Differential Modulating Effect of Acupuncture in Patients With Migraine Without Aura: A Resting Functional Magnetic Resonance Study

Migraine is a common and disabling neurologic disorder that affects millions of people worldwide, causing intense pain, nausea, and sensitivity to light and sound. Although medications are available, many have significant side effects and limited efficacy. Acupuncture has emerged as a promising therapeutic alternative, but the neurologic mechanisms by which it exerts its therapeutic effects remain poorly understood.

This innovative study used functional magnetic resonance imaging (fMRI) to investigate how acupuncture modulates brain activity in patients with migraine without aura. The researchers recruited 40 patients with migraine and 16 healthy controls, all of whom underwent neuroimaging to measure regional homogeneity (ReHo), an indicator of local brain activity.

The methodology included a rigorous 6-week acupuncture treatment protocol consisting of 12 sessions of 20 minutes each, twice a week. The acupuncture points selected followed established Chinese guidelines and included GV-20 (Baihui), EX-HN5 (Taiyang), and the bilateral points GB-20 (Fengchi), GB-8 (Shuaigu), GB-5 (Xuanlu), GB-15 (Toulinqi), LI-4 (Hegu), and LR-3 (Taichong). Electroacupuncture was applied at specific points at a frequency of 2 Hz.

The neurologic results were notable. Initially, patients with migraine showed significantly reduced cerebellar activity compared with healthy controls. The cerebellum, traditionally associated with motor control, also plays crucial roles in pain processing and emotional regulation. This finding suggests that cerebellar dysfunction may be an underlying mechanism in the pathophysiology of migraine.

After just one acupuncture session, a significant increase in cerebellar activity was observed, indicating an immediate therapeutic effect. This finding is particularly relevant because it demonstrates that acupuncture can rapidly modulate dysfunctional brain regions associated with migraine.

Even more impressive was the cumulative effect of treatment. After 12 sessions, in addition to continued cerebellar improvement, significant activation of the angular gyrus was observed — a brain region critically involved in pain processing and emotional modulation. The angular gyrus is part of the default mode network and participates in higher cognitive functions, emotional processing, and pain perception.

Clinically, the results were equally impressive. Patients experienced a 70% reduction in migraine days, a 47% decrease in pain intensity, and significant improvements in quality of life. Important assessment scales, including the Migraine-Specific Quality of Life Questionnaire (MSQ), the Self-Rating Anxiety Scale (SAS), and the Self-Rating Depression Scale (SDS), showed sustained improvements.

The most notable aspect was the durability of the effects. During the 24-week follow-up period, all therapeutic benefits were maintained, suggesting that acupuncture induces lasting neuroplastic changes that persist well beyond the active treatment period.

Correlation analyses revealed significant associations between changes in angular gyrus activity and clinical improvements, providing objective evidence that the brain changes observed on neuroimaging correspond directly to the therapeutic benefits experienced by patients.

This study provides robust neurobiologic evidence that acupuncture exerts therapeutic effects through modulation of specific neural circuits involved in pain processing and emotional regulation. The findings suggest a biphasic model of action: immediate effects through normalization of dysfunctional cerebellar function, followed by cumulative effects involving activation of more extensive neural networks related to pain control and emotional well-being.

Limitations include the absence of a sham acupuncture control group, the inability to assess effects during acute migraine episodes, and the lack of neuroimaging during the follow-up period. Future studies should address these limitations to confirm and expand these promising findings.