Synaptic loss has been implicated in various neurodegenerative conditions, yet its understanding in multiple system atrophy (MSA) remains limited.

The aim of this study was to examine spatial synaptic density alterations in MSA patients and evaluate the potential of [18F]SynVesT-1 PET as an imaging biomarker for MSA in both diagnosis and monitoring disease severity.

60 MSA patients (30 MSA-P subtype and 30 MSA-C subtype) and 30 age-matched healthy controls (HCs) underwent [18F]SynVesT-1 PET/CT for synaptic density assessment. Visual, voxel, and volumetric region-of-interest (VOI) analyses were employed to elucidate synaptic density patterns in the MSA brain and establish visual diagnostic criteria. VOI-based computer-assisted analyses were utilized to develop diagnostic models for MSA.

Inclusion Criteria:

The MSA patient were diagnosed according to the 2008 Second Consensus Criteria and confirmed by two experienced neurologists.

Exclusion Criteria:

encompassed MRI contraindications, a history of epilepsy, stroke, or brain surgery, intracranial organic lesions unrelated to MSA, usage of levetiracetam or brivaracetam, and a history of alcohol or drug abuse

60 patients diagnosed with MSA were recruited. The patient cohort consisted of 30 MSA-C and 30 MSA-P cases, diagnosed according to the 2008 Second Consensus Criteria and confirmed by two experienced neurologists. Additionally, 30 gender and age-matched HCs were included.