Also not a doctor, but my instinct is that the dance helped the autism. I have ADD and I used to be extremely physically awkward - don't want to self-diagnose dyspraxia, but I'd describe it as my movements being based on a calculus that was different from those of other people. I would have a specific reason for making an awkward movement, but not one other people could anticipate or even recognize, and even I knew it was often strange as I was doing it. I had similar issues in conversation, where I'd find myself saying something strange or awkward but being unable to put the brakes on in time: a horrible feeling, as if one's mouth wasn't fully under one's control.

Well, at about age 26 I got into goa trance music (which shares the steady 4/4 pulse with disco, and is also best enjoyed loud), and I went out dancing a lot. In the space of 2 years it made a huge difference - I went from feeling like a bundle of arms and legs to having superior motor control, from being unable to catch something thrown straight to me (or fumbling it even if I caught it) to being able to catch something mis-thrown or dropped - I could just reach out and pluck something out of the air 2 feet to my side. I didn't even notice it particularly, it was my friends who started commenting on how good my reflexes were. Perhaps this improvement was due to natural and/or artificial alterations of brain chemistry, but I do feel that the extremely metronomic nature of dance music was a major factor. I liked dancing beforehand, but I sucked at it. Something about the loud steady 4/4 pulse served to resynchronize formerly oppositional gears, and over time made it easier to perceive and adapt to other metrical patterns too. I still have problems with polyrhythmic material though :)

Now it sure isn't a total cure - I had other ADD-related problems (and some of the benefits, like being able to hyper-focus for long periods) but it increased my confidence and comfort enough that I started to see the connection between these phenomena, eventually leading to a clinical diagnosis and find ways to manage it. I do wish it wasn't classified as a 'disorder'. Besides the mild stigma associated with that, 'attention deficit' isn't too accurate either, since I've always been able to concentrate for extended periods (like reading a book in a single sitting) and being able to rapidly switch tracks in a busy or chaotic environment can be a singular asset: I'm weak on humdrum planning and time management, but very strong indeed on problem solving, improvisation or adapting to abrupt changes.

Having worked in the arts over the last decade (sound engineering and technical directing), I've met a lot of people with both similar and opposite traits. It's an industry truism that everyone who is any good has either OCD or ADD - creatives and producers obsess over story or budgets, and technicians and keys excel at implementation and mediation. In short, the what and the how, a kind of client/server relationship. Both groups need each other, and both have an all-or-nothing attitude to their selected task. What people can be visionary or bullying; how people can be heroic or intransigent.

Perhaps we should rename OCD and ADD to ideophilia and pragmatophilia.