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

AI-assisted automatic MRI-based tongue volume evaluation in motor neuron disease (MND)

PURPOSE

Motor neuron disease (MND) causes damage to the upper and lower motor neurons including the motor cranial nerves, the latter resulting in bulbar involvement with atrophy of the tongue muscle. To measure tongue atrophy, an operator independent automatic segmentation of the tongue is crucial. The aim of this study was to apply convolutional neural network (CNN) to MRI data in order to determine the volume of the tongue.

METHODS

A single triplanar CNN of U-Net architecture trained on axial, coronal, and sagittal planes was used for the segmentation of the tongue in MRI scans of the head. The 3D volumes were processed slice-wise across the three orientations and the predictions were merged using different voting strategies. This approach was developed using MRI datasets from 20 patients with 'classical' spinal amyotrophic lateral sclerosis (ALS) and 20 healthy controls and, in a pilot study, applied to the tongue volume quantification to 19 controls and 19 ALS patients with the variant progressive bulbar palsy (PBP).

RESULTS

Consensus models with softmax averaging and majority voting achieved highest segmentation accuracy and outperformed predictions on single orientations and consensus models with union and unanimous voting. At the group level, reduction in tongue volume was not observed in classical spinal ALS, but was significant in the PBP group, as compared to controls.

CONCLUSION

Utilizing single U-Net trained on three orthogonal orientations with consequent merging of respective orientations in an optimized consensus model reduces the number of erroneous detections and improves the segmentation of the tongue. The CNN-based automatic segmentation allows for accurate quantification of the tongue volumes in all subjects. The application to the ALS variant PBP showed significant reduction of the tongue volume in these patients and opens the way for unbiased future longitudinal studies in diseases affecting tongue volume.

A Review of In Vitro and In Silico Swallowing Simulators: Design and Applications

Swallowing is a primary and complex behaviour that transports food and drink from the oral cavity, through the pharynx and oesophagus, into the stomach at an appropriate rate and speed. To understand this sophisticated behaviour, a tremendous amount of research has been carried out by utilising the in vivo approach, which is often challenging to perform, poses a risk to the subjects if interventions are undertaken and are seldom able to control for confounding factors. In contrast, in silico (computational) and in vitro (instrumental) methods offer an alternate insight into the process of the human swallowing system. However, the appropriateness of the design and application of these methods have not been formally evaluated. The purpose of this review is to investigate and evaluate the state of the art of in vitro and in silico swallowing simulators, focusing on the evaluation of their mechanical or computational designs in comparison to the corresponding swallowing mechanisms during various phases of swallowing (oral phase, pharyngeal phase and esophageal phase). Additionally, the potential of the simulators is also discussed in various areas of applications, including the study of swallowing impairments, swallowing medications, food process design and dysphagia management. We also address current limitations and recommendations for the future development of existing simulators.

Neurophysiological and imaging biomarkers of lower motor neuron dysfunction in motor neuron diseases/amyotrophic lateral sclerosis: IFCN handbook chapter

This chapter discusses comprehensive neurophysiological biomarkers utilised in motor neuron disease (MND) and, in particular, its commonest form, amyotrophic lateral sclerosis (ALS). These encompass the conventional techniques including nerve conduction studies (NCS), needle and high-density surface electromyography (EMG) and H-reflex studies as well as novel techniques. In the last two decades, new methods of assessing the loss of motor units in a muscle have been developed, that are more convenient than earlier methods of motor unit number estimation (MUNE),and may use either electrical stimulation (e.g. MScanFit MUNE) or voluntary activation (MUNIX). Electrical impedance myography (EIM) is another novel approach for the evaluation that relies upon the application and measurement of high-frequency, low-intensity electrical current. Nerve excitability techniques (NET) also provide insights into the function of an axon and reflect the changes in resting membrane potential, ion channel dysfunction and the structural integrity of the axon and myelin sheath. Furthermore, imaging ultrasound techniques as well as magnetic resonance imaging are capable of detecting the constituents of morphological changes in the nerve and muscle. The chapter provides a critical description of the ability of each technique to provide neurophysiological insight into the complex pathophysiology of MND/ALS. However, it is important to recognise the strengths and limitations of each approach in order to clarify utility. These neurophysiological biomarkers have demonstrated reliability, specificity and provide additional information to validate and assess lower motor neuron dysfunction. Their use has expanded the knowledge about MND/ALS and enhanced our understanding of the relationship between motor units, axons, reflexes and other neural circuits in relation to clinical features of patients with MND/ALS at different stages of the disease. Taken together, the ultimate goal is to aid early diagnosis, distinguish potential disease mimics, monitor and stage disease progression, quantify response to treatment and develop potential therapeutic interventions.

Methodological Procedures to Acquire and Analyze Ultrasound Images of Swallowing: A Scoping Review

This scoping review aimed to identify methodological procedures for acquiring and analyzing ultrasound images related to swallowing in adults and older adults. The inclusion criteria were based on the PCC strategy (participants, concept, and context), as follows: population (adults and older adults), concept (ultrasound assessment), and context (swallowing assessment). The review included observational, experimental, descriptive, and analytical studies and excluded those that were not available in full, animal studies, in vitro studies, letters to the editor, errata, study protocols, and those that used ultrasound for purposes other than swallowing. There were no language and time restrictions. Two independent blinded professionals selected 81 articles that met the inclusion criteria from different databases. The most evaluated parameters included tongue morphology and movements, hyoid bone displacement, swallowing muscle area, and pharyngeal residue detection, such as pharyngeal wall mobility. They used convex and linear transducers (3 MHz to 8 MHz) positioned in the submental, laryngeal, and lateral regions of the neck. The subjects were seated and instructed to eat different food volumes and consistencies. The literature mapping showed that ultrasound is a promising diagnostic tool, helping clinicians understand swallowing disorders, as it provides static and dynamic images in different modes and positions. Also, patients receive real-time biofeedback of changes related to dysphagia.

