The Pilot Study of the Utilization of Suggested Immobilization Test (SIT) for Diagnostic Confirmation of Restless Leg Syndrome in Thai Population

The Suggested Immobilization Test (SIT) is a provocative test. RLS symptoms (urge to move the leg and leg paresthesia) are primarily observed during wakefulness, especially at rest, in the evening, and/or during the night. During the test, the patient remains in a bed (or a reclining chair), at a 45° angle with legs outstretched. Originally, the SIT only quantified leg motor activity. Since 2002, it also includes the assessment of leg discomfort, which is estimated by the patient every 5 min, on a 100-mm horizontal visual analogue scale. Leg movements are quantified using surface electromyography (EMG) from bilateral anterior tibialis muscles. Using these pathological thresholds, the clinical RLS/WED diagnosis is correctly predicted in 88% of subjects with a sensitivity of 82% and a specificity of 100%.