Dysphagia In Parkinson's Disease Research Articles

Dysphagia in Parkinson's disease: A bibliometric and visualization analysis from 2002 to 2022

BackgroundDysphagia, or difficulty swallowing, is a prevalent complication of Parkinson's disease (PD), which can significantly impair quality of life. Despite the numerous studies on dysphagia in PD published in various journals, there remains a dearth of bibliometric analysis within this domain. This study thus aims to examine the global patterns of research on dysphagia after PD over the past 20 years, employing a visual analysis. Material and methodsThis investigation aimed to gather pertinent publications concerning dysphagia in PD from the SCI-Expanded database of the Web of Science Core Collection (WoSCC), covering the period from 2002 to 2022. To dissect and visually represent the collated corpus, we harnessed the capacities of CiteSpace, VOSviewer and R software for meticulous bibliometric scrutiny. ResultsThe bibliometric study encompassed a total of 692 publications. Within the scope of autocratic nations, the USA emerged as the leading country in the quantity of research outputs. The University of Florida stood out as the most prolific academic entity, with Troche MS being the foremost author, contributing to 21 publications. The journal "Dysphagia" featured as the prime venue for publication. Key trending terms identified over the last 20 years include "Parkinson's disease," "dysphagia," "oropharyngeal dysphagia," and "prevalence." ConclusionBibliometric analysis on dysphagia in PD offers a detailed overview of the development of scholarly publications, enabling scholars to grasp the current state of research within their field. It also serves as a benchmark for shaping future research directions.

Dysphagia Pattern in Early to Moderate Parkinson's Disease Caused by Abnormal Pharyngeal Kinematic Function.

Airway invasion is common in patients with Parkinson's disease (PD) and can cause serious complications. However, a PD-related dysphagic pattern has not been clearly elucidated. In this study, 53 patients with early to moderate PD were enrolled to undergo a videofluoroscopic study of swallowing evaluation (VFSS) and a battery of neuropsychological assessments. A set of VFSS variables (three visuoperceptual, nine temporal, and six spatial) were measured. The main effects of bolus viscosity and volume on airway invasion were calculated. Statistical analyses were performed to determine key kinematic factors of airway invasion for swallowing each bolus type. Airway invasion frequency was significantly higher for liquid boluses (liquid vs. pudding P < 0.001; liquid vs. honey P = 0.006). Laryngeal vestibule closure reaction time (LVCrt) was the key kinematic factor of airway invasion for 3ml liquid swallow (P = 0.040), anterior displacement of hyoid bone was the key kinematic factor for both 5ml and 10ml liquid swallows (P = 0.010, 0.034, respectively). Male sex and advanced Hoehn and Yahr stage were significantly related to reduced anterior displacement of hyoid bone. These results reveal the dysphagic pattern related to PD, demonstrating that prolonged LVCrt and reduced anterior displacement of hyoid bone are two crucial kinematic factors contributing to airway invasion during the liquid swallow. In addition, hyoid bone dysfunction was correlated with disease severity and male sex. Our findings warrant further investigation of the pathophysiological mechanism of dysphagia in PD and would guide clinical intervention.

Dysphagia in Parkinson Disease: Part II—Current Treatment Options and Insights from Animal Research

Dysphagia in Parkinson Disease: Part II—Current Treatment Options and Insights from Animal Research

Association of dysphagia with altered brain glucose metabolism in Parkinson's disease.

Dysphagia is a major clinical concern in Parkinson's disease (PD). However, the relationship between the development of phase-specific dysphagia and the regional brain glucose metabolism remains unclear. Our objective was to investigate the distributions of brain glucose metabolism specific to oral and pharyngeal phases of dysphagia in PD. In this retrospective cross-sectional study, patients with PD who underwent videofluoroscopic swallowing study (VFSS) and 18 F-fluorodeoxy-glucose positron emission tomography at intervals of <1 month were included. Each swallow was assessed by the binarized Videofluoroscopic Dysphagia Scale with 14 subitems, seven each for the oral and pharyngeal phases. Metabolism mapping was performed by superimposing significant clusters of subitems belonging to each of the two phases using voxel-wise Firth's penalized binary logistic regression model, adjusting for age and PD duration at VFSS. Eighty-two patients with PD who met the inclusion criteria were included in the analysis. The oral phase dysphagia-specific overlap map showed hypermetabolism in the right inferior temporal gyrus, bilateral cerebellum, superior frontal gyrus, and anterior cingulate cortices. Hypometabolism in the bilateral orbital and triangular parts of the inferior to middle frontal gyrus was also correlated with the occurrence of oral phase dysphagia. The development of pharyngeal phase dysphagia was related to hypermetabolism of posterior aspects of the bilateral parietal lobes, cerebellum, and hypometabolism of the mediodorsal aspects of anterior cingulate and middle to superior frontal gyri. These findings suggest that phase-specific distribution of brain glucose metabolism may explain the dysphagia of PD.

