Clinical characteristics of dysphagic stroke patients with salivary aspiration: A STROBE-compliant retrospective study

Development and validation of a risk prediction model for aspiration in patients with acute ischemic stroke

BACKGROUND

Aspiration is a frequently observed complication in individuals diagnosed with acute ischemic stroke, leading to potentially severe consequences. However, the availability of predictive tools for assessing aspiration probabilities remains limited. Hence, our study aimed to develop and validate a nomogram for accurately predicting aspiration probability in patients with acute ischemic stroke.

METHODS

We analyzed 30 potential risk factors associated with aspiration in 359 adult patients diagnosed with acute ischemic stroke. Advanced statistical techniques, such as Least absolute shrinkage and selection operator (LASSO) and Multivariate Logistic regression, were employed to identify independent predictors. Subsequently, we developed a nomogram prediction model based on these predictors, which underwent internal validation through 1000 bootstrap resampling. Two additional cohorts (Cohort A n = 64; Cohort B, n = 105) were included for external validation. The discriminatory power and calibration performance of the nomogram were assessed using rigorous methods, including the Hosmer-Lemeshow test, area under the receiver operating characteristic curve (AUC), calibration curve analyses, and decision curve analyses (DCA).

RESULTS

The nomogram was established based on four variables: sputum suction, brain stem infarction, temporal lobe infarction, and Barthel Index score. The predictive model exhibited satisfactory discriminative ability, with an area under the receiver operating characteristic curve of 0.853 (95 % confidence interval, 0.795-0.910), which remained consistent at 0.852 (95 % confidence interval, 0.794-0.912) during the internal validation. The Hosmer-Lemeshow test (P = 0.394) and calibration curve demonstrated favorable consistency between the predicted and observed outcomes in the development cohort. The AUC was 0.872 (95 % confidence interval, 0.783-0.962) in validation cohort A and 0.877 (95 % confidence interval, 0.764-0.989) in validation cohort B, demonstrating sustained accuracy. DCA showed a good net clinical benefit of the nomogram.

CONCLUSIONS

A nomogram for predicting the probability of aspiration in patients with acute ischemia has been successfully developed and validated.

Post-stroke respiratory complications using machine learning with voice features from mobile devices

Abnormal voice may identify those at risk of post-stroke aspiration. This study was aimed to determine whether machine learning algorithms with voice recorded via a mobile device can accurately classify those with dysphagia at risk of tube feeding and post-stroke aspiration pneumonia and be used as digital biomarkers. Voice samples from patients referred for swallowing disturbance in a university-affiliated hospital were collected prospectively using a mobile device. Subjects that required tube feeding were further classified to high risk of respiratory complication, based on the voluntary cough strength and abnormal chest x-ray images. A total of 449 samples were obtained, with 234 requiring tube feeding and 113 showing high risk of respiratory complications. The eXtreme gradient boosting multimodal models that included abnormal acoustic features and clinical variables showed high sensitivity levels of 88.7% (95% CI 82.6–94.7) and 84.5% (95% CI 76.9–92.1) in the classification of those at risk of tube feeding and at high risk of respiratory complications; respectively. In both cases, voice features proved to be the strongest contributing factors in these models. Voice features may be considered as viable digital biomarkers in those at risk of respiratory complications related to post-stroke dysphagia.

Usefulness of the Modified Videofluoroscopic Dysphagia Scale in Determining the Allowance of Oral Feeding in Patients with Dysphagia Due to Deconditioning or Frailty

Introduction: In patients with dysphagia due to deconditioning or frailty, as with other disorders that cause swallowing disorders, the videofluoroscopic swallowing study (VFSS) is the gold standard for dysphagia evaluation. However, the interpretation of VFSS results is somewhat complicated and requires considerable experience in the field. Therefore, in this study we evaluated the usefulness of the modified videofluoroscopic dysphagia scale (mVDS) in determining whether to allow oral feeding in patients with dysphagia due to deconditioning or frailty. Methods: Data from the VFSS of 50 patients with dysphagia due to deconditioning or frailty were retrospectively collected. We evaluated the association between mVDS and the selected feeding method based on VFSS findings, and between mVDS and the presence of aspiration pneumonia. Results: Multivariate logistic analysis showed that the mVDS total score had a significant association with oral feeding methods based on VFSS findings in patients with dysphagia due to deconditioning or frailty (p < 0.05). In the receiver operating characteristic (ROC) curve analysis, the area under the ROC curve for the selected feeding method was 0.862 (95% confidence interval, 0.747−0.978; p < 0.0001). Conclusions: mVDS seems a valid scale for determining the allowance of oral feeding, and it can be a useful tool in the clinical setting and in studies that aim to interpret VFSS findings in patients with dysphagia due to deconditioning or frailty. However, studies involving a more general population of patients with dysphagia due to deconditioning or frailty are needed.

