Outcome of Surgery to Improve Swallowing in Patients with Lateral Medullary Syndrome: A Retrospective Cohort Study.

The study investigated surgical interventions to improve dysphagia in patients with lateral medullary syndrome (LMS), along with optimal scheduling of surgery and prognostic factors. In this retrospective, single-center cohort study, dysphagia patients with LMS who underwent surgery between January 2010 and December 2021 were enrolled. The National Outcomes Measurement System (NOMS) was used to classify swallowing function (level 1: only tube feeding, level 5: without tube feeding). Patients were divided into four groups. Groups 1 and 2, LMS onset within 1 year, and groups 3 and 4, onset after 1 year. Groups 1 and 3 had infarctions confined to the oblongata. Groups 2 and 4 had infarctions extending to the cerebellum. The primary outcome was the time to achieve NOMS ≥ 5. The final NOMS level and pathological findings were considered. Nineteen cases were included. Group 4 comprised one case and was excluded. The mean overall preoperative NOMS was 1.11. The mean time to NOMS ≥ 5 was 9.6 months (95% confidence interval: 5.04-14.2), and that to NOMS ≥ 5 was 1.67 (1.07-2.26), 11.4 (4.71-18.1), and 7.6 (5.15-10.1) months for groups 1, 2, and 3, respectively. Group 1 achieved NOMS ≥ 5 earlier than groups 2 and 3 (P = 0.01 and 0.03, respectively). The overall final NOMS value was 4.68. Fourteen patients had atrophy or fibrosis of the cricopharyngeal muscle. In conclusion, surgery was effective for effective for treating dysphagia in LMS patients. However, improvement is prolonged if > 1 year has passed since onset or the infarction extended to the cerebellum.

Post-intubation laryngeal injury after COVID-19 treatment causing dyspnea: A report of six cases.

Severe cases of COVID-19 often require orotracheal intubation (OTI) and mechanical ventilation, and post-intubation laryngeal injury (PI-LI) is one of the important complications of OTI. Some studies have claimed that the frequency of PI-LI may be higher in COVID-19 patients as compared with that in non-COVID-19 patients, because of the larger size of endotracheal tube used, the longer OTI time, use of prone positioning of the patients, etc. Herein, we describe six cases of PI-LI who presented with dyspnea after recovering from COVID-19. Five of the patients were male and the median OTI period was 9 days. All the patients showed abnormal endoscopic findings, including posterior glottic synechiae/stenosis or subglottic/posterior glottic granulomas. Four patients required surgical intervention, including tracheostomy, laryngomicrosurgery, or laterofixation of the vocal cord. Many post-COVID-19 patients experience persistent symptoms (post-COVID-19 syndrome), including dyspnea. Two of our patients with dyspnea had been treated by internists as cases of post-COVID-19 syndrome. Therefore, we wish to underscore the need for every healthcare professional to be aware of the possibility of PI-LI after OTI, especially during the ongoing COVID-19 pandemic. Otolaryngologists should undertake endoscopic assessment of the larynx in patients presenting with dyspnea after recovering from COVID-19.

Prevention of cuff injury of the intubation tube by blunt window opening in tracheostomy.

One of the intraoperative complications of tracheostomy under general anesthesia is cuff injury of the intubation tube. In the present study, we investigated whether a blunt tracheal opening is a useful method to avoid cuff injury. A retrospective cohort study was conducted to examine patients who underwent tracheostomy under general anesthesia at a single institution from January 1, 2017 to July 31, 2021. Electrocautery was used to thin the connective tissue between the tracheal rings, and bluntly open the trachea with mosquito forceps or similar instruments. Primary outcomes included cuff injury rate, number of surgeons involved, and career as otolaryngologist at the time of surgery. The secondary outcome was perioperative complications. Of the 64 cases, 3 had cuff injuries. 2 of the 3 had cuff injuries during the creation of an anteriorly based flap. 16 surgeons were involved ranging from the first to sixth year as an otolaryngologist, with the third year of otolaryngologist being the most common. The median physician year for instructors was 18 years. The most common postoperative complication was granulation in 9 cases. There were no cases of incorrect cannula insertion or difficulty in cannula insertion. A blunt tracheal opening was considered useful as a method to prevent cuff injury.

Survival case of rhinocerebral and pulmonary mucormycosis due to Cunninghamella bertholletiae during chemotherapy for acute myeloid leukemia: a case report.

