Major FPS spikes and hitching for a few minutes at a time.

Anyone else get this? I have a high end PC and it runs the game fine but maybe once or twice a day I start getting MAJOR spikes in FPS where the game freezes for a few seconds at a time. I have no idea whats causing it but its costed me a few ranked games when it starts doing it and a team fight breaks out or something. If I wait long enough it goes away and the game runs fine after.

If anyone has had it before, did you find a solution to fix it?