About a year and a half ago, I had an MRI. During the scan something very strange kept happening. The procedure was actually a series of many scans - it took over an hour to get them all done. Before each one, the tech would go through a procedure he called tuning. The machine would hum at three different tones during this tuning. The third hum was where the strange thing would happen. I was on my back with my hands crossed across my belly. As soon as the third hum would start, my arms and hands would feel electric shock and fly apart. No matter how hard I tried to relax and keep my hands clasped, I couldn't. It wasn't painful, but I could not control my muscles at all. It would last maybe a second. The tech said it was the startle reflex. I can't rule it out, but since I knew it was coming each time I don't think that's what it was. I mean, in an MRI there are lots of different, unexpected sounds, and I didn't startle at any of those. Just the third one of the tuning process - every time! Later, when I saw the neurologist, he didn't have an explanation. He just sort of brushed it off. Anyone know what was happening?