A Tutorial on Saliva's Role in Swallowing With a Focus on Sjögren's Syndrome.

Purpose Saliva is integral to swallowing and necessary for oral health. Understanding saliva's origin and properties is important for swallowing assessment and management. Diseases such as Sjögren's syndrome (SS) can affect saliva negatively, often contributing to dysphagia. Our objectives are to (a) highlight saliva's fundamental role in swallowing, (b) provide a bibliometric overview of literature pertaining to SS pathophysiology and effects on saliva, (c) explore implications of salivary changes on swallowing and quality of life in SS and other populations, and (d) provide suggestions for systematic saliva assessment in practice. Method This tutorial reviews saliva production, composition, and involvement in swallowing within health and disease. Using rapid review methodology, we outline the effect of SS on saliva and describe SS etiology, diagnosis, and treatment. We discuss formal saliva assessments and a multidisciplinary approach. Results Saliva plays a vital role in swallowing, particularly lubrication, bolus formation, and oral health. SS affects the salivary glands altering salivary flow rate and composition. We identified 55 studies (N) measuring salivary changes, grouping them according to four strata demarcated by SS classification criteria updates. For some, xerostomia, dysphagia, and reduced life quality result. Formal saliva assessments include the Clinical Oral Dryness Score, Xerostomia Inventory, and Secretion Rating Scale. Multidisciplinary care is optimal for patients with salivary changes. Conclusion Understanding salivary changes in disease may enhance understanding of swallowing and inform dysphagia practice. Expanding swallowing assessments with formal saliva evaluations, and patient perspectives thereof, may aid in developing bespoke treatments, ultimately improving outcomes and quality of life. Supplemental Material https://doi.org/10.23641/asha.12456449.

Late Dysphagia Following Radiotherapy After Nasopharyngeal Carcinoma: A Case Series.

Purpose Standard treatment for nasopharyngeal carcinoma (NPC) is radiation therapy (RT); however, long-term effects of RT frequently include significant swallowing impairments (dysphagia; Gaziano, 2002; Hui, Chan, & Le, 2018). Our objective was to describe swallowing physiology in consecutive outpatients with a history of NPC following RT using standardized methods. Understanding dysphagia characteristics in this patient population could ultimately inform rehabilitation strategies and improve patient outcomes. Method We conducted a retrospective, observational, descriptive study of consecutive outpatients undergoing videofluoroscopic swallowing (VFS) exams at our clinic, from 2009 to 2014. We included those with a diagnosis of NPC treated with RT. Those with other cancer diagnoses; previous tracheostomy; acute neurological injury; and progressive, degenerative neurological conditions were excluded. Two registered MBSImP clinicians, blinded to each other, reviewed and scored the VFS exams according to previously published methods (Martin-Harris et al., 2008). Following unblinding, a single reviewer collected demographic data from the electronic medical record. We reported overall impairment and MBSImP component scores descriptively. Results Of 158 outpatients undergoing VFS, 6 (N) met our inclusion criteria. The median time from completion of RT to outpatient VFS was 21.0 years. Patients reported a variety of dysphagia symptoms. All patients had high oral and pharyngeal residue scores (scores ≥ 2) and high impairment scores on components contributing to bolus transport and airway closure. Conclusions All patients presented with impairments in oral-pharyngeal bolus transport and airway protection. Our results identify specific swallowing impairments for this patient group highlighting possible latent RT effects on swallowing. This population would benefit from dysphagia rehabilitation and maintenance programs informed by multimodal diagnostic approaches.

Regulation of neonatal development of retinal ganglion cell dendrites by neurotrophin-3 overexpression.

The morphology of dendrites constrains and reflects the nature of synaptic inputs to neurons. The visual system has served as a useful model to show how visual function is determined by the arborization patterns of neuronal processes. In retina, light ON and light OFF responding ganglion cells selectively elaborate their dendritic arbors in distinct sublamina, where they receive, respectively, inputs from ON and OFF bipolar cells. During neonatal maturation, the bilaminarly distributed dendritic arbors of ON-OFF retinal ganglion cells (RGCs) are refined to more narrowly localized monolaminar structures characteristic of ON or OFF RGCs. Recently, brain-derived neurotrophic factor (BDNF) has been shown to regulate this laminar refinement, and to enhance the development of dendritic branches selectively of ON RGCs. Although other related neurotrophins are known to regulate neuronal process formation in the central nervous system, little is known about their action in maturing retina. Here, we report that overexpression of neurotrophin-3 (NT-3) in the eye accelerates RGC laminar refinement before eye opening. Furthermore, NT-3 overexpression increases dendritic branch number but reduces dendritic elongation preferentially in ON-OFF RGCs, a process that also occurs before eye opening. NT-3 overexpression does affect dendritic maturation in ON RGCs, but to a much less degree. Taken together, our results suggest that NT-3 and BDNF exhibit overlapping effects in laminar refinement but distinct RGC-cell-type specific effects in shaping dendritic arborization during postnatal development.