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Updated: Jun 24, 2026

Ultrasound-guided Botulinum Toxin-A Injections: A Method of Treating Sialorrhea
Published on: November 9, 2016
Repeated botulinum toxin type A injections to treat patients with Frey syndrome
Remco de Bree1, Jeff E Duyndam, Dirk J Kuik
1Department of Otolaryngology/Head and Neck Surgery, VU University Medical Center, De Boelelaan 1117, PO Box 7057, 1007 MB Amsterdam, The Netherlands. r.bree@vumc.nl
Objective:
To determine the effectiveness of repeated intracutaneous injections of botulinum toxin A to treat Frey syndrome.
Patients:
Between January 6, 1999, and July 1, 2005, 22 patients with Frey syndrome (12 men and 10 women) received repeated intracutaneous injections of botulinum toxin type A.
Main Outcome Measures:
Before each treatment, the time since the previous treatment; the size of the affected area, as determined by a starch-iodine test; and subjective quantification of symptoms, as assessed by the previously used Frey Questionnaire Card, were recorded.
Results:
All patients underwent at least 3 treatments. Univariate analysis of variance showed a significant difference (P <.001) in the between-treatment interval. Univariate analysis of variance showed a significant difference in the size of the affected area in accordance with the number of treatments received (P <.001). The mean Frey Questionnaire Card score also decreased with repeated treatments.
Conclusions:
In patients with Frey syndrome, repeated treatment with intracutaneous injection of botulinum toxin type A lowered subjective symptom scores, decreased the size of the affected area, and increased the duration of the effect.
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