0419 HEMISPHERIC AND MORPHOLOGICAL CHARACTERISTICS OF SLEEP SPINDLES IN PRIMARY INSOMNIA AND GOOD SLEEPERS

• Published in: Sleep (New York, N.Y.) N.Y.), 2017-04, Vol.40 (suppl_1), p.A155-A155
• Main Authors: Gazecki, S, Bottary, RM, Purcell, S, Moore, KN, Lasko, NB, Milad, MR, Pace-Schott, EF
• Format: Article
• Language: English
• Subjects: Insomnia; Morphology; Sleep
• ISSN: 0161-8105; 1550-9109
• DOI: 10.1093/sleepj/zsx050.418

Abstract Introduction: Sleep spindles are implicated in memory consolidation and possibly altered in psychopathology. However, little is known about quantitative and morphological abnormalities in Primary Insomnia (PI). We explored differences in sleep spindle characteristics between PI and Good Sleepers (GS). Methods: Following an acclimation night, 23 PI (16 female, Age: M=21.3, SD=14.3yrs) and 19 GS (14 female, Age: M=32.6, SD=14.9yrs) completed consecutive nights of home sleep monitoring (psg-2 and psg-3) prior to a fear conditioning and extinction task. Signal processing of artifact free scalp EEG was accomplished using co-author S.P’s open source C/C++ program (http://zzz.bwh.harvard.edu). Canonical (13.5Hz), fast (15Hz), and slow (11Hz), spindles were detected from bilateral central (C3, C4; canonical and fast) and frontal (F3, F4; slow) derivations using wavelet analysis with adaptive thresholds. Spindle Amplitude, Density and Duration were calculated for detected spindles. For canonical, fast and slow spindle frequency types, two-group (PI vs. GS) x 2 Night (psg-2 vs. psg-3) x 2 Hemisphere (left vs. right) ANOVAs for Amplitude, Density and Duration were conducted independently for stages N2 and N3. Results: For canonical spindles, we observed a Hemisphere main effect for N2 Density (left > right, F(1,20) =6.750,p =.017), a main effect trend of Night for N2 Amplitude (night 3>night2, F(1,20)=3.803,p=.065) and Hemisphere for N3 Amplitude (left>right, F(1,20)=4.325,p=.052), and a trend for a Night x Hemisphere interaction for N3 Duration (F(1,20)=3.458,p =.078). For fast spindles, we observed a main effect of Night for N2 Amplitude (psg 3>psg 2, F(1,20)=6.272,p =.021), Group for N3 Duration (PI>GS,F(1,20)=6.107, p=.024), and a Night x Hemisphere interaction trend for Duration (F(1,20)=3.510,p =.077). For slow spindles, we observed a main effect of Group for N2 Duration (PI>GS,F(1,20)=6.460,p=.019) and main effect trend of night for N2 Amplitude (psg3>psg2, F(1,20)=3.258,p=.085) and group for N3 duration (PI>GS,F(1,20)=3.542,p=.075). Conclusion: Hemispheric differences in N2 canonical spindle density is conserved in both PI and GS. N2 fast spindles’ Amplitude increased from psg-2 to psg-3, possibly influenced by task-related learning. Compared to GS, PI demonstrated greater spindle duration for fast spindles in N3 and slow spindles in N2, offering a possible signature for the condition. Support (If Any): R21MH101567.