This project, sponsored by MS research Australia, focuses on sleep apnoea in people with multiple sclerosis (MS). Our recent study, amongst other studies, suggests that sleep apnoea rates are higher in people with MS. However little is known about the causes of sleep apnoea in people with MS and how they might be different from people without MS. This project involves a sleep study including physiological measurements to identify differences in the causes of sleep apnoea between people with and without MS.