Restless legs syndrome

Restless legs syndrome (RLS) is a neurological condition which causes sensations of restlessness in the legs (and sometimes in the arms) during relaxation in the evening or when trying to get to sleep. Patients with RLS often describe the symptoms as being uncomfortable, irritating, or a 'creepy-crawly' feeling, and find it essential to move their limbs in order to obtain relief.

Restless legs syndrome affects 5-10% of the population.

The main features of RLS are:

  • An irresistible urge to the move the legs, often associated with numbness or uncomfortable feelings in the legs (sometimes described as a 'creepy-crawly' sensation or like 'ants marching')
  • Abnormal movement of the legs (even when trying to keep them still)
  • The symptoms are partially or temporarily relieved by moving the legs (usually by rubbing the legs, tossing and turning in bed, stretching and kicking legs, walking or pacing the floor until symptoms settle)
  • Symptoms are worse in the evening and during the night, especially when relaxing (such as watching television or reading) and when lying in bed trying to sleep.

Restless Legs Syndrome may start at any age (even in childhood), however it is most pronounced in adults. It often runs in families. Restless Legs Syndrome in children is often misdiagnosed as growing pains or attention-deficit/hyperactivity disorder (ADHD). The clinical course of RLS fluctuates with time, however it tends to worsen with age. Although RLS most commonly causes symptoms in the legs, the arms can also be affected in severe cases.

In addition to feelings of restlessness and discomfort, around 95% of patients with RLS experience some degree of sleep disturbance, usually in the form of difficulties in initiating and maintaining sleep. Furthermore, 80-90% of patients with RLS have another, similar condition called Periodic Limb Movement Disorder (PLMD), where the legs move involuntarily during sleep, causing sleep fragmentation and daytime tiredness.

RLS often contributes to symptoms of depression and anxiety, particularly when marked sleep-deprivation and sleep-disruption occur.

Causes of Restless Legs Syndrome

The precise cause of RLS is unknown, and is most likely multi-factorial.

There is evidence that dysfunction of a neurotransmitter (a chemical that helps cells in the nervous system communicate with each other) called dopamine may contribute to RLS. 50-65% of RLS cases are genetic.

RLS may also be secondary to other medical conditions including:

  • Nerve damage
  • Kidney failure
  • Iron deficiency
  • Rheumatoid arthritis
  • Diabetes
  • Pregnancy

Diagnosis

The diagnosis of RLS is made clinically, that is, you are diagnosed based on your description of your symptoms. Although an overnight sleep-study is not used to diagnose RLS directly, it is very helpful to measure how long you are awake during the night, and how much sleep-onset delay and sleep-fragmentation occur. However, an overnight sleep-study is the only way to diagnose PLMD, which frequently occurs in combination with RLS.

Treatment

There are several classes of medication which are effective in treating RLS (and which are also used to treat PLMD). These medications treat the symptoms of RLS, and not the underlying cause. Consequently, they must be taken every evening before bed, otherwise the symptoms will return.

Medications which may be prescribed for you include dopaminergic medications, opioids, anticonvulsants and benzodiazepines). Your General Practitioner or Sleep Physician can advise you on what class of medication is most suitable for you.

Non-pharmacological treatments for RLS should be used in conjunction with pharmacologic ones. If you have RLS, you should:

  • Maintain good sleep hygiene, having regular bed times and rising times
  • Ensure that you achieve at least 7 hours of sleep per night
  • Avoid being sleep-deprived, as this can exacerbate RLS and PLMD
  • Avoid caffeine, alcohol, nicotine and heavy meals before retiring to bed
  • Perform moderate physical activity during the day (such as brisk walking)
  • Avoid excessive physical exercise before bed-time, as this tends to make RLS and PLMD worse