Also known as nocturnal myoclonus.

When PLMD was first described in the 1950s, it was called nocturnal myoclonus.

Restless legs syndrome (nocturnal myoclonus), a condition that produces an intense, uncomfortable, and often irresistible urge to move the legs.

Even after falling asleep, more than 80 percent of people with the problem experience "periodic movements of sleep," a condition that until recently was called nocturnal myoclonus.

Periodic limb movement disorder (PLMD), previously known as nocturnal myoclonus, is a sleep disorder where the patient moves limbs involuntarily during sleep, and has symptoms or problems related to the movement.