Periodic Limb Movement Disorder
Periodic limb movement disorder is characterized by involuntary twitching or jerking in the leg muscles during sleep. The symptoms often cause repeated awakening and severely disrupted sleep. The condition is more common in the elderly and in children with attention deficit hyperactivity disorder.
What Is Periodic Limb Movement Disorder?
Periodic limb movement disorder (PLMD) is a condition characterized by involuntary leg twitching or jerking movements during sleep. The leg movements typically occur every 10 to 60 seconds, and sometimes last throughout the night. PLMD is also known as periodic limb movements in sleep or PLMS. The symptoms cause repeated awakening and severely disrupted sleep.
Periodic limb movement disorder is more common in the elderly and in children with attention deficit hyperactivity disorder. The condition was formerly known as sleep myoclonus or nocturnal myoclonus.
Periodic Limb Movement Disorder and Restless Legs Syndrome
More than 80 percent of people with restless legs syndrome (RLS) also experience periodic limb movement disorder (which is actually more common than RLS). And although many people with RLS also develop periodic limb movement disorder, most people with PLMD do not experience RLS.
Unlike restless legs syndrome, the movements caused by periodic limb movement disorder are involuntary, which means that people have no control over them. Periodic limb movement disorder usually involves the lower extremities. However, for some people, the condition can occur in the upper extremities as well.
What Causes This Condition?
The cause of periodic limb movement disorder is unknown. However, certain diseases and conditions seem to be associated with it. These include:
- Iron deficiency anemia
- Spinal cord injuries.