Swallowing in Parkinson's disease: clinical issues and management

Exploring the Neuropsychological Correlates of Swallowing Disorders in People with Parkinson's Disease: a Cross-Sectional Study

Around 80% of persons with Parkinson's disease (PD) present symptoms of dysphagia. Although cognitive impairment may contribute to dysphagia, few studies have investigated the association between the PD neuropsychological profile and objective measures of swallowing dysfunction. Since the swallowing function comprises involuntary but also voluntary actions, we hypothesize that specific measures of attention and executive functions can be underlined in PD-related dysphagia. Therefore, the aim of this study was to extensively investigate the correlation and the relationship between attentive and executive functions and safety/efficiency of pharyngeal phase of swallowing in people with PD. All participants received a fiberoptic endoscopic evaluation of swallowing and were evaluated using the Penetration Aspiration Scale (PAS); the Yale Pharyngeal Residue Severity Rating Scale (IT-YPRSRS), and the Functional Oral Intake Scale (FOIS-IT). Participants also underwent a neuropsychological assessment covering global cognitive status, attention, and frontal executive functions. Correlations and associations between neuropsychological measures and swallowing components were calculated. Twenty-one participants with PD (mean age 69.38 ± 6.58 years, mean disease duration 8.38 ± 5.31 years; mean MDS-UPDRS III 43.95 ± 24.18) completed all evaluations. The most significant correlations were found between attentive functions (i.e., Stroop Time), and executive functions (i.e., Raven's Progressive Matrices, Digit Backward and Semantic Fluency), and FOIS-IT, PAS, and IT-YPRSRS sinuses and valleculae. These associations were not influenced by disease duration. These results suggest that a dysfunction to attentional processes and/or to executive functions can contribute to penetration and the presence of pharyngeal residue in participants with middle-stage PD.

Prevalence and Factors Associated with Drooling in Parkinson’s Disease: Results from a Longitudinal Prospective Cohort and Comparison with a Control Group

Introduction. Drooling in Parkinson’s disease (PD) is frequent but often goes underrecognized. Our aim was to examine the prevalence of drooling in a PD cohort and compare it with a control group. Specifically, we identified factors associated with drooling and conducted subanalyses in a subgroup of very early PD patients. Patients and Methods. PD patients who were recruited from January 2016 to November 2017 (baseline visit; V0) and evaluated again at a 2-year ± 30-day follow-up (V2) from 35 centers in Spain from the COPPADIS cohort were included in this longitudinal prospective study. Subjects were classified as with or without drooling according to item 19 of the NMSS (Nonmotor Symptoms Scale) at V0, V1 (1-year ± 15 days), and V2 for patients and at V0 and V2 for controls. Results. The frequency of drooling in PD patients was 40.1% (277/691) at V0 (2.4% (5/201) in controls; $p$  < 0.0001), 43.7% (264/604) at V1, and 48.2% (242/502) at V2 (3.2% (4/124) in controls; $p$  < 0.0001), with a period prevalence of 63.6% (306/481). Being older (OR = 1.032; $p$  = 0.012), being male (OR = 2.333; $p$  < 0.0001), having greater nonmotor symptom (NMS) burden at the baseline (NMSS total score at V0; OR = 1.020; $p$  < 0.0001), and having a greater increase in the NMS burden from V0 to V2 (change in the NMSS total score from V0 to V2; OR = 1.012; $p$  < 0.0001) were identified as independent predictors of drooling after the 2-year follow-up. Similar results were observed in the group of patients with ≤2 years since symptom onset, with a cumulative prevalence of 64.6% and a higher score on the UPDRS-III at V0 (OR = 1.121; $p$  = 0.007) as a predictor of drooling at V2. Conclusion. Drooling is frequent in PD patients even at the initial onset of the disease and is associated with a greater motor severity and NMS burden.

Behavioural interventions for swallowing in subjects with Parkinson's disease: A mixed methods systematic review

BACKGROUND

Dysphagia is prevalent in subjects with Parkinson's disease (PD). Swallowing intervention to improve or maintain swallowing function is of major importance as dysphagia may considerably impact physical and psycho-social health.

AIMS

A mixed methods systematic review was conducted to summarize and appraise literature reporting (1) effects of behavioural interventions for swallowing in individuals with PD; and (2) participants' perspectives of swallowing interventions.

METHODS & PROCEDURES

Electronic databases were searched systematically in July 2020 for articles published between 2014 and 2020. In addition, studies published between 2000 and 2014 were identified non-systematically through previous reviews. Peer-reviewed quantitative and qualitative research in English or German documenting behavioural interventions for swallowing in individuals with a diagnosis of PD was eligible for inclusion. Participants at all disease stages were included. Behavioural interventions included rehabilitative and compensatory strategies. Studies reporting swallowing outcomes with and without a comparative group were included. For each study, the National Health and Medical Research Council level of evidence was defined. Included studies were critically appraised using the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields. An integrated synthesis was performed after separate analysis of effect data and data reflecting participants' experiences. This review was conducted based on published JBI methodology and the guideline from the Preferred Reporting Items for Systematic Reviews and Meta-Analysis system was followed.

