Convulsions

April 13, 2005 6:21 PM

Every once in a while, as I'm drifting off to sleep, my entire body will twitch, as if in a short convulsion. Anyone know why?

This doesn't happen that often, and I'm almost always somewhat awake when it happens. I can only remember it happening as the result of a dream once, and even then I had only been sleeping a few minutes.

This has been happening literally as long as I can remember, ever since I was really young. For the longest time I figured that it happened to everyone, although from the few people I've asked, that doesn't seem to be the case.

posted by jimmy to Health & Fitness (23 answers total)

Best answer: It's called a myoclonic twitch, and it happens to most people, if not everyone.
posted by jjg at 6:24 PM on April 13, 2005

Response by poster: cool, thanks.
posted by jimmy at 6:26 PM on April 13, 2005

Also called hypnagogic myoclonus, if this old Straight Dope column is to be believed.
posted by xil at 6:27 PM on April 13, 2005

Apparently another term for it is hypnic jerk.
posted by jjg at 6:27 PM on April 13, 2005

I've been trying to answer this question for a couple of years now. My partner has this, violently severe... it's so bad that I have actually been bruised and had the wind knocked out of me. (I end up on the couch most nights)

The most common answer is apparently sleep apnea but that doesn't always apply.
posted by geckoinpdx at 6:28 PM on April 13, 2005

Happens to me too, and no, you are not the only one who thought it only happens to them untill you found askmeta :)
posted by furiousxgeorge at 6:30 PM on April 13, 2005

A book on Astral Projection that I read a long time ago said that this phenomenon is your spirit jerking back into your body (from which is has begun to drift for your nightly dream cycle) in response to an external stimulus. Not something I believe, but interesting nonetheless.
posted by Who_Am_I at 6:36 PM on April 13, 2005

Response by poster: The most common answer is apparently sleep apnea but that doesn't always apply.

I've woken up a couple of times before short of breath, thinking I was about to die. I pretty much just chalked it up to neuroses (thinking I'll experience cardiac arrest while i'm sleeping; I'm pretty fat).

I didn't think much of it the few times it's happened, because it usually passed after a few seconds, although I guess it pretty much fits the description found on that site. I don't know how much I want to self-assess based on symptoms found on an internet page, but then again I'm not that concerned about it. Thanks either way, though.
posted by jimmy at 6:37 PM on April 13, 2005

It could also be Restless Leg Syndrome , which my husband had for years until a doctor diagnosed it (he's now on a medication that makes a huge difference). The twitching thing was definitely a big symptom, and several times a night he would twitch so violently that it would wake him (or me!) up.
posted by handful of rain at 6:40 PM on April 13, 2005

I read a lot of books on brain science, and I remember there being an explanation of the myoclonic twitch in one of those books. I don't remember which one but my guess is that it was probably The Mind at Night, which was mostly about the neuroscience of dreaming.
posted by matildaben at 7:07 PM on April 13, 2005

I've always called them "Nap Jerks" because they often happen to me when I'm napping or just on the edge of sleeping. For me it's always right at that moment of slipping into sleep when my body goes into total relaxation and I get a sensation of falling. My whole body will twitch as if to "catch" itself or brace before hitting the ground.

I've always thought it was pretty cool and kind of like the full body response. It's like a kick of adrenaline.
posted by evoo at 7:13 PM on April 13, 2005

I don't know, I'm not big on a kick of adrenaline when I'm trying to fall asleep. Maybe it's just me.
posted by jjg at 7:15 PM on April 13, 2005

I have the same thing happen when I'm very tired. Personally my chest/back are usually the twitchers, but it does vary.

Interesting thought that hit me -- the feeling is very like dull lectures in school -- that "oh my god mind numb going blank...." when you catch yourself (usually) waking up just in time and jerking suddenly upright.

