Simultaneous fMRI-EEG-Based Characterisation of NREM Parasomnia Disease: Methods and Limitations.

Marek Piorecky,Jiri Horacek,Jan Strobl,Vlastimil Koudelka,Jitka Buskova,Martin Brunovsky,Eva Miletinova,David Tomecek,Vaclava Piorecka,Stanislav Jiricek,Jaroslav Hlinka

doi:10.3390/diagnostics10121087

Abstract

Functional magnetic resonance imaging (fMRI) techniques and electroencephalography (EEG) were used to investigate sleep with a focus on impaired arousal mechanisms in disorders of arousal (DOAs). With a prevalence of 2–4% in adults, DOAs are significant disorders that are currently gaining attention among physicians. The paper describes a simultaneous EEG and fMRI experiment conducted in adult individuals with DOAs (). Both EEG and fMRI data were validated by reproducing well established EEG and fMRI associations. A method for identification of both brain functional areas and EEG rhythms associated with DOAs in shallow sleep was designed. Significant differences between patients and controls were found in delta, theta, and alpha bands during awakening epochs. General linear models of the blood-oxygen-level-dependent signal have shown the secondary visual cortex and dorsal posterior cingulate cortex to be associated with alpha spectral power fluctuations, and the precuneus with delta spectral power fluctuations, specifically in patients and not in controls. Future EEG–fMRI sleep studies should also consider subject comfort as an important aspect in the experimental design.

Highlights

Sleep and its disorders are at the forefront of many researchers’ and physicians’ interests
The proposed methodology was adapted to compare the group of disorders of arousal (DOAs) patients with the control group, and we reported technical and physiological limitations
A unique dataset of simultaneous EEG and Functional magnetic resonance imaging (fMRI) data of adults suffering from parasomnia was obtained

Summary

Introduction

Sleep and its disorders are at the forefront of many researchers’ and physicians’ interests. Sleep disturbances have been reported by 30% of the population. Sleep contains cycles alternating in several phases with different characteristics. The main two types of sleep are called the rapid eye movement (REM) and non-rapid eye movement (NREM) phases. We can further divide the NREM phase into three parts according to the depth of sleep, with the third being the deepest [2]. Like all physiological processes, can be disturbed. Some of the most prevalent sleep disorders are disorders of arousal (DOAs; sleepwalking, confusional arousal, and night terrors). DOAs are the NREM parasomnias characterised by abnormal behavioural (motor or verbal) events during NREM sleep. People with DOAs can have reduced quality of sleep that affects their health [3,4]

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