A 42-year-old man diagnosed with acute myeloid leukemia complained of progressive swelling of the right side of his face with pain 11 days after the third cycle of consolidation therapy with high-dose arabinosylcytosine-cytarabine. Head and neck magnetic resonance imaging showed a mass lesion in his right maxillary sinus with parapharyngeal involvement, which included the right masseter muscle, intraorbital involvement, and an abscess in his brain. Chest computed tomography revealed peribronchial small nodules in his right upper lobe and a necrotic tumor in his right lower lobe. Molds identified as Cunninghamella bertholletiae were isolated from the necrotic ulcer. According to these results, chemotherapy for leukemia was discontinued. High-dose liposomal amphotericin (10 mg/kg/day) was initiated. Because renal dysfunction occurred, the dosage was decreased to 6 mg/kg and combined with 150 mg/day micafungin. Debridement of necrotic tissue in the right maxillary sinus and establishment of the fenestration between the sinus and oral cavity were performed. Subsequently, brain and lung lesions were surgically removed. Rhinocerebral mucormycosis was successfully treated without relapse over 3 years by a 112-day course of intravenous anti-fungal therapy and 223-day course of terbinafine and partial surgical removal, respectively, to maintain masticatory and ocular functions. To our knowledge, there has been no other report of a long-term survival case of rhinocerebral mucormycosis due to C. bertholletiae.

High-speed Videolaryngoscopy: Quantitative Parameters of Glottal Area Waveforms and High-speed Kymography in Healthy Individuals.

OBJECTIVES: We conducted a study to obtain quantitative parameters of the vocal dynamic using high-speed videolaryngoscopy and to characterize the vocal fold vibration pattern of healthy individuals by analyzing glottal area waveforms and high-speed kymography. METHODS: Laryngeal images of 45 healthy individuals were captured using high-speed videolaryngoscopy. The open and speed quotients of the glottal area waveforms and high-speed kymography were obtained and statistically analyzed according to the gender of each individual. RESULTS: Glottal area waveforms revealed average values of 0.85 and 1.16 for open and speed quotients, respectively, for women, and 0.70 and 1.19 for men. Using high-speed kymography, quantitative parameters of open and speed quotients for women were 0.62 and 1.02, respectively, and for men were 0.57 and 1.12. By gender, a significant statistical difference emerged for open quotients obtained from both glottal area waveforms (P = 0.004) and high-speed kymography (P = 0.013). CONCLUSION: Obtained by using computational tools specifically for analyzing laryngeal images from high-speed videolaryngoscopy, quantitative parameters of glottal area waveforms and high-speed kymography in healthy individuals provide reference data and normality for future studies.

Visualization and Estimation of Vibratory Disturbance in Vocal Fold Scar Using High-Speed Digital Imaging.

OBJECTIVE: To explore the method to visualize and quantify the abnormality of vocal fold vibration in vocal fold scar (VFS) using high-speed digital imaging (HSDI). METHODS: HSDI was performed on 12 patients (2 men and 10 women) with VFS and 46 vocally healthy subjects (17 men and 29 women), and the obtained data were quantitatively evaluated by frame-by-frame analysis, laryngotopography (LTG), single-line and multiline kymography, and glottal area waveform. RESULTS: Visualization of a scarred area was feasible in 75% of VFS in the present study using LTG. Quantitative HSDI analysis revealed that VFS had poorer glottal closure (eg, larger open quotients, larger minimal glottal area), reduced vibration in a scarred area (eg, smaller mucosal wave magnitude, mucosal wave persistence, lateral peak index), and greater asymmetry (eg, amplitude difference, mucosal wave magnitude difference, lateral phase difference) than the control group. Correlation study revealed moderate correlations between HSDI-derived parameters and conventional acoustic or aerodynamic parameters (eg, period perturbation quotient). CONCLUSIONS: HSDI is considered to be useful in the diagnosis of VFS, visualization of a scarred area, and quantification of vibratory abnormality.

Quantitative Analysis of Vocal Fold Vibration in Vocal Fold Paralysis With the Use of High-speed Digital Imaging.

