Multiple System Atrophy (MSA) is a chronic and progressive neurological disease, for which unfortunately there is no cure yet. It is known from pathological studies that the synapses (the terminal parts of the neurons) are affected in this disease, but the investigators don't know how, and how much this happens. An imaging tool called Positron Emission Tomography (PET) can study the integrity of the synapses by the use of a dedicated tracer, called [11C]UCB-J. In this study the investigators would like to study how, and how early, the synapse deteriorate in patients with MSA.~For this study, patients with the MSA-P form of disease will be enrolled. Participants will be asked to undergo a clinical visit with questionnaires and scales for motor and cognitive symptoms. Then, participants will come for a [11C]UCB-J PET scan, a [18F]FDG PET scan, to check the metabolism of the brain, and a MRI scan, to help the analysis of the PET. The participants will also be asked to perform a Lumbar puncture for a cerebrospinal fluid draw. This procedure will be optional.~The results will help in understanding better the mechanisms underlying this disease and open new avenues for its treatment.
In this study the investigators would like to investigate the degree of damage of the synapses, an important part of the neurons vital for the communications between neurons, in Multiple System Atrophy (MSA).