Localization of Salivary Glands for Botulinum Toxin Treatment: Ultrasound Versus Landmark Guidance

Abstract

Background Background: Sialorrhea is a troublesome symptom in a variety of neurological diseases. Recently, local injection of botulinum toxin into the salivary glands was approved for treatment of sialorrhea, and injection guidance by anatomical landmarks was suggested. Objective Objective: To compare the accuracy of ultrasound versus previously proposed anatomical landmarks for localizing the salivary glands. Methods Methods: In a cross-sectional study in 21 adults, landmark positions (LM) of the parotid gland (PG) and the submandibular gland (SG) were identified following published recommendations. The ultrasound position (US) was defined as the position representing the maximum gland thickness. The distance between positions, gland thickness, and optimal injection depth were recorded by US. ResultsResults: Gland thickness differed significantly between LM and US positions (PG, 4 vs. 17.8 mm; P < 0.001; SG, 3.5 vs. 13.6 mm; P < 0.001). The spatial deviation between the recommended LM and identified US positions in the horizontal plane was 21 mm to the posterior direction for the PG and 19.6 mm for the SG. The deviation in vertical orientation was small for both glands; however, there was a positive correlation between the distance from the SG to the mandibular bone with age. The optimal injection depth measured by US was 11.8 mm for the PG and 13.6 mm for the SG. This showed to be positively correlated with the body mass index. ConclusionsConclusions: The position of the salivary glands differs from proposed landmarks and depends on the individual age and body weight; therefore, we recommend ultrasound guidance for injection.

Safety of High-Dose Botulinum Toxin Injections for Parotid and Submandibular Gland Radioprotection

“…A post-mortem study showed an almost doubled hit-rate of ultrasound-guided injections in the submandibular glands compared to free-hand injections [12]. The high error-rate even of experienced injectors might be attributable to the variance of submandibular gland size as well as to different inter-and intra-individual distances between gland and mandible [1,13].…”

Therapie der Sialorrhoe mit Botulinumtoxin – ein Update

“…parotis ist gering. Unserer Erfahrung nach deckt sich der empfohlene Injektionspunkt nach Landmarken [100][101][102] mit dem sonographisch bestimmten Ort für die Gl. parotis recht gut.…”

A critical review of incobotulinumtoxinA in the treatment of chronic sialorrhea in pediatric patients

“…Sonographic control of injections is useful, especially when treating the submandibular salivary gland [16,20,21], as swallowing disorders caused by unintentional diffusion into the muscles of the oral floor can be avoided [9]. Numerous studies conducted in adult and pediatric patients with sialorrhea of various etiologies have confirmed that BoNT/A injections (abobotulinumtoxinA, incobotulinumtoxinA, and onabotulinumtoxinA) effectively reduce salivary secretion for periods of up to 3-4 months [1,22].…”

“…Although BoNT/A is more complicated to administer than anticholinergic drugs, in a vulnerable group of patients sensitive to the adverse effects of anticholinergics, the purely local effect and the excellent safety profile outweigh the challenges of the injection procedure. In our opinion, injection of BoNT/A is best achieved using ultrasound to guide needle insertion, a strategy that minimizes the risk of unnecessary adverse events [16,21] (Figure 3). We also suggest initiating a fixed injection schedule every 4 months or more, rather than treating patients when sialorrhea returns.…”