Pathophysiology of Swallowing Dysfunction in Parkinson Disease and Lack of Dopaminergic Impact on the Swallow Function and on the Effect of Thickening Agents

The Effect of Oropharyngeal Resting Tremor on Swallowing Function in a Clinical Cohort of People with Parkinson's Disease

Parkinson's Disease (PD) is a progressive neurodegenerative disease, with hallmark symptomology typically consisting of tremor, bradykinesia, and rigidity. Though the classic "pill-rolling" rest tremor in the hand or upper limb are often the most salient, it can occur throughout the body including the lower limbs, jaw, face, or tongue. There have been investigations into other motor related phenomena potentially affecting swallow function in PwPD previously. However, there have been no investigations of how oropharyngeal resting tremor in structures such as the tongue or larynx explicitly affects swallowing physiology. A retrospective analysis of previously conducted VFSS on 34 patients diagnosed with idiopathic PD (IPD) was performed to examine how individuals that displayed resting tremor during VFSS (Tremor +) and those who did not (Tremor-) differ in swallowing function. Measures of swallowing function including timing intervals of key swallow events, post-swallow residue, and penetration-aspiration scale (PAS) scores were recorded, and key demographic information including time since diagnosis and medication status were extracted from the medical records available. Multivariate models were used to identify differences between tremor groups for timing intervals and post-swallow residue, and chi-squares were computed for differences in PAS score distribution by group and bolus. Sixty-eight percent (23/34) of this sample displayed oropharyngeal resting tremor in at least one structure during VFSS. There were no instances of other tremor types observed in this sample. All participants were taking medication to manage PD symptomology. Significant effects of tremor group were observed for swallow timing intervals related to airway closure (p < 0.001), post-swallow residue (p < 0.05), and swallow safety at the bolus level in the Tremor + group (p < 0.001). These results suggest that PwPD who present with resting tremor in oropharyngeal structures may manifest with different variations in swallowing physiology, including altered timings of swallow events, increased pharyngeal residue, and greater associations of airway invasion with thinner and larger volume boluses. This study highlights the need for substantially more research into how motor fluctuations and phenotypes of PwPD contribute to alterations in swallowing function.

Cough Correlates of Functional Swallow Outcomes in Atypical Parkinsonism

BACKGROUND

Swallow and cough impairments lead to aspiration and reduced clearance of aspirate material. Both behaviors are impaired in Parkinson's disease, but it is unknown whether a similar relationship of dysfunction exists in forms of atypical Parkinsonism (APD). Elucidating this association in APD may lead to early, comprehensive airway protection treatment.

OBJECTIVES

We tested the hypotheses that swallow deficits in APD are associated with impaired cough and that airway protective dysfunction is associated with longer disease duration.

METHODS

Swallowing difficulty was described by 11 participants with APD. Penetration-Aspiration Scale (PAS) and DIGEST scores for thin liquid trials were extracted from medical records of videofluoroscopic swallow study reports. Voluntary and capsaicin induced-reflex cough measures of flow, volume, and timing were analyzed.

RESULTS

While most participants did not have post-swallow residue, ~80% received abnormal PAS scores and reported swallowing difficulty. Those with abnormal PAS scores had lower voluntary cough expired volume (P = 0.037; mean rank difference = 5.0); lower reflex inspiratory flow rate (P = 0.034; mean rank difference = 5.5); and longer reflex expiratory flow rise time (P = 0.034; mean rank difference = 5.5). Higher PAS scores and reduced reflex cough volume acceleration were significantly correlated (r = -0.63; P = 0.04) and longer disease duration predicted larger voluntary cough expired volume (R2  = 0.72) and longer flow rise times (R2  = 0.47).

CONCLUSIONS

As swallow safety worsens, so might the ability to clear the airways with effective cough in in APD; particularly with longer disease duration. Assessing cough in conjunction with swallowing is important for informing airway protection treatment plans in APD.

