Just keep it well watered. It looks like it's coming back. You will probably have some dead branches, as soon as you are sure they are dead, you can prune them off. I had the same thing happen to my two and now they are comepletely leafed out.

I was just at Biltmore in Asheville and some of the damage to the Japanese Maples were heart breaking. There was one that had to be over 100 years old that looks like most of it will have to be cut back.