INTRODUCTION: The goal of this work was to objectively elucidate the vibratory characteristics of vocal fold paralysis (VFP) using high-speed digital imaging (HSDI). METHODS: HSDI was performed in 29 vocally healthy subjects (12 women and 17 men) and in 107 patients with VFP (40 women and 67 men). Then, the HSDI data were evaluated by visual-perceptual rating, single-line kymography, multiline kymography, laryngotopography, and glottal area waveform analysis. RESULTS: Patients with VFP compared with vocally healthy subjects revealed more frequent incomplete glottal closure, greater asymmetry in amplitude, mucosal wave, frequency, and phase, as well as larger open quotient, smaller speed index, larger maximal and minimal glottal area, and smaller glottal area difference. Paralyzed vocal folds in VFP revealed reduced mucosal wave than nonparalyzed vocal folds in VFP or in intact vocal folds in vocally healthy subjects. CONCLUSIONS: HSDI was effective in documenting the characteristics of vocal fold vibrations in patients with VFP and in exploring the vibratory disturbance for estimating the severity of dysphonia.

Quantification of Vocal Fold Vibration in Various Laryngeal Disorders Using High-Speed Digital Imaging.

OBJECTIVE: To quantify vibratory characteristics of various laryngeal disorders seen by high-speed digital imaging (HSDI). METHODS: HSDI was performed on 78 patients with various laryngeal disorders (20 with polyp, 16 with carcinoma, 13 with leukoplakia, 6 with vocal fold nodule, and 33 with others) and 29 vocally healthy subjects. Obtained data were quantitatively evaluated by frame-by-frame analysis, laryngotopography, digital kymography, and glottal area waveform. RESULTS: Overall, patients with laryngeal pathologies showed greater asymmetry in amplitude, mucosal wave and phase, smaller mucosal wave, and poorer glottal closure than vocally healthy subjects. Furthermore, disease-specific vibratory disturbances that generally agreed with the findings in the literature were quantified: comparing polyp with nodule, differences were noted in longitudinal phase difference, amplitude, and mucosal wave. In comparison with leukoplakia and cancer, nonvibrating area was more frequently noted in cancer. CONCLUSIONS: The HSDI analysis of various voice disorders using multiple methods can help phonosurgeons to properly diagnose various laryngeal pathologies and to estimate the degree of their vocal disturbances.

Estimation of inferior-superior vocal fold kinematics from high-speed stereo endoscopic data in vivo.

Despite being an indispensable tool for both researchers and clinicians, traditional endoscopic imaging of the human vocal folds is limited in that it cannot capture their inferior-superior motion. A three-dimensional reconstruction technique using high-speed video imaging of the vocal folds in stereo is explored in an effort to estimate the inferior-superior motion of the medial-most edge of the vocal folds under normal muscle activation in vivo. Traditional stereo-matching algorithms from the field of computer vision are considered and modified to suit the specific challenges of the in vivo application. Inferior-superior motion of the medial vocal fold surface of three healthy speakers is reconstructed over one glottal cycle. The inferior-superior amplitude of the mucosal wave is found to be approximately 13 mm for normal modal voice, reducing to approximately 3 mm for strained falsetto voice, with uncertainty estimated at σ ≈ 2 mm and σ ≈ 1 mm, respectively. Sources of error, and their relative effects on the estimation of the inferior-superior motion, are considered and recommendations are made to improve the technique.

Vocal fold atrophy in a Japanese tertiary medical institute: status quo of the most aged country.

OBJECTIVE: Voice problems in the geriatric population are increasing worldwide. Since the demographic research of geriatric voice patients in Japan, the country of the most advanced Aging Society, is missing, the authors assessed the current trend of geriatric voice patients, especially patients with presbylarynx at a tertiary medical institute of Japan. STUDY DESIGN: Retrospective study. METHODS: From a review of the medical records of newly referred patients, patients aged 65 years and older and patients with vocal fold atrophy were selected, and demographic data, questionnaires, and parameters of aerodynamic and acoustic study, and videostroboscopy were analyzed in terms of age and gender. Subsequently, the difference between patients with presbylarynx and 20 vocally healthy elderly subjects were assessed with multivariate analysis. RESULTS: Of 1157 newly referred patients seen at the Voice Outpatient Clinic between 2006 and 2012, patients aged 65 years and older accounted for 37% (428 patients): there was 7% increase during the past 7 years and the prevalence was considerably higher than any other previous reports. Vocal fold atrophy accounted for 11% (128 patients) of all patients: dysphonia in patients with vocal fold atrophy aggravated as age advanced; there was a gender difference; and multivariate analysis revealed that reflux laryngitis, chronic medical condition, and vocal abuse were risk factors of presbylarynx. CONCLUSION: In Japan, elderly dysphonic patients were prevalent and rapidly increasing in recent years. Age- and gender-related differences should receive attention. Preventive approach on risk factors such as reflux laryngitis, chronic medical condition, and vocal abuse should be considered in the management of presbylarynx.

