Dyspnea in Parkinson’s disease: an approach to diagnosis and management

ABSTRACT

Introduction

Dyspnea is a complex and debilitating non-motor symptom experienced by a significant proportion of PD patients which results in limitations to physical ability and a reduction in quality of life.

Areas covered

The authors highlight the underlying pathophysiological mechanisms that can contribute to dyspnea in PD patients, and provide the clinician with a practical working algorithm for the management of such patients. The authors further highlight important clinical red flags that should be heeded in dyspneic PD patients and discuss therapeutic strategies for managing dyspnea.

Expert opinion

Although awareness of dyspnea in PD is increasing, further studies of its prevalence and natural history at different stages of the disease are needed. In particular, it is important to determine whether dyspnea could be an early or prodromal disease manifestation. Although peripheral mechanisms are likely to play a major role in the pathophysiology of dyspnea, the possibility that central changes in brainstem ventilatory control may also play a part warrants further investigation.

KEYWORDS:

• Dyspnea
• Parkinson’s disease
• brainstem ventilatory dysfunction
• non-motor symptom
• pulmonary dysfunction
• inspiratory muscle training

Article highlights

• Dyspnea is a disabling non-motor symptom that occurs in a significant proportion of PD patients.

• The mechanisms of dyspnea in PD are complex and involve an interplay between the effects of the disease on the respiratory system, sensory and perceptual changes, psychological factors, medication effects and co-morbidities.

• Disordered brainstem control of ventilation is a plausible mechanism for dyspnea but has been under-researched.

• Clinical evaluation of the dyspneic PD patient requires careful attention to the circumstances under which breathlessness occurs and physical examination, together with appropriate investigations to exclude non-disease related causes.

• It is important to consider iatrogenic causes for dyspnea such as pulmonary fibrosis due to the older generation ergot-derived dopamine agonists.

• Management of the dyspneic PD patient involves reassurance, explanation of the cause(s), and modification of the dopaminergic drug regimen when the dyspnea is state-related.

• Counseling and referral to a clinical psychologist may be required when dyspnea is anxiety related.

• Pulmonary rehabilitation, inspiratory muscle training and resistance training are beneficial for improving cardiorespiratory aerobic capacity and performance.

Acknowledgments

The authors acknowledge the assistance of Sue Walters and Alexa Jefferson, and support of Professors Ryan Anderton, Norman Palmer, Graeme Hankey and Jenny Rodger with our research program.

Declaration of interest

S Vijayan receives funding from the following: Australian Government Research Training Program (RTP) Scholarship from the University of Western Australia; Prestige Scholarship from the Perron Institute for Neurological and Transitional Science; Movement Disorders Fellowship grant from Allergan (Australia). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this 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 not funded.