1225 A Case of Phantom Restless Legs Syndrome in a Patient with Unilateral Amputation - Response to Pregabalin

Abstract

Introduction: We report a unique case of restless legs syndrome (RLS) in a phantom limb treated with pregabalin. Report of Case: The patient was a 61 year old woman with a history of RLS whose left leg was amputated due to complications of post-polio syndrome. After amputation, symptoms of RLS persisted in the phantom limb. She reported an urge to move the phantom limb, as well as the remaining limb, that was worse in the evening. When she imagined, or “pretended,” moving the distal (and missing) part of the amputated limb, symptoms subsided. A sleep study obtained after amputation revealed an elevated periodic limb movement index (PLMI) of 24.8 including recording from the muscles of the amputated limb stump. The patient was prescribed pregabalin 75 mg nightly and noted significant improvement in symptoms with the International RLS Study Group (IRLSSG) scale falling from pre-treatment score 27 to a score of 20 with therapy within weeks. We found only 5 prior published case studies of RLS in phantom limbs. The fact that our case had symptoms prior to amputation, makes it more likely that it represents a mechanism related to RLS rather than a pain syndrome triggered by amputation. All prior cases were treated with dopaminergic agonists and a proposed mechanism for the phantom RLS was dysfunction of central dopaminergic systems1. Our case suggests that pregabalin can be a viable option for patients with Phantom RLS. Conclusion: RLS may persist after amputation of the limb, which further supports the central mechanism of restless leg syndrome. Pregabalin should be considered as a potential therapeutic option especially in patients with comorbid sleep disturbance and pain, or in patients at risk for augmentation of RLS symptoms.