Progressive supranuclear palsy Richardson’s (PSP) syndrome is a degenerative brain disorder. It affects movement, gait, mood, vision, speech, swallowing, and behavior. Tau protein accumulation and a neural inflammation may have a key role in PSP. This study tests the relationship of such risk factors with the disease’s severity.

A total of 17 PSP subjects underwent ligand injections and PET scans. Each ligand’s non-displaceable binding potential was quantified in 83 regions of interest. The antagonist and scan values were correlated across all regions. The ligand spatial distributions and scan bindings were subjected to principal component analyses(PCAs). The PSP rating scale compared each spatial component loading with the patient’s clinical severity.

The regional bindings of PK11195 and AV-1451 PET showed a positive correlation. PCA identified four components for each ligand. They show tau and inflammation in distinct brain regions. Positive associations between ligand and loadings were found in cortical and sub-cortical regions. Clinical severity positively correlated with both sub-cortical tau pathology and neuroinflammation.

The tau protein and swelling co-localize in PSP. Their sub-cortical differences are linked to clinical severity. Longitudinal studies are needed for causal knowledge of these molecular pathways. The study helps in designing new therapies with tau and immune-oriented strategies.