title: Aberrant limbic and salience network resting-state functional connectivity in panic disorder without comorbidity.
abstract: BACKGROUND
  Panic disorder (PD) is a prevalent and debilitating disorder but its neurobiology is still poorly understood. We investigated resting-state functional connectivity (RSFC) in PD without comorbidity in three networks that have been linked to PD before. This could provide new insights in how functional integration of brain regions involved in fear and panic might relate to the symptomatology of PD.
  
  
  METHODS
  Eleven PD patients without comorbidity and eleven pair-wise matched healthy controls underwent resting-state fMRI. We used seed regions-of-interest in the bilateral amygdala (limbic network), the bilateral dorsal anterior cingulate cortex (dACC) (salience network), and the bilateral posterior cingulate cortex (default mode network). RSFC of these areas was assessed using seed-based correlations. All results were cluster corrected for multiple comparisons (Z>2.3, p<.05).
  
  
  RESULTS
  Abnormalities were identified in the limbic network with increased RSFC between the right amygdala and the bilateral precuneus in PD patients. In the salience network the dACC demonstrated altered connectivity with frontal, parietal and occipital areas.
  
  
  CONCLUSIONS
  The small sample size and hypothesis-driven approach could restrict finding additional group differences that may exist. Other caveats are reflected in the use of medication by two participants and the acquisition of the resting-state scan at the end of a fixed imaging protocol.
  
  
  CONCLUSIONS
  We found altered RSFC in PD between areas involved in emotion regulation and emotional and somatosensory stimulus processing, as well as an area engaged in self-referential processing, not implicated in models for PD before. These findings extend existing functional neuroanatomical models of PD, as the altered RSFC may underlie increased sensitivity for bodily symptoms.
authors.affiliation: Department of Psychiatry, Leiden University Medical Centre, Leiden, The Netherlands. j.pannekoek@lumc.nl
authors.forename: Justine Nienke
authors.initials: JN
authors.lastname: Pannekoek
authors.forename: Ilya M
authors.initials: IM
authors.lastname: Veer
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: van Tol
authors.forename: Steven J A
authors.initials: SJ
authors.lastname: van der Werff
authors.forename: Liliana R
authors.initials: LR
authors.lastname: Demenescu
authors.forename: André
authors.initials: A
authors.lastname: Aleman
authors.forename: Dick J
authors.initials: DJ
authors.lastname: Veltman
authors.forename: Frans G
authors.initials: FG
authors.lastname: Zitman
authors.forename: Serge A R B
authors.initials: SA
authors.lastname: Rombouts
authors.forename: Nic J A
authors.initials: NJ
authors.lastname: van der Wee
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D015897:Comorbidity; D004644:Emotions / Q000502:physiology*; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000503:physiopathology* / Q000523:psychology; D010296:Parietal Lobe / Q000503:physiopathology