title: Altered blood oxygen level-dependent signal variability in chronic post-traumatic stress disorder during symptom provocation.
abstract: BACKGROUND
  Recent research suggests that variability in brain signal provides important information about brain function in health and disease. However, it is unknown whether blood oxygen level-dependent (BOLD) signal variability is altered in post-traumatic stress disorder (PTSD). We aimed to identify the BOLD signal variability changes of PTSD patients during symptom provocation and compare the brain patterns of BOLD signal variability with those of brain activation.
  
  
  METHODS
  Twelve PTSD patients and 14 age-matched controls, who all experienced a mining accident, underwent clinical assessment as well as fMRI scanning while viewing trauma-related and neutral pictures. BOLD signal variability and brain activation were respectively examined with standard deviation (SD) and general linear model analysis, and compared between the PTSD and control groups. Multiple regression analyses were conducted to explore the association between PTSD symptom severity and these two brain measures across all subjects as well as in the PTSD group.
  
  
  RESULTS
  PTSD patients showed increased activation in the middle occipital gyrus compared with controls, and an inverse correlation was found between PTSD symptom severity and brain activation in the hippocampus and anterior cingulate cortex/medial prefrontal cortex. Brain variability analysis revealed increased SD in the insula, anterior cingulate cortex/medial prefrontal cortex, and vermis, and decreased SD in the parahippocapal gyrus, dorsolateral prefrontal cortex, somatosensory cortex, and striatum. Importantly, SD alterations in several regions were found in both traumatic and neutral conditions and were stratified by PTSD symptom severity.
  
  
  CONCLUSIONS
  BOLD signal variability may be a reliable and sensitive biomarker of PTSD, and combining brain activation and brain variability analysis may provide complementary insight into the neural basis of this disorder.
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Ke
authors.affiliation: Mental Health Institute, the Second Xiangya Hospital, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, People's Republic of China.
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Qi
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Mental Health Institute, the Second Xiangya Hospital, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, People's Republic of China.
authors.forename: Weihui
authors.initials: W
authors.lastname: Li
authors.affiliation: Guangdong Academy of Medical Science, Guangdong General Hospital, Guangdong Mental Health Center, Guangzhou, People's Republic of China.
authors.forename: Cailan
authors.initials: C
authors.lastname: Hou
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, People's Republic of China.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Radiology of the Second Xiangya Hospital, Central South University, Changsha, People's Republic of China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: He
authors.affiliation: Mental Health Institute, the Second Xiangya Hospital, National Technology Institute of Psychiatry, Key Laboratory of Psychiatry and Mental Health of Hunan Province, Central South University, Changsha, People's Republic of China ; Shenzhen Kangning Hospital of Guangdong Province, Shenzhen, People's Republic of China.
authors.forename: Lingjiang
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, Jinling Hospital, Medical School of Nanjing University, Nanjing, People's Republic of China.
authors.forename: Guangming
authors.initials: G
authors.lastname: Lu
keywords: brain variability; functional magnetic resonance imaging; general linear model; insula