Comparing biomechanics and neurophysiology between different phenotypes of patients with oropharyngeal dysphagia

The pathophysiology of oropharyngeal dysphagia (OD) across patient phenotypes may differ. The aim of this study was to compare the biomechanics and neurophysiology of swallowing between healthy volunteers (HVs) and patients with dysphagia as a consequence of aging (OOD), post-stroke (PSOD), Parkinson's disease (POD), or dementia (DOD). A retrospective study including 35 HVs and 109 OOD, 195 PSOD, 78 POD, and 143 DOD patients was performed. Videofluoroscopic data of signs of impaired efficacy and safety, penetration-aspiration scale (PAS) score, and the biomechanics of laryngeal vestibule closure (LVC) and opening (LVO) and of upper esophageal sphincter opening (UESO) were collected. Neurophysiology was assessed with pharyngeal sensory evoked potentials and neurotopography maps. All OD phenotypes showed signs of impaired efficacy and safety of swallowing, increased PAS score (p < 0.001), and delayed time to LVC (p < 0.0001). OOD (p < 0.0001), PSOD (p < 0.0001), and POD (p = 0.0065) patients also had delayed time to LVO, and OOD (p = 0.0062) and DOD (p = 0.0016) patients to UESO. Regarding neurophysiology, all phenotypes presented impaired pharyngeal sensitivity, a significant reduction in cortical activation, and impaired sensory input integration. Additionally, only PSOD was associated with impaired conduction of sensory stimuli. In conclusion, we found common but also specific pathophysiological elements. These results improve our understanding of OD pathophysiology and may help pave the way for phenotype-specific treatments.

Brain and Pharyngeal Responses Associated with Pharmacological Treatments for Oropharyngeal Dysphagia in Older Patients

Impaired pharyngo-laryngeal sensory function is a critical mechanism for oropharyngeal dysphagia (OD). Discovery of the TRP family in sensory nerves opens a window for new active treatments for OD. To summarize our experience of the action mechanism and therapeutic effects of pharyngeal sensory stimulation by TRPV1, TRPA1 and TRPM8 agonists in older patients with OD. Summary of our studies on location and expression of TRP in the human oropharynx and larynx, and clinical trials with acute and after 2 weeks of treatment with TRP agonists in older patients with OD. (1) TRP receptors are widely expressed in the human oropharynx and larynx: TRPV1 was localized in epithelial cells and TRPV1, TRPA1 and TRPM8 in sensory fibers mainly below the basal lamina. (2) Older people present a decline in pharyngeal sensory function, more severe in patients with OD associated with delayed swallow response, impaired airway protection and reduced spontaneous swallowing frequency. (3) Acute stimulation with TRP agonists improved the biomechanics and neurophysiology of swallowing in older patients with OD TRPV1 = TRPA1 > TRPM8. (4) After 2 weeks of treatment, TRPV1 agonists induced cortical changes that correlated with improvements in swallowing biomechanics. TRP agonists are well tolerated and do not induce any major adverse events. TRP receptors are widely expressed in the human oropharynx and larynx with specific patterns. Acute oropharyngeal sensory stimulation with TRP agonists improved neurophysiology, biomechanics of swallow response, and safety of swallowing. Subacute stimulation promotes brain plasticity further improving swallow function in older people with OD.

Isometric tongue endurance and incomplete laryngeal vestibule closure in Parkinson's disease

BACKGROUND

Dysphagia is a common symptom of Parkinson's disease (PD). A delay in laryngeal vestibule closure (LVC) and a reduction in tongue pressure, may affect swallowing safety and increase the risk of pulmonary aspiration.

OBJECTIVE

To verify the relationship between tongue pressure and airway protection in PD patients: (1) comparing tongue pressure measures and physiological events in the pharyngeal phase of swallowing between PD and controls and (2) analysing the association between tongue pressure and LVC in the PD group.

METHODS

Twenty-three patients with idiopathic PD (64.9 years) and 24 healthy controls (64.1 years) participated in this study. All participants underwent the following procedures to verify tongue pressure measurements using the Iowa Oral Performance Instrument: maximum anterior and posterior pressure, isotonic and isometric tongue endurance and anterior and posterior tongue pressure during saliva swallowing. To verify swallowing safety, videofluoroscopic swallowing studies focusing on the pharyngeal phase were performed based on the MBSImP protocol.

RESULTS

Compared to healthy controls, PD exhibited a statistically significant decline in tongue pressure tasks: posterior maximum pressure, isotonic endurance, anterior and posterior isometric endurance and tongue pressure during posterior swallowing. Patients with PD had worse pharyngeal scores, including LVC scores, than controls. PD and incomplete LVC had lower anterior isometric endurance scores when compared to those with complete LVC.

