Study of the PET Tracer 18FMH.MZ to Measure Serotonin 2A Receptors in Patients with Neurodegenerative Diseases including Parkinsons Disease Psychosis

What this Trial Is About

Researchers are studying neurodegenerative diseases such as Parkinson disease, diffuse Lewy body disease, multiple systems atrophy, Huntingtons Disease, and Frontotemporal Dementia to understand differences in serotonin receptor occupancy. The study evaluates how 5HT2A receptor density and occupancy differ in patients with these conditions compared to healthy individuals matched by age and gender. It also explores how pimavanserin treatment affects psychosis symptoms and brain function in Parkinsons disease patients with psychosis. Participants receiving pimavanserin will have their 5HT2A receptor density and occupancy measured using a PET radioligand called R-18FMH.MZ at the start and after 6 weeks of treatment. MRI scans will also assess changes in brain connectivity and blood flow related to psychosis symptoms. Healthy control participants matched by age and gender will be included for comparison. Participants will undergo PET and MRI scans at enrollment and after 6 weeks of pimavanserin treatment to measure receptor changes and brain function. Psychosis severity and functional brain imaging will be evaluated at these timepoints. The study includes adults aged 50 to 85 years, and participants must have a study partner available for visits. Researchers will monitor changes in receptor binding, symptom severity, and brain connectivity throughout the study period.

Characterization of the Serotonin 2A Receptor Selective PET Tracer [18F]MH.MZ in Patients With Neurodegenerative Diseases