Actigraphic recordings in quantification of periodic leg movements during sleep in children

Background: Periodic limb movement disorder (PLMD) has recently emerged as a relatively frequent and markedly underdiagnosed condition in children that induces arousals and sleep fragmentation and leads to poor learning and behavioral problems. Because a cost-effective and widely available alternative to pediatric polysomnography is needed for diagnosis of limb movement disorders, this study sought to examine whether periodic leg movements in children could be reliably identified using recently developed actigraphy software. Methods: Bilateral actigraphs were worn around the feet by 99 children ages 4-12 years during standard clinical overnight polysomnography, which included bilateral anterior tibial electromyogram (EMG). Left and right leg movements were scored independently for comparison purposes. Results: Agreement between fibial EMG and actigraphy-derived events were initially low, with movement indices being overestimated by actigraphy. This agreement was improved when a correction factor based on the average number of movements during arousals as measured by EMG was applied. However, the correction factor itself was found to differ substantially for patients who were diagnosed with PLMD compared to other patients. Conclusions: A novel actigraphic approach currently used for detection of PLM events during sleep in adults is insufficiently accurate to permit reliable estimates in children. (c) 2005 Elsevier B.V. All rights reserved.