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 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.

Results

Amygdala connectivity in both migraine with aura (MWA) and MWoA was increased to the visceroceptive insula relative to healthy subjects and two other chronic pain conditions not associated with CSD: trigeminal neuralgia (TGN) and carpal tunnel syndrome (CTS).

Conclusion

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.