Definition

Restless legs syndrome (RLS) is a neurologic disorder. It is characterized by:

• Unpleasant sensations in the legs
• An irresistible urge to move your legs

The sensations are typically worse during periods of inactivity and usually strongest at night. The symptoms are improved with activity. For this reason, people with RLS generally have insomnia , which may be severe.

Causes

The exact cause is unknown. RLS may occur for no identifiable reason. This is called primary RLS. Or, it may be caused by other conditions or certain drugs. This is called secondary RLS.

Many people with RLS also have periodic limb movement disorder (PLMD). This is a related motor disorder characterized by:

• Involuntary, repetitive, jerking movements
• Interrupted sleep because of movement

Risk Factors

These factors increase your chance of developing RLS. Tell your doctor if you have any of these risk factors:

• Family members with RLS
• Pregnant—Some women have RLS during pregnancy. The symptoms usually go away after giving birth.
• Low iron levels (with or without anemia )—may happen if you give blood a lot.
• Northern European descent
• Chronic disease (which can lead to secondary RLS):
  • Peripheral neuropathy (diabetes)
  • Chronic kidney failure
  • Chronic venous insufficiency (varicose veins)
  • Radiculopathy (nerve problem)
  • Anemia
  • Diabetes
  • Cancer
  • Chronic obstructive pulmonary disease
  • Rheumatoid arthritis
  • Congestive heart failure
• Certain medications (eg, tricyclic antidepressants)
• Withdrawing from certain drugs (eg, selective serotonin reuptake inhibitors [SSRIs], lithium, caffeine, dopamine antagonists, sedating antihistamines)

Symptoms

Symptoms may include:

• Feelings of tingling, creeping, pulling, prickling, "pins and needles," or pain in the legs during periods of rest or inactivity—may also be this feeling in the arms.
• Symptoms typically get worse at night
• A strong urge to relieve these uncomfortable feelings with movement
• Restlessness, including floor pacing, tossing and turning in bed, and rubbing the legs
• Difficulty falling asleep and staying asleep
• Hypersomnia—recurrent episodes of excessive daytime sleepiness or prolonged nighttime sleep

Symptoms may begin at any age. But, they are most common in people older than 60 years old. Symptoms usually increase in the evening and during times of rest, relaxation, or inactivity.

Diagnosis

The doctor will ask about your symptoms and medical history. She will also do a physical and neurologic exam. The diagnosis is based mainly on your symptoms. There is no specific test for RLS. But, tests to check for conditions that may trigger RLS include:

• Blood tests to check iron levels
• Monitoring of leg activity during sleep ("sleep study")
• Study of leg muscles, such as electromyography (EMG) and nerve conduction studies

Nerves of the Leg

© 2009 Nucleus Medical Media, Inc.

Treatment

There is no cure for RLS. Treatments are aimed at relieving or reducing symptoms.

Prevention

There are no guidelines for preventing RLS.