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.

Dynamic suprahyoid muscle ultrasound in assessing oropharyngeal dysphagia in neurological disorders

BACKGROUND

Appropriate evaluation and management of dysphagia are essential in neurological disorders. However, there is currently a lack of a simple yet reliable method for dysphagia evaluation.

AIM

This study aimed to investigate the usefulness of new dynamic M-mode ultrasonography (US) parameters of suprahyoid muscle (SHM) to evaluate dysphagia.

DESIGN

Prospective observational, cross-sectional study.

SETTING

Inpatient setting at neurology department of tertiary medical center.

POPULATION

A total of 89 patients with dysphagia and 175 healthy volunteers were enrolled in the study. Patients were subdivided into mild and severe dysphagia groups depending on the need for dietary changes and disease classification, which included amyotrophic lateral sclerosis, peripheral neuromuscular diseases, and stroke.

METHODS

Dynamic M-mode US was performed during swallowing to obtain the SHM thickness (the baseline thickness of the SHM), SHM displacement (peak-to-peak amplitude of SHM movement), SHM difference (SHM displacement - SHM thickness), SHM ratio (SHM displacement/SHM thickness), peak-to-peak time, and total duration. A videofluoroscopic swallowing study (VFSS) was performed.

RESULTS

Significant differences were found in SHM displacement and SHM difference according to dysphagia severity (P<0.001). The SHM ratio, total duration (P<0.001), and peak-to-peak time (P=0.001) differed significantly according to the patients' underlying diseases. The pharyngeal delay time and penetration-aspiration scale from the VFSS demonstrated significant negative correlations with SHM displacement and difference (P<0.001). By combining SHM difference and total duration, patients with dysphagia could be distinguished from healthy controls, with the highest negative predictive value of 95.6%.

CONCLUSIONS

Dynamic M-mode US of the SHM provided added value in evaluating the severity of dysphagia and differentiating swallowing mechanics of dysphagia related to underlying neurological disorders.

CLINICAL REHABILITATION IMPACT

Dynamic M-mode US of the SHM can serve as a supportive tool for rapid screening and repetitive follow-up of patients with dysphagia, which would contribute to dysphagia rehabilitation in patients with various neurological disorders.

Prospective Observational Study for the Comparison of Screening Methods Including Tongue Pressure and Repetitive Saliva Swallowing With Detailed Videofluoroscopic Swallowing Study Findings in Patients With Acute Stroke

BACKGROUND

Simple, noninvasive, and repeatable screening methods are essential for assessing swallowing disorders. We focused on patients with acute stroke and aimed to assess the characteristics of swallowing screening tests, including the modified Mann Assessment of Swallowing Ability score, tongue pressure, and repetitive saliva swallowing test (RSST), compared with detailed videofluoroscopic swallowing study (VFSS) findings to contribute as a helpful resource for their comprehensive and complementary use.

METHODS AND RESULTS

We enrolled first-ever patients with acute stroke conducting simultaneous assessments, including VFSS, modified Mann Assessment of Swallowing Ability score, tongue pressure measurement, and RSST. VFSS assessed aspiration, laryngeal penetration, oral cavity residue, vallecular residue, pharyngeal residue, and swallowing reflex delay. Screening tests were compared with VFSS findings, and multiple logistic analysis determined variable importance. Cutoff values for each abnormal VFSS finding were assessed using receiver operating characteristic analyses. We evaluated 346 patients (70.5±12.6 years of age, 143 women). The modified Mann Assessment of Swallowing Ability score was significantly associated with all findings except aspiration. Tongue pressure was significantly associated with oral cavity and pharyngeal residue. The RSST was significantly associated with all findings except oral cavity residue. Receiver operating characteristic analyses revealed that the minimum cutoff value for all VFSS abnormal findings was RSST ≤2.

CONCLUSIONS

The modified Mann Assessment of Swallowing Ability is useful for broadly detecting swallowing disorders but may miss mild issues and aspiration. The RSST, with a score of ≤2, is valuable for indicating abnormal VFSS findings. Tongue pressure, especially in oral and pharyngeal residues, is useful. Combining these tests might enhance accuracy of the swallowing evaluation.

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.

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.

Ultrasonography for Eating and Swallowing Assessment: A Narrative Review of Integrated Insights for Noninvasive Clinical Practice

Dysphagia is a syndrome of abnormal eating function resulting from a variety of causative diseases, and is associated with malnutrition. To date, the swallowing function has been difficult to examine without the use of invasive and expensive methods, such as the videofluorographic swallowing study or fiberoptic endoscopic evaluation of swallowing. In recent years, progress has been made in the clinical application of ultrasound equipment for the evaluation of body compositions near the body surface, including the assessment of nutritional status. Ultrasound examination is a noninvasive procedure and relatively inexpensive, and the equipment required is highly portable thanks to innovations such as wireless probes and tablet monitoring devices. The process of using ultrasound to visualize the geniohyoid muscle, digastric muscle, mylohyoid muscle, hyoid bone, tongue, masseter muscle, genioglossus muscle, orbicularis oris muscle, temporalis muscle, pharynx, esophagus, and larynx, and the methods used for evaluating these structures, are provided in this study in detail. This study also aims to propose a protocol for the assessment of swallowing-related muscles that can be applied in real-world clinical practice for the diagnosis of sarcopenic dysphagia, which can occur in elderly patients with sarcopenia, and has received much attention in recent years.

