Periodic limb movement disorder, or involuntary movement of the limbs during sleep, does not have a known cause, but it may originate in the central nervous system. To make a diagnosis ...

What causes these so-called sleep starts? Learn about hypnagogic jerks, or hypnic jerks, including the most common symptoms, ...

It can steal your sleep and make nights less comfortable ... with RLS also have a condition known as periodic limb movement disorder (PLMD) -- involuntary movement of the feet and legs.