CONCLUSION

PD with incomplete LVC scored lower in the anterior isometric endurance task. We observed a potential clinical use of this task for the assessment and management of dysphagia in patients with PD.

Differences in pharyngeal swallow event timing: Healthy aging, Parkinson disease, and amyotrophic lateral sclerosis

Objective

The pharyngeal phase of swallowing involves a coordinated sequence of events. Event durations may be prolonged in people with Parkinson disease (PwPD), and amyotrophic lateral sclerosis (PwALS); however, the cumulative effect of these changes is unexplored. We compared event latencies relative to hyoid burst (HYB) (time zero) to understand differences in deglutatory event timing. We hypothesized PwPD and PwALS would display similarly prolonged cumulative pharyngeal phase durations compared to healthy controls, with greater prolongations with increasing bolus viscosity.

Method

We retrospectively evaluated videofluoroscopic data of healthy adults (n = 78), PwPD (n = 17), and PwALS (n = 20). Participants swallowed 15 boluses of 20% (w/v) barium across five liquid consistencies. Paired raters evaluated nine deglutitive events using the ASPEKT method. Latencies were plotted by consistency relative to HYB and compared across cohorts using Mann-Whitney U tests (p ≤ .05). Cohen's d was calculated for all statistically significant results to determine effect size.

Results

In PwPD, significantly prolonged latencies were observed on thin liquid boluses compared to healthy controls. Latencies to all post-HYB events were significantly prolonged except for maximum upper esophageal sphincter distension. In PwALS, significantly prolonged latencies for events preceding and following HYB were noted on all consistencies compared to healthy controls and PwPD.

Conclusion

In PwPD, event latencies for multiple components of the swallowing sequence were prolonged culminating in overall prolongation of the pharyngeal phase on thin liquid. A similar pattern, but with significantly greater prolongation, was seen in the PwALS, and extended to swallows of all liquid consistencies.

Dysphagia Presentation, Airway Invasion, and Gender Differences in a Clinically Based Sample of People with Parkinson's Disease

Dysphagia in People with Parkinson's Disease (PWPD) is expected to occur in most individuals. The manifestation of dysphagia and its salient swallow dysfunction characteristics leading to decreased airway safety are not well understood. The aim of this study was to quantify dysphagia presentation and severity, examine contributors to airway invasion, and explore gender differences in dysphagia manifestation in PWPD. 60 PWPD in clinical, healthcare settings underwent a Videofluoroscopic Swallow Study (VFSS) after referral for complaints of dysphagia. VFSS records and videos were analyzed to obtain dysphagia diagnosis, Videofluoroscopic Dysphagia Scale (VDS) scores, laryngeal vestibule kinematic timings, and Penetration-Aspiration Scale scores. Frequencies of VDS component and PAS scores were examined. MANOVA and logistic regression analyses were used to identify predictors of penetration and aspiration. Pharyngeal stage dysphagia was prevalent throughout PWPD and presented more frequently than oral stage dysphagia. Pharyngeal residue was a significant predictor for aspiration events. Laryngeal vestibule closure reaction time (LVCrt) and duration time (LVCd) were significant predictors of airway invasion, as were bolus consistency and volume. LVCrt, LVCd, and pharyngeal stage VDS scores were significantly altered in men compared to women in PWPD. A broad clinical sample of PWPD displayed atypical frequencies of airway invasion and frequent atypical scores of oral and pharyngeal stage physiologies. Thicker and smaller bolus consistencies significantly reduced the odds of airway invasion. Men and women presented with significantly different swallow physiology including prolonged LVCrt, LVCd, and more frequent atypical scores of pharyngeal residue and laryngeal elevation.Journal instruction requires a country for affiliations; however, these are missing in affiliation [1, 2]. Please verify if the provided country are correct and amend if necessary.Yes, USA is correct as the provided country.

A narrative review on the role and main findings of the Videofluoroscopic Study of Swallowing in Parkison's disease

PURPOSE

Dysphagia is a common symptom in patients with Parkinson's disease (PD), though it may go undiagnosed until severe complications arise. Dysphagia can be suspected on a clinical basis, but an instrumental assessment is mandatory to confirm its presence and evaluate pathophysiological aspects and severity of the swallowing impairment. Aim of this review is to inform the clinician and the radiologist on the importance and the main radiological findings of the Video-Fluoroscopic-Swallow-Study (VFSS) in patients with PD starting from the most recent literature data on the topic.

