Restless Legs Syndrome Risk, Prevention and Epidemiology

If I am diagnosed with RLS during pregnancy, what are my chances of having this condition permanently?

In most pregnant women with newly developed RLS, symptoms will resolve near the time of delivery. In a small minority, symptoms will persist after delivery, suggesting that the pregnancy might have triggered RLS in those who are genetically predisposed to develop this condition.

In those patients who have previously diagnosed RLS, symptoms may become worse during pregnancy but will improve after delivery; such patients may continue to have symptoms with the same frequency and intensity as noted prior to becoming pregnant.

I have chronic kidney problems. I have started experiencing symptoms of restlessness in the legs in the evening while I am lying in bed trying to get to sleep. Am I developing symptoms of RLS? How common is RLS in kidney failure?

Studies have generally found an increased frequency of RLS (20 to 50% or even higher) in patients with severe kidney failure or end-stage kidney disease, particularly those on dialysis (15 to 70%). There is an ethnic variation in this pattern: Patients from Northern Europe with severe kidney failure have a higher prevalence than similar patients from India and Japan.

The clinical features of RLS in patients with kidney failure are similar to those noted in patients with idiopathic RLS. Some studies, however, suggest that patients with severe kidney failure may have more severe RLS symptoms and more severe sleep disturbances than those with mild kidney failure. There is also a suggestion of increased frequency of deaths in those kidney failure patients who have RLS as compared to those who do not have RLS.

No specific factors have been identified to explain the high frequency of RLS in patients with kidney failure, although it has been suggested that anemia, iron deficiency, and peripheral nerve damage as a result of kidney failure may play roles.

It has not been determined whether aggressive treatment of iron deficiency in patients with severe kidney failure will decrease the severity of their symptoms as well as their morbidity and mortality. A sleep specialist with experience in RLS will be the best physician to answer questions about whether a person with kidney disease is developing RLS symptoms.

I am a 60-year-old man with Parkinson’s disease on levodopa treatment. Recently, I noticed an urge to move my legs while I am in bed trying to get to sleep. Am I developing RLS symptoms? How common is RLS in patients with Parkinson’s disease?

The relationship between RLS and Parkinson’s disease (PD) remains somewhat controversial. Both RLS and PD patients benefit from dopaminergic medications, although RLS patients need much lower doses of these medications compared to PD patients. In many respects, however, these two conditions are quite different.

Basal ganglia
Groups of nerve cells and connecting fibers and neurons located deep in the brain that control movements, gait, posture, and emotions.

Some brain neuroimaging studies show a very mild dysfunction of the basal ganglia (groups of nerve cells and connecting fibers and neurons located deep in the brain that control movements, gait, posture, and emotions); however, other studies have failed to find any such abnormalities.

In contrast, in PD patients, there is severe dysfunction of these structures with marked loss of neurons. In RLS patients, no such loss of neurons has been described. RLS patients show evidence of decreased iron storage in these structures, whereas PD patients exhibit increased iron accumulation.

Earlier studies showed no increased prevalence of RLS in PD. Some recent studies, however, have identified an increased prevalence of RLS in PD patients. It has been noted that most RLS symptoms in PD patients begin after treatment with dopaminergic medications, indicating that perhaps RLS may develop in these PD patients through a mechanism of augmentation.

There may be an increased prevalence of RLS in PD patients, but without further studies, it is not possible to draw any definitive conclusions at this stage. Your sleep doctor should be able to tell you whether you are developing symptoms of RLS, based on the essential RLS diagnostic criteria.

Does a patient with RLS develop Parkinson’s disease later in life?

At the present time, there is no evidence that a patient with RLS will develop PD later in life. Keep in mind, however, that PD and RLS are both fairly common disorders in later life, and sometimes the two conditions may exist together by chance.

To answer this question definitively, what is needed is a good epidemiologic study comparing a large number of ageand sexmatched control subjects and RLS and PD patients to show the prevalence of PD in RLS and determine how many RLS patients will later develop PD.

I suffer from rheumatoid arthritis. I experience pain and indescribable uncomfortable feelings in my legs in the evening while resting. A friend told me that I may have RLS. Is this true? How common is RLS in patients with rheumatoid arthritis?

Two early reports in the 1990s directed our attention to the possibility of increasing prevalence of RLS in patients with rheumatoid arthritis. There has been a resurgence of this hypothesis in recent literature, although contradictory reports on this possibility also exist. Overall, it is believed that there is an increasing prevalence of RLS in rheumatologic disorders including rheumatoid arthritis.