MAIN CONTRIBUTION

A total of 33 studies published in English met the inclusion criteria. Thirty-one studies reported quantitative data, one was qualitative and one was mixed methods. Intervention effects on swallowing function, swallowing safety and swallowing-related quality of life were reported for various treatment approaches. Three studies explored how participants perceived the intervention. Overriding themes including subjects' views regarding treatment schedules and levels of effort or comfort associated with the intervention were identified across these studies. Combining evidence of intervention effects and subjects' experiences was possible for one rehabilitative and one compensatory intervention.

CONCLUSIONS & IMPLICATIONS

Beneficial effects of swallowing interventions have been reported; however, most experiments were case studies of variable methodological quality. Randomized-controlled trials with robust methodology to explore treatment effects in larger samples is needed to guide clinical practice. Research reporting subjects' views is scarce. More studies exploring how individuals perceive behavioural interventions for swallowing are necessary to inform clinical decision-making.

WHAT THIS PAPER ADDS

What is already known on the subject Dysphagia is common in individuals with PD. Swallowing intervention is of major importance as dysphagia may negatively affect physical and psycho-social health of subjects with PD. What this study adds Beneficial effects of behavioural interventions for swallowing, including rehabilitative and compensatory strategies, have been reported; however, available data are mostly based on case studies of variable quality. Data on how participants perceive specific behavioural interventions are lacking. Based on the available data, integration of efficacy data and individuals' experiences is limited. What are the clinical implications of this work? Given the current evidence of intervention effects and individuals' views on behavioural treatment strategies, interventions implemented into clinical practice require careful evaluation on a case-by-case basis. More high-quality research is needed to examine interventions' short- and long-term effects in larger samples to guide clinical practice. In addition to studies evaluating intervention effects, research exploring participants' experiences with interventions is required as a foundation for clinical decision-making.

A protocol for the evaluation of a wearable device for monitoring of symptoms, and cueing for the management of drooling, in people with Parkinson's disease

Drooling is a common symptom of Parkinson's Disease (PD) experienced in up to 70% of people with PD (PwP). Drooling can be a major problem in PwP leading to adverse physical and psychosocial issues. Current medical treatments decrease the production of saliva, whereas the problem is due to decreased swallowing frequency, not over production of saliva. Such treatments are problematic as saliva is essential for good oral health. Therefore, non-invasive treatments options such as behavioural cueing methods are recommended. A wrist-worn device delivering haptic cueing has been demonstrated to be an effective treatment method to increase swallowing frequency and a socially acceptable solution for PwP. However, the device had limited functionality and was tested on a small sample size over a short period of usage. Further work is required to understand the real-world behaviours and usage of the intervention to understand the longer-term effects with a larger sample size. This research will deploy CueBand, a discrete and comfortable wrist-worn device designed to work with a smartphone application to support the real-world evaluation of haptic cueing for the management of drooling. We will recruit 3,000 PwP to wear the device day and night for the intervention period to gain a greater understanding of the effectiveness and acceptability of the technology within real-world use. Additionally, 300 PwP who self-identity as having an issue with drooling will be recruited into an intervention study to evaluate the effectiveness of the wrist-worn CueBand to deliver haptic cueing (3-weeks) compared with smartphone cueing methods (3-weeks). PwP will use our smartphone application to self-assess their drooling frequency, severity, and duration using visual analogue scales and through the completion of daily diaries. Semi-structured interviews to gain feedback about utility of CueBand will be conducted following participants completion of the intervention.

Quipazine Elicits Swallowing in the Arterially Perfused Rat Preparation: A Role for Medullary Raphe Nuclei?

Pharmacological neuromodulation of swallowing may represent a promising therapeutic option to treat dysphagia. Previous studies suggested a serotonergic control of swallowing, but mechanisms remain poorly understood. Here, we investigated the effects of the serotonergic agonist quipazine on swallowing, using the arterially perfused working heart-brainstem (in situ) preparation in rats. Systemic injection of quipazine produced single swallows with motor patterns and swallow-breathing coordination similar to spontaneous swallows, and increased swallow rate with moderate changes in cardiorespiratory functions. Methysergide, a 5-HT2 receptor antagonist, blocked the excitatory effect of quipazine on swallowing, but had no effect on spontaneous swallow rate. Microinjections of quipazine in the nucleus of the solitary tract were without effect. In contrast, similar injections in caudal medullary raphe nuclei increased swallow rate without changes in cardiorespiratory parameters. Thus, quipazine may exert an excitatory effect on raphe neurons via stimulation of 5-HT2A receptors, leading to increased excitability of the swallowing network. In conclusion, we suggest that pharmacological stimulation of swallowing by quipazine in situ represents a valuable model for experimental studies. This work paves the way for future investigations on brainstem serotonergic modulation, and further identification of neural populations and mechanisms involved in swallowing and/or swallow-breathing interaction.