Systematic Review of the Effectiveness of Botulinum Toxin or Radiotherapy for Sialorrhea in Patients with Amyotrophic Lateral Sclerosis

Abstract

Fifty percent of patients with amyotrophic lateral sclerosis (ALS) experience problems handling serous saliva and 20% fail to achieve adequate control of sialorrhea with anticholinergic medications, or experience intolerable adverse effects from these drugs. Both botulinum and radiotherapy have been suggested in the literature as treatments for intractable sialorrhea. In this review, we assess the evidence for the effectiveness and toxicity of botulinum toxin and radiotherapy for sialorrhea in patients with ALS. Relevant studies were retrieved from Medline, Embase and Cochrane Databases. Handsearching of Neurology, Journal of Pain and Symptom Management, and Palliative Medicine and of reference lists, was carried out. Five studies (28 patients) were included in the analysis of botulinum. Of the four studies using an intraglandular method of injection, no adverse effects occurred. Two of these had positive findings of the effect of botulinum in salivary secretion rate and quality of life. In contrast, significant adverse effects were experienced by two patients in a study of retrograde injections into the salivary ducts. Two studies were included in the analysis of radiotherapy (27 patients). Both demonstrated a positive effect of radiotherapy on salivary secretion rate. Some patients experienced mild acute side effects. Because of the small numbers of studies, small sample sizes, and poor quality of reporting, it is not possible to draw firm conclusions. There is some evidence indicating that both botulinum and radiotherapy are well tolerated, effective treatments for persistent sialorrhea in patients with ALS and that the duration of action is up to three months with botulinum and six months with radiotherapy.