Strong correlation of novel sleep electroencephalography coherence markers with diagnosis and severity of posttraumatic stress disorder

Mo H Modarres,Miranda M Lim,Kristianna B Weymann,Ryan A Opel

doi:10.1038/s41598-018-38102-4

Abstract

Objective biomarkers of the presence and severity of posttraumatic stress disorder (PTSD) are elusive, yet badly needed. Electroencephalographic (EEG) coherence represents a promising approach to identifying and understanding brain biomarker activity in PTSD. Overnight polysomnography data containing EEG across sleep and wake states was collected in n = 76 Veterans with and without PTSD from a single site under IRB approval. Brain coherence markers (BCM) were calculated from EEG signals using a novel approach to produce one index for PTSD diagnosis (PTSDdx), and another index for PTSD severity (PTSDsev). PTSDdx showed strong sensitivity to the presence of PTSD in the awake state, during non-rapid eye movement (NREM) stage N2 sleep, and in a hybrid BCM incorporating both awake and NREM sleep states. PTSDsev showed a strong correlation with PTSD symptom severity (using the PTSD Checklist 5, or PCL5 survey) in the awake state, during N2 sleep, and in a hybrid BCM incorporating both awake and NREM sleep states. Thus, sleep EEG-based brain coherence markers can be utilized as an objective means for determining the presence and severity of PTSD. This portable, inexpensive, and non-invasive tool holds promise for better understanding the physiological mechanisms underlying PTSD and for tracking objective responses to treatment.

Highlights

Post-traumatic stress disorder (PTSD) is a chronic and disabling neuropsychiatric disorder that is characterized by severe sleep disturbances, avoidance behaviors, physiological hyper-arousal, and re-experiencing symptoms following exposure to a traumatic event[1]
Because our analyses showed that PTSDdx and PTSD severity (PTSDsev) obtained from each individual awake and sleep state were highly significant in identifying and tracking severity of posttraumatic stress disorder (PTSD), we hypothesized that simultaneous incorporation of the PTSDdx and PTSDsev from all three vigilance states would have a multiplicative effect, and produce accuracies even higher than those markers obtained from individual sleep states
Markers BCMr1, BCMr3, BCMr5, and BCMr6 were larger in individuals with PTSD compared to Controls, while the other four markers were reduced in the PTSD group

Summary

Introduction

Post-traumatic stress disorder (PTSD) is a chronic and disabling neuropsychiatric disorder that is characterized by severe sleep disturbances, avoidance behaviors, physiological hyper-arousal, and re-experiencing symptoms following exposure to a traumatic event[1]. An objective and neuro-physiologically-based method for directly assessing brain function in PTSD is currently unavailable, but badly needed in order to improve diagnostic specificity, as well as to track response to treatment, of PTSD. Alterations in electroencephalography (EEG) and magneto-encephalography (MEG) signals have been previous associated with PTSD, compared with control subjects[20,21,22,23,24] These studies typically examined subjects in the awake state, some using task-based approaches as well as in a state of quiet wakefulness (e.g., resting state functional connectivity). One specific finding of note is from Lee et al.[17], an EEG study that showed decreased resting-state functional connectivity in PTSD compared with control subjects They found that functional connectivity measures were significantly correlated with PTSD symptom severity

Methods

Results

Conclusion