I've been taking ALA for a few months now. (I was taking the regular ALA at 600 Mg/day then switched to the stabilized R form at 200 Mg/day.) I haven't noticed any change that I could attribute to the ALA.

As for your other question - I don't know if there's any scientific studies - but a lot of people say that the symptoms may get worse before they get better as they heal. (On the other hand, feeling worse can also mean they are getting worse.)

I think the most important thing is not to get too freaked out if things feel worse in the short term. In my case my symptoms are a roller coaster - some days I hardly notice the symptoms, other days I wonder how much longer I'll be able to do my job. It's starting to become clear to me that I have to measure improvement or regression over periods of weeks or months - not day to day.