Deep Learning Analysis to Automatically Detect the Presence of Penetration or Aspiration in Videofluoroscopic Swallowing Study

BACKGROUND

Videofluoroscopic swallowing study (VFSS) is currently considered the gold standard to precisely diagnose and quantitatively investigate dysphagia. However, VFSS interpretation is complex and requires consideration of several factors. Therefore, considering the expected impact on dysphagia management, this study aimed to apply deep learning to detect the presence of penetration or aspiration in VFSS of patients with dysphagia automatically.

METHODS

The VFSS data of 190 participants with dysphagia were collected. A total of 10 frame images from one swallowing process were selected (five high-peak images and five low-peak images) for the application of deep learning in a VFSS video of a patient with dysphagia. We applied a convolutional neural network (CNN) for deep learning using the Python programming language. For the classification of VFSS findings (normal swallowing, penetration, and aspiration), the classification was determined in both high-peak and low-peak images. Thereafter, the two classifications determined through high-peak and low-peak images were integrated into a final classification.

RESULTS

The area under the curve (AUC) for the validation dataset of the VFSS image for the CNN model was 0.942 for normal findings, 0.878 for penetration, and 1.000 for aspiration. The macro average AUC was 0.940 and micro average AUC was 0.961.

CONCLUSION

This study demonstrated that deep learning algorithms, particularly the CNN, could be applied for detecting the presence of penetration and aspiration in VFSS of patients with dysphagia.

Usefulness of the Modified Videofluoroscopic Dysphagia Scale in Evaluating Swallowing Function among Patients with Amyotrophic Lateral Sclerosis and Dysphagia

INTRODUCTION

The videofluoroscopic dysphagia scale (VDS) is used to predict the long-term prognosis of dysphagia among patients with the condition. Previously, a modified version of the VDS (mVDS) was established to overcome the relatively low inter-rater reliability of VDS, and was verified in patients with dysphagia, such as stroke patients. However, the validity of mVDS in patients with amyotrophic lateral sclerosis (ALS) has never been proved. Therefore, in this study, we attempted to seek the validity of the mVDS score in patients with ALS suffering from dysphagia.

METHOD

Data from the videofluoroscopic swallowing study (VFSS) of 34 patients with ALS and dysphagia were retrospectively collected. We investigated the presence of aspiration pneumonia and the selected feeding method based on the VFSS. We also evaluated the correlations between the mVDS and the selected feeding method, and between the mVDS and the presence of aspiration pneumonia. Multivariate logistic regression and receiver operating characteristic (ROC) analyses were performed during the data analysis.

RESULTS

In patients with ALS and dysphagia, the mVDS scores were statistically correlated with the selected feeding method (p < 0.05) and the presence of aspiration pneumonia (p < 0.05). In the ROC curve analysis, the area under the ROC curve values for the selected feeding method and the presence of aspiration pneumonia were 0.886 (95% confidence interval (CI), 0.730-0.969; p < 0.0001) and 0.886 (95% CI, 0.730-0.969; p < 0.0001), respectively.

CONCLUSION

The mVDS can be a useful tool for quantifying the severity of dysphagia and interpreting the VFSS findings in patients with ALS and dysphagia. However, further studies involving a more general population of patients with ALS are needed to elucidate a more accurate cut-off value for the allowance of oral feeding and the presence of aspiration pneumonia.

