Abnormal default-mode network homogeneity and its correlations with personality in drug-naive somatization disorder at rest

Abstract

Background: While the default-mode network (DMN) appears to play a crucial role in patients suffering from somatization disorder (SD), the abnormalities of the network homogeneity (NH) of the DMN in SD patients have been poorly explored. The aim of this study is to examine DMN NH using an NH approach in patients suffering from SD at rest and determine its correlations with personality as measured by the Eysenck Personality Questionnaire (EPQ).

Methods: A total of 25 drug-naive patients with SD and 28 sex-, age-, and education-matched healthy controls underwent functional magnetic resonance imaging scans at rest. The data were analyzed by an automated NH method.

Results: Patients showed increased NH in the left superior frontal gyrus and decreased NH in the bilateral precuneus. Moreover, a significantly negative correlation was observed between the NH values in the bilateral precuneus and the EPQ--Neuroticism scores.

Limitations: The present study should be considered preliminary due to a lenient, uncorrected threshold of p<0.01.

Conclusions: The results suggest that abnormal DMN NH exists in drug-naive SD and further highlight the importance of the DMN in the pathophysiology of SD.

Keywords: Eysenck Personality Questionnaire; Network homogeneity; Precuneus; Somatization disorder; Superior frontal gyrus.