NB Hot Topics GP Update Blog

Restless Legs Syndrome

Restless legs syndrome is miserable for patients and (unlike most things we see!) easy to diagnose and treat. It is common (studies report adult prevalence ranging from 2% to 15%) and recent research suggests that restless legs may contribute in up to 22% of people with sleep problems in primary care.

► Just remind me what it is?

A neurological disorder characterised by an irresistible urge to move the limbs and associated with unpleasant sensations.

► How do we make the diagnosis?

Diagnostic criteria (all must be present) are:

· Overwhelming urge to move the legs, usually accompanied by uncomfortable sensations or pain

Symptoms start, or worsen, with rest or inactivity
Symptoms relieved by movement or other stimuli e.g. rubbing the legs
Symptoms worse in the evening
Legs always involved (but it may spread to affect other limbs)
Normal physical examination, including neurological and vascular

Other factors that support the diagnosis include

A positive family history
Frequent involuntary limb movements when asleep or awake

Patients can complete an internationally recognised RLS rating scale to confirm diagnosis and assess severity.

► What causes RLS?

in most people it is a primary idiopathic disorder; 50% have a family history suggesting a genetic basis
The 3 major causes of secondary RLS are:

Pregnancy (occurs in 20% of pregnant women, usually in the last trimester and usually resolves within a few weeks of delivery)
Iron deficiency (present in 25% of people with RLS)
Renal failure (CKD stage 5, occurs in 20% of people undergoing dialysis, often resolves after transplantation)

There are associations with a wide range of other conditions e.g.

Parkinson’s, Peripheral neuropathy, Hypothyroidism, Diabetes, Rheumatoid

Drugs can exacerbate it:

Antidepressants and lithium
Neuroleptics and sedating antihistamines
Dopamine blocking anti-emetics e.g. metoclopramide
Calcium channel blockers

What investigations should I do?

Serum ferritin in all patients

Treat with iron if <50mcg/ml

If renal failure or inflammatory disease, ferritin may of course be elevated in which case look at transferrin saturation (<20% suggests iron deficiency)

Consider renal function, FBC, TFTs, glucose and B12 guided by history and exam

What is the evidence for treatment?

There is evidence to support lifestyle changes in RLS including:

· Reducing caffeine and alcohol

· Taking regular aerobic exercise

· Regular massage therapy

For drug treatment, there is evidence to support the use of dopamine agonists for RLS Cochrane Review and also for levodopa for RLS Cochrane review

Because of the association with depleted iron stores, it is routine practice to recommend iron supplementation if the serum ferritin is low. However a recent iron supplementation in RLS Cochrane review failed to show evidence of benefit.

There seems to be a lack of evidence for physiotherapy, CBT and mindfulness but we would argue that all of these will be worth trying given their strong evidence-base in other chronic neurological conditions.

In summary, what approach should I take with my patient?

Œ Make the diagnosis…using diagnostic criteria above

Is it primary (family history?) or secondary (associated conditions or drugs)?

Ž Investigations

Check iron studies in all
Consider U and E, FBC, TSH, glucose, B12

Consider a treatment trial with iron if ferritin <50mcg/ml

Assess severity RLS rating scale

‘ Management

Review medication and stop/change exacerbating drugs

Mild RLS: advice and reassurance sufficient

Good sleep hygiene
Reduce caffeine and alcohol, stop smoking
Increase physical activity
Simple walking, stretching, relaxation exercises
Mental distraction techniques and massaging affected limbs

Moderate to severe RLS, consider drug treatment

Intermittent symptoms (<3 times per week), off-label levodopa taken when symptoms occur or are anticipated
If frequent or daily symptoms, dopamine agonist is treatment of choice (e.g. ropinirole, pramipexole are licensed for RLS, doses in the BNF). Warn patients regarding the risk of 'impulse control disorders' with these drugs, and best avoided if at risk e.g. current or past problems with behavioural or chemical addiction.
Gabapentin, taken regularly, is an option though it has less evidence to support it