Brain sensory network activity underlies reduced nociceptive initiated and nociplastic pain via acupuncture in fibromyalgia.

Fibromyalgia is a chronic condition causing widespread pain throughout the body, along with fatigue and heightened sensitivity to touch and pressure. Pain in fibromyalgia comes from two sources: signals from the body detecting tissue damage (nociceptive pain) and abnormal brain processing of those signals (nociplastic pain). Researchers wanted to understand how electroacupuncture—acupuncture using mild electrical stimulation—affects both types of pain.

This study included 44 women with fibromyalgia who received either electroacupuncture or a sham treatment (inactive laser) twice weekly for four weeks. Researchers used brain imaging (fMRI) and pressure-pain tests before and after treatment to measure changes in pain tolerance and brain activity.

Results showed that electroacupuncture increased participants' tolerance to pressure pain and reduced widespread body pain. Brain scans revealed increased activity in the primary somatosensory cortex—the brain region that processes touch and pain signals from the body. Stronger connections between sensory and emotional processing brain regions also developed. These findings suggest electroacupuncture works through a "bottom-up" pathway, meaning it starts by changing how the body sends pain signals, which then influences how the brain interprets pain.

In contrast, the sham treatment only affected "top-down" brain pathways related to expectations and beliefs about treatment, without changing actual pain signal processing.

For patients with fibromyalgia experiencing both body-based and brain-based pain, electroacupuncture may offer meaningful relief by addressing both pain mechanisms. The treatment appears particularly beneficial for those with increased pain sensitivity and widespread symptoms. To explore this option, seek care from a licensed acupuncturist with experience treating chronic pain conditions.

This randomized controlled trial (n=44 female fibromyalgia patients) investigated neural mechanisms underlying electroacupuncture's effects on nociceptive and nociplastic pain. Participants received electroacupuncture (n=19) or sham laser treatment (n=25) biweekly for four weeks, with fMRI assessment during evoked pressure-pain stimulation pre- and post-intervention.

Electroacupuncture significantly increased pressure-pain tolerance while reducing widespread pain. Mediation analysis revealed this clinical improvement was associated with increased primary somatosensory cortex (S1) activation and enhanced S1-insula functional connectivity during nociceptive stimulation, consistent with bottom-up sensory processing. Conversely, sham treatment reduced widespread pain through decreased precuneus activity and precuneus-insula connectivity, reflecting top-down cognitive-affective modulation without peripheral nociceptive changes.

Findings demonstrate mechanistic dissociation between verum and sham acupuncture: electroacupuncture modulates both peripheral nociceptive input and central nociplastic processing through sensory network engagement, while sham effects operate exclusively via descending pain modulation. This supports electroacupuncture for fibromyalgia patients with both pain phenotypes and may inform patient selection criteria for optimizing acupuncture interventions in chronic pain populations.