Swallowing sound evaluation using an electronic stethoscope and artificial intelligence analysis for patients with amyotrophic lateral sclerosis

Background and purpose

Non-invasive, simple, and repetitive swallowing evaluation is required to prevent aspiration pneumonia in neurological care. We investigated the usefulness of swallowing sound evaluation in patients with amyotrophic lateral sclerosis (ALS) using our new electronic stethoscope artificial intelligence (AI) analysis tool.

Methods

We studied patients with ALS who provided written informed consent. We used an electronic stethoscope, placed a Bluetooth-enabled electronic stethoscope on the upper end of the sternum, performed a 3-mL water swallow three times, and remotely identified the intermittent sound components of the water flow caused at that time by AI, with the maximum value as the swallowing sound index. We examined the correlation between the swallowing sound index and patient background, including swallowing-related parameters.

Results

We evaluated 24 patients with ALS (age 64.0 ± 11.8 years, 13 women, median duration of illness 17.5 months). The median ALS Functional Rating Scale-Revised (ALSFRS-R) score was 41 (minimum 18, maximum 47). In all cases, the mean swallowing sound index was 0.209 ± 0.088. A multivariate analysis showed that a decrease in the swallowing sound index was significantly associated with a low ALSFRS-R score, an ALSFRS-R bulbar symptom score, % vital capacity, tongue pressure, a Mann Assessment of Swallowing Ability (MASA) score, and a MASA pharyngeal phase-related score.

Conclusion

Swallowing sound evaluation using an electronic stethoscope AI analysis showed a correlation with existing indicators in swallowing evaluation in ALS and suggested its usefulness as a new method. This is expected to be a useful examination method in home and remote medical care.

Ultrasonographic and manometric study of the tongue as biomarkers of dysphagia in patients with amyotrophic lateral sclerosis

BACKGROUND

The possibility of having methods to assess dysphagia in amyotrophic lateral sclerosis (ALS) patients in a minimally invasive manner could facilitate follow-up and allow performing of therapeutic interventions at earlier stages of the disease. The aim of the study was to analyze the role of tongue strength and thickness in ALS patients and their correlation with dysphagia and bulbar function.

METHODS

A sample of outpatients with ALS was evaluated for demographic and clinical features. Tongue thickness and strength have been measured for each patient, and quantitative and qualitative data of the videofluoroscopy swallow study have been analyzed.

RESULTS

Of the 38 ALS patients studied, 47.4% were women, and 26.3% had bulbar onset. The median time between symptom onset and the study was 24 months (IQR 11.5-48), and 55.3% of the patients were carriers of non-invasive mechanical ventilation. Tongue strength identified patients with impaired oral and pharyngeal transit and those with bolus residue scale (BRS) > 1 or penetration-aspiration scale (PAS) ≥ 3. In contrast, tongue thickness is only associated with impaired oral transit. Finally, anterior tongue strength ≤ 34 kPa and posterior tongue strength ≤ 34.5 kPa detected ALS penetrators/aspirators (PAS ≥ 3) and patients with ALS with post-swallow residue (BRS > 1).

CONCLUSIONS

Our results suggest that measures that assess the functionality (strength) of the tongue are more valuable than morphological measurements (thickness) for the follow-up of patients with ALS. Alterations of the anterior and posterior lingual strength correlate with the presence of bronchoaspiration and post-swallowing residue (BRS > 1).

Application of Ultrasonography in Neurogenic Dysphagia: A Systematic Review

Swallowing disorders are common in neurological diseases, with dysphagia representing one of the most prevalent complications that may cause poor quality of life, reduce independence, and increase mortality. Rapid identification of dysphagia is necessary to reduce the risk of penetration and aspiration, and to early start rehabilitation protocols. Among the methods that can be used to evaluate dysphagia and its components, ultrasound imaging has been suggested to support the evaluation of dysphagia by providing measures of both static and dynamic anatomical components. The aim of this systematic review is to evaluate the usefulness of ultrasonography in neurogenic dysphagia according to current literature. From 2000 to 2020, 633 studies with the appropriate search terms for ultrasound and dysphagia were identified. After screening them, 10 studies were included in the qualitative analysis. Patients with the following neurologic conditions were studied with ultrasonography for dysphagia: Parkinson's disease, muscle dystrophy, amyotrophic lateral sclerosis, and stroke. The main outcomes of ultrasonography were swallowing muscles thickness (e.g., tongue), and dynamic measures such as hyoid displacement. The different protocols used in the studies, as well as their outcomes, did not allow to provide standard procedures and normative or cut-off values in the presented diseases. Because there are a variety of tools, methods, and techniques that have been used in the studies that were reviewed, it is difficult to evaluate them using established standards. However, ultrasonography correlates well with clinical evaluation of dysphagia and therefore has prognostic and rehabilitation potential. Future studies should aim to develop and utilize a common interdisciplinary protocol that includes standard procedures and outcomes to define normative values applicable in the different conditions.

Comparison of Lingual Pressure Generation Capacity in Parkinson Disease, Amyotrophic Lateral Sclerosis, and Healthy Aging

PURPOSE

The tongue plays a key role in bolus propulsion during swallowing, with reduced lingual pressure generation representing a risk factor for impaired swallowing safety and efficiency. We compared lingual pressure generation capacity in people with Parkinson disease (PwPD), people with amyotrophic lateral sclerosis (PwALS), and healthy older adults. We hypothesized that both patient cohorts would demonstrate reduced maximum anterior isometric pressure (MAIP) and regular effort saliva swallow (RESS) pressures compared with healthy controls, with the greatest reductions expected in the ALS cohort.

METHOD

We enrolled 20 PwPD, 18 PwALS, and 20 healthy adults over 60 years of age. The Iowa Oral Performance Instrument was used to measure MAIP, RESS, and lingual functional reserve (LFR, i.e., MAIP - RESS). Descriptive statistics were calculated; between-groups differences were explored using univariate analyses of variance and post hoc Sidak tests with alpha set at .05.

