Potential mechanisms of acupuncture in regulating neuroinflammation and central sensitization in chronic pain: a narrative review of preclinical, clinical, and translational evidence.

Chronic pain (CP) is not a single disease. Its mechanisms vary across patients and pain phenotypes. In many cases, persistent pain is related to neuroinflammation and central sensitization. Acupuncture, especially electroacupuncture, is widely used in clinical practice. Recent evidence suggests that acupuncture may provide more than a short-time pain relief, potentially by modulating neuroinflammation and central sensitization. However, the relationships among acupuncture, neuroinflammatory regulation, central sensitization, and phenotype-specific clinical responses remain unclear. This narrative review summarizes studies in this field. We searched PubMed for articles published between January 2016 and February 2026 and screened references of relevant publications. Some earlier landmark studies were also included to explain key concepts. Experimental studies suggest that acupuncture potentially regulates central sensitization by influencing spinal glial activation, synaptic plasticity, descending pain inhibitory pathways, and autonomic-immune interactions. Clinical studies show more heterogeneous results. Patients with more central sensitization-related symptoms may experience improvements not only in pain intensity but also in sleep quality, fatigue, mood, and overall quality of life. In CP with mixed mechanisms, acupuncture may facilitate symptom relief and functional recovery. In neuropathic pain, measures such as allodynia, hyperalgesia, and other sensory symptoms may better reflect treatment response than pain intensity alone. Tools including the Central Sensitization Inventory, quantitative sensory testing, conditioned pain modulation, functional magnetic resonance imaging, and related biomarkers potentially help explain inter-individual differences in treatment responses. Current evidence is limited by heterogeneity in patient selection, acupuncture parameters, outcome measures, and the weak mechanistic links between preclinical findings and clinical endpoints.