Myoclonus (pronounced "my-OCK-lo-nus") is a sudden muscle spasm that you can’t control. It can be a natural reflex – like jumping when something scares you or getting the hiccups from laughing too ...

Myoclonus is a sudden, random muscle jerk. It can happen alone or stem from a medical condition. Possible causes include medication side effects, damage to the nervous system, and disorders that ...