Peripheral neuropathy (PN) is a condition resulting from damage to the peripheral nerves, which are the communication network outside of the brain and spinal cord. This damage often leads to symptoms like a gradual onset of numbness, tingling, and a sharp, burning, or throbbing pain, most commonly affecting the hands and feet. Managing this discomfort often requires non-pharmacological strategies, such as using a Transcutaneous Electrical Nerve Stimulation (TENS) unit. A TENS unit is a small, battery-powered device that delivers mild, low-voltage electrical pulses through electrodes placed on the skin. This guide provides practical instruction on using this non-invasive tool for self-management of PN pain under the supervision of a healthcare provider.
How TENS Addresses Peripheral Neuropathy Pain
TENS therapy relieves nerve pain primarily through the Gate Control Theory of Pain. This theory suggests that the electrical stimulation activates non-painful sensory nerves, which effectively “closes a gate” in the spinal cord to block or reduce the transmission of painful signals before they can reach the brain.
TENS also stimulates the body’s internal pain-management system. The electrical impulses promote the release of endorphins, natural, opioid-like chemicals that bind to receptor sites in the nervous system to reduce the perception of pain.
These two approaches are often differentiated by the settings used, with high-frequency stimulation primarily targeting the gate control effect and low-frequency stimulation focusing on endorphin release. TENS units offer symptomatic relief by temporarily disrupting pain signals, but the device does not repair the underlying nerve damage causing peripheral neuropathy.
Correct Pad Placement for Neuropathic Symptoms
Effective TENS application requires proper skin preparation to ensure optimal conductivity and pad adhesion. Clean the area where the electrodes will be placed with soap and water, then dry the skin completely before placing the pads. This removes oils or lotions that interfere with the electrical current.
Since peripheral neuropathy often presents in the feet and lower legs, strategic pad placement is necessary. One effective strategy is to place the pads directly over the area of most significant pain, such as the sides or top of the foot. Alternatively, pads can be placed along the path of the nerve that supplies the painful area, often in the calf muscles or thigh.
Pads must be spaced appropriately to allow the current to flow through the target tissue. The electrodes should be at least one to two inches apart, but ideally no more than six inches apart, to ensure the electrical field is concentrated effectively. Avoid placing pads directly over joints, irritated skin, open wounds, or areas where major arteries run close to the surface, such as the front or back of the ankle.
Choosing the Right Program and Intensity
TENS units utilize three primary parameters that can be adjusted to customize the therapy: frequency (measured in Hertz, Hz), pulse width (measured in microseconds, µs), and intensity (measured in milliamperes, mA). For managing acute or sharp neuropathic pain, the high-frequency setting (Conventional TENS) is recommended. This mode uses a high frequency (typically 80 to 130 Hz) and a short pulse width, which immediately engages the gate control mechanism and produces a comfortable, steady buzzing or tingling sensation.
For deeper, chronic pain, a low-frequency setting (Acupuncture-like TENS) may be more effective. This setting uses a low frequency (around 2 to 10 Hz) and often a higher pulse width, which is better at stimulating the release of endorphins. This mode may cause a noticeable muscle twitch or tapping sensation, though it should not be painful.
Regardless of the frequency setting, the intensity must be slowly increased until a strong, yet comfortable, tingling or buzzing sensation is achieved. The sensation should feel robust enough to be a distraction from the pain, but it should never be painful or cause a severe, uncontrolled muscle contraction. Finding this optimal intensity level is necessary for effective treatment.
Important Precautions and When to Avoid TENS Use
While TENS is generally safe, several precautions and contraindications must be respected. TENS should never be used if an individual has an implanted electronic device (e.g., cardiac pacemaker, internal defibrillator, or spinal cord stimulator), as the electrical impulses could interfere with device function.
Specific areas of the body must also be avoided when placing the electrodes. Never place pads over the front or sides of the neck, as this could affect the carotid arteries or cause a dangerous drop in blood pressure. Placement over the head, across the chest, or directly over the eyes is also prohibited.
Individuals with peripheral neuropathy must be cautious about using TENS over areas of skin with impaired sensation. Since the user may not be able to feel the intensity of the current, there is an increased risk of skin irritation or burns if the intensity is set too high. TENS should also be avoided on damaged, infected, or irritated skin.
Typical TENS sessions last between 30 and 60 minutes and can be repeated two to three times daily as needed for relief. Before beginning a TENS regimen, consult with a physician or physical therapist to confirm the diagnosis and receive guidance on appropriate settings and placement.