Mouse Stuttering

I have had terrible Mouse Stuttering, and it's only related to League of Legends. Every other game is smooth with no issues. But for some reason, League is causing terrible issues with my mouse, and it starts randomly w/o anything really triggering it that I notice.

With no apps in the background (aside my AV) my mouse will start skipping around the screen everywhere, it's not smooth anymore, and then very randomly, will get stuck in the side of the screen for a moment, as I pan all the way across the map, then it will come back to being able to be moved again. it stays like this until I restart my PC.

I can run heroes of the storm, Rust, WoW, Planetside 2, 7d2d, no issues at all. It's only LoL that this happens in.

ALSO, I thought the issue was related to windows 8.1 as there are many complaints to windows 8.1 with Gamin mice (I use Logitech G700S) so I formatted my PC, and installed a fresh install of windows 7..... it's still happening. I can't figure this out. Something with my mouse that League doesn't like?