Case report where 18F‑Flortaucipir PET showed asymmetric basal ganglia uptake in an amyloid‑negative patient with corticobasal syndrome, supporting a 4R tauopathy phenotype and suggesting expanded utility of this tracer beyond its current FDA indication.
Supports use of tau PET as a diagnostic biomarker in 4R tauopathies associated with atypical parkinsonism, which could improve patient selection and outcome measures for tau‑targeted therapeutic development.