What is restless legs syndrome?, It’s an irresistible and involuntary need to move the legs, a debilitating and surprisingly common disorder that causes considerable discomfort to sufferers during the waking hours and almost always results in long sleepless nights, in turn causing a soul-destroying weariness that can play havoc with work, social activities and general well-being.

How common is RLS?

RLS is a surprisingly common disorder. In the US up to 8% of the population may suffer from the condition. Recent evidence suggests that nearly 6% of men in Sweden have the disorder. Similar data is not yet available for the UK. Available evidence suggests that at least in European and US population of European extraction RLS may be the most common of the movement disorders. There is currently no data availale on the prevalence of RLS in other ethnic groups. Many people may have a mild form of RLS, but in about 20% symptoms may be severe and disabling and may merit specialist treatment.

If doctors knew exactly what RLS is they’d be well on their way to finding a universal cure. For the moment they describe Restless Legs Syndrome as a sensorimotor disorder – which mean it has something to do with the nervous system and involuntary movements initiated by the nervous system – and recognise that it may cause considerable discomfort in patients in the waking hours and may have a profound impact on sleep. In severe cases the associated sleep deficit may have a detrimental effect on daytime work, social activities and general well being. In the worst cases sleep deprivation and the inability to tolerate certain activities (such as sitting for long periods at a desk) can lead to job loss, and relationship problems. Most commonly the legs alone are affected but the upper limbs may also be involved. Complicating the issue is the fact that RLS isn’t the only condition that can cause legs to twitch or shake. For instance leg cramps, pain in the legs due to arthritis or simply positional discomfort may mimic some of the symptoms of RLS.

What causes RLS?

To put it bluntly, the cause of this extraordinary complaint is simply not known. There is evidence to show that it runs in families, so it is possibly a genetic condition. A DNA scan of a large French-Canadian family showed a significant linkage on one chromosome, providing real evidence that a gene could confer susceptibility to RLS. Since then additional links have been found of two other chromosomes. Recent work suggest that RLS may be common in people suffering from Parkinson’s disease, though it also seems that suffering from RLS does not increase the risk of developing Parkinson’s disease.