A systematic review of the perspectives of botulinum toxin use on the quality of life of neurological patients with drooling

To investigate the effectiveness of botulinum toxin in the salivary glands of patients with neurological impairment and drooling and its impact on the quality of life.

This systematic review was registered with the International Prospective Register of Systematic Reviews (CRD 42,023,435,242) and conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses. An electronic search was performed in the PubMed/MEDLINE, Embase, Scopus, Cochrane Library, and clinical trial databases until August 2023, no language restriction. Cohort studies and randomized clinical trials of patients diagnosed with drooling and neurological impairment who used botulinum toxin on the salivary gland were included, which evaluated subjective quality of life parameters. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist and Risk of Bias 2 tools. The certainty of the evidence was analyzed using the Grading of Recommendations Assessment, Development, and Evaluation approach.

Eight studies involving 317 patients were included. All studies, through subjective parameters, suggested the effectiveness of botulinum toxin in reducing drooling, resulting in an improvement in the quality of life. Three studies demonstrated improvements in swallowing and four in cases of respiratory diseases. Two clinical trials had a high risk of bias, whereas one had low risk. The five cohort studies that were evaluated had a high risk of bias. The certainty of the evidence was considered low.

Based on the patient/caregivers’ perception of improvement in drooling, dysphagia, and respiratory symptoms, it can be inferred that botulinum toxin application reduces subjective drooling in neurologically compromised patients. Its impact contributes to the general well-being and quality of life.

Injection of botulinum toxin into the salivary glands can be considered an alternative technique to surgical or medicinal approaches in reducing drooling. It is effective, less invasive and without significant side effects. It promotes a positive impact on the well-being and quality of life of neurological patients.