Mouse jitters in League of Legends can be caused by dust on the mouse sensor or mouse pad, as well as faulty wireless transmitter/receiver and USB Port.

Dirt could be covering the infrared sensor under your mouse. There could also be dirt inside the scroll wheel, in which case you’ll have to open the mouse with a screwdriver and use canned air ...

The DPI switch button is more than just an extra feature on your mouse. It’s a built-in way to instantly change how sensitive your mouse feels, whether you’re gaming, editing, or browsing.