RESULTS

Mean MAIPs for the PD, ALS, and heathy cohorts were 54.7, 33.5, and 47.4 kPa, respectively. Significantly lower MAIP was found in PwALS compared with PwPD and healthy controls. RESS values did not differ significantly across groups. LFR was significantly higher in PwPD versus PwALS and healthy controls.

CONCLUSIONS

Lingual pressure generation capacity and functional reserve were reduced in PwALS, but not in PwPD, beyond changes seen with healthy aging. Both patient cohorts displayed preserved lingual pressure during saliva swallows. Future studies exploring longitudinal changes in tongue pressure generation on isometric and saliva swallowing tasks will be needed to confirm whether tongue pressure measures serve as noninvasive clinical biomarkers of swallowing impairment.

Temporal muscle thickness and survival in patients with amyotrophic lateral sclerosis

Temporal muscle thickness (TMT) is a new potential MRI biomarker, which has shown prognostic relevance in neuro-oncology. We aim at investigating the potential prognostic value of TMT in patients with Amyotrophic Lateral Sclerosis (ALS). We retrospectively evaluated 30 ALS patients, whose clinical, Magnetic Resonance Imaging (MRI) and Electrodiagnostic testing (EDX) data were available, in comparison to age-matched 30 healthy subjects. TMT calculated on T1-weighted MR images was significantly lower in ALS patients than in healthy subjects (p < 0.001), correlating with the ALS Functional Rating Scale (FRS) (p:0.018) and compound motor action potential (CMAP) (p:0.012) in the patients group. Multivariate analysis of overall survival (OS) showed that the only parameters that remained significant were TMT (p:0.002, OR 0.45, 95%vCI: 0.28-0.75) and ALS FRS-R (p:0.023, OR: 0.80, 95%CI: 0.67-0.92). TMT seems to be a promising surrogate biomarker of survival and functional status in ALS. Our data deserve further investigations in multicenter and prospective trials.

FUS as a cause of familial Amyotrophic lateral sclerosis, a case report in a pregnant patient

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease. In 10% the disease is familial and rarely occurs in childbearing age women. A 28-year-old female pregnancy patient presented a two-month history of dropped head syndrome, dysphagia, muscle weakness, atrophy, and lingual wasting. Electromyography supported the diagnosis of ALS. Due to family history and background, we carried out molecular genetic testing. We identified a novel variant of uncertain significance: c. 1566 G > C (p.Arg522Ser) in exon 15 in FUS gene. Our findings provide the first case of ALS onset during pregnancy with a novel mutation in FUS gene reported in Mexico.

Tongue measurements and pharyngeal residue in amyotrophic lateral sclerosis

Aim: We aimed to analyze the relationship between tongue measurements and vallecular residue in patients with amyotrophic lateral sclerosis (ALS). Materials & methods: Twenty-one patients with ALS were assessed for posterior maximum tongue isometric pressure (PMTIP) and posterior tongue isometric endurance (PTIE) by the Iowa Oral Performance Instrument; vallecular residue after 10 ml of moderately thickened consistency by Fiberoptic Endoscopic Evaluation of Swallowing; and tongue thickness (TT) by ultrasonography. Results: PMTIP, PTIE and TT were decreased compared with the reference values for healthy individuals and were not different between patients with and without vallecular residue. Conclusion: In ALS, PMTIP, PTIE and TT are not good predictors of vallecular residue in the tested volume and food consistency.

Characteristics and Prognostic Factors of Swallowing Dysfunction in Patients with Lateral Medullary Infarction

OBJECTIVES

Lateral medullary infarction mainly impairs the pharyngeal phase of swallowing. We aimed to investigate the utility of the assessment tools of swallowing function in patients with lateral medullary infarction and to determine the factors that could predict the outcomes of swallowing function.

MATERIALS AND METHODS

15 patients with lateral medullary infarction who were admitted to Suiseikai Kajikawa Hospital between August 1, 2016, and March 31, 2020 (age 62.7 ± 14.8 years, 5 women) were enrolled in this prospective study. The diagnosis was made using brain magnetic resonance imaging. We analyzed the factors associated with severe swallowing dysfunction, which was defined as the necessity for tube feeding on the 90th day from admission, with multiple logistic regression analysis.

RESULTS

Multivariate analyses identified the repetitive saliva swallowing test, modified water swallowing test, and vertical spread of stroke lesions as independent significant factors affecting severe swallowing dysfunction (p = 0.002, 0.016, and 0.011, respectively). The sub-scores of the pharyngeal phase of the Mann Assessment of Swallowing Ability were also significantly associated with severe swallowing dysfunction (p < 0.001). However, tongue pressure, severe passage pattern abnormality on videofluoroscopic examination, and vertebral artery dissection were not significantly associated with swallowing dysfunction.

CONCLUSIONS

Since lateral medullary infarction presents with swallowing dysfunction mainly in the pharyngeal phase, tools that can be used to evaluate the pharyngeal phase of swallowing, such as repetitive saliva swallowing test and modified water swallowing test, are moreuseful than tongue pressure measurement.

Review Article "Spotlight on Ultrasonography in the Diagnosis of Peripheral Nerve Disease: The Evidence to Date"

Neuromuscular ultrasound is rapidly becoming incorporated into clinical practice as a standard tool in the assessment of peripheral nerve diseases. Ultrasound complements clinical phenotyping and electrodiagnostic evaluation, providing critical structural anatomical information to enhance diagnosis and identify structural pathology. This review article examines the evidence supporting neuromuscular ultrasound in the diagnosis of compressive mononeuropathies, traumatic nerve injury, generalised peripheral neuropathy and motor neuron disease. Extending the sonographic evaluation of nerves beyond simple morphological measurements has the potential to improve diagnostics in peripheral neuropathy, as well as advancing the understanding of pathological mechanisms, which in turn will promote precise therapies and improve therapeutic outcomes.

