Restless Legs Syndrome

Restless legs syndrome (RLS) is a common (3-15% of the population) and sometimes very unpleasant problem in which people have uncontrollable urges to move their legs. If they do not move, they will begin to feel uncomfortable, painful or odd sensations in their legs, and sometimes also in other parts of the body. The restlessness may last for minutes or even hours. Movement affords people very temporary relief. The sensations are usually between the ankle and the knees, but they can also involve the thighs. If other parts of the body are involved it always makes us question the diagnosis.

The severity of the problem is highly variable, running from a mild annoyance to an incapacitating problem. In most people the symptoms are worse when sitting or at night, and often lead to loss of sleep. Not surprisingly many people feel of exhausted and irritable during the day.

With such enormous variations in the severity of the problem, and even the parts of the legs affected, it is highly likely that RLS is a symptom of a group of illnesses.

The International Restless Legs Syndrome Study Group (IRLSSG) identified four criteria that must be present for an RLS diagnosis:

1. An urge to move, usually due to uncomfortable sensations that occur primarily in the legs.
2. Motor restlessness, expressed as activity, that relieves the urge to move.
3. Worsening of symptoms by relaxation.
4. Variability over the course of the day-night cycle, with symptoms worse in the evening and early in the night.

About 80% of the people with restless legs syndrome also suffer from a separate condition called periodic limb movements in sleep (PLMS). Periodic limb movements in sleep are involuntary jerking movements in extremities, usually the legs. You can have PLMS without having RLS, and vice versa.

RLS may start at any age, including early childhood, and is a progressive disease for a certain percentage of sufferers, although it has been known for the symptoms to disappear permanently in some sufferers. The condition runs in families; children of RLS sufferers are more likely than other people to develop RLS.

It has some similarities to a syndrome known as akathisia that occurs in people taking some medications that work in the dopamine pathways of the brain. There are some subtle ways of telling the two apart, but RLS also seems to be caused by disturbances in one of the dopamine pathways of the brain.

It has been known for many years that there is an association between RLS and iron deficiency, but this link is probably not causal: just giving iron only helps a proportion of sufferers. But because of this link, everyone with RLS should have their ferritin levels tested; ferritin levels should be at least 75 mcg for those with RLS. If it’s below this level, iron supplements may help, but they are best administered by a physician, because ferritin needs to be monitored and there are down sides to taking too much iron. In a moment I'll tell you about some very new research on iron and RLS

Caffeine and other stimulants usually make RLS worse. Restless legs syndrome frequently occurs during pregnancy. About 15% of pregnant women develop RLS symptoms during the last few months of their pregnancy. The sensations usually stop after the woman delivers the baby.

We normally divide RLS into primary and secondary. Primary RLS usually starts before age 40 and the onset is often slow. The RLS may disappear for months, or even years. But it can be progressive and get worse as the person ages.

Secondary RLS often had a sudden onset and may be daily from the very beginning. Apart from pregnancy, secondary RLS is a result of a number of medical conditions, so it is always important to rule them out. They include:

1. Iron deficiency anemia
2. Macrocytic anemia due to folate or vitamin B12 deficiency
3. Diabetes mellitus
4. Peripheral neuropathy
5. Alcohol abuse
6. Some types of cancer, particularly of the lung
7. Celiac disease
8. Renal failure
9. Inflammatory arthritis

There have been reports of associations of RLS with other illnesses, but most seem rare. Interestingly people who undergo surgery often find that RLS symptoms become worse, which may be another clue as to the cause of the problem.

An international conference entitled SLEEP 2006, the 20th Anniversary Meeting of the Associated Professional Sleep Societies took place from June 17-22, 2006 in Salt Lake City, Utah. There were a great many interesting papers this year, including several on RLS

An international group of collaborators presented the results of the first population-based pediatric RLS survey. They used the National Institutes of Health pediatric RLS diagnostic criteria and collected data from over 10,000 families. The criteria for definite RLS were met in 1.9% of 8- to 11-year-olds and in 2% of 12- to 17-year-olds. Two different papers explored the value of using a single screening question to identify possible RLS patients. Those who answered, “Yes,” then answered more detailed questions to determine whether they met the International RLS Study Group diagnostic criteria.

A single screening question can eliminate people without RLS rapidly and direct appropriate subjects to further evaluation. Two groups of researchers found a high level of sensitivity with the question, "When you try to relax in the evening or sleep at night, do you ever have unpleasant, restless feelings that can be relieved by walking or movement?"

As I mentioned, it has been known for decades that RLS may be associated with low iron, and especially with low ferritin levels. These may be present in symptomatic RLS patients during pregnancy and in people with iron-deficiency anemia and end-stage renal disease. Previous studies had suggested that supplemental iron was beneficial for RLS patients with low ferritin levels. One paper presented further evidence of the possible efficacy of supplemental iron in the treatment of selected RLS patients with a prospective, randomized, placebo-controlled, double-blind study of RLS patients with low to normal ferritin levels (15-75 mcg/L). The RLS subjects were given either placebo or iron 325 mg twice daily and were monitored with a validated RLS symptom scale. The preliminary findings showed that the iron supplementation group had significant increases in their ferritin levels and had improved quality of life compared with those on placebo; however, the interim data presented did not show a significant change in the RLS symptom score. The study is ongoing.

Treatment for RLS is based on how disruptive the symptoms are. Apart from iron, people should review their lifestyle and see what changes could be made to reduce or eliminate their RLS symptoms. These include: Finding the right level of exercise (too much worsens it, too little may trigger it)
Eliminating caffeine
Stopping smoking
Reducing alcohol intake

Several drugs have been tried for RLS: Some of the same medications used in Parkinson's disease, benzodiazepines, anticonvulsants like carbamazepine and gabapentin.

Last month saw the publication of an important paper indicating that the medicine pramipexole, another anti-Parkinsonan drug, helps many people with RLS

In the next article I shall review some of the other approaches used by Integrated Medicine.

Comments

[SUGAR]

Very good information Doc. I saw your blog listed on typepad while I was about to do some of my own work and decided I'd take a look. I'll tell my friends to check you out. Have a great conference!!

[Richard Petty]

I'm delighted that you found it useful!

Kind regards,

RP