Many children and adults with MECP2 duplication syndrome experience excessive drooling. Some are treated medically to reduce this problem. This post discusses some of the pros and cons of medical treatment for drooling. Ptyalism and sialorrhea are medical terms that are medical terms that are sometimes used as synonyms for drooling although their precise definitions may differ slightly.
What causes drooling? There are two major factors that can contribute to drooling. (1) Drooling can be caused by the inability to keep saliva in the mouth or swallow saliva. This is the most common cause of drooling. (2) Drooling also can be caused in some cases by an overproduction of saliva. In rare cases, both these factors may be present and combine to result in drooling. In individuals with MECP2 duplication syndrome, it is clear that the first factor, inability to keep saliva in the mouth or swallow excess saliva, is present. It is unclear whether these individuals produce excess saliva. Research is needed to determine whether individuals with MECP2 duplication syndrome actually produce unusually large quantities of saliva or not. The association between the certain variants in the MECP2 gene and Sjögren’s syndrome, a condition that reduces salivary function provides some additional reason for entertaining this possibility.
The inability to manage swallow or keep saliva in the mouth appears to have at least three components in individuals with MECP2 duplication syndrome. First, low muscle tone in in the oral area and low muscle tone making it difficult to keep one’s head up make it difficult to control saliva in the mouth. Second, it appears that a weakened swallow reflex interferes with normal swallowing of accumulated saliva in the mouth. Third, limited postural control often results in positioning that promotes drooling.
What Treatments are available for reducing or eliminating drooling? Several medications have been used to reduce the production of saliva. Surgery has been used in some cases to reduce or eliminate production of saliva. Radiation of the parotid glands has been used to treat drooling in some cases. Botulism toxin injections have also been used to reduce saliva production. It is important to note that medical and surgical treatments target the production of saliva and do not target improvement of swallowing or helping the individual manage saliva that is produced.
Physical and occupational therapy (PT/OT) can also be used to help minimize drooling. These PT/OT interventions do not reduce production of saliva; They attempt to promote swallowing and improve retention of saliva in the mouth.
What are some reasons for treatment?
Drooling is messy and may act as a barrier to social acceptance. Drooling is typically considered as socially unacceptable and may be a significant obstacle to social opportunities.
Drooling can cause dehydration. It is estimated that a healthy adult produces 750 to 1500 ml of saliva each day.If a major portion of this is lost through drooling, a lot more fluid intake is needed to make up for this loss. Many individuals with MECP2 duplication syndrome have difficulties getting enough fluids and have bouts of significant dehydration. Drooling can contribute significantly to these problems.
Drooling promotes chapping, particularly in cold weather. In cold climates with sub-zero temperatures and winter winds, a wet face or wet clothing can be a significant problem. Freezing can do serious damage to the skin and significant discomfort.
Potentially unsanitary. While the role of drooling in sanitation is somewhat controversial and saliva has important antiseptic properties, drool, particularly when it contains significant amounts of food particles, may present a sanitation risk.
What are potential risks of treatments?
Radiation treatment treatment involves some long-term risk of developing future cancer. For this reason, it is typically only recommended for educing production of saliva in individuals who are extremely elderly or who otherwise are expected to survive for a short period of time.
Since most treatments are aimed at reducing saliva production rather than improving retention and swallowing of saliva, these treatments can result in dry mouth and other problems associated with inadequate salivary function. These may include increased susceptibility to infection, increased dental and gum disease, and difficulties in swallowing. There may be increased risk for candida and staphylococcus infections, and these risks may be particularly problematic for individuals with poorly functioning immune systems, such as those with MECP2 duplication syndrome. Since medications that are used to treat drooling typically also result in dry eyes and nasal passages, the increased vulnerability to infection may be further accentuated, and additional problems such as nosebleeds may result.
Some drug treatments have additional side effects. Scopolamine and glycopyrrolate (Robinul) may cause urinary retention which can worsen a problem already present in many individuals with MECP2 duplication syndrome. Scopolamine can also cause auditory and visual hallucinations, anxiety, and restlessness. Scopolamine needs to be used with caution in individuals who have seizure disorders both because it may increase seizures in some individuals and because it can interact with some seizure medications. Glycopyrrolate (Robinul) can cause constipation, and this can be a particularly serious issue in individuals with MECP2 duplication syndrome. About 25% of those using this medication appear to have behavior changes. Both scopolamine and glycopyrrolate, as well as other drugs used to reduce salivation (e.g., atropine) have a host of other side effects that need to be carefully considered. One of the concerns with using any of these drugs with individuals with limited communication is that many side effects are subjective and may not be directly observable to others.
In addition, many individuals with MECP2 Duplication Syndrome are taking a wide variety of other medications. Each new medication adds additional risk for potential drug interactions. Adding more medications needs to be done with considerable concern and should not be taken on unless clearly needed.
Botulism toxin injections to some of the salivary glands have been successful in some individuals and are generally considered to have fewer side effects than most of the other medications. There are some risks associated with the procedure that need to be considered. While all of them should be discussed with the doctors involved before a decision is made to proceed, one may have special relevance for individuals with MECP2 duplication syndrome. In some cases, the botulism toxin is misdirected or spreads to nerves involved in swallowing and can cause difficulties in swallowing. This could potentially have particularly negative effects on individuals already at risk for swallowing difficulties and aspiration. In addition, the risks may be increased for individuals with MECP2 Duplication Syndrome, who may not keep still during the injections and may require sedation which add some additional risks of sedation.
Considering these concerns, measures to control drooling need to be considered with a great deal of caution for individuals with MECP2 duplication syndrome. Any potential benefits need to be carefully weighed against potential harm. Families considering these treatments should fully discuss the risks and benefits with the treating physician.
If undertaken at all, measures to control drooling might be considered on a part-time basis. For example, atropine drops have sometimes been used for short-term treatment. So some parents may consider treating before a winter sleigh ride to prevent chapping, or a social event to reduce issues of social rejection.
This is a good review article that is available on line:
Bavikatte, G., Sit P.L., & Hassoon, A.(2012). Management of Drooling of saliva. BJMP, 5(1):a507