Treatment of unintentional drooling of saliva in motor neuron disease

Unintentional drooling of saliva (sialorrhea) is a distressing symptom suffered by up to 25% of patients with motor neuron disease. The management of sialorrhea currently involves the use of suction, drug treatments and more invasive approaches, including injection of botulinum toxin to the salivary glands, radiotherapy to the salivary glands and ligation (surgery to tie off) of the salivary gland ducts.

An extensive search of the literature identified only one randomized controlled trial, of 20 patients, which could be included in the review. This study reported a beneficial effect of botulinum toxin type B injected into the parotid and submandibular salivary glands in patients with MND on a single occasion. The study appeared to have low risk of bias, and no serious adverse events were recorded.

Although other treatments are supported by case control studies, there was no evidence to compare the effectiveness of different treatments for sialorrhea. Further research is needed to compare the different treatments available and to optimise treatment regimens.

Authors' conclusions: 

There is some evidence for use of botulinum toxin injections to salivary glands for the treatment of sialorrhea in MND. Further research is required on this important symptom. Data are needed on the problem of sialorrhea in MND and its measurement, both by patient self report measures and objective tests. These will allow the development of better randomized controlled trials.

Read the full abstract...

Motor neuron disease (MND), also known as amyotrophic lateral sclerosis, is a progressive, neurodegenerative condition which may cause dysphagia, as well as limb weakness, dysarthria, emotional lability and respiratory failure. Since normal salivary production is 0.5 to 1.5 litres daily, loss of salivary clearance due to dysphagia leads to salivary pooling and sialorrhea, often resulting in distress and inconvenience to patients.


To systematically review evidence on treatment of sialorrhea in MND, including medications, radiotherapy and surgery.

Search strategy: 

We searched the Cochrane Neuromuscular Disease Group Specialized Register (1 October 2010), the Cochrane Central Register of Controlled Trials )(CENTRAL) (The Cochrane Library issue 3, 2010), MEDLINE (January 1966 to September 2010), EMBASE (January 1980 to September 2010), AMED (1985 to September 2010) and CINAHL Plus (January 1937 September 2010). All bibliographies of the identified randomized trials were reviewed and authors contacted as needed. Known experts in the field were contacted to identify further published and unpublished papers.

Selection criteria: 

We included randomized and quasi-randomised controlled studies on any intervention for sialorrhea and related symptoms, in people with MND.

Data collection and analysis: 

Review authors summarised data independently in a customised data collection form and confirmed data presented in Cochrane Review Manager software.

Main results: 

Only one randomized controlled trial was identified. This was a well designed study of botulinum toxin B injected into parotid and submandibular glands of 20 patients, which showed positive results for four weeks (Jackson 2009). There was low risk of bias in the study and no significant adverse events reported.