PMID- 24332046 OWN - NLM STAT- MEDLINE DCOM- 20140923 LR - 20211021 IS - 1878-5506 (Electronic) IS - 1389-9457 (Print) IS - 1389-9457 (Linking) VI - 15 IP - 1 DP - 2014 Jan TI - Valid measures of periodic leg movements (PLMs) during a suggested immobilization test using the PAM-RL leg activity monitors require adjusting detection parameters for noise and signal in each recording. PG - 132-7 LID - S1389-9457(13)01156-8 [pii] LID - 10.1016/j.sleep.2013.08.788 [doi] AB - OBJECTIVE AND BACKGROUND: Individuals with restless legs syndrome (RLS) (Willis-Ekbom disease [WED]) usually have periodic leg movements (PLMs). The suggested immobilization test (SIT) measures sensory and motor features of WED during wakefulness. Surface electromyogram (EMG) recordings of the anterior tibialis (AT) are used as the standard for counting PLMs. However, due to several limitations, leg activity meters such as the PAM-RL were advanced as a potential substitute. In our study, we assessed the validity of the measurements of PLM during wakefulness (PLMW) in the SIT for PAM-RL using both default and custom detection threshold parameters compared to AT EMG. METHODS: Data were obtained from 39 participants who were diagnosed with primary WED and who were on stable medication as part of another study using the SIT to repeatedly evaluate WED symptoms over 6-12 months. EMG recordings and PAM-RL, when available, were used to detect PLMW for each SIT. Complete PAM-RL and polysomnography (PSG) EMG data were available for 253 SITs from that study. The default PAM-RL (dPAM-RL) detected leg movements based on manufacturer's noise (resting) and signal (movement) amplitude criteria developed to accurately detect PLM during sleep (PLMS). The custom PAM-RL (cPAM-RL) similarly detected leg movements except the noise and movement detection parameters were adjusted to match the PAM-RL data for each SIT. RESULTS: The distributions of the differences between either dPAM-RL or cPAM-RL and EMG PLMW were strongly leptokurtic (Kurtosis >2) with many small differences and a few unusually large differences. These distributions are better described by median and quartile ranges than mean and standard deviation. Despite an adequate correlation (r=0.66) between the dPAM-RL and EMG recordings, the dPAM-RL on average significantly underscored the number of PLMW (median: quartiles=-13: -51.2, 0.0) and on Bland-Altman plots had a significant magnitude bias with greater underscoring for larger average PLMW/h. There also was an adequate correlation (r=0.70) between cPAM-RL and EMG but with minimal underscoring of PLMW (median quartiles=0.0; -20, 10) and no significant magnitude bias. Two scorers independently scoring 13% of the SITs showed an adequate interscorer reliability of 0.96-0.98. CONCLUSIONS: Our study confirms our expectation that measuring PLMW in a SIT using dPAM-RL is not valid and that adjustments to the detection threshold criteria are required. The PAM-RL, using parameters customized for each SIT provided a valid and reliable measure of PLMW with minimal magnitude bias compared to the AT EMG recordings. CI - Copyright (c) 2013 Elsevier B.V. All rights reserved. FAU - Yang, Myung Sung AU - Yang MS AD - Johns Hopkins University, 5501 Hopkins Bayview Circle, 1B.70, Baltimore, MD 21224, USA. FAU - Montplaisir, Jacques AU - Montplaisir J AD - Universite de Montreal, Hopital du Sacre-Coeur de Montreal, 5400 Boulevard Gouin Ouest Montreal, Quebec H4J 1C5, Canada. FAU - Desautels, Alex AU - Desautels A AD - Universite de Montreal, Hopital du Sacre-Coeur de Montreal, 5400 Boulevard Gouin Ouest Montreal, Quebec H4J 1C5, Canada. FAU - Winkelman, John W AU - Winkelman JW AD - Harvard Medical School, 1505 Commonwealth Ave 5th Floor, Brighton, MA 02135, USA. FAU - Cramer Bornemann, Michel A AU - Cramer Bornemann MA AD - University of Minnesota, 425 E River Rd, Minneapolis, MN 55455, USA. FAU - Earley, Christopher J AU - Earley CJ AD - Johns Hopkins University, 5501 Hopkins Bayview Circle, 1B.82, Baltimore, MD 21224, USA. FAU - Allen, Richard P AU - Allen RP AD - Johns Hopkins University, 5501 Hopkins Bayview Circle, 1B.70, Baltimore, MD 21224, USA. Electronic address: richardjhu@mac.com. LA - eng GR - R01 NS075184/NS/NINDS NIH HHS/United States PT - Clinical Trial PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't PT - Validation Study DEP - 20131016 PL - Netherlands TA - Sleep Med JT - Sleep medicine JID - 100898759 RN - 0 (Analgesics, Opioid) RN - 0 (Dopamine Agonists) SB - IM MH - Adult MH - Aged MH - Aged, 80 and over MH - Analgesics, Opioid/therapeutic use MH - Dopamine Agonists/therapeutic use MH - Electromyography/instrumentation/methods/*standards MH - Female MH - Humans MH - Immobilization/methods/standards MH - Male MH - Middle Aged MH - Muscle, Skeletal/physiopathology MH - Nocturnal Myoclonus Syndrome/*diagnosis/drug therapy/*physiopathology MH - Polysomnography MH - Reproducibility of Results MH - Restless Legs Syndrome/*diagnosis/drug therapy/*physiopathology MH - Signal Processing, Computer-Assisted MH - Signal-To-Noise Ratio MH - Wakefulness/physiology PMC - PMC3921115 MID - NIHMS537219 OTO - NOTNLM OT - Leg activity monitors OT - PAM-RL OT - Periodic leg movements during wakefulness (PLMW) OT - Polysomnography OT - Restless Legs Syndrome (RLS) OT - Suggested immobilization test (SIT) OT - Willis Ekbom disease (WED) COIS- Conflict of interest: 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.2013.08.788. EDAT- 2013/12/18 06:00 MHDA- 2014/09/24 06:00 PMCR- 2015/01/01 CRDT- 2013/12/17 06:00 PHST- 2013/04/08 00:00 [received] PHST- 2013/08/26 00:00 [revised] PHST- 2013/08/30 00:00 [accepted] PHST- 2013/12/17 06:00 [entrez] PHST- 2013/12/18 06:00 [pubmed] PHST- 2014/09/24 06:00 [medline] PHST- 2015/01/01 00:00 [pmc-release] AID - S1389-9457(13)01156-8 [pii] AID - 10.1016/j.sleep.2013.08.788 [doi] PST - ppublish SO - Sleep Med. 2014 Jan;15(1):132-7. doi: 10.1016/j.sleep.2013.08.788. Epub 2013 Oct 16.