Potential new treatments are experimental, that’s why they need to go through clinical trials, so therefore they carry a greater risk of the unknown; of course any treatment (but in particular drug treatment) has gone through extensive testing before it is accepted for use in humans. But the unknown risk is a stumbling block for me. I am a scientist you see (I have a DPhil in Genetics) and I simply cannot go into something without looking at the current state of knowledge in the scientific literature. I am lucky in that I have acquired the skills to understand the science and I know (because I’ve done it) that research also deals largely with unknowns. Again, I hear the objection, “if you don’t take part in clinical trials we will never know”.
For me it comes down to this: with the current state of my Parkinson’s being fairly tolerant of periods of good movement I have too much to lose if something went wrong and it is my sense of duty to myself to preserve my health for as long as possible that stops me from signing up. I imagine in the future when the extent of my decline shifts the emphasis to “I’ve got nothing left to lose” it will break down the barriers and I will be game for anything; inject me, probe me, scan me, break me, mend me! But, for now, I don’t want to risk the life I have at the moment; I want to enjoy it while it lasts. Is this selfish? Maybe. Understandable?