Lately I have been getting pins and needles sensation on my upper back. It feels like I'm about to get the chills and then I get that sensation. I started taking Propecia and I also take Xanax. I have taken these pills in the past and have never experienced this. Could it be a combination of that? I also take a multivitamin and green tea diet supplement. I consume these all at the same time in the morning. It seems like it's happening more frequently. I do get tremors/shakes, which I have a had for a number of years. And when I consulted with a neurologist years ago, he said that it's nothing to worry about. Any advice?