Restless legs syndrome

Pathophysiology

 

  • Poorly understood
  • Reduced basal ganglia iron is the most consistent neural correlate
  • Symptoms can improve with dopaminergic medications

Epidemiology

  • Family history in 50%, high twin concordance
  • Other risk factors include iron deficiency, uraemia and chronic kidney disease, pregnancy and peripheral neuropathy

Symptoms

  • Unpleasant urge to move the legs
  • Description often subjective and variable
  • Worse during inactivity in the evenings
  • Made worse with diphenhydramine (often taken to help with sleep)
  • Relieved by movement
  • Characteristic limb movements during sleep, which can be associated with waking.

On examination

Diagnosis

Differential:

  • Hypnic myoclonic jerks
  • Akathisia (associated with neuroleptics)
  • Cramps
  • Vascular insufficiency

Tests:

  • FBC & Fe studies – to assess iron
  • U&E – to assess uraemia

Diagnosis is clinical.

Treatments

  • Spontaneous remission in at least 30%
  • Iron replacement not supported by meta-analyses of randomised trials
  • Good sleep hygiene
  • Dopamine agonists show best response in chronic sufferers
    • Pramipexole and Ropinirole have both shown superiority over placebo
  • Pregabalin has also been shown to be superior to placebo