Facts on RLS
Restless Legs Syndrome
RLS is a neurological sensory-motor disorder defined by an urge to move the legs accompanied by leg discomfort.
Even though RLS is common, it is still a highly underdiagnosed neurologic movement disorder. Some physicians wrongly attribute the symptoms to nervousness, insomnia, stress, arthritis, muscle cramps or aging.
Study results from the last decade indicate a prevalence rate between 5-15 percent. The prevalence of clinically significant RLS is around 3 percent.
RLS sensations are often described as a burning, creeping or tugging feeling or like having insects crawling inside the legs. It is present at rest and generally relieved by movement. The symptoms vary during the day, but in general they are most prominent in the evening or during the night. As a result, most people with RLS have difficulties falling asleep and staying asleep. If untreated, the condition may cause exhaustion and daytime fatigue.
Often called paresthesias (abnormal sensations) or dysesthesias (unpleasant abnormal sensations), the sensations of RLS range in severity from uncomfortable to irritating to painful.
Some people with RLS will not seek medical attention, because they are afraid not be taken seriously, that their symptoms are too mild, or that their condition is not treatable.
Causes of RLS
RLS is commonly divided in two different groups; primary RLS, where no causative factor except a possible genetic disposition can be found; and secondary RLS.
A family record of the condition is seen in more than 50 percent of the cases. People with familial RLS tend to be younger when the symptoms start and have a slow progression of the condition.
Secondary RLS can be traced back to:
- Anemia or low iron levels. If iron levels or anemia is corrected, patients may experience a reduction in symptoms.
- Chronic diseases such as kidney failure, diabetes and peripheral neuropathy. Treating the underlying condition often provides relief from RLS symptoms.
- Pregnancy, especially in the last trimester. Symptoms usually disappear within 4 weeks after delivery.
- Certain medications – such as antinausea drugs (prochlorperazine or metoclopramide), certain antidepressants, some antiseizure drugs, antipsychotic drugs (haloperidol or phenothiazine derivatives) and antihistamines – may aggravate symptoms. Patients can talk to their physicians about the possibility of changing medications.
- Alcohol, tobacco, tea, coffee and other beverages containing caffeine may aggravate or trigger symptoms in patients who are predisposed to develop RLS.
Some studies have shown that a reduction or a complete elimination of the mentioned substances and medications may relieve symptoms, although it remains unclear whether elimination of the substances and medications can prevent RLS symptoms from occurring at all.
Gender
RLS occurs in both genders, although the incidence is higher in women.
Age
The syndrome may appear at any age, even as early as infancy. Among children RLS is often regarded as growing pains. However, most patients who are severely affected are middle-aged or older. The disorder appears to increase in severity with age.
Periodic Limb Movement Disorder (PLMD)
More than 80 percent of people suffering from RLS also have periodic limb movement (PLM) during sleep.
PLM is characterized by involuntary leg twitching or jerking movements during sleep, which typically occur every 5 to 90 seconds and sometimes throughout the night.
The PLM causes repeated awakening and severely disrupted sleep. Unlike the other features of RLS, the PLM are involuntary – meaning people have no control over them.
People with PLM do not necessarily have RLS.