Dysphagia in Parkinson Disease: Part I - Pathophysiology and Diagnostic Practices.

Dysphagia affects the majority of individuals with Parkinson disease (PD) and is not typically diagnosed until later in disease progression. This review will cover the current understanding of PD pathophysiology, and provides an overview of dysphagia in PD including diagnostic practices, gaps in knowledge, and future directions. Many non-motor and other motor signs of PD appear in the prodrome prior to the manifestation of hall- mark signs and diagnosis. While dysphagia often presents already in the prodrome, it is not routinely addressed in standard neurology examinations. Dysphagia in PD can result in compromised efficiency and safety of swallowing, which significantly contributes to malnutrition and dehydration, decrease quality of life, and increase mortality. The heterogeneous clinical presentation of PD complicates diagnostic procedures which often leads to delayed treatment. Research has advanced our knowledge of mechanisms underlying PD, but dysphagia is still largely understudied, especially in the prodromal stage.

Dysphagia Requiring Medical Attention in Parkinson's Disease: A Korean Population-Based Study.

Patients with Parkinson's disease (PD) experience both motor and non-motor symptoms, including dysphagia. Although PD is closely associated with dysphagia, the prevalence or risk of dysphagia in PD is unclear, especially in Asian countries. The prevalence of PD and dysphagia with PD in the general population was analyzed using the Korean National Health Insurance Service (NHIS) database. The prevalence per 100,000 persons of PD and dysphagia with PD from 2006 to 2015 was analyzed in the general population aged ≥ 40 years. Patients newly diagnosed with PD between 2010 and 2015 were compared with those without PD. The prevalence of PD and dysphagia in patients with PD increased continuously during the study period and was highest in the ninth decade of life. The percentage of patients with dysphagia in patients with PD increased with age. Patients with PD showed an adjusted hazard ratio of 3.132 (2.955-3.320) for dysphagia compared to those without PD. This nationwide study showed increasing trends in the prevalence of PD and dysphagia among patients with PD in Korea between 2006 and 2015. The risk of dysphagia was three times higher in patients with PD than that in those without PD, highlighting the importance of providing particular attention.

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

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. 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. 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 ? 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.

Striatal Dopaminergic Loss and Dysphagia in Parkinson Disease.

To better understand the development of dysphagia in patients with Parkinson disease (PD) and to identify possible neuromodulatory target regions of dysphagia, we studied the striatal dopamine transporter (DAT) availability distribution by subtype of dysphagia. In this retrospective cross-sectional study, patients with PD who underwent videofluoroscopic swallowing study and N-(3-[18F]fluoropropyl)-2β-carbon ethoxy-3β-(4-iodophenyl) nortropane (18F-FP-CIT) PET at intervals of less than 1 month were analyzed. The 14 binarized subitem scores of the Videofluoroscopic Dysphagia Scale were analyzed using a voxel-wise Firth's penalized binary logistic regression model, adjusting for age and disease duration at videofluoroscopic swallowing study. Sixty-five patients with PD were finally included. Striatal mapping showed association of decreased DAT availability with 5 subitems with 1 or more clusters surviving the statistical threshold: 1 oral phase and 4 pharyngeal phase subitems. The overlap maps created by superimposing clusters for all 5 statistically significant subitems revealed associations of dysphagia in PD with decreased DAT availability in the bilateral ventral striatum. Of these, 4 subitems belonging to the pharyngeal phase-specific dysphagia were additionally found to be related to dopaminergic degeneration of the bilateral anterior-to-posterior caudate and ventral striatum. These findings suggest that subitem/phase-specific striatal subregional dopaminergic depletion may explain the dysphagia of PD. This dopaminergic degeneration of striatal subregions specific to the phases of dysphagia may serve as a potential target for neuromodulatory brain stimulation through stimulation of cortices functionally connected.

