I wouldn't say thats an extended period of time. A year of steady use would probably just eat some frontal lobe tissue and some inner nose and sinus tissue. If you don't get nose bleeds out of no where and can control your emotions you might not have much damage at all, the only way to see is a brain scan. I know a guy that did coke for 10+ years and was a heavy used. He was a lawyer and could afford the habit. His shit is all fucked up now. Collapsed sepum and sinuses he can't smell a sewage plant standing in the shit puddle. So take that for what it is...

Cocaine is supposedly the only thing that causes irreversible brain damage but you didn't use it enough and my alternative health doc who treats brain chemical imbalances with amino acids, tested via urine, disputes that. I'm sure you're fine, you weren't a heavy user like, say, Stevie Nicks (who seems okay) and Waylon Jennings whom diabetes killed.