Objective:

To assess the utility of the synuclein skin biopsy in a tertiary movement disorder clinic (MDC).  

Background:

Deposition of phosphorylated α-synuclein (P-Syn) in the Central and Peripheral autonomic nervous system has been a core feature of Synucleionopathies. Their diagnosis can be challenging due to the overlap of clinical features. In the early stages, primary parkinsonism is often indistinguishable from secondary parkinsonism. The P-Syn in skin biopsy is an emerging and minimally invasive biomarker with high accuracy.  

Design/Methods:

This is a retrospective study of 111 patients with skin biopsies performed over a 30- month period. Data collected included demographics, clinical features, Pre-test diagnosis and clinical outcomes. A correlation between presumed synucleinopathies and biopsy findings was assessed. Additionally, the percent change in treatment was evaluated post-biopsy.

Results:

Skin biopsies were performed in 2.5% (111 /4,371) of new patient visits over the 30-month period. The cohort was 61.2% male (n=68) and 38.7% female (n=48), with a mean age of 74 ± 7 years (range 48-86). 60.3% of patients had co-pathologies with 2 or more diagnoses. The most common co-pathology was ET-Parkinsonism. (12.6%). It was identified that 59/111 (53.1%) had an abnormal biopsy with 53/59 (89.8%) presumed to have a synucleinopathy. Amongst the patients with a normal biopsy (46.8%), drug induced parkinsonism was the most common diagnosis. Out of all patients with skin biopsy, treatment was adjusted in 63% of patients.  

Conclusions:

Skin biopsy correlates with high accuracy in patients with presumed synucleinopathies. Skin biopsy provides objective pathological data by clarifying diagnoses in complex presentations with multiple pathologies. This tool guides clinicians towards an accurate diagnosis, allows for targeted treatment adjustments, such as initiating disease-specific medications or discontinuing inappropriate therapies. Further research is needed to assess the utilization in early/pre-motor staging as well as delineation of various synucleinopathies. Limitations include - selection bias, retrospective review and short term follow-up.