Novel method for evaluation of eye movements in patients with narcolepsy

TY - JOUR

T1 - Novel method for evaluation of eye movements in patients with narcolepsy

AU - Christensen, Julie A E

AU - Kempfner, Lykke

AU - Leonthin, Helle L

AU - Hvidtfelt, Mathias

AU - Nikolic, Miki

AU - Kornum, Birgitte Rahbek

AU - Jennum, Poul

N1 - Copyright © 2016 Elsevier B.V. All rights reserved.

PY - 2017/5/1

Y1 - 2017/5/1

N2 - BACKGROUND: Narcolepsy causes abnormalities in the control of wake-sleep, non-rapid-eye-movement (non-REM) sleep and REM sleep, which includes specific eye movements (EMs). In this study, we aim to evaluate EM characteristics in narcolepsy as compared to controls using an automated detector.METHODS: We developed a data-driven method to detect EMs during sleep based on two EOG signals recorded as part of a polysomnography (PSG). The method was optimized using the manually scored hypnograms from 36 control subjects. The detector was applied on a clinical sample with subjects suspected for central hypersomnias. Based on PSG, multiple sleep latency test and cerebrospinal fluid hypocretin-1 measures, they were divided into clinical controls (N = 20), narcolepsy type 2 (NT2, N = 19), and narcolepsy type 1 (NT1, N = 28). We investigated the distribution of EMs across sleep stages and cycles.RESULTS: NT1 patients had significantly less EMs during wake, N1, and N2 sleep and more EMs during REM sleep compared to clinical controls, and significantly less EMs during wake and N1 sleep compared to NT2 patients. Furthermore, NT1 patients showed less EMs during NREM sleep in the first sleep cycle and more EMs during NREM sleep in the second sleep cycle compared to clinical controls and NT2 patients.CONCLUSIONS: NT1 patients show an altered distribution of EMs across sleep stages and cycles compared to NT2 patients and clinical controls, suggesting that EMs are directly or indirectly controlled by the hypocretinergic system. A data-driven EM detector may contribute to the evaluation of narcolepsy and other disorders involving the control of EMs.

AB - BACKGROUND: Narcolepsy causes abnormalities in the control of wake-sleep, non-rapid-eye-movement (non-REM) sleep and REM sleep, which includes specific eye movements (EMs). In this study, we aim to evaluate EM characteristics in narcolepsy as compared to controls using an automated detector.METHODS: We developed a data-driven method to detect EMs during sleep based on two EOG signals recorded as part of a polysomnography (PSG). The method was optimized using the manually scored hypnograms from 36 control subjects. The detector was applied on a clinical sample with subjects suspected for central hypersomnias. Based on PSG, multiple sleep latency test and cerebrospinal fluid hypocretin-1 measures, they were divided into clinical controls (N = 20), narcolepsy type 2 (NT2, N = 19), and narcolepsy type 1 (NT1, N = 28). We investigated the distribution of EMs across sleep stages and cycles.RESULTS: NT1 patients had significantly less EMs during wake, N1, and N2 sleep and more EMs during REM sleep compared to clinical controls, and significantly less EMs during wake and N1 sleep compared to NT2 patients. Furthermore, NT1 patients showed less EMs during NREM sleep in the first sleep cycle and more EMs during NREM sleep in the second sleep cycle compared to clinical controls and NT2 patients.CONCLUSIONS: NT1 patients show an altered distribution of EMs across sleep stages and cycles compared to NT2 patients and clinical controls, suggesting that EMs are directly or indirectly controlled by the hypocretinergic system. A data-driven EM detector may contribute to the evaluation of narcolepsy and other disorders involving the control of EMs.

KW - Adolescent

KW - Adult

KW - Denmark/epidemiology

KW - Disorders of Excessive Somnolence/physiopathology

KW - Electrooculography/methods

KW - Eye Movements/physiology

KW - Female

KW - Humans

KW - Intracellular Signaling Peptides and Proteins/cerebrospinal fluid

KW - Male

KW - Middle Aged

KW - Narcolepsy/classification

KW - Orexins/cerebrospinal fluid

KW - Polysomnography/methods

KW - Sleep/physiology

KW - Sleep Stages/physiology

KW - Sleep Wake Disorders/cerebrospinal fluid

KW - Sleep, REM/physiology

KW - Young Adult

U2 - 10.1016/j.sleep.2016.10.016

DO - 10.1016/j.sleep.2016.10.016

M3 - Journal article

C2 - 28087252

SN - 1389-9457

VL - 33

SP - 171

EP - 180

JO - Sleep Medicine

JF - Sleep Medicine

ER -