title: Abnormal spontaneous regional brain activity in primary insomnia: a resting-state functional magnetic resonance imaging study.
abstract: OBJECTIVE
  Investigating functional specialization is crucial for a complete understanding of the neural mechanisms of primary insomnia (PI). Resting-state functional magnetic resonance imaging (fMRI) is a useful tool to explore the functional specialization of PI. However, only a few studies have focused on the functional specialization of PI using resting-state fMRI and results of these studies were far from consistent. Thus, the current study aimed to investigate functional specialization of PI using resting-state fMRI with amplitude of low frequency fluctuations (ALFFs) algorithm.
  
  
  METHODS
  In this study, 55 PI patients and 44 healthy controls were included. ALFF values were compared between the two groups using two-sample t-test. The relationship of abnormal ALFF values with clinical characteristics and duration of insomnia was investigated using Pearson's correlation analysis.
  
  
  RESULTS
  PI patients showed lower ALFF values in the left orbitofrontal cortex/inferior frontal gyrus, right middle frontal gyrus, left inferior parietal lobule, and bilateral cerebellum posterior lobes, while higher ALFF values in the right middle/inferior temporal that extended to the right occipital lobe. In addition, we found that the duration of PI negatively correlated with ALFF values in the left orbitofrontal cortex/inferior frontal gyrus, and the Pittsburgh Sleep Quality Index score negatively correlated with ALFF values in the left inferior parietal lobule.
  
  
  CONCLUSIONS
  The present study added information to limited studies on functional specialization and provided evidence for hyperarousal hypothesis in PI.
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, The Third Clinical Medical College of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Xiaofen
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Mengshi
authors.initials: M
authors.lastname: Dong
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, The Third Clinical Medical College of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, The Third Clinical Medical College of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Kelei
authors.initials: K
authors.lastname: Hua
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Changhong
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Zhan
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China; Department of Renal Transplantation, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Medical Imaging, The Affiliated Guangdong No 2 Provincial People's Hospital of Southern Medical University, Guangzhou, People's Republic of China.
authors.forename: Guihua
authors.initials: G
authors.lastname: Jiang
keywords: amplitude of low frequency fluctuations; primary insomnia; resting-state fMRI; spontaneous brain activity