Once in a great while, when I am falling asleep, relaxed as a person can be, I will tense up suddenly, become rigid for a couple seconds and then resume the relaxed state.
I’m nearly asleep when this happens. There is no pain or other discomfort and by the time the next morning comes along, I forget it happens.
I live alone and sleep (mostly) alone. As it happens, an episode happened the other night when I had a guest in my bed. As we were cooking breakfast, she wondered what happened and then I vaguely remember it happening. I know it has happened occasionally in the past, maybe 4 or 5 times a year.
I really don’t know a better way to describe the sensation. A similar sensation occurs when I am trying to stay awake and I catch myself dozing off.
For the record, I do have a history of sleep walking, especially if I am really tired when I go to bed. The night of the episode, I had a taken a couple of aspirin for a scratchy throat but I was not under the influence of any other drugs, including alcohol.
disclaimer, I am not asking for medical advice, I just wonder if there is a name for this. Googling"sleep disorders" did not help too much.