In vivo visualization of tau deposits in corticobasal syndrome by ¹⁸ F-THK5351 PET

Abstract

F-THK5351 PET demonstrated high tracer signal in sites susceptible to tau deposition in patients with CBS. F-THK5351 should be considered as a promising candidate radiotracer for the in vivo imaging of tau deposits in CBS.

Longitudinal changes of tau PET imaging in relation to hypometabolism in prodromal and Alzheimer’s disease dementia

“…[ 18 retention was detected predominantly in the basal ganglia, the thalami and the white matter, but also in isocortical areas, in these patients. Asymmetrical [ 18 F]FDG uptake was observed at baseline in isocortical areas, the basal ganglia and the thalami in both patients; however, the pattern of [ 18 F]FDG uptake was more asymmetrical in case 6 than in case 5 (Figure 3b).…”

“…To find the ROIs in which [ 18 F]THK5317 retention increased over time, the proportion of patients in the AD groups (prodromal and dementia) in whom the annual rate of change was greater than the third quartile of the test-retest repeatability range for [ 18 F]THK5317 retention, time point (baseline or follow-up) and their interaction as fixed factors, allowing for random intercepts across different patients and brain lobes (nested design). Simple slopes analyses were used to assess multiple linear regression two-way interactions.…”

“…14,44 Global cognition (measured with MMSE) declined significantly in patients with AD; this decline correlated with decreased [ 18 F]THK5317 retention (negatively); the correlations with episodic memory, however, did not survive correction for multiple comparisons and can be considered preliminary due to the small number of patients completing the episodic memory testing. The current data are in line with earlier cross-sectional findings 45 and support the notion that while tau deposition in the temporal cortex may be related to the earliest memory impairment, global cognitive changes are more closely related with hypometabolism in the relevant areas than with measures of tau propagation.…”

“…With regard to the AD dementia patients, case 3 had milder cognitive impairment at baseline (as measured with MMSE) that remained stable over the follow-up interval, while the cognitive impairment in case 4 was worse at baseline and showed a clear further decline at follow-up (loss of seven points on MMSE). [ 18 (Figures 4b and c), while decreased [ 18 F]FDG uptake in the posterior cingulate gyrus predicted decreased MMSE scores (Supplementary Figure 3); however, the statistical significance of the RAVL encoding score predictions did not survive correction for multiple comparisons for any of the tracers in the selected ROIs.…”

“…Case series have revealed high regional retention of the tau tracers in patients with clinical diagnoses of corticobasal syndrome (CBS), but the regional distribution in these cases was different from that in patients with AD. 12,[16][17][18] The understanding of the in vivo propagation of the pathology in the different degenerative tauopathies, however, remains elusive.…”