The efficacy of Botulinum toxin A (BoNT-A) in Asian population has not been properly studied and there is no literature available on the most efficacious dose of BoNT-A for sialorrhoea treatment. This research is aimed to find the dose of Dysport® that would be efficacious without treatment-related adverse events and the duration of effectiveness of the drug for sialorrhea treatment in Malaysian patients. The efficacy, safety, tolerability and adverse effects of three doses of Dysport®(50MU, 100MU and 200MU) are examined at 2,6,12 and 24 weeks post injection in this double-blinding, randomized trial.

Study Objectives:

To determine the efficacy, safety, tolerability and adverse effects of three doses of Dysport® (50MU, 100MU and 200MU) in the treatment of sialorrhoea in Asian patients with neurological disorders/diseases and to determine the most efficacious dose.

Study design:

Dose-ranging double blind pilot study.

Sample size:

At least 30 adult patients with various neurological disorders complicated with sialorrhoea including stroke, motor neurone disease, traumatic brain injury and Parkinsonism would be divided into 3 dosing groups.

Study method:

Patients who satisfy inclusion criteria and have given informed consent would be randomized into 3 equal groups given different total doses-50MU, 100MU, 200MU. The total dose will be divided equally and give to each of 4 salivary glands viz. the submandibular and parotid gland bilaterally. For example, if 200MU is to be given in total, 50MU would be given to each gland. Injections would be given via a 25G needle to each gland with ultrasound guidance for better needle placement. One site will be injected per gland.

Primary outcome measure The percentage reduction in the rate of saliva production (as measured by difference in mean weight of dental rolls per minute from baseline) for each of the groups given different doses of Dysport® at 2,6,12 and 24 weeks post injection.

Secondary outcome measure

1. Patient's subjective assessment of improvement in sialorrhoea using the Drooling Frequency and Severity Scale (Thomas-Stonell scale) at 2,6,12 and 24 weeks post-injection.
2. Duration to maximum reduction in salivation (as measured by the maximum reduction in weight of dental rolls)

Inclusion Criteria:

1. Patients ≥ 18 years old.
2. Patients with neurological disorder including stroke, motor neurone disease, traumatic brain injury and Parkinsonism, diagnosis confirmed clinically by their treating physicians.
3. Patients with a Thomas-Stonell Drooling Frequency and Severity Scale combined drooling ranking of ≥5.
4. Patients who are able to give signed informed consent and are willing and able to comply with scheduled visits, treatment plan and other study procedure.

Exclusion Criteria:

1. Patients who are pregnant.
2. Patients with bleeding disorders or who are on anticoagulants.