Are there salivary gland size changes with repetitive onabotulinum toxin A (OBTXA) injections for sialorrhea treatment in children, and do they correlate with clinical outcomes?
Background: OBTXA injection is a well-established option for management of pediatric drooling (sialorrhea), which is considered pathological after four years of age. Several management modalities exist, including anticholinergic drugs, rehabilitation with oral and motor therapy, surgical intervention, and local irradiation of salivary glands. The long-term effect of repetitive OBTXA injection in pediatric salivary glands is still not well known, however.
Explore this issue:March 2016
Study design: Case control study conducted between October 2013 and February 2014 of 60 patients (22 treatment, 38 control) with a mean age of 7 years.
Setting: Montreal Children’s Hospital, McGill University Health Center, Montreal, Quebec, Canada.
Synopsis: Using ultrasound, authors found a decreased area in all salivary glands, ranging from an 11% to 17% difference in comparison to the control group. The anterior-posterior (AP) dimension decreased in both left and right submandibular glands, but not significantly in parotid glands. The mediolateral (ML) or depth dimension was also decreased significantly in all glands. Using a logistic regression model adjusting for BMI, age, and gender, the treatment group had a significantly smaller area in the submandibular glands, and for the left parotid but not the right. There was no significant difference in AP measurement for the parotids, but a significantly smaller measurement in the submandibular glands. Parallel to size changes, the echogenicity of the salivary glands differed between the treatment and control groups, and authors found a slight increase in heterogenicity and cystic changes. There were also irregular lobulated contours with a loss of convexity in both parotid and submandibular glands, and there were no variable anatomical variations in any of the salivary glands or visual neovascularization in the treatment group. Limitations included the small treatment group sample for statistical analysis.
Bottom line: The chronic use of intraglandular OBTXA reduced the size of the salivary glands measured ultrasonographically and correlated with successful clinical results.
Citation: Cardona C, Saint-Martin C, Daniel SJ. Effect of recurrent onabotulinum toxin A injection into the salivary glands: an ultrasound measurement. Laryngoscope. 2016;126:596-601.