Evaluation of vocal fold vibration with an assessment form for high-speed digital imaging: comparative study between healthy young and elderly subjects.

OBJECTIVES/STUDY DESIGN: We conducted a prospective study with a subjective assessment form for high-speed digital imaging (HSDI) to elucidate the features of vocal fold vibrations in vocally healthy subjects and to clarify gender- and age-related differences. METHODS: Healthy adult volunteers participated in this study. They were divided into young (aged 35 and younger) and elderly (aged 65 and older) groups, and the scores of an assessment form for HSDI characteristics elaborated at our institution were statistically analyzed. RESULTS: Twenty-six young subjects (males: 9, females: 17; mean age: 27 years) and 20 elderly subjects (males: 8, females: 12; mean age: 72 years) were assigned to our study. Posterior gap and posterior-to-anterior longitudinal phase difference were characteristic to young females, whereas in young males, mucosal wave, anterior-to-posterior longitudinal phase difference, and supraglottic hyperactivity were frequent. In elderly males, axis shift, asymmetry, supraglottic hyperactivity, increased mucosal wave, lateral phase difference, and anterior-to-posterior longitudinal phase difference were frequent; and in elderly females, high incidence of lateral phase difference, atrophic change, anterior gap, and asymmetry were observed. CONCLUSIONS: The results show that the behaviors of vocal fold vibrations were diverse even in healthy subjects with no vocal complaints or history of laryngeal diseases, and hence, the diversity of vocal fold vibrations in normal subjects must be taken into account in evaluating vocal fold vibrations.

Single institutional analysis of trends over 45 years in etiology of vocal fold paralysis.

OBJECTIVE: It is important to assess the causes of vocal fold paralysis. Many studies have reported causes of paralysis, but few reports have shown changes in longitudinal etiology in a single institution. METHODS: We investigated the medical records of 797 patients with vocal fold paralysis from 1990 to 2005 at the voice and bronchoesophageal outpatient clinics at the University of Tokyo Hospital. We evaluated the etiology of paralysis, and compared our results with a previous study by Hirose in our clinic from 1961 to 1989 to assess changes in etiology. RESULTS: The postoperative group comprised 466 patients (58.5%), while the non-surgical group comprised 331 (41.5%) patients. In the postoperative group, the most common cause of paralysis was thyroid surgery (106 cases), and other common causes were surgery for aortic aneurysm (61 cases) and tracheal intubation (58 cases). In the non-surgical group, idiopathic paralysis (134 cases) was the most common cause. Other common causes were lung cancer (34 cases) and cerebrovascular disease (24 cases). In a previous study from our clinic, the rate of postoperative paralysis was 43.5%. In the current analysis, the percentage of postoperative patients has increased remarkably compared with that of the previous report while the rate of idiopathic paralysis, has decreased by half. CONCLUSION: The increase in postoperative cases of paralysis may be caused by the increasing frequency of operations for many diseases, due to the progress of medical techniques in recent years. The decrease in idiopathic cases may be related to the advances of diagnostic devices such as CT and MRI.

Arytenoid adduction for correcting vocal fold asymmetry: high-speed imaging.

OBJECTIVES: We hypothesized that high-speed digital imaging provides a quantitative method to evaluate the effect of arytenoid adduction for the correction of asymmetric and irregular vocal fold vibration in unilateral vocal fold paralysis. METHODS: Six subjects with unilateral vocal fold paralysis participated in the study (4 male, 2 female; mean [-SD] age, 52.5 +/- 21.3 years). Videokymographic and laryngotopographic methods for image analysis were performed for high-speed recordings of vocal fold vibration for visualizing the glottal vibratory patterns, and for quantifying the frequency of vibration of each vocal fold, respectively. Comparisons of the paralyzed and the normal vocal folds were made before and after arytenoid adduction. RESULTS: Analysis of the laryngotopographs revealed 2 distinct frequencies of vibration for the paralyzed and the contralateral vocal folds for all subjects before surgery. After arytenoid adduction, the vibration frequencies became identical or nearly identical in all subjects. CONCLUSIONS: Asymmetric vibration in vocal fold paralysis was exemplified by differences in vibration frequency between the vocal folds. The present data showed that after arytenoid adduction the vibration frequencies and the vibratory patterns of the contralateral vocal folds approached symmetry. This surgical procedure could improve the functional symmetry of the larynx for phonation.

Collagen injection for correcting vocal fold asymmetry: high-speed imaging.

