This study aimed to assess the secondary benefits and adverse effects of
botulinum toxin A injections into the parotid and submandibular glands in children with
developmental disability and to determine whether these effects are related to reduction in
drooling. Twenty-six children were injected (14 boys and 12 girls; mean age, 11 years 3 months). The
Drooling Impact Scale and a secondary effects questionnaire covering aspects of eating, speech, saliva management, and sleep, were administered to the main carer at specific times before and after injection. Group mean preinjection and postinjection item and domain scores were compared using paired t tests. Change scores were calculated; individually categorized as improvement, no change, or deterioration; and related to change in
drooling scores using linear regression analysis. Over 4 weeks, evidence of improvement was seen for the entire group with respect to
drooling (P < 0.001), eating (P = 0.05), speech (P = 0.04), and sleep (P = 0.01), but not saliva management. Conversely, a minority of families reported worsening of eating skills after the
injections that was directly related to lack of improvement in
drooling. Because a minority of children unpredictably experience temporary adverse effects after
botulinum toxin A injections into the salivary glands, swallowing function and nutritional status should be taken into account before proceeding with treatment.