The list keeps growing of varied symptoms associated with Parkinson’s disease (PD). So often thought of as a neurodegenerative motor disorder characterized by issues with movement such as tremors, freezing, bradykinesia and postural instability, the list of non-motor symptoms is expanding as we learn more about the condition. Some of the most common non-motor complaints are mood disorders, cognitive changes, and vision problems, fatigue, sleep disorders and issues with impulse control.
The autonomic nervous system regulates certain automatic body processes, those that take place without our thinking about them. It gets information from the body and the environment and stimulates the body to respond. Blood pressure, digestion, heart and breathing rates, and the production of body fluids including saliva, are among the functions.1
Dry mouth (xerostomia) is a common but often unreported symptom of PD. It is a condition that results in decreased saliva production. Saliva keeps our mouths wet and helps to clean it by swallowing. It contains enzymes that aid in digestion. People may experience varying degrees of dry mouth, which can impact swallowing and contribute to tooth decay and mouth infections.3 Dry mouth can be an early indication of autonomic involvement in PD.2,4 It can affect your ability to speak and to eat. Some dry mouth conditions can lead to salivary gland dysfunction, resulting in more serious conditions.
Dry mouth can be caused by several factors including:
Medications: Prescription and over the counter (OTC) medicines are some of the most common causes of dry mouth. Reducing, stopping or changing certain medications can relieve dry mouth.
Age: Advanced age alone is not a cause of dry mouth but half of those over age 60 take multiple maintenance medications that can trigger it.
Medical conditions: Diabetes, Sjögren’s Syndrome and Parkinson’s disease can all cause you to experience dry mouth.
There are several connections between Parkinson’s disease and dry mouth. Repeated swallowing consumes the available saliva that keeps the mouth moist. It is often related to the drugs used to manage PD, particularly anticholinergics. A physician may be able to change or adjust medications and dosages to reduce dry mouth.4
Importance of Saliva
Saliva is a liquid substance secreted by glands into the mouth. It is needed to maintain good oral health including strong, clean teeth and an infection-free mouth. It lubricates and protects tissue inside the mouth, breaks down food that helps you taste, and assists with chewing and swallowing. A clean mouth helps to fight infection while reducing tooth decay.4
Treating dry mouth
Your doctor or dentist can offer guidance on how to manage symptoms of dry mouth. Some easy steps to try include:
Avoid sugary or acidic snacks, foods, and drinks
Suck on candy that contains xylitol, a natural sweetener that reduces tooth decay
Chew sugar-free gum that can stimulate saliva
Sip water to keep the mouth moist and hydrated
Brush with a fluoride toothpaste
Use a fluoride rinse or brush-on fluoride gel before bedtime
Avoid mouthwash that contains alcohol which increases dry mouth
Use saliva substitutes – liquid or aerosol products sprayed into the mouth that are designed to moisten and relieve pain. Look for products with xylitol, carboxymethylcellulose or hydroxyethyl cellulose
Try a mouthwash designed for dry mouth. Products are made by Act, Biotene, Colgate, Gum, SmartMouth, and TheraBreath among others
Don’t use antihistamines and decongestants that can dry you out, check with your doctor about what is best for you.
Breathe through your nose, not your mouth.
Use a humidifier to add moisture to the air
Visit the dentist twice a year for a check up and cleanings to assure a healthy mouth5
Talk to your health care team if your dry mouth doesn’t resolve over time. There could be other causes including medication side effects or dry mouth could be an indication of other significant medical conditions.
Low, P. Overview of the Autonomic Nervous System. Available at: https://www.merckmanuals.com/home/brain,-spinal-cord,-and-nerve-disorders/autonomic-nervous-system-disorders/overview-of-the-autonomic-nervous-system#v746364. Accessed 12.12.18
Cersosimo, MG, Raina, GB, et al. Dry mouth: an overlooked autonomic symptom of Parkinson's disease. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23939300. Accessed 12.12.18.
Parkinson’s disease & Dry Mouth. Available at: https://www.biotene.com/what-is-dry-mouth/parkinsons-disease/. Accessed 12.12.18.
Causes of Dry Mouth (xerostomia). Available at: https://www.oracoat.com/pages/causes-of-dry-mouth-xerostomia. Accessed 12.12.18.
Oral Health & Parkinson’s Disease. Available at:https://d2icp22po6iej.cloudfront.net/wp-content/uploads/2017/02/APDA-Oral_Health.pdf. Accessed 12.12.18.
Salinas, TJ. Dry mouth treatment: Tips for controlling dry mouth. Available at:
https://www.mayoclinic.org/diseases-conditions/dry-mouth/expert-answers/dry-mouth/faq-20058424. Accessed 12.12.18.