I have had these spasms for many years. Sleep study doctor and other of my many Doctors never seen anyone So bad. Could be just one limb or the entire body. I make guttural sounds when it is severe. Wife is a RN of 30 years and never seen anything so bad. Keeps me up at night's. Can happen anytime of day or night. I have to watch what medications I can go on since I am a cardiac patient with a LVAD, a pump for my hearty. Some say it could be my Dopamine is low in my brain. If it is that, there is not much to do.