Synaptic Loss in Primary Tauopathies Revealed by [11 C]UCB-J Positron Emission Tomography
Publication: Movement Disorders
Negin Holland, P. Simon Jones, George Savulich, Julie K. Wiggins, Young T. Hong, Tim D. Fryer, Roido Manavaki, Selena Milicevic Sephton, Istvan Boros, Maura Malpetti, Frank H. Hezemans, Franklin I. Aigbirhio, Jonathan P. Coles, John O’Brien, James B. Rowe
11 July 2020
In this study the researchers tested the hypothesis that synaptic density is reduced in the primary tauopathies of progressive supranuclear palsy (PSP) (Richardson’s syndrome) and amyloid‐negative corticobasal syndrome (CBS).
Nine CBS patients had negative amyloid biomarkers determined by [11C]PiB PET and hence were deemed likely to have corticobasal degeneration (CBD). Patients with PSP‐Richardson’s syndrome and amyloid‐negative CBS were impaired in executive, memory, and visuospatial tasks. [11C]UCB‐J binding was reduced across frontal, temporal, parietal, and occipital lobes, cingulate, hippocampus, insula, amygdala, and subcortical structures in both PSP and CBD patients compared to controls (P < 0.01), with median reductions up to 50%, consistent with postmortem data. Reductions of 20% to 30% were widespread even in areas of the brain with minimal atrophy. There was a negative correlation between global [11C]UCB‐J binding and the PSP and CBD rating scales (R = –0.61, P < 0.002; R = –0.72, P < 0.001, respectively) and a positive correlation with the revised Addenbrooke’s Cognitive Examination (R = 0.52; P = 0.01).
The researchers confirm severe synaptic loss in PSP and CBD in proportion to disease severity, providing critical insight into the pathophysiology of primary degenerative tauopathies. [11C]UCB‐J may facilitate treatment strategies for disease‐modification, synaptic maintenance, or restoration.
