The study is designed as a randomised, stratified, controlled trial of the efficacy and safety of riluzole (up to 200mg daily) versus placebo in MSA and PSP. The primary outcome measure is survival at 36 months. Power calculations suggested that we would need to recruit ~400 patients into each stratum (MSA, PSP) in order to detect a reduction in the relative risk (RR) of death at 36 months with 80% power and two-sided a=0.05. Using modified consensus criteria (to provide greater sensitivity) we recruited 766 patients (363 PSP, 404 MSA) over 2 years (1999-2001). The first patients recruited are about to enter the open-label study. The final analysis of the primary efficacy measure is planned for December 2005. Secondary outcome measures include safety, rate of change in UPDRS and other rating scales including a parkinson’s plus symtoms rating scale (PPSS), changes in cognitive function assessed using the Mattis Dementia Rating Scale, the Frontal Assessment Battery, The Bushke Selective Reminding Test, The Neuropsychiatric Inventory, and other tests of memory and executive function. QL and Health economic data is collected using the SF36 and a Client Service Receipt Inventory (CSRI). Assessments are made at 6 monthly intervals. Standardised MRI has been acquired in ~70% of cases at entry and will be repeated at 36 months where possible. DNA has been collected from ~75% of cases. 100 brains have been donated and are being analysed using a standardised protocol.