By Mary Spremulli
Drooling can be an embarrassing and annoying problem for individuals with a neurodegenerative disease, and a fairly common symptom in persons with Parkinson’s disease (PD) who often complain of “too much saliva.” Dysphagia (swallowing problems) and drooling seem to go hand in hand and both are present in 70% to 100% of persons with PD, although patients may not always recognize that drooling represents an underlying swallowing problem and may ignore this and other symptoms until coughing and choking when eating and drinking become more frequent.
Technically, drooling is defined as excessive pooling and poor control of saliva in the oral cavity that might be caused by impaired salivary clearance whereas sialorrhea refers to overflow or overproduction of saliva, and in individuals with PD, both factors need to be addressed.
We normally swallow saliva all day long and rarely give much thought to its role in our body, but saliva has multiple essential functions in relation to the digestive process taking place in the upper parts of the gastrointestinal tract including: taste, chewing, bolus formation, swallowing, enzymatic digestion and maintenance of tooth and mucosal integrity. Saliva is derived predominantly from three paired major salivary glands, the parotid, submandibular and sublingual glands, which together, account for about 90% of the fluid. The parotid and submandibular glands also become the target for Botulinum injections if this treatment is selected as a means of managing sialorrhea.
Salivary secretion is regulated by a complex reﬂex arch consisting of receptors and nerves which carry impulses from the mouth to a central connection (salivation center) in the brain which in turn, sends information to the salivary glands via the parasympathetic (rest and digest system) autonomic nerve bundles. The glossopharyngeal and vagus parasympathetic nerves innervate glands of the upper GI tract including the salivary glands. Lewy body type pathology has been found in these nerves, and this, along with autonomic nervous system dysfunction, which is common in Parkinson’s disease, may lead to increased production of saliva, and when paired with stooped posture, reduced tongue co-ordination, and reduced oral-pharyngeal sensation, results in drooling.
Slower spontaneous swallow frequency rates have been reported in patients with Parkinson’s disease and changes in spontaneous or reflexive swallowing frequency have been suggested by swallowing researchers to be a sensitive index for dysphagia in at-risk populations. So, with both mechanical and neurological mechanisms at play, silent aspiration and laryngeal penetration of saliva are common features in Parkinson’s individuals, and if chronic can lead to aspiration pneumonia.
Treatment approaches for Sialorrhea
When seeing patients who complain of excessive saliva and drooling, it is important that they be referred for a swallowing evaluation, which should include an instrumental swallowing assessment allowing for visualization of the structures involved and to help in determining if there are other problems which needs to be addressed.
Behavioral management strategies which may be helpful early on include: chewing sugarless gum, which will increase the flow of saliva, but also the rate of swallowing frequency, with a preference for cinnamon or sour flavors. Ginger tea and dry ginger may have a bit of an astringent affect.
An inexpensive tennis wrist band can be more hygienic and acceptable than tissues or handkerchiefs for managing drooling and may also serve as a visual cue to swallow saliva as opposed to wiping one’s mouth.
Atropine drops administered sublingually (under the tongue) are prescribed by some neurologist. The anti-cholinergic effect of this medication will help to dry up oral secretions, but must also be used with caution with persons with PD and elderly patients due to potential negative side effects which can include: confusion, blurred vision, and constipation, already potential problems for persons with PD.
Botulinum toxin injections have now become a common effective treatment for management of excessive saliva as the Botulinum toxin blocks the release of acytecholine, a neurotransmitter which acts upon the cholinergic parasympathetic secromotor fibers in salivary glands resulting in less production of saliva. This treatment, however, requires a skilled injector, and patients need to be aware that an overly dry mouth may impact swallowing and the loss of some antibacterial effects of saliva on oral hygiene, requires diligent oral care.
Mary Spremulli, MA,CCC-SLP is owner of Voice Aerobics, a private practice located in Punta Gorda offering evaluation and treatment for adults with speech, voice and swallowing problems. To schedule an appointment and to learn more visit voiceaerobicsdvd.com or call 941-204-1515.