OBJECTIVES: We hypothesized that high-speed digital imaging with videokymographic and laryngotopographic analysis would provide a quantitative method to evaluate the effect of collagen injection for the correction of asymmetric and irregular vocal fold vibration in unilateral vocal fold paralysis. METHODS: Videokymographic and laryngotopographic analysis was performed for high-speed digital recordings of vocal fold vibration for visualizing the glottal vibratory patterns, and for quantifying the frequency of vibration of each vocal fold, respectively, including comparisons between the paralyzed and normal vocal folds before and after surgery. This included prospective observations of 11 subjects with unilateral vocal fold paralysis (4 male, 7 female; mean +/- SD age, 67.1 +/- 12.0 years) using high-speed digital image analysis before and after collagen injection. RESULTS: Analysis of the laryngotopographs revealed 2 distinct frequencies of vibration for the paralyzed and contralateral vocal folds for 8 of the 11 subjects before surgery. After collagen injection, the vibration frequencies became identical, despite asymmetric vibration amplitudes. Asymmetric vibration amplitudes were also observed in the other 3 subjects before surgery, but the amplitudes became symmetric after collagen injection, despite a persistent phase shift. CONCLUSIONS: Asymmetric vibration in vocal fold paralysis was exemplified by differences in vibration frequency and amplitude between the vocal folds. The present study showed that after collagen injection, these aspects of vibratory patterns improved toward symmetry. This surgical procedure could improve the functional symmetry of the larynx for phonation.

High-speed digital imaging of the neoglottis after supracricoid laryngectomy with cricohyoidoepiglottopexy.

OBJECTIVE: To determine the utility of high-speed digital imaging (HSDI) in evaluating vocal kinetics of the neoglottis after supracricoid laryngectomy with cricohyoidoepiglottopexy (SCL-CHEP). STUDY DESIGN: Case series. SETTING: The University of Tokyo Hospital. SUBJECTS AND METHODS: High-speed digital recordings of laryngeal images were obtained from six patients after SCL-CHEP to clarify the vocal kinetics of the postoperative neoglottis. Simultaneous recording of electroglottograms (EGGs) were obtained and multiline kymograms were generated on the basis of the recorded images. The distribution of frequency, amplitude, and phase in the neoglottis were visualized by using gradients of colors superimposed onto the glottal and supraglottal areas of laryngeal images to produce laryngeal topograms. Furthermore, waveforms of estimated laryngeal sound source (ELSS) were obtained on the basis of glottal inverse filtering of the vocal signal to reflect vibratory motions in the neoglottis. The vibratory part of the neoglottis was determined as a possible sound source when the frequencies of the ELSS, EGG, and laryngeal topograms, as well as the waveforms of ELSS, EGG, and kymograms, were consistent with each other. RESULTS: Spaces between the arytenoid(s) and epiglottis (5 patients) or pyriform sinus mucosa (1 patient) were estimated as the major source of sound during postoperative vocalization. The possible sound source could be determined by HSDI, even in the neoglottis, with more than one vibratory position. CONCLUSION: HSDI could be useful for evaluating the vocal kinetics of the neoglottis after SCL-CHEP.

An effective management regimen for laryngeal granuloma caused by gastro-esophageal reflux: combination therapy with suggestions for lifestyle modifications.

According to our previous study, lifestyle modification in combination with drug therapy is much more effective than drug therapy alone in cases of laryngopharyngeal reflux (LPR). Most patients with LPR will have chronic gastro-esophageal reflux diseases (GERD) and require long-term medical therapy for control, resulting in high total expenditure on pharmacologic agents. We combined pharmacologic management with lifestyle modifications for the management of GERD with successful outcomes in patients with GERD-related laryngeal granulomas. Although further studies are needed, guidance concerning lifestyle modifications in combination with PPI therapy may be not only a clinically effective but also a cost-effective method for the management of laryngeal granulomas caused by gastro-esophageal reflux.

Tonsillar cyst of the false vocal cord.

OBJECTIVES/HYPOTHESIS: To report, for the first time, tonsillar cyst of the false vocal cord. STUDY DESIGN: Case report. METHODS: Case presentation and literature review. RESULTS: A 74-year-old woman with a mass in the false vocal cord presented with hoarseness. Histopathological examination revealed tonsillar cyst. Marsupialization via microlaryngeal approach failed. Finally the cyst was resected successfully through a lateral cervical approach with concomitant tracheotomy. CONCLUSIONS: This is the first report of tonsillar cyst in the false vocal cord in English literature. The cyst was finally resected through the lateral cervical approach with success.

