Based on previous promising results, the next step for the validation of a multimodal MRI method in diagnosis and follow up of patients reached by parkinsonian syndromes is (i) to test whether the multimodal neuroimaging is able to discriminate at the individual level, patients with multiple system atrophy parkinsonism (MSA) and patients with idiopathic Parkinson's disease (PD) (ii) to determine whether the method is sensitive to measure changes over time for the two diseases, according to imaging, neuropsychological and other clinical data. Patients will be compared with healthy controls.

30 patients with PD, 30 patients with MSA and 30 healthy controls will be examined in a 3Tesla MRI.

The aim of our project is to demonstrate that our multimodal MRI method can discriminate both diseases with a similar clinical presentation and monitor the progress of the disease. CIC's expertise in recruitment and assessment of patients, and the powers of the INSERM U825 in terms of development and processing in neuroimaging guarantee the feasibility of the project and its successful completion.

Inclusion Criteria:

• informed consent signed
• right handed patients
• Mini Mental Score > 22
• no other neurological disease than Parkinson's Disease (PD) or Multiple System Atrophy (MSA)
• non-demented patients reached by PD or MSA (according to diagnosis criteria from UK PD Brain Bank and from Gilman and colleagues, 1998, for PD and MSA respectively)
• for PD patients only : Hoehn and Yahr score from 2 to 3

Exclusion Criteria:

• claustrophobia
• contraindications to MRI (cardiac or auditive prothesis, pacemakers, cerebral clip, stimulating electrodes)
• pregnant women
• major neuropsychiatric disease
• refusal to be informed in case of cerebral anomaly detected during MRI acquisition
• uncompensated thyroid deficit