillary and mandibular teeth in 41 participants, teeth and residual ridges in 15 participants, maxillary and mandibular residual ridges in 10 participants, and tongue and palate in six participants. Two participants failed to crush the SJ; the active sites in both participants were the tongue and palate. No participant using the tongue and palate as active sites could crush the HJ. Furthermore, 64 participants could crush the SJ and 23 could crush the HJ using the tongue and palate. The cutoff value of the tongue pressure for crushability of the HJ was 22.0 kPa. Assessing tongue pressure and intraoral active sites involved in food crushing could help determine an appropriate diet for older adults requiring nursing home care.

Oral hypofunction and its relation to frailty and sarcopenia in community-dwelling older people.

OBJECTIVE: The purpose of this study was to examine the frequency of oral hypofunction in community-dwelling older people and determine its relationship with frailty and sarcopenia. BACKGROUND: Previous studies have shown that frailty and sarcopenia are associated with decreased oral function. However, these studies have only evaluated frailty or sarcopenia alone and have not evaluated their relationship with each other. MATERIALS AND METHODS: The participants were community-dwelling independent older people in Kyoto. Their oral function evaluation included seven items (oral hygiene, oral dryness, occlusal force, tongue-lip motor function, tongue pressure, masticatory function and swallowing function). Oral hypofunction was defined as abnormalities in at least three of these items. The frailty status was classified into three categories (robust, pre-frail and frail) according to the frailty phenotype and deficit-accumulation models. Sarcopenia was defined according to the Asian Working Group for Sarcopenia (AWGS) Consensus. The relationships between oral function and frailty were analysed using logistic regression analyses, after adjusting for sarcopenia. RESULTS: Among the 340 participants that were analysed (69 men, 271 women; average age: 75.0 years), 182 (53.5%) had oral hypofunction (40 men, 142 women; average age: 76.8 years). There was a significant relationship between oral hypofunction and deficit-accumulation model-assessed frailty, after adjusting for sarcopenia. CONCLUSION: Almost half of the community-dwelling older people have oral hypofunction, which is significantly related to comprehensive frailty and sarcopenia.

Comparison of the Iowa Oral Performance Instrument and JMS tongue pressure measurement device.

BACKGROUND/PURPOSE: Tongue pressure measurement conveys important information about eating and swallowing function. The Iowa Oral Performance Instrument® (IOPI) and KAY Swallowing Workstation® are internationally used for tongue pressure measurement, but for legal reasons cannot be used in Japan; rather the JMS tongue pressure measurement device® has been approved for use in Japan. However, it is not clear whether measurement obtained with these devices are directly comparable. MATERIALS AND METHODS: This study investigated the correlation between the maximum tongue pressure data measured by the IOPI and the JMS tongue pressure measurement device in young healthy participants (34 males; 23.2 ±â€¯2.0 years old, and 40 females; 21.4 ±â€¯1.3 years old). RESULTS: Measurements obtained with these two devices showed significant correlations in the total cohort, and in male and female participants, separately (P < 0.05). CONCLUSION: These findings demonstrate that the measurements obtained with the JMS device is comparable to those obtained with the IOPI. In Japan, JMS tongue pressure measurement device is used not only in dysphagia research field, but also geriatrics field, and extensive and detailed investigations has been carried out.

Improper sitting posture while eating adversely affects maximum tongue pressure.

BACKGROUND/PURPOSE: Although many studies have examined the efficacy of neck and trunk positioning during eating, few studies have examined how the positioning of the lower extremities affects swallowing function. The purpose of this study was to examine how tongue pressure, which is an important factor during swallowing, is affected by eating postures in bed and wheelchair. MATERIALS AND METHODS: A total of 43 healthy adults (13 men and 30 women; 29.0 ±â€¯5.9 years) and 33 elderly individuals requiring long-term care (14 men and 19 women; 83.6 ±â€¯7.8 years) participated.In both healthy and elderly participants, tongue pressure was measured in four different postures: a good and poor postures in bed (postures 1 and 2, respectively), and a good and poor postures in a reclining wheelchair (posture 3 and 4, respectively). RESULTS: Among the healthy participants, the mean tongue pressure was significantly higher in posture 1 (40.2 ±â€¯7.24 kPa) than in posture 2 (37.6 ±â€¯8.68 kPa) or posture 4 (38.2 ±â€¯8.14 kPa) (P < 0.05). Tongue pressure was also significantly higher in posture 3 (41.3 ±â€¯7.75 kPa) than in either posture 2 or 4 (P < 0.05).Among the elderly participants, the median tongue pressure in posture 1 (16.9 kPa; interquartile range [IQR], 9.4-21.6 kPa) was significantly higher than that in posture 2 (14.1 kPa; IQR, 9.2-21.6 kPa). Tongue pressure in posture 3 (18.5 kPa; IQR, 14.2-26.0 kPa) was significantly higher than that in either posture 1 or 2, and posture 4 (15.9 kPa; IQR, 10.6-22.9 kPa). CONCLUSION: Posture during eating can potentially affect tongue pressure.

Five-year change in maximum tongue pressure and physical function in community-dwelling elderly adults.

BACKGROUND/PURPOSE: To identify age-related changes in maximum tongue pressure (MTP), it is necessary to determine individual biological age. The fitness age score (FAS) is used to calculate the biological age, based on the one-leg standing time with eyes open, vertical jump height, grip strength, functional reach, and 10-m walk time. MATERIALS AND METHODS: The study included 112 community-dwelling elderly adults (42 males and 70 females). We investigated MTP, FAS, and body mass index (BMI) at baseline and 5 years later. MTP was determined with a pressure measurement device. RESULTS: A significant reduction in MTP, FAS, and BMI in both male and female subjects was observed at 5 years. A negative correlation between change in MTP and baseline MTP was observed, but there was no correlation between MTP change and baseline FAS, BMI, and change in FAS and BMI. CONCLUSION: Age-related decline in MTP might be associated with high MTP, reflecting decreased reserve. Additionally, age-related decline in tongue function might be different from that of physical function.

