The Relationship between Brain Morphology and Polysomnography in Healthy Good Sleepers

Abstract

BackgroundNormal sleep continuity and architecture show remarkable inter-individual variability. Previous studies suggest that brain morphology may explain inter-individual differences in sleep variables.MethodThirty-eight healthy subjects spent two consecutive nights at the sleep laboratory with polysomnographic monitoring. Furthermore, high-resolution T1-weighted MRI datasets were acquired in all participants. EEG sleep recordings were analyzed using standard sleep staging criteria and power spectral analysis. Using the FreeSurfer software for automated segmentation, 174 variables were determined representing the volume and thickness of cortical segments and the volume of subcortical brain areas. Regression analyses were performed to examine the relationship with polysomnographic and spectral EEG power variables.ResultsThe analysis did not provide any support for the a-priori formulated hypotheses of an association between brain morphology and polysomnographic variables. Exploratory analyses revealed that the thickness of the left caudal anterior cingulate cortex was positively associated with EEG beta2 power (24–32 Hz) during REM sleep. The volume of the left postcentral gyrus was positively associated with periodic leg movements during sleep (PLMS).ConclusionsThe function of the anterior cingulate cortex as well as EEG beta power during REM sleep have been related to dreaming and sleep-related memory consolidation, which may explain the observed correlation. Increased volumes of the postcentral gyrus may be the result of increased sensory input associated with PLMS. However, due to the exploratory nature of the corresponding analyses, these results have to be replicated before drawing firm conclusions.

Sleeping oxygen saturation, rapid eye movement sleep, and the adaptation of postprandial metabolic function in insulin sensitive and resistant individuals without diabetes

“…It is established that sleep architecture has enhanced night-to-night variability, which will reduce the reliability of these measures. However, the presently observed time spent in sleep stages relative to TST was comparable with reported values from previous studies of healthy adults [40, 41]. It is notable, in this respect, that the present findings have demonstrated significant relationships among objective measures obtained using various methodologies and independent postprandial assessments.…”

“…By the euglycemic clamp, 50% of the participants had insulin resistance (i.e., insulin-mediated glucose disposal ≤4.5 mg·min −1 ·kg −1 ) [37, 38]. Of the sample, mean sleeping SaO 2 was within normal limits (95% or above) for all participants [39, 40]. Time spent in sleep stages relative to TST was comparable with previous studies of healthy adults [40, 41].…”

“…Of the sample, mean sleeping SaO 2 was within normal limits (95% or above) for all participants [39, 40]. Time spent in sleep stages relative to TST was comparable with previous studies of healthy adults [40, 41]. In sum, although the participants were healthy, having no clinical conditions or prescribed cardiometabolic or sleeping medications, a large proportion of subjects were overweight or obese, about one-quarter of them evidenced dyslipidemia, and about half of the persons displayed signs of early glucose dysregulation.…”

Magnetic Resonance Spectroscopy in Patients with Insomnia: A Repeated Measurement Study

“…Resting-state functional connectivity data of the sample has been published elsewhere [ 27 ]. Six PI patients, all non-remitters to cognitive-behavioral therapy for insomnia, and 19 healthy controls have already participated in previous neuroimaging studies of our research group [ 28 , 29 , 30 , 31 ]. For screening purposes, a semi-standardized psychiatric and sleep-related interview was conducted in all participants by an experienced psychiatrist to rule out any lifetime history of psychiatric disorder, or (additional) sleep disorder.…”

The exploratory power of sleep effort, dysfunctional beliefs and arousal for insomnia severity and polysomnography‐determined sleep

“…The present analysis represents a secondary analysis of data collected primarily for other projects of our workgroup. The three primary studies comprised a magnetic resonance imaging (MRI) study (Baglioni et al, 2014a,b;Reinhard et al, 2014;Spiegelhalder et al, 2013Spiegelhalder et al, , 2014, an ongoing study on direct current stimulation (Frase et al, 2013) and an ongoing project on the perception of sleep and dreams in patients with insomnia (DFG Project RI 565/13-1). The research question and analysis of the present paper were not covered in the primary studies.…”