Restless Legs Syndrome (RLS)

Definition

Restless legs syndrome (RLS) is a neurologic disorder characterized by unpleasant sensations in the legs and an irresistible urge to move them. 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 of RLS is unknown. RLS may occur for no identifiable reason (primary RLS), or may be caused by other medical conditions or use of certain drugs (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 that interrupt sleep.

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 disappear after giving birth.
• Low iron levels (with or without anemia)—This may happen if you give blood frequently.
• 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—Half of patients complain of restlessness in the arms as well as legs.
• 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 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, and 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

Treatment

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

Prevention

There are no guidelines for preventing RLS.