Background:

Parkinson's Disease and the Atypical Parkinsonian Disorder (like Multiple System Atrophy, Progressive Supranuclear Palsy, Corticobasal Degeneration, Lewy Body Dementia) are disease entities with partly common symptomatology. Especially very early in the course of disease, the differentiation between both disease entities can be challenging, even for specialists in the field of movement disorder. However, the establishment of a correct diagnosis is very important for adequate patientcounseling, treatment and the correct inclusion of patients in research trials. Ancillary diagnostic investigations are looked upon to aid in this diagnostic dilemma.

Objective:

To investigate the value of ancillary diagnostic investigations, more specific MRI, analysis of cerebrospinal fluids and a second opinion in a specialized movement disorder centre, to differentiate Parkinson's disease and the Atypical Parkisonisonian disorder.

Inclusion Criteria:

• Hypokinetic rigid syndrome
• Disease duration of maximum 36 months

Exclusion Criteria:

• Probable diagnosis of PD without any red flags
• Probable diagnosis MSA
• Probable diagnosis PSP
• Diagnosis CBD
• Diagnosis DLB
• Probable diagnosis Vascular Parkinsonism
• Other neurodegenerative disease than parkinsonism
• A prior history of brain surgery
• Instable comorbidity

Adult patients with a hypokinetic-rigid syndrome with a disease duration of maximum 36 months and in whom a definitive diagnosis has not been established yet.