Mechanisms of Swallowing, Speech and Voice Disorders in Parkinson's Disease: Literature Review with Our First Evidence for the Periperal Nervous System Involvement.

The majority of patients with Parkinson's disease (PD) develop swallowing, speech, and voice (SSV) disorders. Importantly, swallowing difficulty or dysphagia and related aspiration are life-threatening conditions for PD patients. Although PD treatments have significant therapeutic effects on limb motor function, their effects on SSV disorders are less impressive.

The Vocal Flutter of Multiple System Atrophy: A Parkinsonian-Type Phenomenon?

Background: Early features of multiple system atrophy (MSA) are similar to those in Parkinson's disease (PD), which can challenge differential diagnosis. Identifying clinical markers that help distinguish MSA from forms of parkinsonism is essential to promptly implement the most appropriate management plan. In the context of a thorough neurological evaluation, the presence of a vocal flutter might be considered a potential feature of MSA-parkinsonian type (MSA-P).

Impacts of Deep Brain Stimulation of the Globus Pallidus Internus on Swallowing: A Retrospective, Cross-Sectional Study.

Deep brain stimulation (DBS) is a common treatment for motor symptoms of Parkinson disease (PD), a condition associated with increased risk of dysphagia. The effect of DBS on swallowing function has not been comprehensively evaluated using gold-standard imaging techniques, particularly for globus pallidus internus (GPi) DBS. The objective of this retrospective, cross-sectional study was to identify differences in swallowing safety and timing kinematics among PD subjects with and without GPi DBS.

Characterization of Ethyl Butyrate-Induced Cough Before and After Breath Control Techniques in Healthy Adults.

Purpose: Methods for cough elicitation frequently involve aerosolized tussive agents. Here, we sought to determine whether healthy individuals demonstrate a quantifiable cough response after inhaling a volatile ester and if breath control techniques modify this chemically induced cough response.

Method: Sixty adult male and female participants inhaled prepared liquid dilutions of ethyl butyrate dissolved in paraffin oil at 20%, 40%, and 60% v/v concentrations in triplicate, with presentation order randomized.

Impact of Vocal Fry and Speaker Gender on Listener Perceptions of Speaker Personal Attributes.

Objectives: Many studies have investigated listener perceptions of speakers who use vocal fry, but results remain mixed. This study aimed to investigate how vocal fry and speaker gender impact listener perceptions of a speaker's likeability, intelligence, attractiveness, and salary-attainment, described as "attributes." We hypothesized speakers with vocal fry would be evaluated more negatively on all attributes than speakers without vocal fry, with female speakers rated more negatively than male speakers.

A Survey of Speech-Language Pathologists' Experience With Clinical Cough Assessment.

Purpose: The purpose of this study was to determine if students (clinicians-intraining) and clinicians of speech-language pathology assess cough during clinical swallow evaluations. We also sought to determine if participants received background education and training regarding implementation of clinical cough assessment. Finally, we aimed to identify participant interest in a cough assessment training program.

Reflexive Airway Sensorimotor Responses in Individuals with Amyotrophic Lateral Sclerosis.

Background: Progressive motor denervation in amyotrophic lateral sclerosis (ALS) leads to reduced expiratory cough flow and diminished airway clearance physiologic capacity. Although ALS is thought to primarily impact motor systems, preliminary data from our laboratory suggest degradation of afferent pathways that regulate reflexive cough responses to radiographically confirmed aspiration. We, therefore, aimed to delineate both sensory and motor responses to a tussigenic airway irritant in individuals with ALS compared to healthy controls.

Management of Dysphagia in Acquired and Progressive Neurologic Conditions.

As the act of deglutition involves much of the central and peripheral nervous systems, neurologic disease can affect swallowing behaviors ranging from mild to profound in severity. The key in working with neurogenic dysphagia is to have a solid foundation in normal swallowing processes, including neural control. Within this framework, then, understanding how the neurologic condition affects neural control will guide hypothesis-based assessment and evidence-based treatment.

Cough physiology in elderly women with nontuberculous mycobacterial lung infections.

Elderly white, thin, nonsmoking women appear to be more susceptible to lung infections with complex and other nontuberculous mycobacteria (NTM). It has been postulated that such disease in women is related to suppression of their cough. We hypothesized that patients with pulmonary NTM (pNTM) infections may have altered cough physiology compared with unaffected control subjects.

Rehabilitation of Swallowing and Cough Functions Following Stroke: An Expiratory Muscle Strength Training Trial.

