Analysis of Cutaneous Phosphorylated Alpha-Synuclein to Identify Patients at Risk of Progressing From Essential Tremor to Parkinson's Disease

Background and Rationale Essential tremor (ET) affects over 6 million Americans and approximately 5% of adults over age 60. Patients with ET have a 10-20 times higher risk of developing Parkinson's disease (PD) compared to age-matched populations, with approximately 1% converting to PD annually. Post-mortem studies reveal Lewy body pathology in some ET patients, suggesting a subset may have prodromal PD. Current diagnostic tools (DaTscan, SYNTap) are either insufficiently sensitive for early disease, too expensive, or too invasive for routine screening. The Syn-One Test offers a minimally invasive approach to detect phosphorylated α-synuclein (P-SYN) pathology in skin biopsies. Primary Objectives 1. Identify which ET patients have P-SYN pathology indicative of prodromal PD 2. Predict which patients are most likely to phenoconvert to PD