I read chapter 10 first on GDNF and PD. A main point is the protective role of estradiol (one reason PD is more common in men than in women).

"The estrogen 17β-estradiol plays a determinant protective role through its antioxidant, anti-inflammatory, and anti-apoptotic actions. Moreover, 17β- estradiol is capable of inducing the expression of neurotrophic factors, namely GDNF, which can have a determinant contribution to the aforementioned protective effects of 17β- estradiol."

My first symptom (tremor) coincided with menopause. I did my research and promptly started on bioidentical hormones at optimal doses, including estradiol. I noticed that much of the research on the protective effect of estrogen on PD stopped when the WHI study came out (which showed deleterious effects of synthetic estrogens and progestins). I mentioned to my MDS that I was finding good (old) research on estradiol and PD, and she said, no, no, no, exercise, exercise, exercise. I do exercise but I have found that estradiol cream has helped with my PD.

I think it is important to explore all avenues to combat this hydra-headed disease. I am glad that I did my research and followed through, despite the poo-pooing of my MDS.