Longitudinal Changes of Tongue Thickness and Tongue Pressure in Neuromuscular Disorders

Background

Swallowing dysfunction is related to major cause of adverse events and an indicator of shorter survival among patients with neuromuscular disorders (NMD). It is critical to assess the swallowing function during disease progression, however, there are limited tools that can easily evaluate swallowing function without using videofluoroscopic or videoendoscopic examination. Here, we evaluated the longitudinal changes in tongue thickness (TT) and maximum tongue pressure (MTP) among patients with amyotrophic lateral sclerosis (ALS), myotonic dystrophy type 1 (DM1), and Duchenne muscular dystrophy (DMD).

Methods

Between 2010 and 2020, TT and MTP were measured from 21 ALS, 30 DM1, and 14 DMD patients (mean ages of 66.9, 44.5, and 21.4 years, respectively) at intervals of more than half a year. TT was measured, by ultrasonography, as the distance from the mylohyoid muscle raphe to the tongue dorsum, and MTP was determined by measuring the maximum compression on a small balloon when pressing the tongue against the palate. Then we examined the relationship between these evaluations and patient background and swallowing function.

Results

Mean follow-up periods were 24.0 months in the ALS group, 47.2 months in the DM1group, and 61.1 months in the DMD group. The DMD group demonstrated larger first TT than the other groups, while the DM1 group had lower first MTP than the ALS group. The ALS group showed a greater average monthly reduction in mean TT than the DM1 group and greater monthly reductions in mean body weight (BW) and MTP than the other groups. Significant differences between the first and last BW, TT, and MTP measures were found only in the ALS group.

Conclusions

This study suggests that ALS is associated with more rapid degeneration of tongue function over several years compared to DMD and DM1.

Relationship between tongue pressure and dysphagia diet in patients with acute stroke

A dysphagia diet is important for patients with stroke to help manage their nutritional state and prevent aspiration pneumonia. Tongue pressure measurement is a simple, non-invasive, and objective method for diagnosing dysphagia. We hypothesized that tongue pressure may be useful in making a choice of diet for patients with acute stroke. Using balloon-type equipment, tongue pressure was measured in 80 patients with acute stroke. On admission, a multidisciplinary swallowing team including doctors, nurses, speech therapists, and management dietitians evaluated and decided on the possibility of oral intake and diet form; the tongue pressure was unknown to the team. Diet form was defined and classified as dysphagia diet Codes 0 to 4 and normal form (Code 5 in this study) according to the 2013 Japanese Dysphagia Diet Criteria. In multivariate analysis, only tongue pressure was significantly associated with the dysphagia diet form (p<0.001). Receiver operating characteristic analyses revealed that the optimal cutoff tongue pressure for predicting diet Codes 1, 2, 3, 4, and 5 was 3.6 (p<0.001, area under the curve [AUC] = 0.997), 9.6 (p<0.001, AUC = 0.973), 12.8 (p<0.001, AUC = 0.963), 16.5 (p<0.001, AUC = 0.979), and 17.3 kPa (p<0.001, AUC = 0.982), respectively. Tongue pressure is one of the sensitive indicators for choosing dysphagia diet forms in patients with acute stroke. A combination of simple modalities will increase the accuracy of the swallowing assessment and choice of the diet form.

Dysphagia in a persistently vegetative patient improved by orthodontic treatment of severe dental misalignment

INTRODUCTION

We describe the treatment of severe dysphagia in a patient left in a persistent vegetative state after an episode of hypoxic-ischemic encephalopathy following a traffic accident.

CASE REPORT

A 38-year-old man was in a persistent vegetative state since a traffic accident in 2005, which resulted in cardiopulmonary arrest and hypoxic-ischemic encephalopathy. His airway had been secured with a tracheostomy, and a gastric tube had been inserted; however, he continued to suffer from urinary tract infections, glossoptosis, and silent aspiration of saliva. Both the maxilla and mandible had very narrow dental arches, with the mandibular incisors exhibiting severe lingual inclination.

COURSE

We first corrected the dentition in the narrow maxillary arch, followed by the mandibular arch. As the dental alignment improved, tongue movements appeared during oral care, and endoscopy also revealed signs of an active saliva swallowing reflex.

DISCUSSION

The "training approach" generally used to treat severe dysphagia is usually impossible in persistently vegetative patients. In our patient, the tongue movements and saliva swallowing reflex appeared after we expanded the narrow dental arches, suggesting that an orthodontic approach can be effective in such cases. Our findings can be applied to similar cases of vegetative patients to facilitate better oral care and outcomes.

Simplified cough test can predict the risk for pneumonia in patients with acute stroke

We investigated the association between the results of a simplified cough test and pneumonia onset in 226 patients with acute stroke admitted to Suiseikai Kajikawa Hospital from April to December, 2018. For the simplified cough test, performed on admission, patients orally inhaled a mist of 1% citric acid–physiological saline using a portable mesh nebulizer. When the first cough was evoked or if it remained absent for 30 seconds (indicating an abnormal result), the test was ended. Patients also completed the repetitive saliva swallowing test (RSST) and modified water swallowing test. We monitored patients for pneumonia signs for 30 days post-admission. Eighteen patients exhibited an abnormal simplified cough test result. On multivariate analysis, an abnormal RSST result was independently associated with an abnormal simplified cough test result. Seventeen patients developed pneumonia. The adjusted Cox proportional hazard model for pneumonia onset revealed that the simplified cough test had predictive power for pneumonia onset (hazard ratio, 10.52; 95% confidence interval, 3.72–29.72). The simplified cough test is a strong indicator for predicting the pneumonia development in patients with acute stroke; it should be added to existing bedside screening tests for predicting pneumonia risk, allowing appropriate and timely intervention.

