Search

Background: Anecdotal evidence suggests that patients diagnosed with the parkinsonian subtype of multiple system atrophy (MSA-P) may show uptake of the second-generation tau positron emission tomography (PET) tracer 18 F-Florzolotau (previously known as 18 F-APN-1607) in the putamen.Objectives: This study systematically investigated the localization and magnitude of 18 F-Florzolotau uptake in a relatively large cohort of patients with MSA-P.Methods: 18 F-Florzolotau PET imaging was performed in 31 patients with MSA-P, 24 patients with Parkinson's disease (PD), and 20 age-matched healthy controls. 18 F-Florzolotau signal in the striatum was analyzed by visual inspection and classified as either positive or negative. Regional 18 F-Florzolotau binding was also expressed as standardized uptake value ratio (SUVR) to assess whether it was associated with core symptoms of MSA-P after adjustment for potential confounders.Results: By visual inspection and semiquantitative SUVR comparisons, patients with MSA-P showed elevated 18 F-Florzolotau uptake in the putamen, globus pallidus, and dentate-a finding that was not observed in PD. This increased signal was significantly associated with the core symptoms of MSA-P. In addition, patients with MSA-P with cerebellar ataxia showed an elevated 18 F-Florzolotau uptake in the cerebellar dentate.Conclusions: 18 F-Florzolotau tau PET imaging findings may reflect the clinical severity of MSA-P and can potentially discriminate between this condition and PD. © 2022 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: Recent development in tau‐sensitive tracers has sparkled significant interest in tracking tauopathies using positron emission tomography (PET) biomarkers. However, the ability of 18F‐florzolotau PET imaging to topographically characterize tau pathology in corticobasal syndrome (CBS) remains unclear. Further, the question as to whether disease‐level differences exist with other neurodegenerative tauopathies is still unanswered. Objective: To analyze the topographical patterns of tau pathology in the living brains of patients with CBS using 18F‐florzolotau PET imaging and to examine whether differences with other tauopathies exist. Methods: 18F‐florzolotau PET imaging was performed in 20 consecutive patients with CBS, 20 cognitively healthy controls (HCs), 20 patients with Alzheimer's disease (AD), and 16 patients with progressive supranuclear palsy–Richardson's syndrome (PSP‐RS). Cerebrospinal fluid (CSF) levels of β‐amyloid biomarkers were quantified in all patients with CBS. 18F‐florzolotau uptake was quantitatively assessed using standardized uptake value ratios. Results: Of the 20 patients with CBS, 19 (95%) were negative for CSF biomarkers of amyloid pathology; of them, three had negative 18F‐florzolotau PET findings. Compared with HCs, patients with CBS showed increased 18F‐florzolotau signals in both cortical and subcortical regions. In addition, patients with CBS were characterized by higher tracer retentions in subcortical regions compared with those with AD and showed a trend toward higher signals in cortical areas compared with PSP‐RS. An asymmetric pattern of 18F‐florzolotau uptake was associated with an asymmetry of motor severity in patients with CBS. Conclusions: In vivo 18F‐florzolotau PET imaging holds promise for distinguishing CBS in the spectrum of neurodegenerative tauopathies. © 2023 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: 18 F-APN-1607 is a novel tau PET tracer characterized by high binding affinity for 3- and 4-repeat tau deposits. Whether 18 F-APN-1607 PET imaging is clinically useful in PSP remains unclear.Objectives: The objective of this study was to investigate the clinical utility of 18 F-APN-1607 PET in the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP.Methods: We enrolled 3 groups consisting of patients with PSP (n = 20), patients with α-synucleinopathies (MSA with predominant parkinsonism, n = 7; PD, n = 10), and age- and sex-matched healthy controls (n = 13). The binding patterns of 18 F-APN-1607 in PET/CT imaging were investigated. Regional standardized uptake ratios were compared across groups and examined in relation to their utility in the differential diagnosis of PSP versus α-synucleinopathies. Finally, the relationships between clinical severity scores and 18 F-APN-1607 uptake were investigated after adjustment for age, sex, and disease duration.Results: Compared with healthy controls, patients with PSP showed increased 18 F-APN-1607 binding in several subcortical regions, including the striatum, putamen, globus pallidus, thalamus, subthalamic nucleus, midbrain, tegmentum, substantia nigra, pontine base, red nucleus, raphe nuclei, and locus coeruleus. We identified specific regions that were capable of distinguishing PSP from α-synucleinopathies. The severity of PSP was positively correlated with the amount of 18 F-APN-1607 uptake in the subthalamic nucleus, midbrain, substantia nigra, red nucleus, pontine base, and raphe nuclei.Conclusions: 18 F-APN-1607 PET imaging holds promise for the diagnosis, differential diagnosis, and assessment of disease severity in patients with PSP. © 2021 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]