Objectives: Augmentation of symptom severity is the main complication of dopaminergic treatment of restless legs syndrome (RLS). The current article reports on the considerations of augmentation that were made during a European Restless Legs Syndrome Study Group (EURLSSG)-sponsored Consensus Conference in April 2006 at the Max Planck Institute (MPI) in Munich, Germany, the conclusions of which were endorsed by the International RLS Study Group (IRLSSG) and the World Association of Sleep Medicine (WASM). The Consensus Conference sought to develop a better understanding of augmentation and generate a better operational definition for its clinical identification.

Design and methods: Current concepts of the pathophysiology, clinical features, and therapy of RLS augmentation were evaluated by subgroups who presented a summary of their findings for general consideration and discussion. Recent data indicating sensitivity and specificity of augmentation features for identification of augmentation were also evaluated. The diagnostic criteria of augmentation developed at the National Institutes of Health (NIH) conference in 2002 were reviewed in light of current data and theoretical understanding of augmentation. The diagnostic value and criteria for each of the accepted features of augmentation were considered by the group. A consensus was then developed for a revised statement of the diagnostic criteria for augmentation.

Results: Five major diagnostic features of augmentation were identified: usual time of RLS symptom onset each day, number of body parts with RLS symptoms, latency to symptoms at rest, severity of the symptoms when they occur, and effects of dopaminergic medication on symptoms. The quantitative data available relating the time of RLS onset and the presence of other features indicated optimal augmentation criteria of either a 4-h advance in usual starting time for RLS symptoms or a combination of the occurrence of other features. A paradoxical response to changes in medication dose also indicates augmentation. Clinical significance of augmentation is defined.

Conclusion: The Consensus Conference agreed upon new operational criteria for the clinical diagnosis of RLS augmentation: the MPI diagnostic criteria for augmentation. Areas needing further consideration for validating these criteria and for understanding the underlying biology of RLS augmentation are indicated.