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