drugs, drug induced RLS like anti-dopaminergics, hypoactivity of dopamine system, decreased connec- tion to dopamine receptors in basal ganglia4,10,11 im- plicate this hypothesis that dopamine system in- volvement may be the main cause. The diagnosis is clinical and the most important role in diagnosis is the history of uncomfortable feeling in limbs which oc- curs only at rest and is aggravated in evening and night time and is relieved by limb movement.1,11 Di- agnostic criteria published by IRLSG (International RLS Study Group) were shown in Table 1.12 Some laboratory studies are necessary for diagnosis com- pletion including renal function test, cell blood count, serum iron, ferritin and folic acid levels, EMG-NCV and polysomnography for periodic limb movement syndrome(PLMS).1,4,11 In recent years, questionnaire for diagnosis and severity determination of RLS has been established by Benoy and Kohnen which is a gold standard for the diagnosis and severity determi- nation. The questionnaire includes 10 questions while each question is rated between 0 and 4. Points be- tween 1 and 10 are considered mild, 11 to 20 as mod- erate, 21 to 30 as severe and 31 to 40 cas very se- vere.4,9,13,14 Differential diagnosis are peripheral neu- ron diseases such as painful peripheral neuropathy, vascular diseases such as peripheral vascular diseases, varicose and erythromelalgia, movement disorders such as akathisia, extra pyramidal tremor, etc.1,4,11 RLS treatment is based on two approaches including pharmacologic and non-pharmacologic. Non- pharmacologic approaches include treatment of the underlying causes like iron supplementary consump- Selenium in restless leg syndrome tion in iron deficient patients, kidney transplantation in uremic patients, drug induced RLS withdrawal, prevention of stimulating subject consumptions such nicotine, alcohol and caffeine. Also sleep hygiene has an important role in reduction of the disturbances.1,4,9 Pharmacologic approaches include dopaminergic drugs such as levodopa,9,15 pramipexole,9 ropin- rinol2,9,15 and pergolide,2,15 benzodiazepines,15 opioids such as propoxyphen subsulicylate,2 antiepileptics such as gabapentin,2 iron and folic acid.15 Selenium was discovered by Brezilus in 1814.16 In 1957, Foltz and Schwarz implicated that selenium is a rare essential element existing in dietary regimen and has a preventive role for the diseases.17 Body selenium concentration is related to its soil concentration.18,19 This concentration in some countries like United States of America is high and is low in China.20-22 In 1973, Rotrack and colleagues demonstrated the anti- oxidative role of selenium.15 Role of selenium as anti- oxidant and anti-inflammatory in reverse striatal do- pamine depletion23 and decrease in thyrosine hydrox- ylase activity were shown.24,25 Selenium is adminis- tered by two routes in selenium deficient patients in- cluding enteral and parenteral. Also it is prescribed as supplementary diet in pregnant or breast-feeding mothers.26 In advised doses, no side effects were re- ported. Even no intoxicated cases with doses up to 400 mg for prostate cancer prevention were shown.27-30 Be- cause of its safety, and anti-oxidative and dopaminer- gic promoting actions and dopaminergic agonist side effects, we were encouraged to establish this study to determine the effect of selenium in RLS treatment. Table1: Diagnostic criteria for RLS Essential criteria 1. An urge to move the legs usually accompanied by uncomfortable and unpleasant sensation in the legs. 2. The urge to move or unpleasant sensations to be begun or worsen during periods of rest or inactivity such as lying or sitting. 3. The urge to move or unpleasant sensations to be partially or totally relieved by movement such as walking or stretching at least as long as the activity continues. 4. The urge to move or unpleasant sensation to be worsen in the evening or night than during the day or only to be occurred in the evening or night. Supportive features 1. Positive family history 2. Positive response to dopaminergic therapy 3. Periodic limbs movements Associated features 1. Natural clinical course 2. Sleep disturbance 3. Medical evaluation/physical examination. WWW.ircmj.com Vol 14 January 2012 15