A primary challenge in the diagnosis of neurological disorders is differentiating between conditions that share clinical features. Absent of a clear diagnosis, proper and effective patient care is hindered. Therefore, there is a great need for accessible diagnostic tools that help provide clarity to diagnosing clinicians.
In a recent study in the Journal of Parkinson’s Disease, researchers found that alpha-synuclein deposits in nerve fibers in the skin were useful in distinguishing Parkinson’s disease from supranuclear palsy (PSP) and corticobasal syndrome (CBS). Although PSP and Parkinson’s present with similar clinical features, PSP is characterized by tau protein aggregates, whereas Parkinson’s is characterized by alpha-synuclein aggregates. CBS is characterized by a mix of tau and alpha-synuclein, with tau being predominant.
The study recruited 18 patients with PSP, 8 with CBS, 26 patients with Parkinson’s disease, and 26 healthy controls. Two 3-mm skin punch biopsies were collected from each patient and analyzed with immunostaining for the presence of alpha-synuclein.
Alpha-synuclein deposits were present in 2 (7.7%) patients with PSP or CBS and in none of the healthy controls. Conversely, alpha-synuclein was detected in all patients with Parkinson’s disease. The authors note that the patients with PSP/CBS who tested positive for alpha-synuclein showed some features that were abnormal for PSP/CBS but consistent with synucleinopathies.
The results support the utility of alpha-synuclein detection in nerve fibers of the skin for accurately distinguishing between patients with Parkinson’s and patients with PSP or CBS.