The first study presents a summary of ashwaganda. The second paper presents a comparison between PD in India vs PD in other parts of the world.
Second study is long and thorough, not a quick read.
From 2nd, India studies tend to focus on non-motor traits and India genetics.
An Overview on Ashwagandha: A Rasayana (Rejuvenator) of Ayurveda.
ncbi.nlm.nih.gov/pmc/articl...
Research in Parkinson's disease in India: A review.
Pratibha Surathi, Ketan Jhunjhunwala, [...], and Pramod Kumar Pal.