title: The missing link: enhanced functional connectivity between amygdala and visceroceptive cortex in migraine.
abstract: BACKGROUND
  Migraine is a neurovascular disorder in which altered functional connectivity between pain-modulating circuits and the limbic system may play a role. Cortical spreading depression (CSD), which underlies migraine aura (MWA), induces C-fos expression in the amygdala. The role of CSD and amygdala connectivity in migraine without aura (MwoA) is less clear and may differentiate migraine from other chronic pain disorders.
  
  
  METHODS
  Using resting-state functional MRI, we compared functional connectivity between the amygdala and the cortex in MWA and MWoA patients as well as in healthy subjects and in two other chronic pain conditions not associated with CSD: trigeminal neuralgia (TGN) and carpal tunnel syndrome (CTS).
  
  
  RESULTS
  Amygdala connectivity in both MWA and MWoA was increased to the visceroceptive insula relative to all other groups examined.
  
  
  CONCLUSIONS
  The observed increased connectivity within the limbic/viscerosensory network, present only in migraineurs, adds to the evidence of a neurolimbic pain network dysfunction and may reflect repetitive episodes of CSD leading to the development of migraine pain.
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, MA, USA.
authors.forename: Nouchine
authors.initials: N
authors.lastname: Hadjikhani
authors.forename: Noreen
authors.initials: N
authors.lastname: Ward
authors.forename: Jasmine
authors.initials: J
authors.lastname: Boshyan
authors.forename: Vitaly
authors.initials: V
authors.lastname: Napadow
authors.forename: Yumi
authors.initials: Y
authors.lastname: Maeda
authors.forename: Andrea
authors.initials: A
authors.lastname: Truini
authors.forename: Francesca
authors.initials: F
authors.lastname: Caramia
authors.forename: Emanuele
authors.initials: E
authors.lastname: Tinelli
authors.forename: Caterina
authors.initials: C
authors.lastname: Mainero
mesh_terms: D000679:Amygdala / Q000503:physiopathology*; D001931:Brain Mapping; D006801:Humans; D008279:Magnetic Resonance Imaging; D020325:Migraine with Aura / Q000503:physiopathology*; D020326:Migraine without Aura / Q000503:physiopathology*; D009434:Neural Pathways / Q000503:physiopathology; D013003:Somatosensory Cortex / Q000503:physiopathology*
keywords: Migraine; amygdala; cortical spreading depression; insula; neurolimbic pain network