Restless leg syndrome

What is restless legs syndrome?

Restless legs syndrome (RLS), also called Wittmack-Ekbom syndrome or Willis-Ekbom disease, is a rather common type of neurological disorder. Approximately 5-10% of the German population suffers from RLS, although only 20% of those affected experience symptoms so severe that treatment is necessary. Females are twice as likely to suffer from this disorder as males.

Restless legs syndrome is the "disease involving uneasy legs". Depending on how severe the syndrome is, patients may suffer in a different way. RLS is characterized by a strong urge to move, especially in the legs and mainly at rest, that can be eased by movement. Symptoms are especially prominent in the evening and at night.

A problem with this condition is that outsiders find it difficult to appreciate the patient's distress. In addition, patients usually do not perceive the restlessness and the urge to move as symptoms of the disease. They are more concerned with the consequences, like sleep disturbances, lack of relaxation and reduced performance. Patients with marked signs of the disease tend to avoid all situations in which they must sit still for a long time, like going to the theater, flying or meetings, so their social life an become seriously restricted.

Which symptoms are associated with restless legs syndrome?

RLS patients have an increased urge to move their legs (and in some cases their arms as well), which in about 88% of cases is perceived as an unpleasant feeling. Among these are tingling, pulling, stabbing or cramp-like pain in the affected limbs. Patients often find it difficult to express their symptoms in words.

An urge to move is defined as an unpleasant, agonizing sensation of restlessness, strain or tenderness of the body parts, usually localized deeply and only relieved by movement. The symptoms usually appear when resting the body, i.e. mostly in the evening and at night.

In 80% of patients, so-called "periodic limb movements" (PLM) can be detected in the sleep laboratory (by means of polysomnography). PLMs are repetitive twitching movements of the legs that may last from minutes to hours. RLS is highly stressful for the affected person, particularly due to the consequences of the symptoms. They suffer from sleep disturbances, a drop in performance and a reduced quality of life. Due to the chronic fatigue, the chance of accidents in the household or in traffic is increased.

On average, the symptoms occur before the age of 30. Because the condition usually worsens chronically over the years, patients typically need treatment between 50 and 60 years of age. The severity of the disease can vary greatly, and intervals without symptoms are also possible.

How does RLS develop?

The precise cause of this disorder remains unknown to this day. However, it is thought to be partly caused by defects in the transmission of signals along the nerve pathways. Idiopathic and symptomatic forms of this disease can be distinguished. In idiopathic RLS, there is no known triggering cause. In symptomatic RLS, the syndrome is brought on by another underlying disease, for example, severe renal insufficiency, thyroid disorders, pregnancy, iron deficiency or medications ( particularly certain antidepressants).

Over half of the patients have relatives who suffer from RLS (positive family history). By now, a few genetic risk factors are known, for which there is a high incidence in patients with the disease. However, restless legs syndrome is a complex genetic disease if it runs in families, so not just one single gene leads to the development of the syndrome.

How is restless legs syndrome diagnosed?

The diagnosis of RLS is a "clinical diagnosis." In other words, there are no technical tests required to diagnose the condition. In order to confirm the finding, a thorough and specific patient interview is crucial. Diagnosis of RLS can be difficult since it is based on subjective information reported by patients who may not perceive their strong urge to move as an important sign of the disease. Patients rather tend to complain about the sleep disturbances. Besides a precise interview, it is necessary to undergo a neurological examination, which is usually normal, and a blood test.

As there are some primary diseases which lead to RLS, these must be considered when diagnosing the syndrome. For instance, RLS is often associated with iron deficiency, uremia (due to renal insufficiency), polyneuropathy (nerve disorders), depression and anxiety disorders. Restless legs syndrome can also also develop as a side effect of certain medications. During pregnancy, likely caused in part by iron deficiency, approximately 1 in 3 - 4 women develop this condition. However, after childbirth the symptoms usually improve until they are no longer present.

Already in childhood, some signs of RLS can be observed. However, false diagnoses are unfortunately very common ("hyperactive child").

Restless legs syndrome - What is helpful?

The decision to treat the disease is made according to the degree of distress and the severity of the urge to move and sleep disturbances. Mild forms can be managed with massages, footbaths, squats or by avoiding factors that exacerbate RLS (e.g. coffee, alcohol, heat, strenuous physical exertion, stress).

Therapy for RLS purely treats the symptoms. The cause of the disease itself cannot be treated. Therefore, so-called dopaminergic drugs (e.g. L-dopa, dopamine agonists) are the main focus of therapy. These drugs modulate the amount of dopamine (a signal agent of the nerve pathways) in the patient's brain and hence can reduce their urge to move. The dose of medication is set individually for each patient. Reported side effects of dopamine agonists include nausea, lightheadedness and dizziness. Some patients may develop an addictive behavior (binge eating, extravagance, increased libido, gambling, etc.). All these potential side effects should be discussed in advance with the patient.

The most important complication of RLS treatment is the so-called "augmentation". This is when the body becomes "accustomed" to the dopaminergic drug, which means that the symptoms of the disease return earlier after taking the drug and can even intensify. The main factor determining whether augmentation develops is the dose of the medication taken by the patient each day.

Today, RLS patients can receive a great deal of support, for example in support groups. In case you have any of the symptoms mentioned above or if you have any further questions about RLS, please feel free to contact one of our neurologists or sleep physicians (somnologists).