Association between stroke lesions and videofluoroscopic findings in acute stroke patients

BACKGROUND AND PURPOSE

We aimed to assess stroke lesions, which play a key role in determining swallowing dysfunction, and findings of videofluoroscopy (VF), which provides the most accurate instrumental assessment for evaluating swallowing function, in patients with acute stroke.

METHODS

We enrolled 342 patients with first-time acute stroke (age 70.4 ± 12.6 years, 142 female). Patients with dementia and altered mental status due to severe stroke were excluded. All patients underwent cranial magnetic resonance imaging to identify the location of stroke lesion, VF, and tongue pressure measurement.

RESULTS

Aspiration was detected in 45 (13.2%) patients. Multivariate analysis identified parietal lobe lesion and the National Institutes of Health Stroke Scale (NIHSS) score as independent significant factors for aspiration (odds ratio 6.33, 95% confidence interval [CI] 2.25-17.84, p < 0.001; odds ratio 1.12, 95% CI 1.03-1.20, p = 0.004, respectively). Swallowing reflex delay was detected in 58 (17.0%) patients. Multivariate analysis identified habitual drinking, basal ganglia lesion, and the NIHSS score as independent significant factors for swallowing reflex delay (odds ratio 0.51, 95% CI 0.26-0.99, p = 0.047; odds ratio 1.91, 95% CI 1.09-3.67, p = 0.041; odds ratio 1.12, 95% CI 1.05-1.20, p < 0.001, respectively). Additionally, oral cavity and pharyngeal residues were independently associated with tongue pressure.

CONCLUSION

Parietal lobe lesions are associated with aspiration and basal ganglia lesions with swallowing reflex delay.

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 ± 5.9 years) and 33 elderly individuals requiring long-term care (14 men and 19 women; 83.6 ± 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 ± 7.24 kPa) than in posture 2 (37.6 ± 8.68 kPa) or posture 4 (38.2 ± 8.14 kPa) (P < 0.05). Tongue pressure was also significantly higher in posture 3 (41.3 ± 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.

Tongue thickness measured by ultrasonography is associated with tongue pressure in the Japanese elderly

The term "oral frailty" reflects the fact that oral health is associated with physical frailty and mortality. The gold standard methods for evaluating the swallowing function have several problems, including the need for specialized equipment, the risk of radiation exposure and aspiration, and general physicians not possessing the requisite training to perform the examination. Hence, several simple and non-invasive techniques have been developed for evaluating swallowing function, such as those for measuring tongue pressure and tongue thickness. The aim of this study was to investigate the relationship between tongue thickness ultrasonography and tongue pressure in the Japanese elderly. We evaluated 254 elderly patients, who underwent tongue ultrasonography and tongue pressure measurement. To determine tongue thickness, we measured the vertical distance from the surface of the mylohyoid muscle to the tongue dorsum using ultrasonography. The results of the analyses revealed that tongue thickness was linearly associated with tongue pressure in both sexes. In male participants, dyslipidemia, lower leg circumference, and tongue pressure were independently and significantly associated with tongue thickness. In female participants, body mass index and tongue pressure were independently and significantly associated with tongue thickness. The optimal cutoff for tongue thickness to predict the tongue pressure of < 20 kPa was 41.3 mm in males, and 39.3 mm in females. In the Japanese elderly, tongue thickness using ultrasonography is associated with tongue pressure. Tongue thickness and tongue pressure, which are sensitive markers for oral frailty, decrease with age. We conclude that tongue ultrasonography provides a less invasive technique for determining tongue thickness and predicts oral frailty for elderly patients.

Quantitative ultrasound of the tongue: Echo intensity is a potential biomarker of bulbar dysfunction in amyotrophic lateral sclerosis

OBJECTIVES

To learn if quantitative ultrasound (QUS) distinguishes the tongues of healthy participants and amyotrophic lateral sclerosis (ALS) patients by echo intensity (EI) and to evaluate if EI correlates with measures of bulbar function.

METHODS

Ultrasound was performed along the midline of the anterior tongue surface in 16 ALS patients and 16 age-matched controls using a linear hockey stick 16-7 MHz transducer. A region of interest was manually drawn and then EI was determined for the upper 1/3 of the muscle. For patients, the ALS functional rating scale - revised (ALSFRS-R) was used to calculate bulbar sub-scores and the Iowa Oral Performance Instrument (IOPI) was used to measure tongue strength.

RESULTS

EI was significantly higher in ALS patients than in healthy participants (49.8 versus 37.8 arbitrary units, p < 0.01). In the patient group, EI was negatively correlated with ALSFRS-R bulbar sub-score (R_S = -0.65, p < 0.01). An inverse correlation between EI and tongue strength did not reach significance (R_S = -0.34, p = 0.28).

CONCLUSIONS

This study suggests that EI can differentiate healthy from diseased tongue muscle, and correlates with a standard functional measure in ALS patients.

SIGNIFICANCE

Tongue EI may represent a novel biomarker for bulbar dysfunction in ALS.

How Do Orodispersible Tablets Behave in an In Vitro Oral Cavity Model: A Pilot Study

Orodispersible tablets (ODTs) offer rapid disintegration of the dosage form when placed on the tongue, which leads to fast release of the active pharmaceutical ingredient. Despite increased use in diverse patient populations, there have been numerous challenges associated with ODTs. One such concern is the lack of standardised assessment of disintegration behaviour. In the European Pharmacopoeia, ‘orodispersibles’ are defined as such if disintegration time is faster than 3 min. Common in vitro measurement methods only provide single time point data and have limited physiological accuracy. To determine more bio-predictive disintegration kinetics, a bench-top in vitro oral cavity model (OCM) was modified and piloted to assess disintegration of three ODTs of differing hardness. All ODTs disintegrated similarly within the OCM—surface breakdown/swelling, initial ‘wash away’ and final ‘wash away’. The distinct advantage presented within this pilot study using the OCM is the opportunity to ascertain disintegration behaviour profiles of ODTs by evaluating changes in the observable area during simulated oral processing. The model could be implemented as a decision-support tool during the early stages of the drug design process to improve acceptability and further understand ODT disintegration behaviour.

