No abstract

Objective We examined the functional connectivity (FC) in patients with migraine compared with healthy subjects before and after C2 peripheral nerve field stimulation with electroacupuncture (EA-C2-PNfS) to evaluate the effect of EA-C2-PNfS and elucidate the mechanism of migraine. Methods Twenty-six patients with migraine and 24 healthy controls were recruited. All patients underwent resting state functional magnetic resonance imaging before and after 3 months of EA-C2-PNfS. We evaluated a numerical rating scale, the Headache Impact Test, and the Self-Rating Depression Scale, which assesses depression. Healthy controls underwent magnetic resonance imaging twice at a 3-month interval without acupuncture. An analysis of FC in the region of interest in the pain matrix was performed. Results Twenty patients with migraine and 23 healthy controls (mean ± standard deviation: 44.9 ± 12.9 years of age) were included. Three patients had migraine with aura (55.0 ± 18.0 years of age), 11 patients had migraine without aura (MWoA) (45.6 ± 14.6 years of age), and six patients had chronic migraine (40.8 ± 13.9 years of age). The clinical assessments significantly improved after EA-C2-PNfS in the MWoA group only. In FC analysis, the MWoA group showed a significant decrease after EA-C2-PNfS in FC between the right hypothalamus and left insula. Right hypothalamus–related FC was lower before acupuncture in the chronic migraine group than in the MWoA group. Conclusion After EA-C2-PNfS for MWoA, significant changes in FC were observed at the hypothalamus and insula. Our results indicate that EA-C2-PNfS could improve migraine headache by modifying pain-related FC.

No abstract

Magnetic resonance imaging (MRI) has been used to investigate migraine pathophysiology because it is a non-invasive technique. The main aim of clinical imaging for patients with headaches is to exclude secondary headaches due to organic lesions. Conventional structural imaging techniques such as routine MRI demonstrate white matter lesions, changes in gray matter volume or cortical thickness, and cerebral blood flow in patients with migraine. Changes in metabolite levels are observed by magnetic resonance spectroscopy. Diffusion tensor imaging, neurite orientation dispersion, density imaging, and functional MRI reveal dynamic real-time functional changes in brain microstructures. These analyses have been applied not only for comparing patients with migraine and healthy controls but also for understanding the dynamic changes in brain function during the cyclic migraine ictal phase. Although these analyses have demonstrated migraine pathophysiology, there are still many limitations. Following the improvement in imaging technology, further research on this topic is in progress.