Objective: To determine the effect of expiratory muscle strength training (EMST) on both cough and swallow function in stroke patients.

Design: Prospective pre-post intervention trial with 1 participant group.

Setting: Two outpatient rehabilitation clinics.

Alterations in oropharyngeal sensory evoked potentials (PSEP) with Parkinson's disease.

Movement of a food bolus from the oral cavity into the oropharynx activates pharyngeal sensory mechanoreceptors. Using electroencephalography, somatosensory cortical-evoked potentials resulting from oropharyngeal mechanical stimulation (PSEP) have been studied in young healthy individuals. However, limited information is known about changes in processing of oropharyngeal afferent signals with Parkinson's disease (PD).

Rate of aspiration pneumonia in hospitalized Parkinson's disease patients: a cross-sectional study.

Background: Aspiration pneumonia is an important cause of morbidity and mortality in Parkinson's disease (PD). Clinical characteristics of PD patients in addition to specific alterations in swallowing mechanisms contribute to higher swallowing times and impairment in the effective clearance of the airway. These issues may render patients more prone to dysphagia and aspiration events.

Comparison of voluntary and reflex cough effectiveness in Parkinson's disease.

Introduction: Multiple airway protective mechanisms are impacted with Parkinson's disease (PD), including swallowing and cough. Cough serves to eject material from the lower airways, and can be produced voluntarily (on command) and reflexively in response to aspirate material or other airway irritants. Voluntary cough effectiveness is reduced in PD however it is not known whether reflex cough is affected as well.

Negative emotional stimulation decreases respiratory sensory gating in healthy humans.

We tested the hypothesis that negative emotions decrease the respiratory-related evoked potentials (RREP) sensory gating (RSG). RREP were elicited by paired inspiratory occlusions. RSG was calculated as the difference in the averaged RREP peak N1 amplitude between the second (S2) and the first occlusion (S1).

A framework for understanding shared substrates of airway protection.

Deficits of airway protection can have deleterious effects to health and quality of life. Effective airway protection requires a continuum of behaviors including swallowing and cough. Swallowing prevents material from entering the airway and coughing ejects endogenous material from the airway.

Sequential voluntary cough and aspiration or aspiration risk in Parkinson's disease.

Background: Disordered swallowing, or dysphagia, is almost always present to some degree in people with Parkinson's disease (PD), either causing aspiration or greatly increasing the risk for aspiration during swallowing. This likely contributes to aspiration pneumonia, a leading cause of death in this patient population. Effective airway protection is dependent upon multiple behaviors, including cough and swallowing.

Lung volume measured during sequential swallowing in healthy young adults.

Purpose: Outcomes from studying the coordinative relationship between respiratory and swallow subsystems are inconsistent for sequential swallows, and the lung volume at the initiation of sequential swallowing remains undefined. The first goal of this study was to quantify the lung volume at initiation of sequential swallowing ingestion cycles and to identify the respiratory pattern(s) surrounding each sequential swallow ingestion cycle. The second goal was to compare these results with existing data for single swallows.

Peak morphology and scalp topography of the pharyngeal sensory-evoked potential.

The initiation of the pharyngeal stage of swallowing is dependent upon sensory input to the brainstem and cortex. The event-related evoked potential provides a measure of neuronal electrical activity as it relates to a specific stimulus. Air-puff stimulation to the posterior pharyngeal wall produces a sensory-evoked potential (PSEP) waveform.

Cortical gating of oropharyngeal sensory stimuli.

Somatosensory evoked potentials provide a measure of cortical neuronal activation in response to various types of sensory stimuli. In order to prevent flooding of the cortex with redundant information various sensory stimuli are gated cortically such that response to stimulus 2 (S2) is significantly reduced in amplitude compared to stimulus 1 (S1). Upper airway protective mechanisms, such as swallowing and cough, are dependent on sensory input for triggering and modifying their motor output.

Evidence-based systematic review: Oropharyngeal dysphagia behavioral treatments. Part V--applications for clinicians and researchers.

Evidence-based practice (EBP) involves the integration of three essential principles: (1) the current best available research, (2) the clinician's experience and expertise, and (3) the patient's values and preferences. This report is the last in a series that presents the culmination of a collaborative effort between the American Speech-Language-Hearing Association and the Department of Veterans Affairs to examine the state of the evidence on seven behavioral swallowing interventions. This article addresses how speech-language pathologists treating individuals with oropharyngeal dysphagia can incorporate EBP into their clinical decision-making process.