5 Introduction Multiple System Atrophy (MSA) is a slowly progressing neurodegenerative disease that is characterized by i) a hypokinetic movement disorder which defines MSA of the parkinsonian type (MSA-P) or by ii) cerebellar symptoms which define MSA of the cerebellar type (MSA-C). In both types the movement disorder can be accompanied by vegetative symptoms such as orthostatic hypotension. In contrast to Parkinson's disease (PD), the effect of dopaminergic medication on the parkinsonian symptoms is very limited. In spite of several efforts, no disease modifying therapy has been identified so far. Several lines of evidence including epidemiological, in vitro, and in vivo data, suggest that Epigallocatechin gallate (EGCG) might be able to delay disease progression of MSA by modifying several aspects in the pathogenesis of MSA such as protein aggregation, oxidative stress and iron accumulation. Therefore, this study is designed to investigate the influence of EGCG on disease progression in patients with MSA. To assess the effect on disease progression, clinical evaluation and MR-imaging will be applied in a bi-center, prospective, placebo-controlled, double-blind randomized phase III trial. The primary outcome measure will be the change in motor symptoms from V1 to V7 measured by the UMSARS-ME comparing placebo- vs. verum-treated patients. The secondary efficacy endpoint will be the change from V1 to V7 in the total UMSARS score, in the CGI score and in MRI parameters (global and regional atrophy / iron deposition) comparing placebo- vs. verum-treated patients.