V.K.
My son is special needs too, but he deals with the effects from Shaken Baby Syndrome. He used to hit himself too, and I always thought it was just because he was frustrated. Maybe your little guy is just tired and has no other outlet to vent the grouchies. I have heard of people trying a vest to weigh them down alittle bit, but I have never tried it. They say that it calms and comforts them. Or maybe give him something in bed to keep his hands busy? Maybe books or a stuffed animal?
My advice is, don't worry too much. I used to worry all the time about what was wrong with him, what I should be doing to help, etc. It was taking over my life! Somethings you just have to chalk up to a power beyond you. All kids have challenges in life, ours are just alittle different.