The Relationship Between Lingual Strength and Functional Swallowing Outcomes in Parkinson's Disease.

The purpose of this retrospective study was to determine whether reduced lingual strength was associated with functional swallowing outcomes in individuals with Parkinson's disease (PD). Participants (N = 42) completed evaluations of maximal lingual isometric pressure (MIP) and mean lingual swallowing pressure (MSP), and flexible endoscopic evaluations of swallowing. Regression models were used to determine the association between lingual strength and functional swallowing outcomes of airway invasion, the presence of post-swallow pharyngeal residue, and the amount of pharyngeal residue (when present). Results revealed that higher MIP (p = 0.002, OR 0.93) and higher MSP (p = 0.001 OR 0.88) were associated with less airway invasion of thin liquids. Both MIP and MSP were able to differentiate between those with and without dysphagia (MIP: AUC 0.7935, p = 0.001; MSP: AUC 0.75, p = 0.026). Neither MIP nor MSP was related to the presence of residue. However, when thin liquid oropharyngeal residue was present, both MIP (p < 0.001, OR 0.99) and MSP (p < 0.001; OR 0.98) were significantly associated with the amount of residue observed. Similarly, when thin liquid hypopharyngeal residue was present, MIP (p < 0.001, OR 0.99) and MSP (p < 0.001, OR 0.98) were associated with the amount of residue observed. These findings suggest a relationship between reduced lingual strength and worse thin liquid swallowing safety and efficiency; however, the magnitude of these effects was small. This indicates that lingual strength is one important contributing factor to functional swallowing impairments in PD and may identify those with unsafe swallowing. These findings have important clinical implications for including lingual strength in the screening, assessment, and management of dysphagia in PD.

Cardiac sympathetic denervation could be associated with dysphagia in Parkinson's disease.

BackgroundDysphagia is an important non-motor symptom that is closely associated with quality of living and mortality in Parkinson's disease (PD). However, the pathophysiology of dysphagia in PD remains inconclusive. We tried to confirm whether the occurrence of dysphagia could be related to sympathetic degeneration using cardiac 123I-metaiodobenzylguanidine (MIBG) scintigraphy.MethodsWe prospectively recruited 27 PD patients and classified them into two groups (PD with dysphagia vs. PD without dysphagia) by Swallowing Disturbance Questionnaire (SDQ) score and compared the clinical characteristics, videofluoroscopic swallowing study (VFSS) findings and parameters from cardiac MIBG scintigraphy.ResultsThe mean early and late H/M ratios were significantly lower in the PD with dysphagia group than those in the PD without dysphagia group (1.39 ± 0.21 vs. 1.86 ± 0.21, p < 0.01; 1.26 ± 0.18 vs. 1.82 ± 0.29, p < 0.01). In the correlation analysis, both the early and late H/M ratios were negatively correlated with the SDQ score and total VDS score (r = −0.65, p < 0.01; r = −0.53, p < 0.01; r = −0.65, p < 0.01, r = −0.58, p < 0.01).ConclusionWe confirmed that cardiac sympathetic denervation might be associated with the presence and severity of dysphagia. This finding indicates that dysphagia in PD could be associated with a nondopaminergic mechanism.

Neuromuscular Pathology of Extrinsic Tongue Muscles in the Pink1‐/‐ Rat Model of Parkinson Disease

