title: Design and validation of a periodic leg movement detector.
abstract: Periodic Limb Movements (PLMs) are episodic, involuntary movements caused by fairly specific muscle contractions that occur during sleep and can be scored during nocturnal polysomnography (NPSG). Because leg movements (LM) may be accompanied by an arousal or sleep fragmentation, a high PLM index (i.e. average number of PLMs per hour) may have an effect on an individual's overall health and wellbeing. This study presents the design and validation of the Stanford PLM automatic detector (S-PLMAD), a robust, automated leg movement detector to score PLM. NPSG studies from adult participants of the Wisconsin Sleep Cohort (WSC, n = 1,073, 2000-2004) and successive Stanford Sleep Cohort (SSC) patients (n = 760, 1999-2007) undergoing baseline NPSG were used in the design and validation of this study. The scoring algorithm of the S-PLMAD was initially based on the 2007 American Association of Sleep Medicine clinical scoring rules. It was first tested against other published algorithms using manually scored LM in the WSC. Rules were then modified to accommodate baseline noise and electrocardiography interference and to better exclude LM adjacent to respiratory events. The S-PLMAD incorporates adaptive noise cancelling of cardiac interference and noise-floor adjustable detection thresholds, removes LM secondary to sleep disordered breathing within 5 sec of respiratory events, and is robust to transient artifacts. Furthermore, it provides PLM indices for sleep (PLMS) and wake plus periodicity index and other metrics. To validate the final S-PLMAD, experts visually scored 78 studies in normal sleepers and patients with restless legs syndrome, sleep disordered breathing, rapid eye movement sleep behavior disorder, narcolepsy-cataplexy, insomnia, and delayed sleep phase syndrome. PLM indices were highly correlated between expert, visually scored PLMS and automatic scorings (r² = 0.94 in WSC and r² = 0.94 in SSC). In conclusion, The S-PLMAD is a robust and high throughput PLM detector that functions well in controls and sleep disorder patients.
authors.affiliation: Center for Sleep Sciences and Medicine, Stanford University, Palo Alto, California, United States of America; Department of Electrical Engineering, Stanford University, Palo Alto, California, United States of America.
authors.forename: Hyatt
authors.initials: H
authors.lastname: Moore
authors.affiliation: Center for Sleep Sciences and Medicine, Stanford University, Palo Alto, California, United States of America.
authors.forename: Eileen
authors.initials: E
authors.lastname: Leary
authors.affiliation: Center for Sleep Sciences and Medicine, Stanford University, Palo Alto, California, United States of America.
authors.forename: Seo-Young
authors.initials: SY
authors.lastname: Lee
authors.affiliation: Center for Sleep Sciences and Medicine, Stanford University, Palo Alto, California, United States of America.
authors.forename: Oscar
authors.initials: O
authors.lastname: Carrillo
authors.affiliation: Department of Population Health Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Robin
authors.initials: R
authors.lastname: Stubbs
authors.affiliation: Department of Population Health Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Paul
authors.initials: P
authors.lastname: Peppard
authors.affiliation: Department of Population Health Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Terry
authors.initials: T
authors.lastname: Young
authors.affiliation: Department of Electrical Engineering, Stanford University, Palo Alto, California, United States of America.
authors.forename: Bernard
authors.initials: B
authors.lastname: Widrow
authors.affiliation: Center for Sleep Sciences and Medicine, Stanford University, Palo Alto, California, United States of America.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Mignot
mesh_terms: D000328:Adult; D000465:Algorithms; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007866:Leg / Q000503:physiopathology*; D008297:Male; D008490:Medical Informatics / Q000379:methods*; D008875:Middle Aged; D009068:Movement; D009207:Myoclonus / Q000175:diagnosis* / Q000503:physiopathology*