Enhanced Pain-Induced Activation of Pain Processing Regions in Interictal Episodic Migraine (S32.004)

Objective: To investigate the interictal migraine brain response to noxious somatosensory stimuli using functional magnetic resonance imaging (fMRI). Background: Migraine consists of recurrent attacks of headache and prominent hypersensitivities to stimuli. Between attacks migraineurs have persistent hypersensitivities and hypervigilance regarding their next migraine. Based upon these symptoms and prior studies, we anticipated migraineurs would have atypical pain-induced activation of pain processing regions. However, this study used a whole-brain analysis to identify specific regions with aberrant pain-induced activation in migraine, yielding insights into particular aspects of pain processing that are atypical in migraine. Methods: fMRI assessed whole brain responses to moderately painful heat applied to the left forearm in 24 adult interictal episodic migraine subjects and 27 healthy controls. Regions that had significant differential activation in migraine subjects compared to control subjects were identified. Pain-induced changes in blood-oxygenation level dependent (BOLD) signal in these identified regions were correlated with headache frequency and number of years with migraine. Results: Migraineurs had greater pain-induced activation of lentiform nucleus, fusiform gyrus, subthalamic nucleus, hippocampus, middle cingulate cortex, premotor cortex, somatosensory cortex and dorsolateral prefrontal cortex, and less activation in precentral gyrus and superior temporal gyrus. There were significant correlations between activation strength and headache frequency for the middle cingulate (r=0.627, p=.001), right dorsolateral prefrontal cortex (r=.568, p=.004), left fusiform gyrus (r=0.487, p=.016), left precentral gyrus (r=.415, p=.044), and left hippocampus (r=0.404, p=.05) and with number of migraine years for left fusiform gyrus (r=0.425, p=.038). Conclusions: The interictal migraine brain has enhanced pain-induced activation of brain regions that participate in different aspects of pain processing. However, the majority of regions with enhanced activation participate in cognitive aspects of pain perception. Enhanced cognitive processing of pain by interictal migraineurs may reflect a cerebral hypersensitivity related to high expectations and hypervigilance for pain. Study supported by: NIHK23NS070891 Disclosure: Dr. Schwedt has received personal compensation for activities with Allergan. Dr. Schwedt has received personal compensation in an editorial capacity from the American Headache Society and from the American Academy of Pain Medicine. Dr. Schwedt has received research support from Merck. Dr. Chong has nothing to disclose. Dr. Chiang has nothing to disclose. Dr. Baxter has nothing to disclose. Dr. Schlaggar has nothing to disclose. Dr. Dodick has received personal compensation for activities with Allergan, Inc., Pfizer Inc., Merck & Co., Inc., ENeura NuPathe, Colucid, Alder, Artaeus, Eli Lilly & Company, Amgen Inc., WL Gore, Bristol-Myers Squibb Company, Ethicon J&J, ATI, Zogenix, Cognimed, Intramed, Scientiae, Syndergy, Curatio CME, and Pfizer Inc. Dr. Dodick has received personal compensation in an editorial capacity for Sage Publishing, Lippincott, Oxford University Press, Cambridge University Press, UpToDate, and Web MD.