IntroductionParkinson disease (PD) affects the central and peripheral nervous systems resulting in widespread pathology. Recently, more research attention has been directed toward peripheral nerves and muscles as potential sources of pathology relating to oromotor control and swallowing. Swallowing impairment (dysphagia) presents during the prodromal phase of the disease, worsens over time, and can result in serious health and quality of life impairment. Post‐mortem human analyses show pathology of nerves and muscles of the pharynx and larynx. However less is known about tongue muscles. To study clinically relevant oromotor and swallow deficits across disease progression, we use the Pink1‐/‐ rat model of early‐onset autosomal dominant PD. We have shown oromotor and swallow dysfunction in the prodromal and early stages of disease (4‐8 months) in Pink1‐/‐ rats. At 6 months there were no differences between Pink1‐/‐ and WT genioglossus (GG) muscle in many measures of muscle biology, nor was there evidence of denervation. However, we speculate this may occur later in disease progression. We hypothesize that Pink1‐/‐ GG muscles will have smaller myofiber sizes with a shift in myofiber heavy chain isoform profiles toward slower profiles compared to WT GG muscles. Additionally, we hypothesize that that Pink1‐/‐ GG NMJs will be fewer in total number with less overlap of pre‐ and post‐synaptic structures and greater motor endplate area and dispersion ratios compared to WT GG NMJs. Data and analyses are ongoing; results with expanded methodology will be presented.MethodsWe evaluated the GG muscles of 10‐month‐old rats, Pink1‐/‐ (n=2) WT (n=2)(Sage Labs, Boyertown, PA, USA). Fixed tissues were flash frozen and sectioned at 20 microns. We labeled pre‐synaptic structures with primary antibodies to NF‐M &amp; ZNP‐1 (red fluorophore secondaries) and post‐synaptic acetylcholine receptors at the motor endplate with alpha‐bungarotoxin‐AF488 (green fluorophore). Images were taken at 20x using a fluorescent microscope (Olympus, Bx53, USA) and analyzed with ImageJ (imagej.nih.gov). Then we counted the total number of motor endplates (green) in each tissue section. We also counted how many motor endplates co‐localized with nerve terminals (red) to quantify the number of structurally intact NMJs. Here we report effects sizes due to an incomplete data set.ResultsPreliminary results demonstrated modest effect size with trends towards WT rats having more total NMJs (Cohen’s D=0.359) which was compatible with our hypothesis, but a lower proportion of structurally intact NMJs (Cohen’s D=0.454) contrary to our hypothesis.DiscussionPreliminary results suggest differences in total NMJs and NMJ structure between WT and Pink1‐/‐ rats. We will report data sets of myofiber cross‐sectional area, myofiber type composition, and the NMJ parameters of total number, overlap of pre‐ and post‐synaptic structures, motor endplate area, and dispersion ratio. These results will provide a substantial presentation of the neuromuscular phenotype present at mid‐disease timepoints in Pink1‐/‐ rats aged 10 months. Investigating neuromuscular biology of extrinsic tongue muscles and swallow‐related structures is vital for understanding of the onset, sequelae, and underlying pathology of dysphagia in PD. These results are important to an ongoing effort to develop novel therapies targeted at the devastating swallowing deficits in PD.

Effectiveness of Interventions for Dysphagia in Parkinson Disease: A Systematic Review.

Purpose:Dysphagia is a common sequela of Parkinson disease (PD) and is associated with malnutrition, aspiration pneumonia, and mortality. This review article synthesized evidence regarding the effectiveness of interventions for dysphagia in PD.Method:Electronic searches were conducted in Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, CINAHL, and speechBITE. Of the 2,015 articles identified, 26 met eligibility criteria: interventional or observational studies with at least five or more participants evaluating dysphagia interventions in adults with PD-related dysphagia, with outcomes measured using videofluoroscopic swallowing study (VFSS), fiberoptic endoscopic evaluation of swallowing (FEES), or electromyography (EMG). Risk of bias (RoB) was evaluated using the Evidence Project tool and predetermined criteria regarding the rigor of swallowing outcome measures.Results:Interventions were classified as follows: pharmacological (n = 11), neurostimulation (n = 8), and behavioral (n = 7). Primary outcome measures varied across studies, including swallowing timing, safety, and efficiency, and were measured using VFSS (n = 17), FEES (n = 6), and EMG (n = 4). Critical appraisal of study findings for RoB, methodological rigor, and transparency showed the majority of studies failed to adequately describe contrast media used, signal acquisition settings, and rater blinding to time point. Low certainty evidence generally suggested improved swallow timing with exercises with biofeedback and deep brain stimulation (DBS), improved safety with DBS and expiratory muscle strength training, and improved efficiency with the Lee Silverman Voice Treatment and levodopa.Conclusions:Studies with lower RoB and greater experimental rigor showed potential benefit in improving swallowing efficiency but not safety. Further research investigating discrete changes in swallowing pathophysiology post-intervention is warranted to guide dysphagia management in PD.Supplemental Material: https://doi.org/10.23641/asha.17132162

