Periodic Limb Movement Disorder

1. Causes of Fatigue Slideshow Pictures
2. Take the Sleep Quiz!
3. Foods That Help or Harm Your Sleep Slideshow Pictures

• Periodic Limb Movement Disorder Overview
• Periodic Limb Movement Disorder Causes
• Periodic Limb Movement Disorder Symptoms
• Exams and Tests
• Periodic Limb Movement Disorder Treatment
• Medical Treatment
• Medications
• Next Steps
• Follow-up
• Prevention
• Outlook
• For More Information
• Web Links
• Synonyms and Keywords
• Authors and Editors
• Read more on Periodic Limb Movement Disorder from Healthwise
• Viewer Comments: Periodic Limb Movement Disorder - Diagnosis

Periodic limb movement disorder (PLMD) is repetitive cramping or jerking of the legs during sleep. It is the only movement disorder that occurs only during sleep, and it is sometimes called periodic leg (or limb) movements during sleep. "Periodic" refers to the fact that the movements are repetitive and rhythmic, occurring about every 20-40 seconds. PLMD is also considered a sleep disorder, because the movements often disrupt sleep and lead to daytime sleepiness.

PLMD may occur with other sleep disorders. Itis often linked with restless legs syndrome, but they are not the same thing. Restless legs syndrome is a condition involving strange sensations in the legs (and sometimes arms) while awake and an irresistible urge to move the limbs to relieve the sensations. At least 80% of people with restless legs syndrome have PLMD, but the reverse is not true.

When PLMD was first described in the 1950s, it was called nocturnal myoclonus. Nocturnal means night, and myoclonus is a rapid, rhythmic contraction of a group of muscles similar to that seen in seizures. PLMD movements are not myoclonus, however, and the original name is not used today.

PLMD can occur at any age. Like many sleep disorders, PLMD is more common in middle-aged and older people.

Must Read Articles Related to Periodic Limb Movement Disorder

Disorders That Disrupt Sleep (Parasomnias) Parasomnias are disruptive sleep-related disorders. They are characterized by undesirable physical or verbal behaviors or experiences. Parasomnias occur in asso...learn more >>

Insomnia Insomnia affects most people at some point in their lifetime. Insomnia is actually a symptoms of a condition, disease, or situation. Non-medical treatment of in...learn more >>

Restless Legs Syndrome Restless legs syndrome (RLS) is a disorder of the part of the nervous system that affects movements of the legs. Because it usually interferes with sleep, it al...learn more >>

See the Entire Periodic Limb Movement Disorder Topic Guide »