MATERIALS AND METHODS

Databases analysis identified 98 papers (January 2000/October 2022) of which 55 were excluded after reading title, abstract and full-text. After evaluation of the selected articles and their references 7 additional papers were added.

RESULTS

Fifty papers were reviewed to answer the following four main questions: Should VFSS be routinely used to screen dysphagia? Compared to other diagnostic tools, what is the role of VFSS in PD patients with suspected dysphagia? What are the main VFSS findings and technical expedients ? What is the role of VFSS in the choice of the best treatment strategy ?

CONCLUSIONS

VFSS represents a gold standard technique in the diagnostic evaluation of dysphagia in PD, having a fundamental role in the identification of patients with high risk of aspiration pneumonia and also being extremely helpful to guide to the choice of treatment strategies for dysphagia.

Physiological Mechanisms and Associated Pathophysiology of Dysphagia in Older Adults

Dysphagia can be a common secondary sequela of neurological and neurodegenerative disorders in older adults. Early screening, identification, and management of dysphagia is essential to avoid serious complications, including malnutrition, dehydration, aspiration pneumonia; and promote quality of life. Although individuals of all ages may experience swallowing difficulties, dysphagia and its complications are more common in older adults. This literature review aims to provide an overview of the physiological mechanisms of normal swallowing in healthy individuals and age-related changes to swallowing function, the pathophysiology of dysphagia associated with three common neurological disorders affecting older adults (stroke, Parkinson's disease, and dementia), and implications for interdisciplinary clinical practice. Increased awareness of these issues may contribute to a more timely and efficient identification of older adults with dysphagia and to improve overall dysphagia management.

Consensus on the treatment of dysphagia in Parkinson's disease

BACKGROUND

Dysphagia is common in Parkinson's disease (PD). The effects of antiparkinsonian drugs on dysphagia are controversial. Several treatments for dysphagia are available but there is no consensus on their efficacy in PD.

OBJECTIVE

To conduct a systematic review of the literature and to define consensus statements on the treatment of dysphagia in PD and related nutritional management.

METHODS

A multinational group of experts in the field of neurogenic dysphagia and/or Parkinson's disease conducted a systematic evaluation of the literature and reported the results according to PRISMA guidelines. The evidence from the retrieved studies was analyzed and discussed in a consensus conference organized in Pavia, Italy, and the consensus statements were drafted. The final version of statements was subsequently achieved by e-mail consensus.

RESULTS

The literature review retrieved 64 papers on treatment and nutrition of patients with PD and dysphagia, mainly of Class IV quality. Based on the literature and expert opinion in cases where the evidence was limited or lacking, 26 statements were developed.

CONCLUSIONS

The statements developed by the Consensus panel provide a guidance for a multi-disciplinary treatment of dysphagia in patients with PD, involving neurologists, otorhinolaryngologists, gastroenterologists, phoniatricians, speech-language pathologists, dieticians, and clinical nutritionists.

The Frequency of Atypical and Extreme Values for Pharyngeal Phase Swallowing Measures in Mild Parkinson Disease Compared to Healthy Aging

Purpose Dysphagia is thought to be prevalent and a leading cause of morbidity and mortality in people with Parkinson disease (PwPD). The aim of this study was to compare the frequencies of atypical and extreme values for measures of swallowing physiology in PwPD and in an age- and sex-matched cohort of healthy adults. Atypical and extreme values were defined, respectively, as values falling in the 25% and 5% tails of the reference distribution for healthy adults under age 60 years. Method A standard videofluoroscopy (VF) protocol was performed in 17 adults with mild PD and 17 age- and sex-matched healthy adults using 20% w/v liquid barium ranging from thin to extremely thick consistency. Blinded VF analysis was performed according to the Analysis of Swallowing Physiology: Events, Kinematics and Timing Method. Frequencies for atypical and extreme values were tabulated by cohort and compared using odds ratios. Results Increased frequencies of atypical values (> 25%) were seen in the PwPD for prolonged swallow reaction time, prolonged time-to-laryngeal-vestibule-closure (LVC), and poor pharyngeal constriction. However, these findings were also observed in the healthy controls. The PwPD showed significantly higher odds of atypical values for narrow upper esophageal sphincter (UES) diameter on thin liquids, a short hyoid-burst-to-UES-opening interval on extremely thick liquids, and prolonged time-to-LVC, LVC duration, and UES opening duration on multiple consistencies. The frequencies of extreme values failed to show any significant cohort differences for any parameter. Conclusions In this study, a group of people with mild PD did not show clear evidence of swallowing impairments distinct from the changes seen in a healthy age-matched control group when odds ratios were used to compare the frequencies of atypical values between PwPD and the control group; only a few parameters showed significant differences. These were findings of significantly higher frequencies in PwPD of prolonged LVC and UES opening duration. Supplemental Material https://doi.org/10.23641/asha.15032241.