Nevertheless, it is important to differentiate RLS symptoms from the pain and discomfort associated with arthritis, as some of the symptoms of these two conditions may be similar. In patients with arthritis, the pain and discomfort are limited to the joints; this pain may become more intense in the evening, mimicking RLS. The pain and discomfort in RLS improve on walking. In contrast, in arthritis, the pain becomes worse when walking.

Furthermore, the uncomfortable feelings in RLS are limited not just to the joints but occur most commonly in the legs between the knees and ankles, although other body parts may be involved. Physicians taking care of patients suffering from rheumatologic disorders should be aware of the four essential diagnostic criteria for RLS so that they can effectively differentiate between RLS and arthritic conditions.

I am a 59-year-old man who has been experiencing restlessness of the whole body throughout the day. I cannot sit still; I keep moving all the time. I have been taking a neuroleptic medication for a “nervous breakdown.” My friend looked up my symptoms on the Internet and told me that I have RLS. Is this true?

RLS certainly needs to be considered in this scenario, although RLS symptoms—at least in the beginning—are not present throughout the day. RLS symptoms initially occur in the evening or are present exclusively in the evening; as the disease progresses into advanced stages, however, patients may have symptoms in the daytime.

Akathisia
A “subjective desire to be in constant motion” associated with “an inability to sit or stand still” and a “drive to pace up and down”[FDA definition].

In this case, the symptoms point to another condition that is often mistaken for RLS and that commonly occurs as a long-term side effect of neuroleptic medications— namely, akathisia (derived from the Greek word meaning “inability to sit”).

There are two essential features of akathisia: a subjective feeling of inner restlessness and an objective feature of motor restlessness, which is most commonly induced by neuroleptic (nerve-calming) medications. A U.S. Food and Drug Administration (FDA) Task Force defined akathisia as a “subjective desire to be in constant motion” associated with “an inability to sit or stand still” and a “drive to pace up and down.”

The inner feeling of restlessness or fidgetiness causes forced walking. As a result, a person with akathisia may have difficulty sitting still and may keep moving, crossing and uncrossing the legs, swaying and rocking back and forth, and constantly shifting body positions during sitting.

In akathisia, the whole body is in restless motion; in RLS, the urge to move while restless is limited to the legs. Another feature that differentiates akathisia from RLS is that the movements of restlessness in akathisia are present throughout the day but may become worse in the evening. There is no pattern of worsening or exclusive presentation of the symptoms in the evening, however—unlike that noted in RLS.

Finally, the movements in akathisia do not occur as a result of an urge to move preceded by discomfort, unlike that noted in RLS. The fundamental feature of RLS is presence or worsening of symptoms during inactivity or quiescence. In contrast, in akathisia, the movements are present not only during inactivity, but also while standing and walking, as if the whole body is in constant motion. Patients with akathisia also do not complain of uncomfortable or disagreeable sensations in the legs (except in rare cases).

The most important feature in this scenario is that the patient has been taking a neuroleptic medication, which is most likely causing the symptoms of restlessness rather than RLS. Therefore, it is unlikely that this patient has RLS. Note, however, that in advanced stages of RLS, some patients may complain of generalized restlessness involving the whole body without obtaining any significant relief from the movements, making it difficult to differentiate this type of RLS from akathisia. Such patients will have a prior history of characteristic symptoms fulfilling all the four essential criteria for RLS.

Neuroleptic: Nerve-calming medication.

I have RLS that is moderately controlled on medication. Will I have RLS all my life or does the medication cure the disease?

This very important question focuses on the course and natural history of RLS. RLS is generally considered a chronic disorder with a progressive course.

Although some patients will experience intermittent remissions of symptoms for weeks to months, overall the disease progresses over time. The course of the disease is usually more slowly progressive in those who develop symptoms at an earlier age (younger than 45 years) than in those persons whose symptoms first appear at a later age.

The patients presenting to the physicians at a later age generally experience a more rapid course, and the RLS is often associated with comorbid conditions that may have been responsible for or aggravated the RLS.

In the family history study conducted at Johns Hopkins University Hospital, more than 95% of those patients interviewed had the disease for an average of almost 20 years. It is important for the physicians caring for RLS to remember the chronicity of the condition and to appreciate that RLS is similar to some other chronic medical conditions, such as hypertension and diabetes mellitus, requiring monitoring and treatment throughout the patient’s entire life.

My 8-year-old child was diagnosed with “growing pains.” Is this a correct diagnosis or can he have RLS?

The diagnosis of growing pains in a child may be a problematic one, as some patients with the diagnosis of growing pains may actually be experiencing RLS symptoms.

A subgroup of patients have been diagnosed as having both conditions simultaneously. There is also a general misperception that RLS is an adult disease and does not occur in children.

