Trial Outcomes & Findings for Florbetapir F 18 PET Imaging of Beta-amyloid in Parkinson's Disease Patients (NCT NCT00857532)

Florbetapir F 18 PET Imaging of Beta-amyloid in Parkinson's Disease Patients

Standardized uptake value ratios (SUVR) were calculated and compared between subjects with PD and controls. Subjects with Parkinson's Disease (PD) were stratified into one of three groups based on performance on the age and education adjusted Mattis Dementia Rating Scale (DRS-2). The age and education adjusted DRS-2 ranges from 0 (lowest cognitive function) to 20 (highest cognitive function). SUVR is the ratio of tracer uptake in predefined cortical regions, relative to uptake in the whole cerebellum. SUVR values higher than 1 indicate greater amyloid burden in the predefined cortical regions as compared to cerebellum whereas scores less than 1 indicate the opposite. This outcome measure only reports data from the subjects analyzed in this study, the data from normal controls was obtained from a pre-existing database and is not reported here.

Correlation between amyloid burden (global florbetapir SUVR) and cognitive decline (DRS-2 score) was determined using Spearman's rank order correlation method where SUVR was the dependent variable and the DRS-2 score was the independent variable. This analysis was performed for total DRS-2 score and the five DRS-2 subscale scores. The subscales (score range) are: Attention (0-37), Initiation/Perseveration (0-37), Construction (0-6), Conceptualization (0-39) and Memory (0-25). The total DRS-2 score is the sum of the subscale scores and ranges from 0-144. Higher DRS-2 scores indicate greater cognitive function.

Correlation between amyloid burden (florbetapir SUVR) and cerebrospinal fluid (CSF) biomarker values (amyloid beta, tau and phospho-tau) was determined using Spearman's rank order correlation in a subset of subjects undergoing CSF analysis where SUVR was the dependent variable and CSF biomarker values were the independent variables.