Mouse glitch?

I've been having a issue lately in may games. Every time I get into game my mouse is stuck to the bottom of the screen and I can't move it at all. Whenever I leave the game client it goes back to working perfectly fine however. I keep having to dc since i literally can't move my champ and its leading to my team losses due to the lack of a player. Is this glitch coming from me or the client? Should I just try to reinstall the client to see if that fixes it?

P.s. My comp it a MacBook Pro (13-inch, Mid 2009) version 10.10 Is the Yosemite update a possible cause?