Altered spontaneous neuronal activity of visual cortex and medial anterior cingulate cortex in treatment-naïve posttraumatic stress disorder

Abstract

Background: Although no more traumatic stimuli exists, a variety of symptoms are persisting in chronic Posttraumatic Stress Disorder (PTSD) patients. It is therefore necessary to explore the spontaneous brain activity of treatment-naïve PTSD patients during resting-state.

Method: Seventeen treatment-naïve PTSD patients and twenty traumatized controls were recruited and underwent a resting functional magnetic resonance imaging (Rs-fMRI) scan. The differences of regional brain spontaneous activity between the participants with and without PTSD were measured by Amplitude of Low-frequency fluctuation (ALFF). The relationship between the altered brain measurements and the symptoms of PTSD were analyzed.

Result: Compared to traumatized controls, the PTSD group showed significantly altered ALFF in many emotion-related brain regions, such as the medial anterior cingulate cortex (MACC), dorsolateral prefrontal cortex (DLPFC), insular (IC), middle temporal gyrus (MTG), and ventral posterior cingulate cortex (VPCC). Interestingly this is the first report of a hyperactive visual cortex (V1/V2) during resting-state in treatment-naïve PTSD patients. There were significant positive correlations between ALFF values in the bilateral visual cortex and re-experiencing or avoidance in PTSD. Negative correlation was observed between ALFF values in MACC and avoidance.

Conclusion: This study suggested that the visual cortex and the MACC may be involved in the characteristic symptoms of chronic PTSD, such as re-experiencing and avoidance. Future studies that focus on these areas of the brain are required, as alteration of these areas may act as a biomarker and could be targeted in future treatments for PTSD.