Potential mechanisms of acupuncture for neuropathic pain based on the somatosensory system

# Acupuncture for Neuropathic Pain: A Therapeutic Approach Through the Somatosensory System

Neuropathic pain represents one of the most complex challenges in modern medicine, affecting more than 7% of the world's population. This devastating condition arises when there are injuries or diseases affecting the somatosensory system — the nerve network responsible for transmitting sensations from the body to the central nervous system. Patients frequently describe the pain as burning, electric shocks, or stabbing, accompanied by hypersensitivity to touch and temperature. Beyond physical suffering, neuropathic pain causes profound impacts on quality of life, leading to depression, anxiety, and functional disability.

Conventional treatment through medications frequently has limited efficacy and significant adverse effects, creating an urgent need for safer and more effective complementary therapies.

This scientific review examined how acupuncture may be a promising treatment for neuropathic pain, analyzing more than 900 studies published over the past two decades. The researchers conducted a comprehensive search of the main medical databases, including English-language articles that investigated the use of manual acupuncture and electroacupuncture in the treatment of neuropathic pain. After rigorous analysis, 388 relevant articles were selected, including 22 clinical studies, 59 systematic reviews and meta-analyses, and 307 experimental studies. The methodology focused specifically on the role of the somatosensory system in mediating the analgesic effects of acupuncture, examining everything from peripheral mechanisms to the brain processes involved in pain relief.

The results demonstrated that acupuncture offers significant benefits for various types of neuropathic pain, including trigeminal neuralgia, sciatic pain, diabetic neuropathy, postherpetic neuralgia, and pain after spinal cord injury. The clinical studies revealed that acupuncture not only reduces pain intensity but also improves nerve function and patients' quality of life. Low-frequency electroacupuncture (2 Hz) proved particularly effective, providing more lasting analgesia than high frequency (100 Hz). The mechanisms of action involve multiple levels of the nervous system: in the periphery, acupuncture reduces the activation of pain-related ion channels such as TRPV1 and P2X3; in the spinal cord, it suppresses activation of glial cells (microglia and astrocytes) that release inflammatory substances; in the brain, it activates descending pain control systems through the release of neurotransmitters such as serotonin, norepinephrine, and endogenous opioid peptides.

For patients, these findings offer real hope for relief without the adverse effects of traditional medications. Acupuncture has been shown to be remarkably safe, with most patients reporting no adverse effects. The treatment can be used alone or in combination with other therapies, offering a personalized approach. For healthcare providers, the results provide robust scientific evidence for incorporating acupuncture into the multidisciplinary management of neuropathic pain.

Appropriate selection of acupoints — local to the area of pain, regional along the affected meridians, or distal based on traditional Chinese medicine theory — allows targeted treatments for different conditions. The frequency and intensity of stimulation can be adjusted according to the patient's individual response.

Despite the promising results, the study acknowledges some important limitations. Heterogeneity between the analyzed studies makes it difficult to establish universal standardized protocols. It is still not fully clarified why some acupoints are more effective than others, or what the precise differences are between manual acupuncture and electroacupuncture for specific conditions. Future research should focus on high-quality clinical trials comparing different acupuncture modalities, establishing optimized protocols for each type of neuropathic pain, and exploring more deeply the neurobiological mechanisms involved.

In conclusion, acupuncture emerges as a valuable and scientifically grounded therapeutic alternative for the treatment of neuropathic pain. By modulating the somatosensory system at multiple levels — from the periphery to the brain — it offers a holistic approach that goes beyond simple symptomatic relief, potentially restoring the natural balance of the body's pain control systems.