Validation and Inter-rater Reliability of the Modified Videofluoroscopic Dysphagia Scale (mVDS) in Dysphagic Patients with Multiple Etiologies

BACKGROUND

the Videofluoroscopic Dysphagia Scale (VDS) is used to interpret and predict the long-term prognosis of patients with dysphagia. However, the inter-rater agreement of the VDS was shown to be lower in a previous study. To overcome the mentioned limitation of the VDS, a modified version (mVDS) was created and applied clinically. We aimed to validate its usefulness in determining the appropriate feeding method and predicting the prognosis of dysphagia.

METHODS

the videofluroscopic swallowing study (VFSS) data of 50 patients with dysphagia were collected retrospectively. The VFSS data were evaluated using the mVDS, and the inter-rater reliability was calculated. We also evaluated the association between the mVDS and type of feeding method selected, and between the mVDS and presence of aspiration pneumonia in patients with dysphagia.

RESULTS

among the different parameters of mVDS, "aspiration" showed the highest reliability (k = 0.767), followed by "mastication" and "lip closure" (k = 0.648 and k = 0.634, respectively). Conversely, "triggering pharyngeal swallow" and "pyriformis residue" demonstrated the lowest reliabilities (k = 0.312 and k = 0.324, respectively). The intraclass correlation coefficient (ICC), which is used as a measure of the reliability of the total mVDS score, was 0.876. In all patients with dysphagia, the mVDS score correlated significantly with the type of feeding method selected (p < 0.05), and the presence of aspiration pneumonia (p < 0.05).

CONCLUSION

the ICC of the total mVDS score was 0.876. Therefore, the mVDS could be a useful tool for quantifying the severity of dysphagia. It could be helpful in the analysis of the VFSS findings among patients with dysphagia in clinical settings and research.

Usefulness of the Modified Videofluoroscopic Dysphagia Scale in Choosing the Feeding Method for Stroke Patients with Dysphagia

INTRODUCTION

The Videofluoroscopic Dysphagia Scale (VDS) is used to predict the long-term prognosis of dysphagia in patients with strokes. However, the inter-rater reliability of the VDS was low in a previous study. To overcome the mentioned limitations of the VDS, the modified version of the VDS (mVDS) was created and clinically applied to evaluate its usefulness in choosing the feeding method for stroke patients with dysphagia.

METHODS

The videofluoroscopic swallowing study (VFSS) data of 56 stroke patients with dysphagia were collected retrospectively. We investigated the presence of aspiration pneumonia and the selected feeding method. We also evaluated the correlations between the mVDS and the selected feeding method, and between the mVDS and the presence of aspiration pneumonia after stroke. Univariate logistic regression and receiver operating characteristic analyses were used in the data analysis.

RESULTS

The inter-rater reliability (Cronbach α value) of the total score of the mVDS was 0.886, which was consistent with very good inter-rater reliability. In all patients with dysphagia, the supratentorial stroke subgroup, and the infratentorial stroke subgroup, the mVDS scores were statistically correlated with the feeding method selected (p < 0.05) and the presence of aspiration pneumonia (p < 0.05).

CONCLUSIONS

The mVDS can be a useful scale for quantifying the severity of dysphagia, and it can be a useful tool in the clinical setting and in studies for interpreting the VFSS findings in stroke patients with dysphagia. Further studies with a greater number of patients and various stroke etiologies are required for more generalized applications of the mVDS.

Correlation of Videofluoroscopic Swallowing Study Findings With Radionuclide Salivagram in Chronic Brain-Injured Patients

Objective

To investigate the correlation between videofluoroscopic swallowing study (VFSS) and radionuclide salivagram findings in chronic brain-injured patients with dysphagia.

Methods

Medical records of chronic brain-injured patients who underwent radionuclide salivagram and VFSS were retrospectively analyzed. Patients were divided into two groups according to salivagram findings. Differences in patient characteristics and clinical factors, including Mini-Mental State Examination (MMSE), Modified Barthel Index (MBI), Functional Ambulatory Category (FAC), feeding method, tracheostomy state, and VFSS findings between the two groups were investigated.