Impact of Progression of Parkinson's Disease on Swallowing Ability and Oral Environment

This study investigated the impact of the severity and treatment of Parkinson's disease (PD) on the swallowing ability and oral environment of patients. Swallowing dysfunction increases the aspiration risk and may lead to poor oral health among patients with PD. We investigated the influences of PD progression and drug treatment on the swallowing ability and oral environment using simple noninvasive screening measurements. We recruited 87 patients with PD (mean age, 71.9 ± 8.0 years; mean Hoehn and Yahr score, 2.9 ± 0.9). The PD condition was assessed in each patient using the unified Parkinson's disease rating scale (UPDRS) part III, diet type and oropharyngeal function using the swallowing disturbances questionnaire (SDQ), maximum bite force (MBF), tongue pressure (TP), and oral bacterial count (OBC). Levodopa equivalent daily dose (LEDD) was also calculated for 56 participants. Based on an SDQ score of ≥11, 29.5% of patients were dysphagic, but almost all were still on a regular diet. The SDQ score was positively correlated with disease duration (rho = 0.228, p=0.047) and UPDRS part III score (rho = 0.307, p=0.007) but was negatively correlated with OBC (rho = -0.289, p=0.012). OBC was significantly higher among patients with an SDQ score of <11 (nondysphagic) (p=0.01), and the SDQ score was lower in patients with higher OBC requiring professional oral care (p=0.03). However, OBC was also negatively correlated with LEDD (rho = -0.411, p=0.004). These results indicated low self-awareness of dysphagia among the participants and an association between dysphagia and PD progression. Moreover, the oral environment could have deteriorated with swallowing dysfunction. Patients and clinicians should be aware that higher LEDD can increase xerostomia and associated deficits in oral health.

Analysis of Quality of Life and Nutritional Status in Elderly Patients with Dysphagia in Order to Prevent Hospital Admissions in a COVID-19 Pandemic

(1) Background: Oropharyngeal dysphagia (OD) is currently recognized as one of the geriatric syndromes due to its high frequency in older people and its associated complications, which have a direct impact on quality of life. The main objective is to determine the effectiveness of telehealth consultation for the re-evaluation of nutritional status and quality of life assessment in older people diagnosed with OD associated with active use of thickeners to prevent hospital admissions in a COVID-19 pandemic. (2) Methods: an observational, descriptive, and longitudinal study that included a sample of 33 subjects with age equal or superior to 65 years diagnosed with OD with conserved cognitive capacity. The nutritional status was evaluated through the Mini-Nutritional Assessment (MNA) questionnaire and biochemical parameters and, the quality of life was determined through the Swallowing Quality of Life (SWAL-QOL) questionnaire. (3) Results: Thirty-three older patients with OD were recruited (54.5% women), with a mean age of 83.5 ± 7.6 years. The main cause of OD in the study population was neurodegenerative disease (51.5%), followed by cerebrovascular disease (33.3%), and other causes (15.2%). Sixty point six percent of patients were found to be at risk of malnutrition. The MNA score was significantly correlated to albumin (r: 0.600, p < 0.001) and total proteins (r: 0.435, p = 0.015), but not to total cholesterol (r: -0.116, p = 0.534) or lymphocytes (r: -0.056, p = 0.758). The mean total score of the SWAL-QOL was 75.1 ± 16.4 points. (4) Conclusions: the quality of life of the subjects related to the use of a thickener is good. Although the body mass index (BMI) and average biochemical, nutritional parameters of the subjects are within the range of normality, the MNA has detected a high percentage of subjects with the risk of malnutrition, which suggests the need for continuous re-evaluation in these patients, demonstrating the viability of the telematic route in this research.