Sleep-Induced Glottis Closure in Multiple System Atrophy Evaluated by Four-Dimensional Computed Tomography

Vocal Fold Motion Impairment in Neurodegenerative Diseases

Vocal fold motion impairment (VFMI) is the inappropriate movement of the vocal folds during respiration, leading to vocal fold adduction and/or abduction problems and causing respiratory and vocal impairments. Neurodegenerative diseases (NDDs) are a wide range of disorders characterized by progressive loss of neurons and deposition of altered proteins in the brain and peripheral organs. VFMI may be unrecognized in patients with NDDs. VFMI in NDDs is caused by the following: laryngeal muscle weakness due to muscular atrophy, caused by brainstem and motor neuron degeneration in amyotrophic lateral sclerosis; hyperactivity of laryngeal adductors in Parkinson's disease; and varying degrees of laryngeal adductor hypertonia and abductor paralysis in multiple system atrophy. Management of VFMI depends on whether there is a presence of glottic insufficiency or insufficient glottic opening with/without severe dysphagia. VFMI treatment options for glottic insufficiency range from surgical interventions, including injection laryngoplasty and medialization thyroplasty, to behavioral therapies; for insufficient glottic opening, various options are available based on the severity and underlying cause of the condition, including continuous positive airway pressure therapy, botulinum toxin injection, tracheostomy, vocal fold surgery, or a combination of interventions. In this review, we outline the mechanisms, clinical features, and management of VFMI in NDDs and provide a guide for physicians who may encounter these clinical features in their patients. NDDs are always progressive; hence, timely evaluation, proper diagnosis, and appropriate management of the patient will greatly affect their vocal, respiratory, and swallowing functions as well as their quality of life.

Management and Treatment for Dysphagia in Neurodegenerative Disorders

Patients with neurodegenerative disorders (NDDs) often experience functional dysphagia, which may involve dysfunction in a specific phase of swallowing or in the entire process. This review outlines the approach to dysphagia in the setting of NDDs. Distinguishing the etiology of dysphagia can be difficult, and it is important to always look out for signs pointing to NDD as the cause. Thorough diagnostic work-up is essential, and it includes a comprehensive history and physical examination, alongside swallowing function tests, such as fiberoptic endoscopic evaluation of swallowing, videofluoroscopic swallowing study, and high-resolution manometry. Management requires a multidisciplinary approach with a treatment plan tailored to each patient. This involves dietary guidance, swallowing rehabilitation, and surgery in cases in which improvement with rehabilitation is inadequate. Surgery may involve altering certain pharyngolaryngeal structures to facilitate swallowing and reduce the risk of aspiration (swallowing improvement surgery) or separating the airway and digestive tract while sacrificing laryngeal function, with the main goal of preventing aspiration (aspiration prevention surgery). Proper management stems from recognizing the impact of these disorders on swallowing and consistently finding ways to improve the quality of life of patients.

Quantitative analyzes of the variability in airways via four-dimensional dynamic ventilation CT in patients with chronic obstructive pulmonary disease: correlation with spirometry data and severity of airflow limitation

Background

In chronic obstructive pulmonary disease (COPD) patients, the diagnosis and assessment of disease severity are mainly based on spirometry, which may lead to misjudgments due to poor patient compliance. Thoracic four-dimensional dynamic ventilation computed tomography (4D-CT) provides more airway data approximating true physiological function than conventional CT. We aimed to determine dynamic changes in airways to elucidate the pathological mechanism underlying COPD and predict the severity of airflow limitation in patients.

Methods

Forty-two COPD patients underwent 4D-CT and spirometry. The minimum lumen diameter changed with the breathing cycle in 4th-generation airways and was continuously measured in the apical (RB1), lateral (RB4) and posterior basal segments (RB10) of the right lung. The minimum lumen diameter in the peak inspiration and peak expiration as well as the peak expiratory/peak inspiratory ratio (E/I ratio), and dynamic coefficient of variance (CV) were calculated.

Results

Correlations of FEV1% with the CV of minimum lumen diameter in RB1 (ρ=-0.473, P=0.002) and in RB10 (ρ=-0.480, P=0.005) were observed, suggesting that the dynamic variability in 4th-generation airways was associated with airflow limitation in COPD patients. The CV of the minimum lumen diameter in RB1 significantly differed between the GOLD I + II and GOLD III + IV groups {8.59 [interquartile range (IQR), 6.63-14.86] vs. 14.64 (10.65-25.88), respectively; P=0.016}, suggesting that the dynamic CV in RB1 increased significantly in the GOLD III + IV group, which had worse pulmonary ventilation function. Based on the receiver operating characteristic (ROC) curve analysis, CV-RB1 predicted FEV1% <50% with an optimal cut-off of 9.43% [sensitivity 85.7%, specificity 57.1%, area under the curve (AUC) 0.717].

Conclusions

4D-CT might be an available method to help diagnose and evaluate the severity of COPD.

Dynamic Analysis Of Male "Extra-high Voice" Using Multi-row Detector Computed Tomography

OBJECTIVES/HYPOTHESIS

Some people who practice singing on a daily basis may be able to produce a voice higher than the upper limit of the normal range (extra high voice), but there is much regarding the movement of the larynx that remains unknown. We have been conducting dynamic analysis of the larynx using multi-row detection computed tomography (MD-CT) at our university and report herein an analysis of the extra high voice.

STUDY DESIGN

Observational.

METHODS

Images of a normal male participant capable of extremely high-frequency speech (the highest speech range is C7 [2093 Hz] and the singing application range is up to B5 [988 Hz]) during speech were captured by MD-CT. The acquisition time was 2 seconds, and the rise of the voice from low to high and then to very high tones was recorded. Ten frames per second were analyzed as three-dimensional images.

RESULTS

In the fundamental frequency range from A3 to D5 (220-587 Hz), laryngeal elevation movements were observed as the voice rose in pitch. However, posterior upward displacement of the laryngeal cartilage was observed as the frequency range increased from E5 to B5 (659-988 Hz).

CONCLUSIONS

In the E5-B5 range, laryngeal movements were different from those observed in the previous range. MD-CT analysis is useful in the study of this range because it allows visualization of laryngeal movements that are unclear using endoscopy or external examination.

Swallowing computed tomography and virtual reality as novel imaging modalities for the diagnosis of clicking larynx: Two case reports

Globus sensation and pain causes are difficult to identify by conventional examination methods. With technology advances, new imaging methods including swallowing computed tomography (CT) and virtual reality (VR) have emerged and are contributing to definite diagnoses. We report two cases of cervical discomfort diagnosed as clicking larynx using swallowing CT/VR . Case 1 is a 55-year-old man. There were no findings on laryngoscopy or swallowing examinations, but swallowing CT/VR showed that the thyroid cartilage collided with the hyoid bone during swallowing, leading to the diagnosis of a clicking larynx. The patient was obese and is under observation hoping that weight loss will improve symptoms. Case 2 is a 32-year-old transgender man. He is receiving male hormones for gender identity disorder. He was diagnosed with a clicking larynx using swallowing CT/VR. Hormonal therapy may have increased the size of the thyroid cartilage, likely causing the symptoms. As they didn't choose surgical treatment, no symptomatic relief was achieved, but identifiying the cause contributed to improved patient satisfaction. Swallowing CT/VR is useful not only for evaluating the swallowing function, but also the underlying etiology of globus sensation and pain upon swallowing. Further clinical applications of this technique are expected for motion induced cervical symptoms.