Sleep Medicine 16 (2015) 897
Contents lists available at ScienceDirect
Sleep Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / s l e e p
Letter to the Editor Characterization of the painful restless legs syndrome To the Editor: Painful restless legs syndrome (RLS) has been reported 70 years ago by Ekbom [1]. Although it can affect more than half of RLS patients in some clinical series [2], this form of RLS has not been investigated until recently. We read with interest the article by Cho et al. [3] that reported a retrospective study characterizing clinically and polysomnographically painful versus non-painful RLS (38 versus 122 patients). The main conclusion was that painful RLS is a more severe form of RLS (based on RLS severity and quality of life scales, lower Ferritin levels, and depression, anxiety, and health scales). In addition, the mean periodic leg movements in sleep index (PLMI) and the frequency of the clinically significant PLMI (≥15 per hour) were lower in the painful RLS subgroup. We have two concerns about study by Cho et al. [3]. We were surprised that the authors completely overlooked a previous study about the clinical characterization of the painful versus non-painful RLS [4]. Based on an RLS clinical series (34 versus 22 patients) and a sample from the French RLS association (407 versus 327 subjects), this prior study already showed that painful RLS was a more severe form of RLS with frequent burning sensations and overall more intense sensory and affective descriptors [4]. Moreover, Cho et al. [3] did not mention anything about the treatments of the RLS patients in their study. This could have altered the PLMI results, specifically if the painful RLS patients received more treatment than the non-painful RLS patients. In summary, the study by Cho et al. [3] is the first one to characterize the polysomnographic features of painful RLS but a prospective study with untreated RLS patients is warranted to confirm their finding of a lower PLMI in painful RLS.
Conflict of interest The author does not have any conflict of interest.
http://dx.doi.org/10.1016/j.sleep.2015.04.008 1389-9457/© 2015 Elsevier B.V. All rights reserved.
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2015.04.008.
References [1] Ekbom KA. Restless legs: clinical study of hitherto overlooked disease in legs characterized by peculiar paresthesia (‘Anxietas tibiarum’), pain and weakness and occurring in two main forms, asthenia crurum paraesthetica and asthenia crurum dolorosa. Acta Med Scand 1945;158(Suppl.):1–123. [2] Karroum EG, Golmard JL, Leu-Semenescu S, et al. Sensations in restless legs syndrome. Sleep Med 2012;13:402–8. [3] Cho YW, Song ML, Earley CJ, et al. Prevalence and clinical characteristics of patients with restless legs syndrome with painful symptoms. Sleep Med 2015. Available from: http://dx.doi.org/doi:10.1016/j.sleep.2014.12.024. [4] Karroum EG, Golmard JL, Leu-Semenescu S, et al. Painful restless legs syndrome: a severe, burning form of the disease. Clin J Pain 2015;31(5):459–66. doi:10.1097/ AJP.0000000000000133.
Elias G. Karroum Department of Neurology, Southern Illinois University School of Medicine, PO Box 19643, Springfield, IL 62794-9643, USA Isabelle Arnulf * Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, Paris, France Pierre and Marie Curie University, Paris, France Brain and Spinal Cord Research Institute (CRICM)-UPMC/Inserm U1127/CNRS UMR7225, Paris, France * Address: Service des Pathologies du Sommeil, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Boulevard de l’Hôpital, 75651 Paris Cedex 13, France. Tel.: +33 1 42 16 77 02; fax: +33 1 42 16 77 00. E-mail address: [email protected] Available online 28 April 2015
Contents lists available at ScienceDirect
Sleep Medicine j o u r n a l h o m e p a g e : w w w. e l s e v i e r. c o m / l o c a t e / s l e e p
Letter to the Editor Characterization of the painful restless legs syndrome To the Editor: Painful restless legs syndrome (RLS) has been reported 70 years ago by Ekbom [1]. Although it can affect more than half of RLS patients in some clinical series [2], this form of RLS has not been investigated until recently. We read with interest the article by Cho et al. [3] that reported a retrospective study characterizing clinically and polysomnographically painful versus non-painful RLS (38 versus 122 patients). The main conclusion was that painful RLS is a more severe form of RLS (based on RLS severity and quality of life scales, lower Ferritin levels, and depression, anxiety, and health scales). In addition, the mean periodic leg movements in sleep index (PLMI) and the frequency of the clinically significant PLMI (≥15 per hour) were lower in the painful RLS subgroup. We have two concerns about study by Cho et al. [3]. We were surprised that the authors completely overlooked a previous study about the clinical characterization of the painful versus non-painful RLS [4]. Based on an RLS clinical series (34 versus 22 patients) and a sample from the French RLS association (407 versus 327 subjects), this prior study already showed that painful RLS was a more severe form of RLS with frequent burning sensations and overall more intense sensory and affective descriptors [4]. Moreover, Cho et al. [3] did not mention anything about the treatments of the RLS patients in their study. This could have altered the PLMI results, specifically if the painful RLS patients received more treatment than the non-painful RLS patients. In summary, the study by Cho et al. [3] is the first one to characterize the polysomnographic features of painful RLS but a prospective study with untreated RLS patients is warranted to confirm their finding of a lower PLMI in painful RLS.
Conflict of interest The author does not have any conflict of interest.
http://dx.doi.org/10.1016/j.sleep.2015.04.008 1389-9457/© 2015 Elsevier B.V. All rights reserved.
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: http://dx.doi.org/10.1016/j.sleep.2015.04.008.
References [1] Ekbom KA. Restless legs: clinical study of hitherto overlooked disease in legs characterized by peculiar paresthesia (‘Anxietas tibiarum’), pain and weakness and occurring in two main forms, asthenia crurum paraesthetica and asthenia crurum dolorosa. Acta Med Scand 1945;158(Suppl.):1–123. [2] Karroum EG, Golmard JL, Leu-Semenescu S, et al. Sensations in restless legs syndrome. Sleep Med 2012;13:402–8. [3] Cho YW, Song ML, Earley CJ, et al. Prevalence and clinical characteristics of patients with restless legs syndrome with painful symptoms. Sleep Med 2015. Available from: http://dx.doi.org/doi:10.1016/j.sleep.2014.12.024. [4] Karroum EG, Golmard JL, Leu-Semenescu S, et al. Painful restless legs syndrome: a severe, burning form of the disease. Clin J Pain 2015;31(5):459–66. doi:10.1097/ AJP.0000000000000133.
Elias G. Karroum Department of Neurology, Southern Illinois University School of Medicine, PO Box 19643, Springfield, IL 62794-9643, USA Isabelle Arnulf * Sleep Disorder Unit, Pitié-Salpêtrière University Hospital, Paris, France Pierre and Marie Curie University, Paris, France Brain and Spinal Cord Research Institute (CRICM)-UPMC/Inserm U1127/CNRS UMR7225, Paris, France * Address: Service des Pathologies du Sommeil, Groupe Hospitalier Pitié-Salpêtrière, 47-83 Boulevard de l’Hôpital, 75651 Paris Cedex 13, France. Tel.: +33 1 42 16 77 02; fax: +33 1 42 16 77 00. E-mail address: [email protected] Available online 28 April 2015