Clinical usefulness of endoscopic intranasal dacryocystorhinostomy.

CONCLUSIONS: Endoscopic intranasal dacryocystorhinostomy (DCR) has the following advantages over external surgery: pain and hemorrhage are minimal; postoperative facial swelling and scarring are absent; and symptoms resolve rapidly after surgery. Furthermore, as no significant differences in postoperative results were apparent between external and endoscopic intranasal DCR, and because no facial skin incision is required, the clinical usefulness of endoscopic intranasal DCR is high. OBJECTIVES: In the treatment of nasolacrimal duct obstruction or chronic dacryocystitis in which epiphora or ocular discharge are chief complaints, endoscopic intranasal DCR is a safe, easy, minimally invasive, and reliable approach. In the present study, we describe the surgical procedures, techniques, and results of endoscopic intranasal DCR, and investigate its clinical usefulness. SUBJECTS AND METHODS: The subjects were 21 patients with nasolacrimal duct obstruction who underwent a total of 24 endoscopic intranasal DCR procedures. Etiologies of the obstruction were, respectively, cryptogenic (62.5%), secondary to partial maxillectomy (16.7%), complication of sinus surgery (12.5%), and due to underlying disease--Wegener's granulomatosis (4.2%) or nasal T-cell lymphoma (4.2%). To assess the clinical usefulness of this procedure, postoperative courses were assessed by reviewing medical records and conducting telephone interviews. In addition, to assess the therapeutic effects, postoperative results were statistically compared to those of external DCR. RESULTS: Closure of the surgical opening was seen in two cases (8.3%). In both cases, after the closed region was opened using an endoscopic procedure, symptoms resolved. Finally, lacrimal passage obstruction was not observed by lacrimal irrigation in any patient. None of the patients in the present study experienced major complications during or after surgery, and since their symptoms improved, the degree of satisfaction was high. When compared to external DCR, endoscopic intranasal DCR showed no statistically significant difference in postoperative results, thus confirming that similar therapeutic effects could be obtained for the two procedures.

High-speed digital imaging and electroglottography of tracheoesophageal phonation by Amatsu's method.

BACKGROUND: Our previous findings have indicated that the thyropharyngeal muscles form a retropharyngeal prominence during alaryngeal phonation via the TE fistula. This prominence forms a so-called 'neoglottis', which is thought to function as the vibratory source. To better understand the mechanism of TE phonation, we analyzed the vibration of the neoglottis using electroglottography (EGG) and a high-speed digital imaging system. PATIENTS AND METHODS: Two volunteers who use TE phonation for their daily speech communication were subjected to this study. The vibrations of the neoglottis were recorded simultaneously as EGG and high-speed imaging with acoustic signals. RESULTS: The vibrations of the neoglottis, recorded by means of high-speed digital imaging, were exactly synchronized with the waveforms of the acoustic signals and EGG. CONCLUSIONS: These results further confirm the neoglottis as the source of vibration during tracheoesophageal (TE) phonation.

Videofluoroscopic assessment of swallowing function in patients with myasthenia gravis.

Swallowing function in myasthenia gravis (MG) was investigated by videofluoroscopy (VF). A total of 23 VF examinations were performed on 11 MG patients at various time points over the exacerbation and remission stages of disease. The assessment parameters on VF examination are set as follows: bolus transport from the mouth to the pharynx, bolus holding in the oral cavity, velopharyngeal seal, tongue base movement, pharyngeal constriction, laryngeal elevation, upper esophageal sphincter (UES) opening, and bolus stasis at the pyriform sinus (PS). Aspiration was also assessed on VF examination. Aspiration was seen in 34.8%, and half of these cases involved silent aspiration. Three of four cases that showed silent aspiration went on to experience aspiration pneumonia during the follow-up term. By Spearman's rank correlation, disturbance of laryngeal elevation was significantly correlated with aspiration (p=0.001), and incomplete UES opening was not significantly, but tended to be, correlated with aspiration (p=0.067). Although other parameters in the oral and pharyngeal phase on VF examination, such as bolus transport from the oral cavity to the pharynx, pharyngeal constriction, or stasis at the PS, were remarkably disturbed (in more than 50% of the examinations), those parameters were not good indicators for aspiration. When a disturbance of laryngeal elevation is found at a bedside clinical test, we recommend performing precise swallowing evaluation, such as VF, Fiberoptic Endoscopic Evaluation of Swallowing (FEES), and/or scintigraphic assessment of swallowing, for MG patients, to detect silent aspiration.