Hi
@Bamma , one of my sisters for sure and myself get this occasionally, but there's a loud bang, a jerk (muscle spasm I think, but no feeling of being hit on the head. The hardest part is waking and wondering if it was a bang (external)? I've heard of EHS and it seems to be it, benign and I know at least a couple of causes they think are attention issues/ abnormalities in the brain when transitioning between the sleep-wake stage, a spike in sensory neuron activity, possibly stress or exhaustion. I believe there are other causes as well. I get migraines (in general) my sister does not. Her blood pressure is abnormally high and mine is now abnormally low. The 1st time you wonder if you had an aneurism, or a car drove in to the house? lol. I think I get a bright flash but I can't say I can recall for certain. It's unpredictable and doesn't happen that often for me. (We both have arthritis in our necks, she also had a serious injury involving C3.)