Answer:
He went from being mentally handicapped, to super genius, then back to mentally handicapped.
Step-by-step explanation:
His IQ was in the mental ret*rdation range until tests were done on him and he was an experiment. His IQ then became so high that he became a super genius at everything he learned. His brain started decaying and he went back to being mentally h*ndicapped except even more so than before. Hope this is what you're looking for :)