Sonographic and 3T-MRI-based evaluation of the tongue in ALS

A few systematic imaging studies employing ultrasound (HRUS) and magnetic resonance imaging (MRI) have suggested tongue measures to aid in diagnosis of amyotrophic lateral sclerosis (ALS). The relationship between structural tongue alterations and the ALS patients' bulbar and overall motor function has not yet been elucidated. We here thus aimed to understand how in-vivo tongue alterations relate to motor function and motor function evolution over time in ALS. Our study included 206 ALS patients and 104 age- and sex-matched controls that underwent HRUS and 3T MRI of the tongue at baseline. Sonographic measures comprised coronal tongue echointensity, area, height, width and height/width ratio, while MRI measures comprised sagittal T1 intensity, tongue area, position and shape. Imaging-derived markers were related to baseline and longitudinal bulbar and overall motor function. Baseline T1 intensity was lower in ALS patients with more severe bulbar involvement at baseline. Smaller baseline coronal (HRUS) and sagittal (MRI) tongue area, smaller coronal height (HRUS) and width (HRUS) as well as more rounded sagittal tongue shape predicated more rapid functional impairment - not only of bulbar, but also of overall motor function - in ALS. Our results suggest that in-vivo sonography und MRI tongue measures could aid as biomarkers to reflect bulbar and motor function impairment.

Multi-dimensional electrical impedance myography of the tongue as a potential biomarker for amyotrophic lateral sclerosis

OBJECTIVE

In amyotrophic lateral sclerosis (ALS) bulbar disease biomarkers are lacking. We evaluated a novel tongue electrical impedance myography (EIM) system, utilising both 2D and 3D electrode configurations for detection of tongue pathology.

METHODS

Longitudinal multi-frequency phase angle spectra were recorded from 41 patients with ALS (baseline, 3 and 6 months) and 30 healthy volunteers (baseline and 6 months). ALS functional rating scale-revised (ALSFRS-R) data and quantitative tongue strength measurements were collected. EIM data were analysed for reliability (intra-class correlation coefficient; ICC) and differences between patients and volunteers ascertained using both univariate (Mann-Whitney U test) and multivariate techniques (feature selection and L2 norm).

RESULTS

The device produced highly reliable data (pooled ICC: 0.836). Significant EIM differences were apparent between ALS patients and healthy volunteers (P < 0.001). EIM data demonstrated a significant relationship to tongue strength and bulbar ALSFRS-R scores (P < 0.015). The EIM recordings revealed a group level longitudinal change over 6 months and consistently identified patients in whom symptoms or tongue strength changed.

CONCLUSIONS

The novel EIM tongue system produces reliable data and can differentiate between healthy muscle and ALS-related disease.

SIGNIFICANCE

Tongue EIM utilising multiple frequencies and electrode configurations has potential as a bulbar disease biomarker in ALS.

Clinical and research applications of neuromuscular ultrasound in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by dysfunction at multiple levels of the neuraxis. It remains a clinical diagnosis without a definitive diagnostic investigation. Electrodiagnostic testing provides supportive information and, along with imaging and biochemical markers, can help exclude mimicking conditions. Neuromuscular ultrasound has a valuable role in the diagnosis and monitoring of ALS and provides complementary information to clinical assessment and electrodiagnostic testing as well as insights into the underlying pathophysiology of this disease. This review highlights the evidence for ultrasound in the evaluation of bulbar, limb and respiratory musculature and peripheral nerves in ALS. Further research in this evolving area is required.

Ultrasonography in Peripheral Nervous System Diagnosis

PURPOSE OF REVIEW

High-resolution ultrasound has made it possible to view most nerves and muscles in real time and to identify pathologic change in size, echo texture, and vascularity. This article focuses on the principles underlying ultrasound imaging and the application of ultrasound imaging to clinical disorders commonly seen in an electrodiagnostic laboratory.

RECENT FINDINGS

Ultrasound is a sensitive and specific tool for evaluating myopathic and neurogenic muscle disease. It provides useful information about muscles difficult to study with other technologies, such as the tongue and diaphragm, and is also helpful in evaluating smaller muscles in the hands or feet where correlation with electrodiagnostic studies is possible. For nerves, the resolution of ultrasound is such that it can sensitively identify focal nerve enlargement, which is accurate in the diagnosis of entrapment neuropathies. Furthermore, it can recognize diffuse or multifocal nerve enlargement seen in hereditary and inflammatory neuropathies.

SUMMARY

Neuromuscular ultrasound is an informative noninvasive tool for evaluating nerve and muscle disease. As the technology continues to advance and becomes widely available, it may become a routine part of residency training, neuromuscular research, and clinical practice.