Association between buccal mucosa ridging and oral or occlusal status among older people.

OBJECTIVES: This study aimed to evaluate the association between buccal mucosa ridging and oral or occlusal statuses among older people. SUBJECTS AND METHODS: This cross-sectional study examined 262 independent older people (mean age, 74.2 ± 5.9 years) who participated in the Kyoto Elderly Physical Fitness Measurement Research Project. The predictor variables were oral statuses (number of present teeth and torus palatinus, torus mandibularis, temporomandibular joint noise, clenching, or grinding) and oral functions (occlusal pressure, cheek pressure, oral diadochokinesis, and tongue pressure). The outcome variable was the buccal mucosa ridging status (presence or absence). Additional variables were age, sex, body mass index, grip strength, and wearing dentures. We compared these variables between participants with and without buccal mucosa ridging using a univariate analysis and multiple logistic regression analysis. RESULTS: Buccal mucosa ridging was present in 177 (67.6%) people. Multiple logistic regression analysis revealed a close association of buccal mucosa ridging with torus mandibularis, tooth clenching and grinding and occlusal pressure, and cheek pressure. CONCLUSIONS: Over 50% of the participants showed buccal mucosa ridging; this was significantly associated with higher cheek pressure, lower occlusal pressure, torus mandibularis, and tooth clenching and grinding.

Maximum Tongue Pressure is Associated with Swallowing Dysfunction in ALS Patients.

Maximum tongue pressure (MTP) measurement is a convenient, less invasive assessment that has been developed to quantify tongue strength; however, it is unclear whether MTP is useful for the detection of swallowing disorders in amyotrophic lateral sclerosis (ALS) patients. The purpose of this study was to clarify the relationship between MTP and the characteristics of swallowing disorders on videofluorography and to determine the usefulness of tongue pressure measurement for the assessment of swallowing function in ALS patients. Twenty-five ALS patients were evaluated according to the ALS functional rating scale-revised (ALSFRS-R), and their ability to swallow yogurt was observed via videofluorography. MTP was measured using a device (TPM-01, JMS, Hiroshima) equipped with a balloon probe. Then, the relationships between the ALSFRS-R score, swallowing function, and MTP were analyzed. MTP was significantly lower in the subjects with reduced tongue function (p = 0.002) or with pharyngeal residue (p = 0.006) than in the subjects with normal characteristics. Bolus formation and oral transit time and pharyngeal transit time were significantly prolonged among those with reduced MTP. MTP at a cut-off value of 21.0 kPa was associated with a full score on the bulbar-related items of the ALSFRS-R. MTP may serve as a new diagnostic tool for the early detection of swallowing dysfunction in ALS patients, because of its good relationship with their swallowing characteristics.

Development of a candy-sucking test for evaluating oral function in elderly patients with dementia: A pilot study.

AIM: To maintain oral intake in elderly patients with dementia, it is important to evaluate their oral function. However, these patients often have difficulties following instructions during oral function tests, especially with the progression of dementia. The task of sucking a lollipop candy is simple for elderly patients with mild or severe dementia. The present study aimed to develop a new oral function test - the "candy sucking test" (CST) - for elderly patients with dementia. METHODS: We recruited 23 female elderly patients with dementia (mean age 89.0 ± 6.7 years). First, we determined the number of participants who were able to carry out this new oral function test, compared with other existing tests. Then, swallowing function was evaluated using videofluoroscopy for those who could carry out the CST. RESULTS: More participants were able to perform carry out CST than other function tests (P < 0.05). A significant correlation was observed between the CST value, evaluated as the difference in candy weight, and oral transit time (ρ = -0.62, P < 0.01). CONCLUSIONS: The CST could be useful as a new method for evaluating the oral function of elderly patients with dementia. Geriatr Gerontol Int 2017; 17: 1977-1981.

Tongue thickness evaluation using ultrasonography can predict swallowing function in amyotrophic lateral sclerosis patients.

OBJECTIVE: Dysphagia is a critical issue in amyotrophic lateral sclerosis (ALS) patients. An evaluation of swallowing function is important for assessing the risk of aspiration. We investigated the validity of tongue sonography compared with videofluoroscopic examination for ALS patients. METHODS: We investigated 18 ALS patients. Nine subjects underwent repeated investigations. All of the subjects underwent tongue sonography and videofluoroscopic examination. Additionally, tongue sonography was evaluated in 18 age- and sex-matched healthy volunteers. To determine tongue thickness, we measured the vertical distance from the surface of the mylohyoid muscle to the tongue dorsum using ultrasonography. RESULTS: In the ALS patients, the tongue was significantly thinner than in healthy subjects. Tongue thickness was associated with body mass index and onset type in the ALS patients (p=0.006). Temporal analyses of videofluoroscopy revealed that tongue thickness was associated with oral preparatory and transit time (p=0.032) but not with pharyngeal transit time. Repeated measurement data revealed a decrease in tongue thickness over the course of the measurements (p=0.002). CONCLUSIONS: In ALS patients, reduced tongue thickness suggests disease progression and tongue dysfunction. SIGNIFICANCE: Tongue sonography is a useful modality for the non-invasive and quantitative evaluation of tongue thickness and dysphagia in ALS patients.