Lag Spike when spells are cast

So Ive been having an issue lately where I will get a lag spike every time a spell is cast. There is no change in my fps or ping when it happens. It hasnt always been this way and seems to have started this week. I've tested my internet connection and can play other games with out any issues like Dota 2 and Heros. Is there anyone else out there experiencing this ? and if so is there a fix ?