Results

A total of 124 patients were included in this study. There were no significant differences in MMSE, MBI, FAC, feeding method, and presence of tracheostomy between the two groups. However, the incidence of aspiration pneumonia history was significantly higher in the positive salivagram group. The Functional Dysphagia Scale (FDS) was significantly associated with positive salivagram findings, especially in the pharyngeal phase. A multivariate logistic regression analysis showed that laryngeal elevation and epiglottic closure was statistically significant FDS parameter in predicting salivary aspiration on a salivagram (odds ratio=1.100; 95% confidence interval, 1.017–1.190; p=0.018). The receiver operating characteristic (ROC) curve of FDS in the pharyngeal phase showed that an optimum sensitivity and specificity of 55.1% and 65.4%, respectively, when the cut-off value was 39.

Conclusion

In chronic brain-injured patients, inappropriate laryngeal elevation and epiglottic closure is predictive variable for salivary aspiration. Therefore, performing a radionuclide salivagram in patients with FDS of 39 or less in the pharyngeal phase for prevents aspiration pneumonia from salivary aspiration.

Submandibular Push Exercise Using Visual Feedback from a Pressure Sensor in Patients with Swallowing Difficulties: A Pilot Study

Objectives: We aimed to determine the usefulness and effectiveness of a submandibular push exercise with visual feedback from a pressure sensor in patients with dysphagia through continuous exercise sessions. Methods: Twelve patients with dysphagia of various etiologies were included. A total of five exercise sessions (every 3 or 4 days) over three weeks were conducted. During the submandibular push exercise, patients were instructed to maintain a maximum force for 3 s, repeated for 1 min to measure the number of exercises, the maximum pressure, and the area of the pressure-time graph. We statistically compared the values of each exercise trial. Results: Among the 12 patients, eight completed the exercise sessions. As the number of exercise trials increased, the maximum pressure and the area in the pressure-time graph showed a significant increase compared to the previous attempt (p < 0.05). The maximum pressure and the area of the pressure-time graph improved from the first to the fourth session (p < 0.05). The values were maintained after the fourth session, and there was no significant difference between the fourth and the fifth exercise (p > 0.05). There was no significant difference between successful and non-successful groups, except for the Modified Barthel Index (p < 0.05). Conclusion: Through repetitive exercise training, the submandibular push exercise using visual feedback from a pressure sensor can be applied as an exercise method to strengthen swallowing related muscles, such as the suprahyoid and infrahyoid muscles. However, additional studies including more patients and a long-term study period are warranted to evaluate the effects of the exercise for improvement of dysphagia.

Comparison of three different types of exercises for selective contractions of supra- and infrahyoid muscles

Several exercise methods, such as the Shaker exercise, tongue press exercise, chin tuck against resistance (CTAR) exercise, and submandibular push exercise, have been introduced to strengthen the muscles involved in swallowing. In this study, we compared the effectiveness of the CTAR, submandibular push, and Shaker exercises for the induction of selective supra- and infrahyoid muscle contractions using surface electromyography (EMG). This study is a prospective non-randomized controlled study. Twenty-five healthy subjects and 20 patients experiencing swallowing difficulty were enrolled. During the three different types of exercises, the root mean square (RMS) values of the sternocleidomastoid (SCM), suprahyoid (anterior belly of the digastric and mylohyoid muscles), and infrahyoid (sternothyroid and thyrohyoid muscles) muscles were analyzed using surface EMG. Differences in the activity of swallowing muscles among the three different exercises were analyzed using one-way repeated measured analysis of variance. In terms of both the maximum and mean RMS values of the suprahyoid muscle, the submandibular push exercise showed a larger RMS value than the CTAR and Shaker exercises in healthy subjects (p < 0.05). In terms of both the maximum and mean RMS values of the suprahyoid muscle, the Shaker exercise and submandibular push exercise showed a larger RMS value than the CTAR exercise in patients with swallowing difficulty (p < 0.05). The submandibular push exercise may be effective as a swallowing muscle exercise owing to its superiority in inducing selective contractions of the supra- and infrahyoid muscles. The CTAR and Shaker exercises are also effective in this regard.

