Neuroinflammation and Tau Colocalize in vivo in Progressive Supranuclear Palsy

Objective We examined the relationship between tau pathology and neuroinflammation using [11C]PK11195 and [18F]AV‐1451 PET in 17 patients with progressive supranuclear palsy (PSP) Richardson's syndrome. We tested the hypothesis that neuroinflammation and tau protein aggregation colocalize macroscopically, and correlate with clinical severity. Methods Nondisplaceable binding potential (BPND) for each ligand was quantified in 83 regions of interest (ROIs). The [11C]PK11195 and [18F]AV‐1451 BPND values were correlated across all regions. The spatial distributions of [11C]PK11195 and [18F]AV‐1451 binding were determined by principal component analyses (PCAs), and the loading of each spatial component compared against the patients’ clinical severity (using the PSP rating scale). Results Regional [11C]PK11195 and [18F]AV‐1451 binding were positively correlated (R = 0.577, p