Swallowing Rehabilitation of Dysphagia in Parkinson Disease: Recent Advances and Recommendations

Swallowing Rehabilitation of Dysphagia in Parkinson Disease: Recent Advances and Recommendations

Acupuncture adjuvant treatment for dysphagia in patients with Parkinson's disease: a randomized controlled trial

To observe the effect of acupuncture on swallowing function and nutritional status of patients with Parkinson's disease (PD) dysphagia. A total of 56 patients with PD dysphagia were randomly divided into an observation group and a control group, 28 cases in each one. Both groups were given conventional treatment and swallowing function rehabilitation training.On the basis, the observation group was treated with acupuncture (filiform needling and tongue picking acupuncture). The acupoints of filiform needling were Lianquan (CV 23), Shanglianquan (Extra), Yifeng (TE 17), etc.; and the tongue picking acupuncture was applied at Jinjin (EX-HN 12), Yuye (EX-HN 13) and posterior pharyngeal wall. Rehabilitation training and acupuncture were performed once a day for 5 consecutive days a week, 2 weeks as a course of treatment, 3 courses in total. The swallowing function [oral transit time (OTT), swallowing response time (SRT), pharyngeal transit time (PTT), laryngeal closure duration (LCD)] and nutritional indexes [body mass index (BMI), serum albumin (ALB), serum prealbumin (PA), hemoglobin (Hb)] in the two groups were evaluated before and after treatment, and the clinical effects were compared. After treatment, the paste and liquid OTT, SRT, PTT, LCD in the two groups were shorter than those before treatment (P<0.05), and the observation group was shorter than the control group (P<0.05). After treatment, the nutritional indexes (BMI, ALB, PA, Hb) in the two groups were higher than those before treatment (P<0.05), and the observation group was higher than the control group (P<0.05). The total effective rate of the observation group was 92.9% (26/28), which was better than 67.9% (19/28) of the control group (P<0.05). Acupuncture-assisted rehabilitation training can improve the swallowing function and nutritional status in patients with Parkinson's disease swallowing disorders.

Handheld Cough Testing: A Novel Tool for Cough Assessment and Dysphagia Screening.

Aspiration pneumonia is a leading cause of death in Parkinson's disease (PD), occurring as a result of impaired cough and swallowing function. However, portable diagnostic tools for cough assessment and dysphagia screening are limited. Therefore, the aims of this study were to determine if: (1) 'Handheld Cough Testing' (HCT), a novel tool developed for cough assessments, could detect differences in cough airflow and sensation during reflex and voluntary cough tasks; and (2) HCT could screen for dysphagia in PD with high sensitivity. Twenty-two people with PD underwent HCT and swallowing assessments. Cough airflow ('PEFR') and sensation ('UTC') was recorded during reflex and voluntary cough tasks. Flexible endoscopy was used to identify people with and without dysphagia. Within-subject statistical analyses were used to detect differences in PEFR and UTC across cough tasks and between-subject statistical analyses were used to detect differences in cough function between people with and without dysphagia. Results revealed significant differences in PEFR (p < 0.0005) and UTC (p < 0.0005) across cough tasks using HCT. Additionally, reflex cough PEFR was significantly different between people with and without dysphagia (p < 0.05). A cut-off of 42.5 L/min exhibited an excellent ability to predict dysphagia in people with PD (90.9% sensitivity; 80.0% specificity). This study revealed that HCT was a valid tool for cough assessment and dysphagia screening. It identified differences in cough airflow and sensation during reflex and voluntary cough tasks and screened for people with dysphagia in PD with high sensitivity.

Predictors of Residue and Airway Invasion in Parkinson's Disease.

