A comprehensive review of the diagnosis and treatment of Parkinson’s disease dysphagia and aspiration

ABSTRACT

Introduction

Bulbar dysfunction is common in Parkinson’s disease (PD) with more than 80% of affected individuals developing dysphagia during the course of the disease. Symptoms can begin in the preclinical stage and individuals may remain clinically asymptomatic for years. Furthermore, patients may be unaware of swallowing changes, which contributes to the difference between the prevalence of self-reported dysphagia and deficits identified during instrumental evaluations. Dysphagia is underrecognized and contributes to the development of aspiration pneumonia which is the leading cause of death in PD. Dysphagia in PD is complex and not completely understood. Both dopaminergic and nondopaminergic pathways likely underpin dysphagia.

Areas covered

This comprehensive review will cover the epidemiology, pathophysiology, clinical evaluation, and expert management of dysphagia and aspiration in patients with PD.

Expert Opinion

A multidisciplinary team approach is important to properly identify and manage PD dysphagia. Regular clinical screenings with objective instrumental assessments are necessary for early detection of dysphagia. Studies are needed to better understand the mechanism(s) involved in PD dysphagia, establish markers for early detection and progression, and develop evidence-based treatment options.

KEYWORDS:

• Aspiration
• dysphagia
• evaluation
• management
• Parkinson’s disease
• pathophysiology
• swallowing
• treatment

Article highlights

• More than 80% of patients with PD develop dysphagia during the course of their disease, and it may occur even in pre-symptomatic stages.

• PD dysphagia is associated with aspiration pneumonia, which is the most frequent cause of PD related death.

• Routine screening for dysphagia with swallowing-specific questionnaires and/or clinical bedside swallow evaluation, as well as instrumental evaluation utilizing either videofluoroscopic swallow study (also known as modified barium swallow study) or fiberoptic endoscopic evaluation of swallowing are necessary for detection of dysphagia.

• Management of dysphagia includes compensatory strategies (i.e. postural changes, pacing of bites and sips, bolus volume, etc.), diet modifications, and exercises aimed to strengthen muscles, improve airway safety, and swallow efficiency.

• Clinical predictors of dysphagia in patients with PD include Hoehn and Yahr greater than 3 (advanced PD), dementia, anterior spillage of food and/or liquid from oral cavity (i.e. drooling), weight loss, and a body mass index of <20 kg/m².

• There is one randomized clinical study revealing that expiratory muscle strength training (EMST) may be helpful in the prevention of aspiration in PD.

• A multidisciplinary team approach for early detection and management of dysphagia can improve quality of life, swallowing safety and efficiency, nutrition, and hydration.

Declaration of interest

M S Okun serves as a consultant for the Parkinson’s Foundation and has received research grants from NIH, Parkinson’s Foundation, the Michael J. Fox Foundation, the Parkinson Alliance, Smallwood Foundation, the Bachmann–Strauss Foundation, the Tourette Syndrome Association, and the UF Foundation. M S Okun’s DBS research is supported by NIH R01 NR014852 and R01NS096008. M Okun is PI of the NIH R25NS108939 Training Grant. M S Okun has received royalties for publications with Demos, Manson, Amazon, Smashwords, Books4Patients, Perseus, Robert Rose, Oxford, and Cambridge (movement disorders books). M S Okun is an associate editor for New England Journal of Medicine Journal Watch Neurology. M S Okun has participated in CME and educational activities on movement disorders sponsored by the Academy for Healthcare Learning, PeerView, Prime, QuantiaMD, WebMD/Medscape, Medicus, MedNet, Einstein, MedNet, Henry Stewart, American Academy of Neurology, Movement Disorders Society, and by Vanderbilt University. The institution and not M S Okun receives grants from Medtronic, Abbvie, Boston Scientific, Abbott, and Allergan and the PI has no financial interest in these grants. M S Okun has participated as a site PI and/or co-I for several NIH, foundation, and industry-sponsored trials over the years but has not received honoraria. Research projects at the University of Florida receive device and drug donations.

All authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was supported by an NIH grant on cough with overlap on aspiration, R01 HD091658 (Hegland). The Fixel Institute is supported by a Center of Excellence grant from the Parkinson’s Foundation.