F-18-THK5351 Positron Emission Tomography Imaging in Neurodegenerative Tauopathies

Introduction: We aimed to determine whether in vivo tau deposits and monoamine oxidase B (MAO-B) detection using F-18-THK5351 positron emission tomography (PET) can assist in the differential distribution in patients with corticobasal syndrome (CBS), progressive supranuclear palsy (PSP), and Alzheimer's disease (AD) and whether F-18-THK5351 retention of lesion sites in CBS and PSP can correlate with clinical parameters.Methods: F-18-THK5351 PET was performed in 35 participants, including 7, 9, and 10 patients with CBS, PSP, and AD, respectively, and 9 age-matched normal controls. In CBS and PSP, cognitive and motor functions were assessed using the Montreal Cognitive Assessment, Addenbrooke's Cognitive Examination-Revised, and Frontal Assessment Battery, Unified Parkinson's Disease Rating Scale Motor Score, and PSP Rating Scale.Results: F-18-THK5351 retention was observed in sites susceptible to disease-related pathologies in CBS, PSP, and AD. F-18-THK5351 uptake in the precentral gyrus clearly differentiated patients with CBS from those with PSP and AD. Furthermore, F-18-THK5351 uptake in the inferior temporal gyrus clearly differentiated patients with AD from those with CBS and PSP. Regional F-18-THK5351 retention was associated with the cognitive function in CBS and PSP.Conclusion: Measurement of the tau deposits and MAO-B density in the brain using F-18-THK5351 may be helpful for the differential diagnosis of tauopathies and for understanding disease stages.