Neuronal alpha-Synuclein Disease stage progression over five years

The shared code was created to perform analyses for the published article "Neuronal alpha-Synuclein Disease stage progression over five years" [http://doi.org/10.1002/mds.30191]. This code was created to analyze data accessed from the PPMI database (RRID:SCR 006431) on February 5, 2024. As the PPMI database is always evolving, it is possible that the code may not work if the database has changed since the date the code was created. Analytic datasets are not included in the submission. Researchers can request access to PPMI data at the PPMI Study website (https://www.ppmi-info.org/access-data-specimens/download-data).