0615 Defining Optimal Actigraphic Parameters to Quantify Total Sleep Duration in Idiopathic Hypersomnia. (27th April 2018)

• Record Type: Journal Article
• Authors: Cook, J D; Eftekari, S C; Leavitt, L A; Plante, D T
• Is Part Of: Sleep. Volume 41(2018)Supplement 1
• Page Start: A228
• Page End: A228
• Publication Date: 2018-04-27
• Subjects: Sleep -- Physiological aspects -- Periodicals; Sleep disorders -- Periodicals; Sommeil -- Aspect physiologique -- Périodiques; Sommeil, Troubles du -- Périodiques; Sleep disorders; Sleep -- Physiological aspects; Sleep -- physiological aspects; Sleep Wake Disorders; Psychophysiology; Electronic journals; Periodicals; 616.8498
• DOI: 10.1093/sleep/zsy061.614
• Languages: English
• ISSNs: 0161-8105

Abstract

Abstract: Introduction: Objectively measured total sleep time (TST) greater than 11 hours is a diagnostic criterion for idiopathic hypersomnia (IH). Guidelines for quantifying TST using extended duration polysomnography (PSG) are well established, however, optimal actigraphic parameters to quantify excessive sleep time in IH are not clear. Since device settings such as activity threshold and immobility time can sizably impact actigraphically-derived sleep and wake values, this investigation was conducted to determine the optimal actigraphy settings to quantify TST relative to polysomnography (PSG) in IH. Methods: Thirteen individuals with IH underwent nocturnal, ad-libitum PSG while concurrently wearing the Actiwatch-2 (AW2) on their nondominant wrist. PSG lights-off and lights-on time-stamps were used to create AW2 rest intervals. Epochs were 30 seconds for both PSG and AW2. For each recording, sleep-wake threshold was modified using low (20), medium (40), and high (80) activity counts; and sleep-immobility onset/offset was adjusted using 5, 10, 15, 20, 25, and 30 epochs. Sleep variables for all AW2 setting combinations were subsequently compared against PSG using Bland-Altman analysis. Epoch-by-epoch comparisons were also performed to assess sensitivity, specificity, and accuracy of AW2 setting combinations relative to PSG. Results: Standard AW2 settings (medium activity threshold; 20 epoch immobility time) significantly overestimated TST by 28.5 minutes (p = .026). Device performance was consistently better using the low activity threshold, with all permutations demonstrating non-significant differences from PSG. Of combinations tested, low activity threshold and 30 epoch immobility time was most congruent with PSG, underestimating TST by only 4.5 minutes. All sleep-wake thresholds exhibited strong sensitivity and accuracy, with poor specificity. Conclusion: Our results demonstrate actigraphic settings significantly impact the quantification of TST in IH. Device settings should be adjusted accordingly when actigraphy is used to objectively quantify sleep duration in the disorder. Support (If Any): This research was supported by a grant from the American Sleep Medicine Foundation.