The Prevalence and Management of Saliva Problems in Motor Neuron Disease: A 4-Year Analysis of the Scottish Motor Neuron Disease Register

INTRODUCTION: Saliva problems are common and distressing for people with motor neuron disease (pwMND). Despite clinical guidelines for assessment and treatment, management of saliva problems has received little research attention.

OBJECTIVE: We aimed to investigate the prevalence of saliva problems in pwMND, their association with clinical factors, and their management practice using a highly curated population-based register for motor neuron disease (MND) with 99% case ascertainment.

METHODS: We conducted an analysis of pwMND diagnosed between January 2015 and October 2019 using the Scottish MND Register (CARE-MND [Clinical, Audit, Research, and Evaluation of MND]). The association between clinical factors and saliva problems was investigated using univariate and multivariable logistic regression; results are reported as odds ratio (OR) and 95% confidence intervals. A survey of health-care professionals involved in the care of pwMND was performed to contextualize the findings.

RESULTS: 939 pwMND were included. Prevalence of saliva problems was 31.3% (294). Bulbar onset (OR 9.46 [4.7, 19.2]; p < 0.001) but not age, sex, time to diagnosis, or MND subtype were independently associated with the presence of saliva problems in multivariable regression, and 52.7% (155) of those with saliva problems received pharmacological management. The most commonly used medications were hyoscine, amitriptyline, carbocisteine, glycopyrrolate, and atropine. Evidence base (8, 72.7%) and local guidelines (10, 90.9%) were cited as the most important factors influencing treatment decision by survey respondents (n = 11).

CONCLUSION: Saliva problems are common and associated with bulbar onset MND. A substantial proportion of pwMND with saliva problems did not receive recommended treatments. Future research is required to determine the relative efficacy of individual pharmacological treatments.