desperate for answers...

i entered this site hoping anyone here could be of help, please do help...good day! i would like to state my brother's history to really know what his sickness is and can it be treated?please do read and help me...my brother is a loner and has difficulty in math and other subjects, but good in music and other arts when he was young. By the time he reached the age of 16 he stopped going to school esp. when he wasn't already studying in the school he badly wanted and he never got into the basketball varsity. Strange things like he sleeps under the bed with no shirt , he broke things and yells everytime he hears noise or someone laughing or chatting, and always irritated ;he runs at the living room at night when were all asleep and he's always angry. Right now after 6 years,he can't speak anymore, music is his therapy at times,we do things for him like make him pee, brush his teeth and also he like went back to being like a baby or a child; at times when he got bored of  daily routines and whenever he gets angry, hungry or tired he has violent seizures to which we can't manage esp. when he hurt all of us and he's very strong and the only man in the house is our dad whose 65 yrs.old already and not that healthy. our 1st doctor said he has aspergers, the other said mental retardation and he was saying like my brother's brain is shrinking, like he regresses and he said there's no cure for it which devastated me,for he was normal before 16 and i missed those normal moments. i badly wanted him to have his own life and i badly wanted to know if there's any cure to his sickness cause it really depresses me for i love my brother soooo much..please2x help me