Lots of muscles reacting suddenly, without concious direction: just.feels.wierd.
posted by SpookyFish at 7:37 PM on April 13, 2005

Somewhere, possibly sleepnet, I read that it might be tied to the change in blood chemistry as the body moves from waking life to being asleep. I almost want to say I recall nitrogen being mentioned. But, alas, I am sleepy and my google-fu is weakened....
posted by kimota at 7:52 PM on April 13, 2005

Oh, handful of rain, I am for some reason under the impression that Restless Leg Syndrome is mostly a problem that affects people while they're awake or possibly trying to fall asleep, but there's a semi-related malady, Periodic Limb Movement Disorder, that affects people in their sleep. I don't believe it's what jimmy was asking about, but I feel obliged to mention it as a possible lead for future ask.mefi archive searchers.
posted by kimota at 8:04 PM on April 13, 2005

Jimmy, check out this amazing New Yorker article by Oliver Sacks that is about, in part, the enmeshing of myclonic jerks and dreams. It's completely changed how I think about the world, and that's no exaggeration.
posted by waldo at 9:04 PM on April 13, 2005

I'm going to go out on a limb and claim that in fact you twitch every time you fall asleep, and only if it's sufficiently violent do you (or the person you're sleeping next to) remember it.
My personal experience here is that every time I've started sleeping with (in the literal sense) someone new, for the first few weeks I'd notice them twitching as they fell asleep, before me. Evidently it takes me a couple weeks to loosen up enough with someone new to fall asleep before them.
It's readily observable in cats and babies, too, by the way.
posted by Aknaton at 9:17 PM on April 13, 2005

I get these a lot, and most of the time its not really related to a dream, they just happen when Im half asleep and just thinking but not really dreaming yet. Freaks my girlfriend out, like geckoinpdx Ive hurt her a couple of times.. : ( At least I have a name for them now.
posted by phyle at 9:37 PM on April 13, 2005

Actually, I look forward to these convulsions, because they seem to signal that I am just about to fall asleep. I usually have to lie in bed for an hour or so before going to sleep, but if I get one of those convulsions I know I'll be asleep in five minutes.

Still, it's a relief to know that there's a name for these things, and that other people get them too.
posted by Hildago at 10:41 PM on April 13, 2005

I twitch as I fall asleep. Due to how we entwine, before actually sleeping, this often results in my partner getting fingers in a ticklish spot. He then jerks BIG time, waking me up.

My dearly departed cat always knew when I was about to fall asleep (she got cuddles at bedtime) and would remove herself to a safe distance (I wiggle a lot in my sleep). I learned to recognize when I was about to sleep by her actions. Very amusing. I think she mothered me.

Jimmy: Apnea has nothing to do with twitching. Apnea gets noisy and will likely wake your partner. If you might have it, GET CHECKED! I lost my first partner to premature death from heart disease aggravated by apnea. He was only 46. I didn't know apnea back then.
posted by Goofyy at 11:23 PM on April 13, 2005

Holy crap-apples! I get exactly this experience once a month or so, and, as the quote below suggests, up until now, I had always confused the cause and the effect!

The mind is a dangerous playground.

From waldo's link:
Sometimes, as one is falling asleep, there may be a massive, involuntary jerk–amyclonic jerk–of the body. Though such jerks are generated by primitive parts of the brain stem (they are, so to speak, brain-stem reflexes), and as such are without any intrinsic meaning or motive, they may be given meaning and context, turned into acts, by an instantly improvised dream. Thus the jerk may be associated with a dream of tripping, or stepping over a precipice, lunching forward to catch a ball, and so on. Such dreams may be extremely vivid, and have several “scenes.” Subjectively, they appear to start before the jerk, and yet presumably the entire dream mechanism is stimulated by the first, preconscious perception of the jerk. All of this elaborate restructuring of time occurs in a second or less.
posted by Capn at 9:37 AM on April 14, 2005

Wow, I run into this periodically as well. I remember being younger and I had a moment in a dream where a hammer was coming down on me and I woke up with a start. Now, I wonder how the sequence of events actually happened.

AskMe does wonders again.
posted by myopicman at 11:03 AM on April 14, 2005

Happens to me as well and like evoo, there's a sense of falling along with it. A few days ago I was twitching all over as I fell asleep. Weird.
posted by deborah at 11:39 AM on April 14, 2005