Polysomnographic evaluation of augmentation in patients with restless legs syndrome

Abstract

Introduction Augmentation represents nowadays one of the most important issues in the long term treatment of restless legs syndrome. To the best of our knowledge, no polysomnographic study has been performed in this clinical condition. Materials and methods Twenty-one consecutive RLS outpatients (8M, 13F, mean age 68.4 ± 8 yrs) treated with dopamine agonists for a mean period of 6.7 ± 5 yrs and diagnosed as affected by severe, clinically relevant augmentation underwent a complete clinical evaluation and video PSG. We compared polysomnographic and clinical characteristics of patients with periodic limb movements during sleep during augmentation (PLMS+) and without (PLMS−) using a PLMS index >15 as cut-off. Results During augmentation, sleep efficiency was reduced (mean 63.13 ± 21.7%, range 15–95), with values Conclusion Our observation showed that more than half of the patients with augmentation showed an increased motor activity during sleep that could be related to an imbalance of the expression of dopamine D1-like and D2-like receptors during DA treatment. Moreover, we confirm the clinical observation of reduction of sleep duration during augmentation. That should not be underevaluated since it has been hypothesized that sleep deprivation can worsen or elicit augmentation and possibly enhance PLMS in a kind of vicious circle. Acknowledgement The authors thankfully acknowledge Stephany Fulda for their valuable help in conducting this study.