Drooling beyond the age of 4 years is pathological, particularly if it occurs in children with neurological and developmental impairment and disability. Considering the therapeutic spectrum of botulinum toxin A and in view of the innervation of the salivary glands, we postulated that intraglandular injections into the submandibular glands with botulinum toxin A could reduce the secretion of saliva and consequently decrease drooling. Three patients with cerebral palsy and severe drooling were selected and evaluated over a 4-month period. Under ultrasound guidance, one dose of botulinum toxin A was injected bilaterally into the submandibular glands. Saliva secretion was measured at baseline and repeated four times during the following 4 months. In the three patients, maximal salivary flow rate of the sublingual and submandibular glands was reduced by 51% to 63%. The time of the maximal effect differed among the three children. The parents reported a satisfactory reduction of drooling throughout the whole study period. No objectionable disturbances of oral functions were observed. There was mild transient thickening of saliva in one of the patients.
Conclusion: The application of botulinum toxin A to the submandibular gland is a promising technique to reduce salivary flow rate and probably an alternative in the treatment of drooling in children with cerebral palsy.