diagnostic workup

Last reviewed 01/2018

Diagnosis of Restless legs syndrome (RLS) is based on the patient’s history and physical examination. Laboratory investigations may identify secondary causes of RLS (1).

The International Restless Legs Syndrome Study Group (IRLSSG) has proposed four essential criteria for the diagnosis of RLS.

  • an irresistible urge to move the legs which is usually accompanied or caused by uncomfortable, unpleasant sensations in the legs.
    • patients may describe the feeling as, “burning”, “creepy-crawly sensations,” “electrical currents”, or “cola in the veins.” (2,3)
    • whole leg or a part of the leg may be involved
    • shoulders, arms, and trunk may be affected as well (3)
  • the urge to move and unpleasant sensations may begin or exacerbate with rest or inactivity e.g. – when lying or sitting
  • the urge to move and unpleasant sensations may be relieved totally or partially with movement (or leg rubbing and hot/cold baths) (2,3)
  • the urge to move and unpleasant sensations are worse at evening or at night (2)

Diagnosis of the disease is supported by three clinical features

  • improvement of symptoms with the use of dopaminergic agents
  • Periodic limb movements during sleep (PLMS)
  • family history (2)

Associated features of the disease include

  • progressive clinical course (in majority)
  • sleep disturbances (2)

Laboratory investigations used in RLS are:

  • if the neurological examination suggests an associated peripheral neuropathy or radiculopathy, electromyography and nerve conduction studies should be undertaken to document these disorders (3)
  • blood tests
    • serum ferritin - restless legs syndrome is frequently associated with iron deficiency
    • thyroid, fasting glucose, B12, folate
  • polysomnography - can be used in severe RLS and insomnia (2)

Reference: