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).

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.

Overview of sleep & sleep disorders.

Sleep is defined on the basis of behavioural and physiological criteria dividing it into two states: non rapid eye movement (NREM) sleep which is subdivided into three stages (N1, N2, N3); and rapid eye movement (REM) sleep characterized by rapid eye movements, muscle atonia and desynchronized EEG. Circadian rhythm of sleep-wakefulness is controlled by the master clock located in the suprachiasmatic nuclei of the hypothalamus. The neuroanatomical substrates of the NREM sleep are located principally in the ventrolateral preoptic nucleus of the hypothalamus and those of REM sleep are located in pons. A variety of significant physiological changes occur in all body systems and organs during sleep as a result of functional alterations in the autonomic and somatic nervous systems. The international classification of sleep disorders (ICSD, ed 2) lists eight categories of sleep disorders along with appendix A and appendix B. The four major sleep complaints include excessive daytime sleepiness, insomnia, abnormal movements or behaviour during sleep and inability to sleep at the desired time. The most important step in assessing a patient with a sleep complaint is obtaining a detailed history including family and previous histories, medical, psychiatric, neurological, drug, alcohol and substance abuse disorders. Some important laboratory tests for investigating sleep disorders consist of an overnight polysomnography, multiple sleep latency and maintenance of wakefulness tests as well as actigraphy. General physicians should have a basic knowledge of the salient clinical features of common sleep disorders, such as insomnia, obstructive sleep apnoea syndrome, narcolepsy-cataplexy syndrome, circadian rhythm sleep disorders (e.g., jet leg, shift work disorder, etc.) and parasomnias (e.g., partial arousal disorders, REM behaviour disorder, etc.) and these are briefly described in this chapter. The principle of treatment of sleep disorders is first to find cause of the sleep disturbance and vigorously treat the co-morbid conditions causing the sleep disturbance. If a satisfactory treatment is not available for the primary condition or does not resolve the problem, the treatment should be directed at the specific sleep disturbance. Most sleep disorders, once diagnosed, can be managed with limited consultations. The treatment of primary sleep disorders, however, is best handled by a sleep specialist. An overview of sleep and sleep disorders viz., Basic science; international classification and approach; and phenomenology of common sleep disorders are presented.