- RLS is a neurological disorder that comes on just as you're trying to rest.
- It combines pain and other unpleasant sensations with an uncontrollable urge to move your legs.
- The condition itself is complicated by chronic sleep loss—and even relationship issues.
Imagine being tucked into bed and just about asleep, when a sudden full-body muscle spasm wakes you up.
Called a hypnic jerk, most people experience it from time to time, and for healthy people it is only a momentary frustration.
Now imagine experiencing intense discomfort in your legs that comes on every night just as you are ready to relax and persists until you move your legs, chronically interfering with your sleep.
More than 5 million adults in the U.S. suffer from a moderate to severe form of those symptoms, which together are known as restless legs syndrome (RLS).
What Is RLS?
The National Institute of Neurological Disorders and Stroke defines RLS as “throbbing, pulling, creeping or other unpleasant sensations in the legs and an uncontrollable, and sometimes overwhelming, urge to move them.”
According to Sameh Aziz, MD, Pulmonary Medicine and Sleep Medicine specialist, these dysesthesias—unpleasant abnormal sensations—range in severity from irritating to painful.
“It’s a deep, unpleasant pain or tension, usually between the knee and ankle,” he said. “The patient usually describes cramping, tingling and a need to keep moving.”
Patients typically feel no discomfort during the day or when they are active. Their attempts to rest and sleep, however, are repeatedly frustrated by the onset of symptoms.
Because relief comes by moving, many sufferers eventually seek treatment at their partners’ urging.
“It’s not uncommon for the bed partner to complain,” said Dr. Aziz. “By the time they come for a sleep study, they are sleeping in separate beds.”
Causes
Causes of RLS can vary from heredity to iron deficiency. Research has shown that RLS patients often have a deficiency in dopamine, which may be caused by low production or over-metabolism of the dopamine in the brain.
RLS can be difficult to diagnose because there is no test for it and some symptoms present similarly to other illnesses. RLS is diagnosed through clinical observation and, if necessary, a sleep study.
“Periodic limb movement sometimes appears together with RLS, but RLS differs from other forms of muscle spasms," said Dr. Aziz. "It also overlaps with neuropathy, but those patients have more specific pain; they can’t stand for the covers to touch their leg or their feet to touch the bed.”
To screen patients for RLS, Dr. Aziz uses a mnemonic device: U.R.G.E.
“The patient feels an Urge, it is when he is at Rest, he feels compelled to Go, and onset is in the Evening,” he said.
Those four components form the basis of the clinical diagnosis.
Treatment
Although RLS is not progressive in nature, lower dopamine levels in the brain may worsen symptoms. As it interferes with sleep, a cycle of secondary symptoms develops:
- Fatigue
- Irritability
- Decreased motor function
- Cognitive impairment
- Suppressed immune response
The first-line treatment for RLS is usually iron supplementation, as iron deficiency is common among sufferers. A sleep study can identify patterns and sleep interruptions related to apnea that may be relieved by using a CPAP (continuous positive airway pressure) machine.
Because RLS is neurological in nature, its symptoms respond to medications developed for Parkinson’s disease and neuropathy. Clinicians also may prescribe anti-anxiety medications, which have a relaxing effect on the muscles.
These medications can have significant side effects, however, especially when used over long periods of time.
RLS symptoms often respond well to lifestyle changes. Dr. Aziz recommends making sure your physician is aware of all prescriptions, over-the-counter medicines and herbs that you take, as some can aggravate symptoms (for example, Benadryl and antidepressants). In addition:
- Eliminate caffeine altogether
- Minimize the use of alcohol
- Avoid all forms of tobacco
- Engage in light exercise prior to bedtime
- Take a warm shower prior to bed
If you suspect that you or your partner may have RLS, make an appointment with your primary care physician to rule out other underlying disease before referring you for a sleep study.
