Q&A: restless infant sleeper

Kaz writes:

"I've been struggling for the past two months with some irregular sleeping patterns in my newborn and thought perhaps you might have some insight. He's about five months now and only naps in 20-40 minute intervals. He will occasionally go back to sleep if I come in and help him, but often his waking is precedented by him repeatedly scratching the sheet with his fingernails. In fact, his hands seem endlessly restless when he's trying to fall asleep and I typically have to hold them until he's in deep sleep or he'll wake himself up scratch his head, pulling out his pacifier, etc. He does sleep on his own in his own crib. We transitioned him there when he was about six weeks old. We swaddled him when he was an infant for about six weeks but then stopped because we'd read it was detrimental to his development to do it as he got older and also because he seemed to dislike it and fussed more when swaddled. He sleeps pretty well at night (asleep by 8:30/9 and sleeps until 4 am when he wakes to breastfeed and then sleeps again until 7/7:30am). He attempted to take away his pacifier cold turkey for two weeks but this did not help the catnapping and only made him fussy when awake. I typically put him to sleep by rocking and holding him on my chest, which usually takes about 20 minutes.He only started solid foods this past week and hasn't shown any evidence of teething except maybe more drooling. Any ideas??? I'd appreciate any help you can give!"

Since this has been going on for two months, it's not related to eating or teething. It's something that's been going on for longer than that.

The thing that leaps out at me isn't that he's restless, but that he scratches. It's such an unusual detail that I think it must mean something. Unfortunately, I have no idea what it means, and can't squeeze any info out of Lord Google (although this search did teach me how to do baby scratches--a.k.a. "Der Babyscratch"--to improve my DJing technique).

If the readers don't have any insight, you should call up your pediatrician to ask about it. I don't want you to get worried that it means his fingers are going to fall off. It's probably something specific but easily-treatable like "restless finger syndrome" (I made that up) that means he needs more potassium, or something like that. But I've never heard of an infant consistently scratching, so you need to go over my head to someone with actual medical training.