Chorea-acanthocytosis is a rare genetic disorder of the nervous system. It causes involuntary jerks and twitches in the muscles, known as chorea, and star-shaped red blood cells, known as ...

You're relaxing on the sofa when suddenly your eyelid starts twitching. Or perhaps it's a muscle in your arm, your leg, or your foot that begins to spasm—sometimes for a few seconds, sometimes for ...