Restless legs syndrome, or RLS, is characterized by an uncontrollable urge to move the legs to relieve discomfort. It is more prevalent during rest and nighttime. Not all people with night leg spasms have RLS. If cramping also occurs, the cause may be the result of an electrolyte imbalance. The National Institute for Neurologic Disorders and Stroke reports that people with RLS commonly have involuntary leg movements during sleep that may occur every 10 to 60 seconds throughout the night. The biological cause of RLS has not been fully elucidated, but NINDS notes that studies have revealed that the central nervous system chemical messenger, dopamine and low iron levels play a role in RLS. RLS is treated with drugs that act similar to dopamine and/or by restoring iron levels. A 2008 review in the "Journal of American Academy of Nurse Practitioners" reports RLS affects between 5 and 10 percent of the general population.
Genetics
NINDS estimates that approximately 50 percent of people with RLS have family members with the disorder, suggesting genetics play a role in the syndrome. A 2006 review in the journal "Chest" reports that certain areas on chromosomes have been linked to RLS, but a specific gene has not been identified in familial studies. People with familial RLS usually develop symptoms before the age of 45.
Diseases
Diseases that are associated with an increased risk of RLS are end-stage renal disease, diabetes, Parkinson's disease, peripheral vascular disease, arthritis and peripheral neuropathy. A 2007 article in "Alternative Medicine Review" reports that up to 62 percent of patients with end-stage renal disease have RLS. A 2007 study in the journal "Sleep" reports that RLS was present in approximately 18 percent of type 2 diabetics. Obesity is also associated with an increased risk for RLS.
Drugs
NINDS reports that the anti-nausea drugs prochlorperazine and metoclopramide, the anti-seizure drugs phenytoin and droperidol, the antipsychotic drugs haloperidol and phenothiazine derivatives, and some cold and allergy medications intensify the symptoms of RLS. In people who are predisposed to RLS, alcohol, caffeine and nicotine aggravate the symptoms.
Iron Deficiency
People who are deficient in iron are prone to develop RLS. "Alternative Medicine Review" notes that in a study of people with iron deficiency, between 25 and 30 percent exhibit symptoms consistent with RLS. This study also reports that nearly 90 percent of pregnant women have inadequate iron intake and that between 11 and 27 percent develop RLS. Iron deficiency is also prevalent in the elderly, patients with end-stage kidney disease, children who have attention deficit hyperactivity disorder, and patients who have undergone trauma or surgery. In addition to iron deficiency, RLS is associated with folate and magnesium deficiency.
References
- PubMed; "Journal of the American Academy of Nurse Practitioners"; Recognition, Diagnosis and Treatment of Restless Legs Syndrome; J.E. Smith and J.M. Tolson; August 2008
- National Institute for Neurologic Disorders and Stroke: Restless Leg Syndrome Fact Sheet
- "Chest"; Restless Legs Syndrome: A Clinical Update; Charlene E. Gamaldo, M.D., Christopher J. Earley, M.B., B.Ch., Ph.D.; November 2006
- PubMed; "Sleep"; Association of Restless Legs Syndrome in Type 2 Diabetes; G. Merlino et al.; July 2007
- "Alternative Medicine Review"; Restless Leg Syndrome; Lyn Patrick, N.D.; 2007
