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Objective: Somatosensory feedback from upper airway structures is essential for swallowing and airway defense but little is known about the identities and distributions of human upper airway neurons. Furthermore, whether sensory innervation modifies with aging is unknown. In this study, we quantify neuronal and chemosensory cell density in upper airway structures and correlate with age. Methods: Participants underwent biopsies from base of tongue, lateral and midline pharyngeal wall, epiglottis, and arytenoids (N = 25 13 female/12 male; 20–80 years, mean 51.4 years without clinical diagnosis of dysphagia or clinical indication for biopsy). Tissue sections were labeled with antibodies for all neurons, myelinated neurons, and chemosensory cells. Densities of lamina propria innervation, epithelial innervation, solitary chemosensory cells, and taste buds were calculated and correlated with age. Results: Arytenoid had the highest density of innervation and chemosensory cells across all measures compared to other sites. Taste buds were frequently observed in arytenoid and epiglottis. Base of tongue, lateral pharynx, and midline posterior pharynx had minimal innervation and few chemosensory cells. Epithelial innervation was present primarily in close proximity to chemosensory cells and taste buds. Overall innervation and myelinated fibers in the arytenoid lamina propria decline with aging. Conclusion: Findings establish the architecture of healthy adult sensory innervation and demonstrate the varied distribution of laryngopharyngeal innervation, necessary steps toward understanding the sensory basis for swallowing and airway defense. We also document age‐related decline in arytenoid innervation density. These findings suggest that sensory afferent denervation of the upper airway may be a contributing factor to presbyphagia. Level of Evidence: NA Laryngoscope, 133:773–784, 2023 [ABSTRACT FROM AUTHOR]

Background: Disorders of airway protection (cough and swallowing) are pervasive in Parkinson's disease (PD) resulting in a high incidence of aspiration pneumonia and death. However, there are no randomized controlled trials comparing strength and skill‐based approaches to improve airway protection in PD. Objectives: The aim of this study was to compare expiratory muscle strength training (EMST) and sensorimotor training for airway protection (smTAP) to improve cough‐related outcomes in people with PD. Methods: Participants with PD and dysphagia were recruited for this prospective phase II randomized‐blinded controlled clinical trial. Participants completed baseline assessment, 5 weeks of EMST or smTAP, and a post‐training assessment. Primary outcome measures included maximum expiratory pressure (MEP) and voluntary cough peak expiratory flow rate (PEFR). Mixed effects models were used to assess the effects of EMST and smTAP on outcomes. Results: A total of 65 participants received either EMST (n = 34) or smTAP (n = 31). MEP improved from pre‐ to post‐treatment for smTAP (P < 0.001, d = 0.19) and EMST (P < 0.001, d = 0.53). Voluntary PEFR increased from pre‐ to post‐treatment for smTAP (P < 0.001, d = 0.19) and EMST (P < 0.001, d = 0.06). Moreover, reflex cough PEFR (P < 0.001, d = 0.64), reflex cough expired volume (P < 0.001, d = 0.74), and urge to cough (P = 0.018, OR = 2.70) improved for the smTAP group but not for the EMST group. Conclusions: This clinical trial confirmed the efficacy of smTAP to improve reflex and voluntary cough function, above and beyond EMST, the current gold standard. © 2022 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Objectives: When swallowing function is compromised in patients with Parkinson's disease (PD), cough plays a crucial role in clearing the airway and preventing pulmonary complications. The aim of this study was to determine the influence of vocal fold atrophy severity as measured by the bowing index (BI) on airway protection in PD.Methods: Thirty participants with PD completed measures of voluntary and reflex cough. Flexible laryngoscopy with endoscopic evaluation of swallowing allowed for measurement of BI using ImageJ software. Swallowing safety was scored on the Penetration-Aspiration Scale (PAS). Regression and receiver operating characteristic (ROC) analyses were performed to test our study aim.Results: Twenty-four of 30 participants had some degree of vocal fold atrophy (BI >0). When controlling for age, disease duration did not significantly influence BI. BI was not predictive of any sensorimotor parameters of cough including measures of cough airflow, reflex cough threshold, or urge to cough. BI discriminated participants with near-normal (PAS 1-3) swallowing safety from participants with impaired (PAS 4-8) swallowing safety (P = .01, sensitivity: 87.0%, specificity: 71.4%, cutoff value BI >4.6).Conclusion: Vocal fold atrophy is a potential factor contributing to poor swallowing safety in PD. BI was not associated with cough function in this PD cohort, contrary to prior studies that have shown improved cough measures after vocal fold augmentation. Vocal fold atrophy in PD remains an important area of study as a targetable intervention for patients with airway protective dysfunction. Future studies should include measures of glottic closure during vocal fold adduction.Level Of Evidence: Level 3 Laryngoscope, 130:303-308, 2020. [ABSTRACT FROM AUTHOR]

Objective: This study compares variability in measures of hyoid bone displacement and submental muscle size using 2 methods of ultrasound transducer placement: fixed and hand-held. Patients and Methods: Twenty-four healthy participants (11 males, 13 females) aged between 51 and 84 years were scanned using both methods. Repeated measures were collected within and across 3 sessions. Results: A nonlinear mixed effects model was used to estimate the effects of the method, trial, and session. The fixed transducer produced greater within- and across-session variability on several measures compared to the hand-held method. Fixed-transducer measurements of hyoid bone displacement were 9.4% smaller compared to hand-held measurements (F[1, 24.34] = 3.58, p = 0.07). Conclusion: Results suggest that using a fixed transducer does not necessarily improve measurement accuracy of swallowing outcomes in a healthy system. The wide variability in individual measures indicates that further research is required before ultrasound is used for outcome measurement in rehabilitation. [ABSTRACT FROM AUTHOR]