Autism and Encephalitis/could they be related?

I was just watching a little bit of AWAKENINGS which is about the victims of an encephalitis epidemic many, many years ago and they have been catatonic ever since, but now a new drug offers the prospect of reviving them. As I watched I thought of the recent show I watched on autism and I thought...I wonder if the two are somehow related? I wonder if the drug L-dopa...in some form could help those kids with autism...??