Acupuncture has been recognized as an effective treatment for pain relief, including small fiber neuropathy.
To understand how acupuncture can work in alleviating pain, it is essential to explore the neurophysiological mechanisms involved.
Defining Small Fiber Neuropathy
Small fiber neuropathy is a condition that affects the small nerve fibers in the peripheral nervous system. These nerve fibers transmit sensory information, such as pain signals, from the periphery to the central nervous system. When these fibers are damaged or dysfunctional, it can lead to neuropathic pain.
Small fiber neuropathy is characterized by damage to the small unmyelinated (C fibers) and thinly myelinated (A-delta fibers) sensory fibers, which can lead to symptoms such as pain, dysesthesias, and pruritus.
Small fiber neuropathy can be caused by a range of factors, with some of the most common being diabetes, autoimmune diseases, and infections.
- Diabetes is a leading cause of small fiber neuropathy. High blood sugar levels over an extended period can damage the small nerve fibers, leading to neuropathic pain. It is estimated that around half of all individuals with diabetes will experience some form of neuropathy.
- Autoimmune diseases, such as lupus, Sjogren’s syndrome, and rheumatoid arthritis, can also contribute to the development of small fiber neuropathy. In these conditions, the immune system mistakenly attacks the body’s own tissues, including the small nerve fibers, resulting in pain and discomfort.
- Infections, particularly viral infections like HIV, hepatitis C, and Lyme disease, can also trigger small fiber neuropathy. These infections can directly damage the nerve fibers or activate the body’s immune response, leading to inflammation and subsequent nerve damage.
Symptoms of Small Fiber Neuropathy
The primary symptom of small fiber neuropathy is chronic pain, which can vary in intensity and location. Patients often describe the pain as a burning or tingling sensation, and it may be accompanied by numbness, hypersensitivity to touch, or temperature changes. The pain is typically experienced in the hands and feet, but it can also affect other areas of the body.
Other symptoms of small fiber neuropathy can include impaired balance and coordination, muscle weakness, and changes in skin color or texture. Some individuals may also experience autonomic symptoms, such as changes in blood pressure, heart rate, and digestion.
The chronic pain associated with small fiber neuropathy can have a significant impact on an individual’s quality of life. It can interfere with daily activities, disrupt sleep patterns, and cause emotional distress. Managing and alleviating this pain is crucial for enhancing overall well-being and maintaining functionality.
Mechanisms: How Acupuncture Affects the Body
Acupuncture involves the insertion of thin needles into specific points on the body, known as acupuncture points. These points are believed to be related to meridians or energy pathways in Traditional Chinese Medicine. From a neurophysiological perspective, acupuncture stimulates a complex cascade of events that can modulate pain perception and alleviate neuropathic pain.
One of the key mechanisms by which acupuncture can work is through the activation of the body’s natural pain modulation systems. Acupuncture stimulates the release of endogenous opioids, such as endorphins, enkephalins, and dynorphins. These substances act as natural painkillers and can help reduce pain sensations.
Furthermore, acupuncture can also affect the levels of neurotransmitters in the central nervous system. Studies have shown that acupuncture can increase the levels of serotonin and norepinephrine, which are involved in pain modulation. These neurotransmitters can inhibit pain signals and promote a sense of well-being.
Acupuncture significantly relieves neuropathy pain, possibly by affecting molecules in the peripheral nerves and spinal cord (Cho & Kim, 2021, International Journal of Molecular Sciences).
Acupuncture can also modulate the activity of the autonomic nervous system, specifically the sympathetic and parasympathetic branches. By regulating the balance between these two branches, acupuncture can help reduce pain and promote relaxation.
Additionally, acupuncture can induce local tissue responses, such as the release of adenosine and nitric oxide. Adenosine has analgesic properties and can inhibit pain transmission, while nitric oxide can improve blood flow and promote tissue healing.
Acupunture for Small Fiber Neuropathy
The exact mechanisms of acupuncture in the treatment of SFN-related pain are not fully understood, but several theories have been proposed based on research into acupuncture’s effects on chronic pain and the brain’s reward system. One theory suggests that acupuncture can activate the brain’s reward system, which is involved in the modulation of pain. Pain relief is considered a reward and can activate this system, which is also implicated in the negative reinforcement of pain.
The reward effect of acupuncture in relieving chronic pain may be due to its influence on the brain’s reward circuits, which are involved in both reward and pain processing. This multidimensional pain modulation by acupuncture could explain its effectiveness in providing analgesia.
Furthermore, neuroimaging studies, such as those using positron emission tomography (PET), have shown that acupuncture can alter metabolic patterns in the pain matrix network of the brain, which may predict the therapeutic response to acupuncture in patients with chronic pain. These findings suggest that acupuncture may exert its analgesic effects by modulating brain activity in areas associated with pain perception and processing.
References
- Cho, E.-C., & Kim, W. (2021). International Journal of Molecular Sciences: Discusses the molecular mediation of acupuncture in diabetic neuropathy pain. Effect of Acupuncture on Diabetic Neuropathy: A Narrative Review.
- Hu, W.-C. (2014). viXra: Examines acupuncture’s mechanism involving endorphin activation and stress response. The Underlying Neurobiology Mechanism of Acupuncture and Moxibustion.
- Carlsson, C. (2002). Acupuncture in Medicine: Investigates the peripheral and central mechanisms behind acupuncture’s long-term pain relief effects. Acupuncture Mechanisms for Clinically Relevant Long-Term Effects – Reconsideration and a Hypothesis.
- Richardson, D., & Akil, H. (1975). Stereotactic and Functional Neurosurgery: Proposes a peripheral field effect from acupuncture, involving sensory modulation. A Possible Explanation for the Effect of Acupuncture on Pain.
- Andersson, S., & Lundeberg, T. (1995). Medical hypotheses: Discusses the impact of acupuncture on endogenous pain inhibitory systems. Acupuncture–from empiricism to science: functional background to acupuncture effects in pain and disease.
M.D. Orthopaedic Pain Management - University of São Paulo