Reduced synaptic density in patients with progressive supranuclear palsy: An ¹⁸F-SynVest-1 PET study

Progressive supranuclear palsy (PSP) is a disabling movement disorder disease characterized by prominent synaptic loss in its early stage. The present study utilized ¹⁸F-SynVest-1 positron emission tomography (PET) in patients with PSP to assess the expression of synaptic vesicle glycoprotein 2A (SV2A), a marker of synaptic density, with the aim of diagnosing PSP patients.

A total of 13 patients with PSP and 11 healthy controls were enrolled, and they underwent ¹⁸F-SynVest-1 PET scan and brain MRI scan. Voxel-based and region-of-interest (ROI)-based analysis were performed to compare synaptic density between PSP patients and controls. Receiver operating curve (ROC) analysis was used to evaluate the diagnostic efficacy of synaptic density. Spearman correlation analysis was employed to explore the correlation between synaptic density, disease duration, and disease severity.

PSP patients exhibited significantly lower synaptic density in the midbrain, basal ganglia, thalamus, and subregions of frontal lobes compared to controls (p < 0.05). The synaptic density of left caudate effectively distinguished PSP patients from controls with an AUC of 0.94. Additionally, synaptic density showed a strong positive correlation with the midbrain to pons ratio in PSP patients (R = 0.58, p = 0.04).

We applied the ¹⁸F-SynVest-1 PET in PSP patients to display synaptic density changes in vivo for the first time, and the ¹⁸F-SynVest-1 PET showed promise in early detection and monitoring disease severity of PSP.