Thus, even if the child does have characteristic symptoms of RLS fulfilling all four of the essential criteria, the condition may mistakenly be diagnosed as “growing pains.” Some of these patients may also be mistakenly diagnosed with attention-deficit/hyperactivity disorder (ADHD) because of fidgetiness.

Growing pains generally occur in early and late childhood and are characterized by pain that is often stabbing; this pain typically occurs before the child falls asleep or when he or she is waking up from sleep. It predominantly affects the thigh and the calf muscles.

As in RLS, these patients may obtain pain relief from massage or cold or warm baths. Growing pain symptoms are not relieved by movements. Parents should consult a pediatric neurologist or a sleep specialist to clarify whether their child truly has growing pains or is developing RLS symptoms.

My 6-year-old child is always fidgety and restless. Does he have attention-deficit/ hyperactivity disorder or can he have RLS?

Attention-deficit/hyperactivity disorder (ADHD) is characterized by fidgetiness and excessive motor restlessness, in addition to inattention and, in some patients, impulsivity. Any restlessness in a child is not necessarily ADHD; in fact, this condition is often diagnosed in error. Sometimes it is mistaken for RLS, or the true RLS symptoms are mistaken for ADHD.

The Diagnostic and Statistical Manual of Mental Disorders, revised fourth edition (DSM-IV-TR), published in 2000 by the American Psychiatric Association, listed diagnostic criteria for ADHD. These criteria include six or more symptoms of inattention or hyperactivity and/or impulsivity for at least six months, with the symptoms not being consistent with the developmental level of the child.

The symptoms are present before age seven years, and affected children show impairment in two or more settings (e.g., at home or at school). There is clear evidence of interference with the development of appropriate social, academic, or occupational functioning, and the disturbance is not explained by another mental disorder.

Restlessness, inattention, and hyperactivity in some RLS patients may resemble ADHD, and these symptoms may have been caused by chronic sleep deprivation in RLS. Therefore, whether these symptoms suggest an association between RLS and ADHD or are simply the result of chronic sleep disturbance remains to be determined.

Attention-deficit/HYPERACTIVITY disorder (ADHD)
A disorder characterized by fidgetiness, excessive motor restlessness, inattention, and (in some patients) impulsivity.

How do physicians diagnose RLS in children who may not be able to describe their symptoms adequately?

Children may not be able to describe RLS symptoms accurately. As a consequence, they are often misdiagnosed as having growing pains or ADHD. Children will describe the symptoms in their own language (e.g., childish language such as “ouch,” “owies,” or “boo-boos”); their inability to give an accurate description initially led researchers to believe that RLS did not occur in children.

Upon questioning, however, many adult RLS patients describe their symptoms as beginning in childhood and progressing very slowly over the years.

To address this problem, a National Institutes of Health (NIH) Workshop in 2002 established diagnostic criteria specifically for children between an arbitrary age limit of 2 to 12 years; these criteria were published in Sleep Medicine, an international journal dealing with clinical sleep disorders, in 2003.

The criteria for children include all of the adult essential diagnostic criteria plus description of the symptoms in children’s own words or the presence of two of the three supporting criteria of adults. Since these criteria were established for children, more children have been diagnosed with RLS, and there is a growing awareness that RLS is not especially rare in children.

In fact, a recent population-based epidemiological study called the Peds REST Study noted an RLS prevalence of 2% in children between the ages of 8 and 17 years. Reports have also identified an association between iron deficiency, anemia, and childhood RLS, just as in adult RLS populations.

My father, who is 69 years old, has been diagnosed with Alzheimer’s disease. Recently, I have noticed that in the evening when lying in bed, he moves his legs and tries to get up and walk. Are these symptoms due to the nighttime agitation commonly seen in Alzheimer’s disease or is he developing another movement disorder?

Nighttime agitation is very common in patients with Alzheimer’s disease (AD), particularly in the advanced stages of the illness. As evening approaches, these patients will often become very agitated and anxious and begin pacing up and down. These activities may continue throughout the night.

These features, which are part of what is called “sundowning” syndrome or nighttime agitation syndrome, cause severe sleep disturbances at night, often leaving patients sleepy throughout the day. Thus, this pattern represents a reversal of the normal sleep–wake rhythm.

Also, in the advanced stages of AD, some patients have hallucinations (i.e., seeing, hearing, or feeling things which do not exist) and experience vivid, agitated, and fearful dreams. The sundowning or nocturnal agitation syndrome is one of the main reasons for placement of patients with AD in nursing homes or special institutions.

Symptoms such as walking, getting out of bed, and moving would suggest that the patient may have something more than sundowning or hallucinations. Rubbing the legs, trying to get up and walk, and then coming back to bed again repeatedly, when these symptoms occur in cognitively impaired patients, may suggest an additional sleep disorder such as RLS.