Individuals with vs without migraine may have altered connections between the somatosensory cortex and the frontal lobe, according to a study published in the Journal of Headache and Pain.

Migraine was found to be associated with resting state aberrant functional connectivity. In this study, investigators sought to examine functional connectivity in the task-related networks of individuals with migraine using magnetoencephalography (MEG). This is the first study to apply network analysis across a wide frequency range under somatosensory stimuli.

Right-handed patients with migraine without aura (interictal phase; n=22; mean age, 29.27; 68.2% women; mean illness duration, 12.70 years; 36% and 64% with bilateral and unilateral migraine, respectively) and sex- and age-matched healthy controls (n=22; mean age, 28.14; 68.2% women) underwent whole-head MEG, magnetic resonance imaging, and frequency-specific network analysis. A 0.2-msec electrical stimulus was delivered to the right wrist median nerve of each individual. MEG scans were conducted and analyzed in a 1- to 1000-Hz frequency range across multiple bands.

Functional connectivity was increased between the somatosensory cortex and frontal lobe in the high-frequency (250-1000 Hz) range in participants with migraine vs healthy controls. Patients with vs without migraine were found to have a larger degree of connectivity in the theta (4-8 Hz), beta (13-30 Hz), and gamma (30-80 Hz) bands; a greater connectivity strength in the beta and gamma bands; longer pathway length in the beta, gamma, and ripple (80-250 Hz) bands; and an increase in the clustering coefficient for the theta, beta, and gamma bands. These results suggest the existence of elevated cortical networks in individuals with migraine.

No correlations were detected between brain network topographic patterns and migraine clinical features (P >.05). Positive correlations were established between pathway length and headache frequency in both the delta (r=0.525; P =.012) and gamma (r=.565; P =.006) bands, as well as between theta band strength and headache duration (r=.490; P =.021).

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Study limitations include the inclusion of right hand-dominant participants and a small sample size.

“This alteration in functional connectivity may be involved in somatosensory processing in [patients with] migraine and may contribute to understanding migraine pathophysiology and to providing convincing evidence for a spatially targeted migraine therapy,” noted the authors.

Reference

Ren J, Xiang J, Chen Y, Li F, Wu T, Shi J. Abnormal functional connectivity under somatosensory stimulation in migraine: a multi-frequency magnetoencephalography study. J Headache Pain. 2019;20(1):3.

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