Validation of the “L-DOPA test” for diagnosis of restless legs syndrome

✍ Scribed by Karin Stiasny-Kolster; Ralf Kohnen; Jens Carsten Möller; Claudia Trenkwalder; Wolfgang H. Oertel

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 104 KB
• Volume: 21
• Category: Article
• ISSN: 0885-3185
• DOI: 10.1002/mds.20969

✦ Synopsis

Abstract

We developed and validated a standardized test procedure to evaluate the accuracy of the supportive diagnostic criterion “response to dopaminergic treatment” in restless legs syndrome (RLS). Forty‐eight patients who fulfilled at least three of the four essential criteria for RLS, thus including uncertain clinical cases for a nonexpert, were recruited. Patients received a preliminary diagnosis of RLS or non‐RLS. All patients underwent a polysomnography (PSG) and were then asked to perform the diagnostic L‐DOPA test at home, which consisted in the application of one single dose of 100/25 mg L‐DOPA/benserazide and a subsequent observational period of 2 hours. Before, and in 15‐minute intervals after, drug intake, the patients rated the severity of the “symptoms in the legs” and the “urge to move the legs” using a 100‐mm visual analogue scale. Considering a 50% improvement as a positive test result, we found a sensitivity of 88% (“symptoms in the legs”) and 80% (“urge to move the legs”) with a specificity of 100% for both test items. A rate of 90% or 83% of all patients could be correctly diagnosed by the L‐DOPA test. Both scales were able to predict the response to dopaminergic agents in the subsequent course of the treatment by 100%. The periodic leg movements arousal index as assessed by polysomnography was less appropriate for the prediction of the correct diagnosis. We recommend the L‐DOPA test for diagnostic decision making in all patients with an unclear RLS diagnosis according to the essential diagnostic criteria of the International RLS Study Group. © 2006 Movement Disorder Society