CBS and supranuclear palsy, progressive, 1: Additionally,Kaiserova et al. (2021) analyzed 5-OH-IAA in the CSF of patients withPD, MSA, PSP, and CBS,42 revealing thatlevels of this metabolite did not differ significantly from controlsin the tauopathies PSP and CBS but were significantly reduced in thesynucleinopathies PD and MSA.