What is restless legs syndrome?
Also known at Ekbom’s syndrome, restless leg syndrome is a common movement disorder of the nervous system where the legs feel as though they want to exercise or move when the body is trying to rest. The major complaint of sufferers is disruption of sleep and of relaxing activities such as watching television or reading a book. Prolonged car or plane travel can be difficult. It is frequently undiagnosed because people often don’t complain about it to their doctor. The diagnosis is made on the history — there is no special diagnostic test.
What are the symptoms?
There is an urge to move the legs on resting, particularly after retiring to bed. This urge is a response to unpleasant sensations in the legs, especially in the calves. The sensations are commonly and variously described as crawling, creeping, prickly, tingling, itching, contractions, burning, pulling or tugging, electric- or shocklike. However, sometimes patients are unable to describe the sensation or refer to it as simply a compulsion to move the legs. The problem can vary from a minor irritation to a severe disabling condition. In some patients the arms are affected in a similar way. The symptoms seem to be aggravated by warmth or heat. Most patients experience periodic jerking limb movements (also called nocturnal myoclonus) during sleep and sometimes while awake.
Who gets restless legs syndrome?
Anyone can get it and it is common. A Canadian study found 15% of people sampled reported “leg restlessness at bedtime”.
Its prevalence increases with age so it mainly affects elderly people. Women are more prone to get the problem and it is aggravated by pregnancy.
What is the cause?
The exact cause of primary restless leg syndrome is not clear but there appears to be a problem with the function of a chemical transmitting substance in the central nervous system. It is not related to exercise and does not appear to follow strenuous exercise.
What are the medical conditions that can cause it?
The symptoms have been found to be associated with iron deficiency, anaemia, kidney failure (uraemia), hypothyroidism and pregnancy. It is advisable to have iron studies done in sufferers. If low iron levels are found, treatment with iron and vitamin C tablets is recommended. If pregnancy is the cause, the symptoms usually cease within a few weeks of delivery. Patients with uraemia have been cured by kidney transplantation but not by dialysis. Certain drugs can also cause restless leg syndrome. These include antihistamines, antidepressants and the major tranquillisers used in psychiatry. Some drugs used to treat hypertension have also been implicated.
What are the risks or complications?
Restless leg syndrome is not a serious or life-threatening problem and there is no known complication. The disturbing effects are mainly social or psychological. Work, leisure and personal relationships can be undermined. In some instances, patients have become severely depressed.
What is the outlook?
Although it can be a distressing problem, that can come and go for years it usually responds well to treatment.
What is the treatment?
Self-help You may have found that something works for you so keep to that routine.
● Avoid any substances or factors that you know or suspect affect you.
● Use activities that can reduce symptoms, for example, a modest amount of walking before bedtime, massage or prescribed exercises (see figure). NB: getting out of bed and going for a walk or run does not seem to help.
● Good sleep hygiene, namely, regular sleeping hours, gradual relaxation at bedtime, avoidance of non-sleep activities in bed, eg, reading, eating.
● Diet. Follow a very healthy diet. Avoid caffeine drinks, smoking and alcohol.
● Try keeping the legs cooler than the body for sleeping.
● Exercises. A popular treatment is gentle stretching of the legs, particularly of the hamstring and calf muscles for at least five minutes before retiring. This can be done by using a wide crepe bandage, scarf or other length of material around the foot to stretch and then relax the legs (as in figure).
If the simple measures do not work, taking two paracetamol tablets and/or a small dose of a mild muscle relaxant which your doctor will recommend one hour before bedtime may be effective.
Although not much evidence, magnesium supplements before bed time provides positive results in our practice.
Avoid antihistamines and the major tranquillisers. Quinine, which is good for cramps, is usually unhelpful.