Special SectionThe official World Association of Sleep Medicine (WASM) standards for recording and scoring periodic leg movements in sleep (PLMS) and wakefulness (PLMW) developed in collaboration with a task force from the International Restless Legs Syndrome Study Group (IRLSSG)
Section snippets
Prologue
The definition and scoring criteria for periodic leg movements (PLM) during sleep have not changed since 1990 [1] and 1993 [2] and are substantially based on the work carried out by Coleman et al. in 1982 [3]. The aim of the Atlas and Scoring Rules [2] was to provide recommendations for the correct recording of motor events, the use of standard terminology and the definition of some common rules to quantify PLM.
However, the current standard for recording sleep is based on computerized
Respiration and PLM special recording rules
Respiration must be recorded to accurately assess if leg movements are associated with respiratory events and therefore are not pathophysiologic markers for other neurological disorders, such as restless legs syndrome (RLS) or PLM disorder (PLMD). Thus, a leg movement is associated with the breath ending an apnea/hypopnea event or introducing a significant transitory improvement in respiration during apnea/hypopnea when the temporal occurrence of the critical breath event and the leg movement
Cyclic alternating pattern (CAP) recording standards
PLM is often associated with periodic electroencephalographic (EEG) events including arousals, k-alpha complexes and sequences of k-complexes. This periodicity suggests that a central nervous system oscillator may be involved. The cyclic alternating pattern (CAP) [7] is an EEG oscillator composed of these periodic EEG phenomena that underlies many periodic phenomena occurring during sleep, including PLM (see Appendix).
CAP associated with PLM may represent an upstream phenomenon; however, CAP
Leg activity monitoring standards
Activity monitoring of leg or foot movements by a motion detector system provides another measure of leg movements in sleep (Fig. 7). These devices provide the possibility of multiple nights of recording in a home environment, reducing somewhat the vexing problems caused by the relatively large night-to-night within-subject variation reported to occur for PLM [10], [11]. These devices should be able to meet approximately the same scoring criteria for the EMG signal. The following are considered
References (11)
- et al.
Consensus report. Atlas, rules, and recording techniques for the scoring of cyclic alternating pattern (CAP) in human sleep
Sleep Med
(2001) The resurrection of periodic limb movements (PLM): leg activity monitoring and the restless legs syndrome (RLS)
Sleep Med
(2005)- Diagnostic classification steering committee, Thorpy MJ (Chairman). International classification of sleep disorders:...
Recording and scoring leg movements. The Atlas Task Force
Sleep
(1993)Periodic movements in sleep (nocturnal myoclonus) and restless legs syndrome
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