Drooling is a common problem associated with cerebral palsy. The presence of drooling has both health and social consequences. The production of saliva is an important health need in that it plays a role in the digestion of food and functions to maintain the hygiene of the mouth. In cerebral palsy, there is not an overproduction of saliva; the problem is in the swallowing mechanism. Because of the brain injury leading to cerebral palsy, there is poor coordination of the movement of saliva to the throat by the tongue and to the contraction of the muscles of the throat. This is an automatic activity not requiring conscious action. When the automatic mechanism is interrupted due to brain damage, saliva accumulates in the mouth and spills over.

A recent review summarized the present status of the management of drooling.¹ In summary, the article reports:

Surgery: There are several surgical techniques that have been used. These include removal of salivary glands and/or ducts and the repositioning of the ducts so they drain to the back of the mouth. There are very few surgeons who utilize these techniques since the overall functional results have not been satisfactory. In very selected circumstances, diminishing the rate of saliva production by gland removal and then the use of medication has provided relief from very excessive drooling. In general the surgical approach to relief from drooling has not proven to be very useful.

Medication: The drug glycopyrolate serves to decrease the salivary glands production of saliva. The drug is very effective. However, there are usually undesirable side effects: excessive dry mouth, constipation, urinary retention, decreased sweating, skin flushing, and behavioral irritability. Although the side effects are manageable, about 1/3 of persons choose not to continue the medication because of the undesirable side effects. Other drugs have been (and are being) used and the results are about the same. With skill and sensitivity, medications can be of assistance in selected situations in which a decrease in saliva production is obtained with a minimum of side effects. One of the major problems is that drooling varies considerably from day to day and also during the day so that control is a constantly changing need. Thus, the timing of drug use becomes an important part of the treatment schedule.

Other approaches: The use of a neuromuscular blocking agent has been tried for the control of salivary production (i.e. Botox). However, the complication of jaw dislocation has been reported. There does not appear to be any advantage to the use of injectable Botox over other mdications.

Intra-oral devices are under evaluation at this time. These devices serve as an aid to persons receiving behavioral therapy; they promote jaw stability, lip closure, better tongue positioning and swallowing. Experience with them is still very limited and few clinicians are skilled in their use. Better studies are needed to identify specifically under what circumstances these devices are useful.

Comment:

Drooling continues to be an important health and social problem for persons with cerebral palsy. Available medications are marginally effective, and their side effects often discourage their continuing use. Surgery is a last resort when the persons needs exceed its undesirable side effects. Behavioral therapy (oral motor therapy), sometimes assisted by intra-oral devices offer some relief. All in all, the management of drooling in 2002 is not very satisfactory. Some relief is available, but much more needs to be done to improve medications so their side effects are minimized. As we learn more about the specific site of injury to the brain resulting in the poor muscle coordination that leads to drooling, new approaches to the control of drooling should become available.

¹ Blasco, Peter A. (2002) Management of Drooling: 10 years after the Consortium on Drooling, 1990. DMCN 44: 778-781