Q&A: Baby "dancing" in his sleep and waking himself up

Here's a lovely post from my ex-husband about not being with the kids every day.

And now a question I don't know the answer to any more than I ever do, from Leah:

"When it comes to sleep, I quote Tolstoy: “Well-rested families are all alike; every sleep-deprived family is sleep-deprived in its own way.” Yet after hours of fruitless interneting, I still can’t help but think that some other parent has been through a version of what’s going on with my 3-month-old son.

For weeks (with the exception of the usual developmental fussy phases), our night-time routine has been as follows: fall asleep without issue in the co-sleeper next to our bed, wake once or twice to eat, and then, around 4:00 or 5:00, enter a strange semi-sleep in which he starts "dancing the highland jig," as my own mother put it... The arms shoot up, the legs kick, then they come back down for a minute before the process starts over again. Eventually, this wakes him up and causes him to start crying, and while I can usually settle him by nursing, it’s not a settled sleep he re-enters, which means no more sleep for me, either.

I’ve tried swaddling—he breaks free, though I’ll admit that I’m not the world’s most competent swaddler at that hour of the night. I’ve tried bringing him into our bed—he continues to sleep fitfully, and so do I, wondering how long I’ve got before his movements wake him up again. Occasionally, if I tough it out till 6:00 or 6:30, he’ll go down for another jig-free hour, but by then we’re past the time when I need to get up for work. I've also tried experimenting with an earlier bedtime (it’s usually between 7:00 and 8:00), and I try to hew to the 90-minute wakefulness rule for naps during the day (though he's not a terrific napper, which I guess one would expect at this age).

Is this the startle reflex? Is he actually “ready” to get up? I can’t seem to understand why it happens when it does, and why so consistently. Will I get relief when he’s old enough to have more motor control, or is this one of those mysteries that I can simply count on improving at some unspecified point in the future?

Anyway. I hope I'm not out of line in writing you, but the only thing our pediatrician suggested was moving him to another room! Which, you know, fine, but that still would only give me about 15-20 more minutes at each interval, since once he's up, he'll start crying."

So in my defense, Leah's pediatrician doesn't know what to do, either.

I'm going to go to my standard MO, which is to use process of elimination:

1. Gas. Gas? I don't know, but the cycling of the legs sounds like gas. I can't even remember what you're supposed to do about gas anymore except eliminate criciferous vegetables from your diet and try gripe water or mylecon drops. (Have gas treatments advanced in the last 5 years? I'm at the phase of mothering in which gas issues are all about fart jokes.)

2. Silent reflux? How does he sleep when he's not lying flat? If he's able to sleep longer if he's sleeping in a stroller or with his head elevated, then this is probably silent reflux, and he'll probably grow out of it. In the meantime, try elevating the head of the co-sleeper to see if he gets longer stretches at night.

3. Some kind of restless legs/arms thing that would be helped by swaddling? Maybe it's worth it to invest in one of those magic blankets that swaddles your baby for you so you don't have to struggle with it in the middle of the night.

4. Pre-sleepwalking? Is it possible that whatever makes older humans sleepwalk is already manifesting itself in your pre-mobile child? (This one's clearly a random stab, but who knows?)

5. Your son is the heir to the Lord of the Dance?

I'd really look at the first two and see if you can make any small changes to see if it could be gas or reflux. I haven't heard of this kind of dancing thing that lasts for awhile while the child is still sleeping, but on the other hand, all bets are really off when a baby's only three months old.

Has anyone out there gone through this? Is it something common that I just haven't run across? Other things for Leah to try?