Best Practice Recommendations for Stroke Patients with Dysphagia: A Delphi-Based Consensus Study of Experts in Turkey-Part I: Management, Diagnosis, and Follow-up

Dysphagia is one of the most common and important complications of stroke. It is an independent marker of poor outcome after acute stroke and may become chronic after the acute period and continues to affect all aspects of the patient's life. Patients with stroke may encounter any of the medical branches in the emergency room or outpatient clinic, and as in our country, there may not be specialists specific for dysphagia, such as speech-language pathologists (SLP), in every hospital. This study aimed to raise awareness and create a common opinion of medical specialists for stroke patients with dysphagia. This recommendation paper has been written by a multidisciplinary team and offers 45 recommendations for stroke patients with dysphagia. It was created using the eight-step Delphi round via e-mail. This study is mostly specific to Turkey. However, since it contains detailed recommendations from the perspective of various disciplines associated with stroke, this consensus-based recommendation paper is not only a useful guide to address clinical questions in practice for the clinical management of dysphagia in terms of management, diagnosis, and follow-up, but also includes detailed comments for these topics.

Semi-quantitative assessment optimized the grading of pulmonary aspiration on salivagram in children

OBJECTIVE

Salivagram is one of the imaging modalities to detect pulmonary aspiration in children. This study aims to optimize the classification of pulmonary aspiration detected by salivagram with a semi-quantitative analytical method.

METHODS

This is a retrospective study involving 737 patients (471 males, 266 females; aged 1 month to 8 years; mean age 5.3 months, median age 3.0 months old) with suspected pulmonary aspiration, who had salivagram done between January 2018 and June 2019. Positive cases were divided into 10 groups (Grade 1, R2, L2, R2L2, R3, L3, R3L2, R2L3, R3L3, and 4) according to the scintigraphic findings. Aspiration index was determined as the ratio of the count in the respiratory tract to the total count in the image field of view and compared among different groups using the receiver operating characteristics (ROC) curve analysis.

RESULTS

A total of 180 cases had positive scintigraphic findings of various grades of aspiration (24.4%, 180/737). There is a high consistency among the two independent nuclear medicine physicians involved in the study, in determining both the disease gradings (κ = 0.919;95% CI: 0.915-0.923) and aspiration index (ICC = 0.994;95% CI: 0.993-0.996). There is no significant difference (p > 0.05) in aspiration index among the gradings in "mild" group (grade 1, R2, L2, L2R2), and "moderate" group (grade R3, R3L2, R3L3). After dividing the different grades into "mild", "moderate" and "severe" groups, the aspiration index of "mild" group is 4.40 ± 2.01, that of "moderate" group is 16.43 ± 8.20, and that of "severe" group is 46.94 ± 14.81. Difference in groups was statistically significant (p < 0.0001). In ROC curve analysis, AUC of "mild" and "moderate" groups is 0.970 and that of "moderate" and "severe" groups is 0.943; the cut-off value with highest diagnostic efficiency is 6.75 between "mild" and "moderate" groups and 38.00 between "moderate" and "severe" groups.

CONCLUSIONS

We introduced a semi-quantitative analytical method in pulmonary aspiration on salivagram, to optimize and supplement to the current classification of pulmonary aspiration.

The Effect of Deep Brain Stimulation on Swallowing Function in Parkinson's Disease: A Narrative Review

Unlike appendicular motor symptoms, such as bradykinesia and rigidity, in Parkinson's disease (PD), which have already been reported to respond well to deep brain stimulation (DBS), there is limited literature on the effects of DBS on swallowing function in patients with PD. The field lacks consensus as there are conflicting reports among existing studies regarding whether swallowing function improves or declines following DBS implantation. This narrative review aims to summarize and analyze the studies published on the effect of DBS on swallowing function in patients with PD. We collated studies published up to February 2020 using a comprehensive electronic database search of PubMed, SCOPUS, EMBASE, and the Cochrane Library. Two reviewers independently assessed the studies using strict inclusion and exclusion criteria. The primary literature search yielded 529 relevant papers. After reading their titles and abstracts and assessing their eligibility based on the full-text, we finally included and reviewed 14 publications. Nine of these studies reported positive effects of DBS on swallowing function and four studies showed no significant positive results. The remaining study showed decreased swallowing function after unilateral subthalamic nucleus-DBS surgery. In conclusion, we found that DBS has the potential to improve swallowing function in patients with PD. However, high-quality evidence is lacking. To clearly elucidate the effect of DBS on swallowing function in patients with PD, high-quality randomized controlled trials should be conducted in the future.