Dysphagia is a highly prevalent disorder in Parkinson's Disease (PD) characterized by changes in swallowing kinematics, residue, and airway invasion. These changes can lead to serious medical morbidities including malnutrition, aspiration pneumonia, and death. However, little is known about the most predictive causes of residue and airway invasion in this patient population. Therefore, the aims of this study were to (1) assess how disease severity affects residue, airway invasion, and swallowing kinematics in PD; and (2) determine which swallowing kinematic variables were most predictive of residue and airway invasion. A secondary analysis of forty videofluoroscopic swallow studies (VFSS) from individuals with early through mid-stage PD was performed. Airway invasion (Penetration-Aspiration Scale 'PAS'), residue (Bolus Clearance Ratio 'BCR'), and ten spatiotemporal swallowing kinematic variables were analyzed. Statistical analyses were used to determine if disease severity predicted residue, depth of airway invasion, and swallowing kinematics, and to examine which swallowing kinematic variables were most predictive of residue and the presence of airway invasion. Results revealed that residue and the presence of airway invasion were significantly predicted by swallowing kinematics. Specifically, airway invasion was primarily influenced by the extent and timing of airway closure, while residue was primarily influenced by pharyngeal constriction. However, disease severity did not significantly predict changes to swallowing kinematics, extent of residue, or depth of airway invasion during VFSS assessment. This study comprehensively examined the pathophysiology underlying dysphagia in people with early to mid-stage PD. The results of the present study indicate that disease severity alone does not predict swallowing changes in PD, and therefore may not be the best factor to identify risk for dysphagia in PD. However, the swallowing kinematics most predictive of residue and the presence of airway invasion were identified. These findings may help to guide the selection of more effective therapy approaches for improving swallowing safety and efficiency in people with early to mid-stage PD.

Dysphagia in Parkinson's Disease Improves with Vocal Augmentation.

While voice-related disorders in Parkinson's disease (PD) are commonly discussed in the literature, dysphagia in PD is less widely published. Vocal fold augmentation, including injection laryngoplasty (IL), is a well-established treatment for glottal insufficiency (Cates et al. in Otolaryngol Head Neck Surg 155(3):454-457, 2016). This study aimed to observe the effects of IL in PD patients with vocal bowing, with or without therapy, on glottic closure and patient-reported dysphagia outcomes. The study design was based on retrospectively collected database and cohort-case series. PD patients selected for retrospective review over a 2-year period were referred and evaluated in the Voice, Swallowing, and Airway multidisciplinary clinic by speech language pathologist and laryngologist, and were undergoing IL. Charts were reviewed for age, gender, Body Mass Index (BMI), onset of PD, and Movement Disorders Society-Unified Parkinson's Disease Rating Scale Part 3 (MDS-UPDRS) scoring. We compared pre/postoperatively (> 1 < 3months) using validated patient-reported outcome tools: Reflux Symptom Index (RSI), Glottal Function Index (GFI), Eating Assessment Tool-10 (EAT), and stroboscopic examinations. The study included 14 patients undergoing 22 IL or 1.6 IL/patient: mean age 70years (63-80), 100% male, and BMI 25.9 ± 4.3 (mean ± SD). MDS-UPDRS scoring 33 ± 20 (moderate severity), with time between PD diagnosis and IL 8 ± 10years. All patients had pre- and post-stroboscopic examinations; however, only 4:14 underwent formal swallowing evaluation. Overall, 14 IL patients improved on patient-reported measures (ΔRSI = 4; ΔGFI = 3; ΔEAT = 4). Based on the findings of the study, we conclude that PD is a progressive neurodegenerative condition with dysphagia. The presented pilot data suggest that IL may be considered as a beneficial adjunct for PD patients with glottal insufficiency. LEVEL OF EVIDENCE: 4.

Predictive clinical factors for penetration and aspiration in Parkinson's disease.

