Nerve pain, medically known as neuropathic pain, is chronic discomfort caused by damage or disease affecting the somatosensory nervous system. Unlike typical pain that signals tissue damage, neuropathic pain results from malfunctioning nerves sending faulty signals to the brain. People often describe this pain as burning, shooting, stabbing, or an electric shock sensation, which is difficult to manage with standard medications. Electrical stimulation (ES) uses controlled electrical impulses to modulate these faulty pain signals. This non-pharmacological approach offers an alternative for individuals whose chronic nerve pain has not responded adequately to traditional treatments.
How Electrical Signals Interrupt Pain Transmission
The application of electrical impulses disrupts the transmission of pain signals traveling from the body to the brain. The primary mechanism involves the Gate Control Theory of pain: activating large, non-pain-carrying nerve fibers (A-beta fibers) inhibits the transmission of pain signals carried by smaller fibers. By delivering a mild electrical current, ES essentially “closes the gate” in the spinal cord, preventing the pain message from ascending to the brain. This process creates a sensation of tingling or buzzing that replaces the feeling of pain.
Electrical stimulation also activates the body’s natural pain-dampening system, known as endogenous analgesia. The electrical currents stimulate the release of naturally occurring pain-relieving chemicals, such as endorphins, enkephalins, and dynorphins. These chemicals act as endogenous opioids, binding to receptors in the central nervous system to reduce pain perception. Different stimulation frequencies prioritize these mechanisms; high-frequency stimulation often relies on the “gate control” effect, while low-frequency stimulation promotes greater endogenous opioid release.
Non-Invasive and Implantable Devices
Electrical stimulation therapy is delivered through external, non-invasive units or surgically implanted systems. The most accessible method is Transcutaneous Electrical Nerve Stimulation (TENS), which uses small, battery-operated units to deliver low-voltage electrical currents through electrodes placed on the skin. TENS is a non-invasive, low-risk option used for localized nerve pain, often providing temporary relief that patients can manage at home.
More advanced options are available for patients with severe pain that does not respond to external treatments. Spinal Cord Stimulation (SCS) involves a minimally invasive surgical procedure to implant electrodes into the epidural space near the spinal cord. This system delivers electrical pulses directly to the spinal column nerves, masking widespread or complex pain, such as that caused by failed back surgery syndrome.
Targeted Implantable Devices
Peripheral Nerve Stimulation (PNS) and Dorsal Root Ganglion (DRG) stimulation are related implantable methods. They target specific, individual nerves or clusters of nerve cells, making them ideal for highly localized pain in areas like the foot or shoulder. The choice between these devices depends on the location and complexity of the patient’s nerve pain.
Clinical Suitability and Expected Outcomes
Electrical stimulation is a valuable therapeutic tool for specific chronic nerve pain conditions. Spinal Cord Stimulation (SCS) is frequently used for conditions such as Complex Regional Pain Syndrome (CRPS), persistent pain after spine surgery, and intractable neuropathies. Clinical trials report that SCS can reduce chronic neuropathic pain scores by up to 50%. Peripheral Nerve Stimulation (PNS) is highly effective for localized neuropathies, with studies showing significant pain reduction and functional improvement.
For diabetic peripheral neuropathy, electrical stimulation can be an effective adjunctive therapy, showing subjective improvement in symptoms for many patients. The goal of these therapies is generally not to eliminate pain entirely but to provide a meaningful reduction—often defined as a 50% decrease—that improves quality of life and reduces dependence on pain medication. Patients receiving an implantable device, such as SCS, undergo a temporary trial period to ensure substantial pain relief before the permanent system is placed.
Safety Considerations and Accessibility
Electrical stimulation is generally considered a safe treatment, but important contraindications exist. ES should not be used on patients who have an implanted electronic device, such as a cardiac pacemaker or defibrillator, as electrical currents can interfere with their function.
Absolute contraindications include applying stimulation:
- Over an area of active malignancy or cancer.
- Over the anterior neck (carotid sinus).
- Across the chest.
Pregnant individuals are advised to avoid electrical stimulation, as the effects on the fetus are not fully established. Minor side effects from TENS units are rare but can include skin irritation or redness at the electrode placement site. Accessing electrical stimulation often begins with a referral to a pain specialist, who determines clinical suitability. Implantable devices require a trial period and potential insurance authorization due to their higher cost.