Comparison of the macro and microstructure of sleep in a sample of sleep clinic hypersomnia cases - PubMed (original) (raw)

Comparison of the macro and microstructure of sleep in a sample of sleep clinic hypersomnia cases

Alyssa Cairns et al. Neurobiol Sleep Circadian Rhythms. 2019.

Abstract

The purpose of this study was to elucidate the differentiating or grouping EEG characteristics in various hypersomnias (type 1 and type 2 narcolepsy (N-1 and N-2) and idiopathic hypersomnia (IH) compared to an age-matched snoring reference group (SR). Polysomnogram sleep EEG was decomposed into a 4-frequency state model. The IH group had higher sleep efficiency (SE; 92.3% vs. 85.8%; sp < 0.05), lower WASO (IH = 35.4 vs. N-1 = 65.5 min; p < 0.01), but similar (i.e. high) arousal indices as N-1 (~33/h). N-1 and N-2 had earlier REM latency than IH and SR (N-1 = 64.8, N-2 = 76.3 vs. IH/SR = 118 min, p < 0.05). N-1 and N-2 showed an increase in MF1 segments (characteristic of stage 1 and REM) across the night as well as distinct oscillations every 2 h, but MF1 segment timing was advanced by 30 min compared to the SR group (p < 0.05). This suggests the presence of circadian organization to sleep that is timed earlier or of increased pressure and/or lability. MF1 demonstrated a mixed phenotype in IH, with an early 1st oscillation (like N-1 and N-2), 2nd oscillation that overlapped with the SR group, and a surge prior to wake (higher than all groups). This phenotype may reflect a heterogeneous group of individuals, with some having more narcolepsy-like characteristics (i.e. REM) than others. LF domain (delta surrogate) was enhanced in IH and N-1 and more rapidly dissipated compared to N-2 and SR (p < 0.05). This suggests an intact homeostatic sleep pattern that is of higher need/reduced efficiency whereas rapid dissipation may be an underlying mechanism for sleep disruption.

Keywords: MSLT; SOREMP; Sensitivity; Signal processing; Spectral analysis; Spectrum.

PubMed Disclaimer

Figures

Fig. 1

Fig. 1

Fundamental Frequency (Hz) Across time. Fundamental frequency = mean EEG cycles per second (Hz). Each vertical tick on the X-axis represents a 5-min time bin of the PSG (PSG = the first 7 h from Lights out; mean of 22:12 +/− 32 min). SO = mean sleep onset for all groups (no statistical differences between groups). Trend lines represent spline-smoothed changes in mean fundamental frequency over time. Bars represent standard error bars (SEM). Mixed model ANOVA with Bonferroni post-hoc comparisons was used to assess group (N = 4) by time (N = 82 time increments) changes. Main effect of time present with no interaction or group effects.

Fig. 2

Fig. 2

Time-related changes in percent of epoch comprised of each respective EEG frequency segment across time. HF = characteristic of wakefulness, MF2 = characteristic of stage 2, MF1 = characteristic of stage 1 and REM; LF = characteristics of stage 3. Each vertical tick on the X-axis represents a 5-minute time bin of the PSG (PSG = the first 7 h from Lights out; mean of 22:12 +/− 32 min). SO = mean sleep onset for all groups (no statistical differences between groups). Trend lines represent spline-smoothed changes in mean percent of time comprised of each frequency component over time. Bars represent standard error bars (SEM). Mixed model ANOVA with Bonferroni post-hoc comparison to assess group (N = 4) by time (N = 82 time increments) changes. 2 A&B-main effect of time observed, no interaction or group effects. 2C- group by time interaction (p < 0.001); 1st oscillation- early in N-1, N-2 & IH compared to snoring controls p < .05), 2nd oscillation- N-1 & N-2 early vs. IH & snoring reference (p < 0.05); 3rd oscillation- N-1 & N-2 early vs. IH & snoring reference (p < 0.05). 2

d

- group by time interaction (p < 0.001); *a = N-1 & IH high LF domains than N-2 & snoring reference at acrophase (p < 0.05); *b = IH higher LF domains than all others (p < 0.05); precipitously decreasing at 1:00.

Similar articles

Cited by

References

    1. Achermann P. EEG analysis applies to sleep. Epilept. 2009;26:28–33.
    1. American Academy of Sleep Medicine . International Classification of Sleep Disorders. 3rd edn. American Academy of Sleep Medicine; Darien, IL: 2014.
    1. Anderson K.N., Pilsworth S., Sharples L.D., Smith I.E., Shneerson J.M. Idiopathic hypersomnia: a study of 77 cases. SLEEP. 2007;30:1274–1281. - PMC - PubMed
    1. Andlauer O., Moore H., Hong S.C. Predictors of hypocretin (orexin) deficiency in narcolepsy without cataplexy. SLEEP. 2012;35:1247. (55.12) - PMC - PubMed
    1. Andlauer O., Moore H., Jouhier L. Nocturnal rapid eye movement sleep latency for identifying patients with narcolepsy/hypocretin deficiency. JAMA Neurol. 2013;70:891–902. - PMC - PubMed

LinkOut - more resources