Resting State Functional Connectivity in PTSD Veterans: An EEG Study

Posttraumatic stress disorder (PTSD) is a chronic debilitating disorder which may occur as a result of life-threatening mental trauma. Combat experience may lead to PTSD in veterans. In this paper we study resting state functional connectivity based on EEG signals of Iranian veterans with PTSD. We investigate whether there is a significant difference among PTSD group and two control groups including trauma exposed non-PTSD veterans and healthy controls who has not experienced any trauma. Preprocessed signals are divided into epochs. ciPLV (corrected imaginary part of phase locking value) is calculated between each pair of channels, in each sub band as well as the whole band. After studying networks, three graph features are extracted from networks: nodal degree, nodal efficiency and betweenness centrality. Repeated measure ANOVA is used at confidence level of 99%. Results demonstrate consequent networks are significantly different among three groups. Moreover, p-values illustrate three groups are significantly different. They also suggest which features and which channels can be proper choices for automatic classification. In addition to achieved results, our work shares two main features. First, we study combat related PTSD which lasts at least 30 years. Second, brain networks in PTSD group are compared to not only healthy controls, but also trauma-exposed non-PTSD participants.