Do the current swallow-specific subquestions of neurological diagnostic tools reflect the objective swallowing function in Parkinson's disease (PD) patients or are clinical factors superior to predict critical aspiration? In a cross-sectional, observational study a total of 119 Parkinson outpatients were examined clinically and by flexible-endoscopic evaluation of swallowing (FEES). Self-reported dysphagia by subquestions of the MDS-UPDRS and NMS questionnaire and history of subjective aspiration signs were collected. Nearly, all PD patients showed deglutition abnormalities in FEES (113/119) while only 12%-27% of them reported swallowing problems in the swallow-specific subquestions of neurological standard diagnostic tools (MDS-UPDRS and NMS-Quest), and the answers were heterogeneous and poorly reproducible. With a sensitivity of up to a maximum of 50%, self-reported dysphagia is therefore no reliable tool for identifying dysphagia in PD. While most clinical parameters were linked to dysphagia to some extent, logistic regression analysis revealed high age (Odds Ratio (OR) 1.1 in years, 95% CI 1.03-1.18, P<0.01), gender (OR 0.3 for females, 95% CI 0.08-0.97, P=0.04), and affirmed subjective aspiration signs (OR 8.6, 95% CI 3.05-26.52, P<0.001) as the most significant predictors for critical dysphagia. Self-perception of swallowing is no reliable tool for identifying dysphagia and questionnaires are insufficient for detecting previous aspiration. Consequent and specific asking for previous subjective aspiration signs is the single most important measure for identifying PD patients at risk for critical aspiration.

Pink1 -/- Rats Show Early-Onset Swallowing Deficits and Correlative Brainstem Pathology.

Parkinson disease (PD) compromises oropharyngeal swallowing, which negatively affects quality of life and contributes to aspiration pneumonia. Dysphagia often begins early in the disease process, and does not improve with standard therapies. As a result, swallowing deficits are undertreated in the PD population. The Pink1 -/- rat is used to model PD, and demonstrates widespread brainstem neuropathology in combination with early-onset sensorimotor dysfunction; however, to date, swallowing behaviors have not been evaluated. To test the hypothesis that Pink1 -/- rats demonstrate early-onset differences in swallowing, we analyzed within-subject oropharyngeal swallowing using videofluoroscopy. Pink1 -/- and wildtype (WT) controls at 4 (Pink1 -/- n = 16, WT = 16) and 8 (Pink1 -/- n = 12, WT = 12) months of age were tested. The average and maximum bolus size was significantly increased in Pink1 -/- rats at both 4 and 8months. Bolus average velocity was increased at 8months for all animals; yet, Pink1 -/- animals had significantly increased velocities compared to WT at 8months. The data show a significant reduction in mastication rate for Pink1 -/- rats at 8months suggesting the onset of oromotor dysfunction begins at this time point. Relationships among swallowing variables and neuropathological findings, such as increased alpha-synuclein protein in the nucleus ambiguus and reductions in noradrenergic cells in the locus coeruleus in the Pink1 -/- rats, were determined. The presence of early oropharyngeal swallowing deficits and relationships to brainstem pathology in Pink1-/- rat models of PD indicate that this may be a useful model of early swallowing deficits and their mechanisms. These findings suggest clinical implications for early detection and management of dysphagia in PD.

Lingual Pressure as a Clinical Indicator of Swallowing Function in Parkinson's Disease.

Swallowing impairment, or dysphagia, is a known contributor to reduced quality of life, pneumonia, and mortality in Parkinson's disease (PD). However, the contribution of tongue dysfunction, specifically inadequate pressure generation, to dysphagia in PD remains unclear. Our purpose was to determine whether lingual pressures in PD are (a) reduced, (b) reflect medication state, or are (c) consistent with self-reported diet and swallowing function. Twenty-eight persons with idiopathic PD (PwPD) and 28 age- and sex-matched controls completed lingual pressure tasks with the Iowa Oral Performance Instrument. PwPD were tested during practically defined ON and OFF dopaminergic medication states. Participants were also stratified into three sex- and age-matched cohorts (7 men, 5 women): (a) controls, (b) PwPD without self-reported dysphagia symptoms or diet restrictions, and (c) PwPD with self-reported dysphagia symptoms with or without diet restrictions. PwPD exhibited reduced tongue strength and used elevated proportions of tongue strength during swallowing compared with controls (p < .05) without an effect of medication state (p > .05). Reduced tongue strength distinguished PwPD with self-reported dysphagia symptoms from PwPD without reported symptoms or diet restrictions (p = .045) and controls (p = .002). Tongue strength was significantly reduced in PwPD and did not differ by medication state. Tongue strength differentiated between PwPD with and without self-reported swallowing symptoms. Therefore, measures of tongue strength and swallowing pressures may serve as clinical indicators for further dysphagia evaluation and may promote early diagnosis and management of dysphagia in PD.