## Study identification ## **Title:** Dopamine buffering capacity measured by phMRI as a novel biomarker of disease progression in PD **Short title:** Measuring Parkinson’s Disease Progression **Grant support:** Michael J. Fox Foundation ## Brief summary ## This application introduces a novel pharmacodynamic brain imaging method for objectively quantifying disease severity in Parkinson disease (PD). The method is levodopa pharmacological fMRI rapid quantitative pharmacodynamic imaging, or “bucket mapping” for short. ... This study’s goal is to validate “bucket mapping” as an objective, quantitative measure of disease severity in PD. Success would position the new method for use as a surrogate endpoint in clinical studies of putative disease-modifying therapies for PD, potentially speeding up such trials dramatically. ### Specific Aims ### 1. Test whether dopamine buffering capacity in midbrain and posterior putamen, measured by levodopa phMRI, reflects clinical disease severity (disease duration, off-period motor function and clinical asymmetry) in 20 PD patients covering a range of current symptom severity and disease duration. 2. Test whether regional _k_e_ values are affected by clinical treatment (6 weeks of clinically dosed carbidopa-levodopa (CD-LD) in 10 previously untreated PD patients). ## Protocol ## See file `MPDP_protocol_20171019.pdf` (or later version) in Files. ## Registrations ## 23 October 2017 | [Registration](https://osf.io/g7dfy/) | [Registration Form](https://osf.io/g7dfy/register/565fb3678c5e4a66b5582f67)