Restless legs syndrome
In medicine, restless legs syndrome is type of parasomia and is "a neurologic movement disorder of the limbs, often associated with a sleep complaint. Patients with RLS have a characteristic difficulty in trying to depict their symptoms; they may report sensations such as an almost irresistible urge to move the legs, which are not painful but are distinctly bothersome; this can lead to significant physical and emotional disability." 
Sleep may become disrupted, resulting in excessive daytime hypersomnolence. It may be a relatively common disorder; the U.S. National Institute for Neurological Disorders and Stroke estimates 12 million Americans have been diagnosed with it, but also considers it underdiagnosed.
When it was first described by Swedish neurologist Karl Ekbom he proposed that it was "mainly the result of accumulation of metabolites in the legs because of venous congestion. Peripheral nerve abnormalities also have been proposed, but no associated structural changes in nerve endings have been identified." Ekbom's first paper was in the 1940s, but descriptions go back to the 17th century.
"RLS also has been linked to dopaminergic or opiate abnormalities. Centrally acting dopamine receptor antagonists reactivate symptoms when given to patients with the syndrome. Results of single-photon emission computed tomography (SPECT) have suggested deficiency of dopamine D2 receptors. Sympathetic hyperactivity also has been implicated on the basis of observations that sympathetic nerve blockade relieves periodic limb movements of sleep and that alpha-adrenergic blockers improve symptoms of RLS. Studies also have suggested possible underactivity of the serotonin and gamma-aminobutyric acid (GABA) neurotransmitter systems.
Diagnosis and differential diagnosis
The minimum criteria for diagnosis, according to the 1995 International Legs Syndrome Study Group in 1995:
- A compelling urge to move the limbs, usually associated with paresthesias/dysesthesias
- Motor restlessness, as seen in activities such as floor pacing, tossing and turning in bed, and rubbing the legs
- Symptoms worse or exclusively present at rest (ie, lying, sitting) with variable and temporary relief on activity
- Circadian variation of symptoms, which are present in the evening and at night. Often, symptoms are relieved after 5:00 am. In more severe cases, symptoms can be present throughout the day without circadian variation.
Restless Legs Syndrome differs from nocturnal myoclonus syndrome in that in the latter condition the individual does not report adverse sensory stimuli and it is primarily a sleep-associated movement disorder."
Dopinamergic drugs effective against Parkinson's disease, such as levodopa with carbidopa, Pramipexole (Mirapex) and Ropinirole hydrochloride (Requip), have been approved. Benzodiazepines and opioid analgesics may help.
- Juan Latorre, William G. Irr (March 30, 2007), "Restless Legs Sysndrome", eMedicine
- Restless Legs Syndrome Fact Sheet, National Institute for Neurological Disorders and Stroke
- Ekbom KA (September 1960), "Restless legs syndrome", Neurology 10: 868-73.
- Anonymous (2015), Restless legs syndrome (English). Medical Subject Headings. U.S. National Library of Medicine.
- Scholz H, Trenkwalder C, Kohnen R, Riemann D, Kriston L, Hornyak M (2011). "Dopamine agonists for restless legs syndrome.". Cochrane Database Syst Rev 3: CD006009. DOI:10.1002/14651858.CD006009.pub2. PMID 21412893. Research Blogging.
- Lettieri CJ, Eliasson AH (January 2009). "Pneumatic compression devices are an effective therapy for restless legs syndrome: a prospective, randomized, double-blinded, sham-controlled trial". Chest 135 (1): 74–80. DOI:10.1378/chest.08-1665. PMID 19017878. Research Blogging.