Sarcopenic Dysphagia: A Narrative Review from Diagnosis to Intervention

Sarcopenia, defined as a decline in muscle mass and function related to aging, affects both limb and swallowing-related muscles. Sarcopenic dysphagia is characterized by decreased swallowing function; therefore, early detection of subclinical dysphagia and subsequent intervention appear to be crucial in the elderly. Numerous tools have been employed to measure the function, strength, and mass of swallowing-related muscles in sarcopenic elderly. The swallowing function can be evaluated by questionnaires like Eating Assessment Tool, Functional Oral Intake Scale, and Food Intake Level Scale, and tests such as the modified water swallowing test and videofluoroscopic swallowing study. Surface electromyography and high-resolution manometry can be applied for quantifying swallowing-related muscle strength. Modalities such as ultrasonography and magnetic resonance imaging are capable of estimating the swallowing muscle mass. In patients with sarcopenic dysphagia, a thorough assessment should be given followed by an integrated intervention combining swallowing muscle strengthening, nutrition support, food texture modification, physical, and occupational therapies. This article aimed to comprehensively summarize the diagnostic criteria/tools as well as their associations/performance in sarcopenic dysphagia. The intervention strategy will also be narrated in this review.

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.

Assessment of Tongue Strength in Sarcopenia and Sarcopenic Dysphagia: A Systematic Review and Meta-Analysis

Sarcopenic dysphagia is defined as difficulty in swallowing due to sarcopenia, which may be related to weakness of the tongue muscles. This meta-analysis aimed to explore the association between tongue strength and sarcopenia and to determine whether tongue strength measurement could be a specific indicator of sarcopenic dysphagia. We conducted a systematic search of electronic databases from their inception to February 2021 for clinical studies that investigated tongue strength in participants with and without sarcopenia. The primary outcome was the weighted mean difference (WMD) and standardized mean difference (SMD) of tongue pressure between the different groups. The secondary outcome was the correlation of tongue pressure with the subcomponents that defined sarcopenia. Ten studies that involved 1,513 participants were included in the meta-analysis. Compared with those without sarcopenia, patients with sarcopenia had significantly less tongue pressure, with a WMD of −4.353 kPa (95% CI, −7.257 to −1.450) and an SMD of −0.581 (95% CI, −0.715 to −0.446). There was no significant difference in tongue pressure between patients with sarcopenic dysphagia and those with non-sarcopenic dysphagia, with a WMD of −1.262 kPa (95% CI, −8.442 to 5.918) and an SMD of −0.187 (95% CI, −1.059 to 0.686). Significant positive associations were identified between tongue pressure and grip strength and between tongue pressure and gait speed, with correlation coefficients of 0.396 (95% CI, 0.191 to 0.567) and 0.269 (95% CI, 0.015 to 0.490), respectively. Reduced tongue strength is associated with sarcopenia but is not an exclusive marker for sarcopenic dysphagia. Tongue strength correlates with the values of subcomponents that define sarcopenia. In patients with low performance of sarcopenia subcomponent, tongue pressure must be examined to diagnose subclinical dysphagia.Protocol registration: This meta-analysis was registered on INPLASY (registration number INPLASY202120060).