Potential for Behavioural Pressure Modulation at the Upper Oesophageal Sphincter in Healthy Swallowing

Office Procedures in Dysphagia

Dysphagia is a common complaint encountered by otolaryngologists in the United States. Usually, patients are referred to an otolaryngologist or other physician specializing in dysphagia (deglutologist) once empiric therapies have been tried and failed. Further investigation often required the utilization of office esophagoscopy, swallowing fluoroscopy, and now high-resolution pharyngoesophageal manometry with impedance. Over the past decades, significant advances have been made in improving care of patients with dysphagia in the clinic. In this article, diagnostic and therapeutic interventions that can be used to manage patients suffering with dysphagia will be discussed.

Swallowing dysfunctions in patients with disorders of consciousness: Evidence from neuroimaging data, assessment, and management

Following severe brain injuries, a subset of patients may remain in an altered state of consciousness; most of these patients require artificial feeding. Currently, a functional oral phase and the presence of exclusive oral feeding may constitute signs of consciousness. Additionally, the presence of pharyngo-laryngeal secretions, saliva aspiration, cough reflex and tracheostomy are related to the level of consciousness. However, the link between swallowing and consciousness is yet to be fully understood. The primary aim of this review is to establish a comprehensive overview of the relationship between an individual's conscious behaviour and swallowing (reflexive and voluntary). Previous studies of brain activation during volitional and non-volitional swallowing tasks in healthy subjects are also reviewed. We demonstrate that the areas activated by voluntary swallowing tasks (primary sensorimotor, cingulate, insula, premotor, supplementary motor, cerebellum, and operculum) are not specific to deglutitive function but are shared with other motor tasks and brain networks involved in consciousness. This review also outlines suitable assessment and treatment methods for dysphagic patients with disorders of consciousness. Finally, we propose that markers of swallowing could contribute to the development of novel diagnostic guidelines for patients with disorders of consciousness.

Links Between Swallowing and Consciousness: A Narrative Review

This literature review explores a wide range of themes addressing the links between swallowing and consciousness. Signs of consciousness are historically based on the principle of differentiating reflexive from volitional behaviors. We show that the sequencing of the components of swallowing falls on a continuum of voluntary to reflex behaviors and we describe several types of volitional and non-volitional swallowing tasks. The frequency, speed of initiation of the swallowing reflex, efficacy of the pharyngeal phase of swallowing and coordination between respiration and swallowing are influenced by the level of consciousness during non-pathological modifications of consciousness such as sleep and general anesthesia. In patients with severe brain injury, the level of consciousness is associated with several components related to swallowing, such as the possibility of extubation, risk of pneumonia, type of feeding or components directly related to swallowing such as oral or pharyngeal abnormalities. Based on our theoretical and empirical analysis, the efficacy of the oral phase and the ability to receive exclusive oral feeding seem to be the most robust signs of consciousness related to swallowing in patients with disorders of consciousness. Components of the pharyngeal phase (in terms of abilities of saliva management) and evoked cough may be influenced by consciousness, but further studies are necessary to determine if they constitute signs of consciousness as such or only cortically mediated behaviors. This review also highlights the critical lack of tools and techniques to assess and treat dysphagia in patients with disorders of consciousness.

Expanding Rehabilitation Options for Dysphagia: Skill-Based Swallowing Training

Over the past four decades, our understanding of swallowing neural control has expanded dramatically. However, until recently, advances in rehabilitation approaches for dysphagia have not kept pace, with a persistent focussing on strengthening peripheral muscle. This approach is no doubt very appropriate for some if not many of our patients. But what if the dysphagia is not due to muscles weakness? The purpose of this clinical manuscript is to reflect on where we have been, where we are now and perhaps where we need to go in terms of our understanding of swallowing motor control and rehabilitation of motor control impairments. This compilation is presented to clinicians in the hope that suggesting approaches "outside the box" will inspire clinicians to focus their attention "inside the box" to ultimately improve rehabilitation and long-term outcomes for patients with dysphagia.