Patients with Parkinson's disease (PD) often display symptoms, such as constipation, due to denervation of the cholinergic nerves in the gut. It has been hypothesized that PD initiates in the gut years prior to diagnosis. To gain a detailed understanding of the early stages of PD, techniques for quantification of cholinergic nerves are needed. The PET tracer 18F-FEOBV binds specifically to the vesicular acetylcholine transporter, situated in presynaptic cholinergic nerve terminals. The investigators will investigate 18F-FEOBV uptake in the brain and internal organs of 15 patients with moderate-stage PD and compare to 15 healthy controls. Furthermore, findings are correlated to validated clinical tests of the autonomic nervous system. The aim is to validate 18F-FEOBV PET/CT as a clinical imaging modality to diagnose parasympathetic denervation in PD.

Inclusion Criteria:

• Parkinsons disease, disease duration > 4 years, Hoehn & Yahr stage 2-3

Exclusion Criteria:

• Significant neurological diseases (e.g. stroke, tumor)
• Significant psychiatric disease
• Previous major surgery on thoracic and/or abdominal organs
• Significant medical disease (e.g. heart- or liver failure)
• Inflammatory bowel disease
• Gluten intolerance
• Diabetes
• Magnetic Resonance (MR) contraindications (metal in body, claustrophobia)
• Allergy to CT-contrast fluid
• Pacemaker
• Any current or previous cancer involving internal organs
• Peripheral neuropathy (except Parkinsons disease related)

Parkinson patients are moderate stage disease. Healthy subjects have to meet the criteria below.