title: World Association of Sleep Medicine (WASM) 2016 standards for recording and scoring leg movements in polysomnograms developed by a joint task force from the International and the European Restless Legs Syndrome Study Groups (IRLSSG and EURLSSG).
abstract: This report presents the results of the work by a joint task force of the International and European Restless Legs Syndrome Study Groups and World Association of Sleep Medicine that revised and updated the current standards for recording and scoring leg movements (LM) in polysomnographic recordings (PSG). First, the background of the decisions made and the explanations of the new rules are reported and then specific standard rules are presented for recording, detecting, scoring and reporting LM activity in PSG. Each standard rule has been classified with a level of evidence. At the end of the paper, Appendix 1 provides algorithms to aid implementation of these new standards in software tools. There are two main changes introduced by these new rules: 1) Candidate LM (CLM), are any monolateral LM 0.5-10 s long or bilateral LM 0.5-15 s long; 2) periodic LM (PLM) are now defined by runs of at least four consecutive CLM with an intermovement interval ≥10 and ≤ 90 s without any CLM preceded by an interval <10 s interrupting the PLM series. There are also new options defining CLM associated with respiratory events. The PLM rate may now first be determined for all CLM not excluding any related to respiration (providing a consistent number across studies regardless of the rules used to define association with respiration) and, subsequently, the PLM rate should also be calculated without considering the respiratory related events. Finally, special considerations for pediatric studies are provided. The expert visual scoringof LM has only been altered by the new standards to require accepting all LM > 0.5 s regardless of duration, otherwise the technician scores the LM as for the old standards. There is a new criterion for the morphology of LM that applies only to computerized LM detection to better match expert visual detection. Available automatic scoring programs will incorporate all the new rules so that the new standards should reduce technician burden for scoring PLMS.
authors.affiliation: Sleep Research Centre, Department of Neurology I.C., Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS), Troina, Italy. Electronic address: rferri@oasi.en.it.
authors.forename: R
authors.initials: R
authors.lastname: Ferri
authors.affiliation: Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital (EOC) of Lugano, Lugano, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Fulda
authors.affiliation: Center for Restless Legs Study, Department of Neurology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: R P
authors.initials: RP
authors.lastname: Allen
authors.affiliation: Sleep Disorders Center, Department of Neurology, Scientific Institute and University Ospedale San Raffaele, Vita-Salute University, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Zucconi
authors.affiliation: Department of Social and Developmental Psychology, Sapienza University, Rome, Italy.
authors.forename: O
authors.initials: O
authors.lastname: Bruni
authors.affiliation: JFK New Jersey Neuroscience Institute, 65 James Street, Edison, NJ, USA.
authors.forename: S
authors.initials: S
authors.lastname: Chokroverty
authors.affiliation: Sleep Disorders Center, Department of Neurology, Scientific Institute and University Ospedale San Raffaele, Vita-Salute University, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Ferini-Strambi
authors.affiliation: Montreal Neurological Institute and Hospital, McGill University, Montreal Canada and Department of Medicine and Center for Neuroscience Studies, Queen's University, Kingston, Canada.
authors.forename: B
authors.initials: B
authors.lastname: Frauscher
authors.affiliation: Sleep Research Institute, Madrid, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Garcia-Borreguero
authors.affiliation: Baylor College of Medicine, Houston, TX, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hirshkowitz
authors.affiliation: Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
authors.forename: B
authors.initials: B
authors.lastname: Högl
authors.affiliation: Department of Somnology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Inoue
authors.affiliation: Center for Integrative Research on Cardiovascular Aging (CIRCA), Aurora University of Wisconsin Medical Group, Aurora Health Care, Milwaukee, WI, USA.
authors.forename: A
authors.initials: A
authors.lastname: Jahangir
authors.affiliation: Sleep and Epilepsy Center, Neurocenter of Southern Switzerland, Civic Hospital (EOC) of Lugano, Lugano, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Manconi
authors.affiliation: Sleep Center, Children's Hospital of Philadelphia, and University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Marcus
authors.affiliation: University of Illinois School of Medicine at Urbana-Champaign and Carle Foundation Hospital, Urbana, IL, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Picchietti
authors.affiliation: Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, and IRCCS, Istituto delle Scienze Neurologiche, ASL di Bologna, Bologna, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Plazzi
authors.affiliation: Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Winkelman
authors.affiliation: Sleep Disorders Center, University of California San Francisco, San Francisco, CA, USA.
authors.forename: R S
authors.initials: RS
authors.lastname: Zak
mesh_terms: D026683:Advisory Committees; D000465:Algorithms; D004576:Electromyography; D006801:Humans; D009068:Movement / Q000502:physiology*; D020189:Nocturnal Myoclonus Syndrome / Q000175:diagnosis*; D017286:Polysomnography / Q000592:standards*; D012148:Restless Legs Syndrome / Q000175:diagnosis*; D012720:Severity of Illness Index; D012955:Societies, Medical / Q000592:standards
keywords: Electromyography; Periodic leg movements during sleep; Periodic leg movements during wakefulness; Polysomnography; Revised WASM standards