Enhanced Bulbar Function in Amyotrophic Lateral Sclerosis: The Nuedexta Treatment Trial

The goal of this randomized, blinded, crossover clinical trial was to determine whether Nuedexta (dextromethorphan and quinidine) enhanced speech, swallowing, and salivation in patients with ALS. Sixty patients with amyotrophic lateral sclerosis (ALS) received either Nuedexta or placebo for 28 to 30 days, followed by a 10 to 15-day washout period. Subsequently, patients were switched to the opposite treatment arm for the remaining days of the trial. The primary endpoint was a reduction in the self-report Center for Neurologic Study Bulbar Function Scale (CNS-BFS) score. The rater-administered ALS Functional Rating Scale Revised was the principal secondary endpoint. The CNS-BFS score improved with active treatment, decreasing from a mean of 59.3 in the placebo arm of the trial to 53.5 during the drug-treatment arm (p < 0.001). Each of the individual domains of bulbar function interrogated by the CNS-BFS responded to treatment with Nuedexta as follows: salivation: 15.8 versus 14.3 (p = 0.004); speech: 24.6 versus 22.2 (p = 0.003); swallowing: 18.9 versus 17.1 (p = 0.009). Similarly, the bulbar component of the ALS Functional Rating Scale Revised improved with active treatment (p = 0.003), although the drug did not affect the motor and respiratory components of this scale. This study is unique for several reasons. Firstly, it was driven by patient reports of improved speech and swallowing while taking Nuedexta for control of emotional lability. Secondly, the study was conducted over a short duration (70 days), and thirdly, a self-report scale was selected as the principle outcome measure. Considering the importance of bulbar functions, these results, if confirmed, point to an additional use of Nuedexta as an adjunct to the management of ALS.

Trends in Research Literature Describing Dysphagia in Motor Neuron Diseases (MND): A Scoping Review

Dysphagia in motor neuron diseases (MNDs) is highly complex, affecting all stages of swallowing and leading to impaired swallowing safety and efficiency. In order to explore the degree to which research is capturing the symptom of dysphagia in MND, we conducted a scoping review of the existing literature. The primary aims of this review were to identify common themes within the literature on dysphagia in MND, explore patterns and trends in research focus, and identify if any imbalances exist between the research themes related to dysphagia description and management. A comprehensive search strategy yielded 1690 unique articles for review. Following relevance screening, a total of 157 articles were included in the synthesis. Relevant data and keywords were extracted from each article and grouped into themes. Frequency estimates were calculated for each theme to identify trends across research literature. Swallowing impairment in MNDs is described in a variety of ways across current research. The most commonly reported theme was Aspiration/Penetration, mentioned in 73.2% of all included articles; a significant imbalance was identified between reports of swallowing safety and efficiency (p = 0.008). The most frequently reported theme related to dysphagia management was Enteral Nutrition, and very few studies have reported on the efficacy of Rehabilitation/Compensatory recommendations. It is suggested that researchers and clinicians remain mindful of imbalances and gaps in research, and aim to characterize dysphagia in MNDs in a comprehensive manner. Further research investigating discrete, measureable changes in swallowing pathophysiology would be beneficial to delineate the key factors contributing to impaired swallowing safety and efficiency.

Dynamic muscle ultrasound identifies upper motor neuron involvement in amyotrophic lateral sclerosis

OBJECTIVE

The aim of the present study was to elucidate the pattern of change in bulbar muscles using ultrasound in patients diagnosed with amyotrophic lateral sclerosis (ALS).

METHODS

Changes in the mylohyoid and geniohyoid muscle complex (mylohyoid-geniohyoid-muscle-complex) thickness were recorded while swallowing 5 ml of water using M-mode ultrasound in 30 ALS patients compared to 20 healthy controls. The ratio of mylohyoid-geniohyoid-muscle-complex thickness as determined by the maximum thickness of mylohyoid-geniohyoid-muscle-complex during swallowing divided by thickness at rest, was compared between ALS patients and controls, with the correlation between thickness ratio, echogenicity and clinical parameters assessed.

RESULTS

Overall, the thickness ratio in ALS patients was 1.39 ± 0.23 (mean ± SD) compared to 1.55 ± 0.17 in controls (p < 0.05). In sub-analysis, the thickness ratio was significantly decreased in ALS patients with bulbar-onset disease compared to those with limb-onset disease (p < 0.01) and controls (p < 0.01). Thickness ratio negatively correlated with the severity of upper motor neuron involvement in the bulbar region (p < 0.05).

CONCLUSIONS

Bulbar muscle ultrasound represents a novel method to detect impaired mobility and thereby provides an objective assessment of upper motor neuron involvement in the bulbar region of ALS patients.

Prediction of Pneumonia in Acute Stroke Patients Using Tongue Pressure Measurements

Swallowing dysfunction caused by stroke is a risk factor for aspiration pneumonia. Tongue pressure measurement is a simple and noninvasive method for evaluating swallowing dysfunction. We have hypothesized that low tongue pressure may be able to predict pneumonia occurrence in acute stroke patients. Tongue pressure was measured using balloon-type equipment in 220 acute stroke patients. The modified Mann Assessment of Swallowing Ability (MASA) score was evaluated independently on the same day. Tongue pressure was measured every week thereafter. An improvement in tongue pressure was observed within the first 2 weeks. Receiver operating curve analysis was performed to determine the ability of tongue pressure to predict modified MASA score <95, which suggests swallowing dysfunction. The optimal cutoff for tongue pressure was 21.6 kPa (χ2 = 45.82, p<0.001, sensitivity 95.9%, specificity 91.8%, area under the curve = 0.97). The tongue pressure was significantly lower in patients with pneumonia than in those without pneumonia. Using a Cox proportional hazard model for pneumonia onset with a cutoff tongue pressure value of 21.6 kPa and adjustment for age, sex, and National Institutes of Health Stroke Scale score at admission, the tongue pressure had additional predictive power for pneumonia onset (hazard ratio, 7.95; 95% confidence interval, 2.09 to 52.11; p = 0.0013). In the group with low tongue pressure, 27 of 95 patients showed improvement of tongue pressure within 2 weeks. Pneumonia occurred frequently in patients without improvement of tongue pressure, but not in patients with improvement (31/68 and 2/27, p<0.001). Tongue pressure is a sensitive indicator for predicting pneumonia occurrence in acute stroke patients.