# Brain Sensory Network Activity Underlies Reduced Nociceptive-Initiated and Nociplastic Pain via Acupuncture in Fibromyalgia

## TL;DR

The study shows how acupuncture reduces pain in fibromyalgia by altering brain activity and connections related to pain processing.

## Contribution

The study reveals that acupuncture uses a bottom-up mechanism involving sensory brain networks to reduce nociplastic pain.

## Key findings

- Electroacupuncture increased somatosensory activation and connectivity, reducing central nociplastic pain.
- Sham treatment reduced pain via decreased precuneus activation and connectivity.
- Acupuncture's analgesic effect involves afferent input modulating central sensory networks.

## Abstract

Chronic pain may arise from overlapping pain pathways, including nociceptive pain driven by peripheral tissue damage and nociplastic pain arising from central nervous system dysregulation, as seen in fibromyalgia. This study investigated how electroacupuncture (EA) produces analgesia by modulating these pain mechanisms via changes in brain activation and functional connectivity (FC). Following 4-weeks of EA, reductions in widespread pain, a marker of central nociplastic pain, were associated with increased pressure-pain tolerance to peripheral nociceptive stimuli. This nociplastic-nociceptive relationship was mediated by increased somatosensory activation (S1) and S1–insula FC, suggesting that EA operates through a “bottom-up” mechanism of action: afferent input from the needle modulates central sensory networks to reduce nociplastic pain. In contrast, the sham group reduced widespread pain via a “top-down” centrally inhibiting mechanism, characterized by decreased precuneus activation and reduced precuneus–insula FC. These findings elucidate contributions of bottom-up versus top-down circuits in mediating pain relief.