iNOS is known for releasing large amounts of nitric oxide as a defensive tactic. Nitric oxide is a free radical that can be used as a weapon and, therefore, sudden low testosterone essentially puts a huge oxidative load on the brain and may actually do some damage that leads to Parkinson's.  A further verification of this is the fact that, according to one study, men are times more likely to contract Parkinson's and that low testosterone levels have been associated with Parkinson's.  In addition, giving male Parkinson's patients testosterone can help with tremors. 
Disclaimer: The entire contents of this website are based upon the opinions of Dr. Mercola, unless otherwise noted. Individual articles are based upon the opinions of the respective author, who retains copyright as marked. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the research and experience of Dr. Mercola and his community. Dr. Mercola encourages you to make your own health care decisions based upon your research and in partnership with a qualified health care professional. If you are pregnant, nursing, taking medication, or have a medical condition, consult your health care professional before using products based on this content.
Write down a list of the people you need to forgive and then do so. You can do that just yourself, between you and God, or you can do that in person — but it really is important. You can also turn to the Bible and other personal growth books, or seek out the help of a counselor or a good church. Really take care of those emotional issues, specifically resentment, unforgiveness, anger and frustration, and you’ll see that’s going to really help you cleanse you and detoxify spiritually. It’s going to also help naturally raise your testosterone levels.