Living with chronic pain can affect mobility, sleep, work, exercise, and everyday activities. When pain persists despite conservative treatment, physicians may consider additional pain management options based on the underlying diagnosis. One such option is Percutaneous Electrical Nerve Stimulation (PENS), a minimally invasive technique that uses electrical stimulation delivered through thin needle-like electrodes placed through the skin near targeted nerves or painful areas.
PENS is different from traditional surface-based electrical stimulation because the stimulation is delivered percutaneously rather than through electrodes placed only on the skin. The goal is to modulate pain signaling and potentially reduce pain in appropriately selected patients as part of a broader pain management plan.
What is PENS?
PENS stands for Percutaneous Electrical Nerve Stimulation. During treatment, thin needle electrodes are placed through the skin in the area being treated. Low-voltage electrical stimulation is then delivered through these electrodes.
Because the electrodes pass through the skin, PENS should be accurately described as a minimally invasive procedure. It is not a non-invasive treatment.
The FDA classifies percutaneous electrical nerve stimulators as devices used for pain treatment and distinguishes them from transcutaneous devices by the placement of electrodes percutaneously rather than on the surface of the skin.
How does PENS work?
Pain involves electrical and chemical signals traveling through the nervous system. PENS uses controlled electrical stimulation near selected nerves or tissues with the goal of influencing how pain signals are processed.
Unlike treatments that primarily address inflammation or structural abnormalities, PENS is a form of neuromodulation. The stimulation is intended to modify nerve activity associated with pain.
Research into the precise mechanisms and clinical effectiveness of percutaneous electrical stimulation continues, and results can vary according to the pain condition, treatment technique, and individual patient.
What is the difference between PENS and TENS?
PENS and Transcutaneous Electrical Nerve Stimulation (TENS) both use electrical stimulation, but the method of delivering that stimulation is different.
TENS uses electrodes placed on the surface of the skin. Electrical impulses must therefore pass through the skin before reaching deeper tissues.
PENS, in contrast, uses thin electrodes inserted through the skin so that electrical stimulation can be delivered closer to the targeted area.
This difference is why PENS is classified as a minimally invasive treatment rather than a non-invasive therapy.
What types of chronic pain may be evaluated for PENS?
PENS has been studied in a variety of musculoskeletal and chronic pain conditions. However, it is not appropriate for every patient or every type of pain.
Depending on the diagnosis and individual clinical situation, a physician may consider percutaneous electrical stimulation in patients experiencing conditions such as:
- Chronic musculoskeletal pain
- Persistent neck pain
- Chronic back pain
- Neuropathic or nerve-related pain
- Persistent pain that has not adequately responded to conservative treatment
- Selected chronic pain conditions where neuromodulation may be appropriate
A proper diagnosis is important before considering PENS because similar pain symptoms can originate from very different structures and mechanisms.
PENS for chronic back pain
Chronic back pain can originate from spinal joints, discs, muscles, nerves, or a combination of structures. Because the causes of persistent back pain vary significantly between patients, treatment should be based on a medical evaluation rather than symptoms alone.
For selected patients, PENS may be considered as one component of a broader pain management strategy. Other patients may be better suited for physical therapy, medication management, injections, nerve blocks, radiofrequency procedures, or other interventions depending on the diagnosis.
PENS for neck and nerve-related pain
Persistent neck pain may sometimes occur together with neurological symptoms such as burning, tingling, numbness, or radiating discomfort.
Before considering PENS or another neuromodulation treatment, the source of these symptoms should be evaluated. A neurological assessment may help determine whether symptoms are associated with nerve irritation, spinal pathology, peripheral nerve dysfunction, or another condition.
PENS may then be considered for appropriately selected patients when its mechanism and treatment goals are suitable for the identified pain condition.
What happens during a PENS procedure?
The specific technique can vary according to the area being treated and the patient’s diagnosis. In general, the physician identifies the targeted treatment area and places thin needle-like electrodes through the skin.
Controlled electrical stimulation is then delivered through the electrodes for a prescribed period of time. Patients may feel electrical stimulation, tingling, or other sensations during treatment.
Because PENS involves percutaneous electrode placement, the procedure should be performed using appropriate medical technique by a qualified healthcare professional.
Is PENS painful?
Patient experiences vary. Because thin electrodes pass through the skin, some patients may experience temporary discomfort during placement or stimulation.
Temporary soreness, bruising, bleeding, or aggravation of symptoms have been reported with percutaneous electrical stimulation techniques. Individual risks should be discussed before treatment.
The intensity and location of stimulation can also influence what a patient feels during the procedure.
Is PENS a minimally invasive treatment?
Yes. PENS is a minimally invasive treatment.
This distinction is important because PENS is sometimes confused with non-invasive electrical stimulation therapies. With TENS, electrodes remain on the skin. With PENS, thin electrodes penetrate the skin to deliver stimulation closer to the targeted area.
PENS does not involve traditional open surgery, but the percutaneous placement of electrodes means it should not be described as non-invasive.
What are the potential benefits of PENS?
The primary objective of PENS is pain modulation. Research has evaluated its potential effects on pain intensity and pain-related function in musculoskeletal conditions.
Potential treatment goals may include:
- Reducing chronic pain intensity
- Modulating nerve-related pain signals
- Improving tolerance for movement and activity
- Supporting participation in rehabilitation when pain is limiting progress
- Providing an additional option when appropriate conservative treatments have not produced adequate relief
However, PENS should not be presented as a guaranteed solution for chronic pain. Research has found potential reductions in pain in some musculoskeletal conditions, but the overall evidence remains limited and heterogeneous. Treatment response varies between patients.
How effective is PENS for chronic pain?
Research on PENS has produced promising but mixed findings. Systematic reviews have reported reductions in pain intensity in some patients with musculoskeletal pain, while also emphasizing limitations in the available evidence.
Some studies suggest that PENS may reduce pain in the short term, but evidence regarding improvements in disability and sustained long-term benefits is less certain.
Research comparing PENS with TENS has also not established that PENS is consistently superior. For this reason, PENS should be considered based on an individual patient’s diagnosis, previous treatment, symptoms, and overall treatment goals rather than being viewed as universally preferable to other pain therapies.
Who may be a candidate for PENS?
PENS may be considered for selected patients with persistent pain after a medical evaluation has identified the likely source and mechanism of their symptoms.
A physician may review:
- The location and duration of pain
- The suspected source of symptoms
- Whether pain appears musculoskeletal, neuropathic, or mixed
- Previous treatments and the patient’s response
- Medical history and medications
- Other conditions that could affect treatment safety
Not every patient with chronic pain is a candidate for PENS, and other treatments may be more appropriate depending on the diagnosis.
What happens before PENS treatment?
A detailed evaluation should occur before treatment. Chronic pain is not a single diagnosis, and determining its source is essential for choosing an appropriate intervention.
Evaluation may include:
- A detailed medical history
- Physical and neurological examination
- Assessment of strength, sensation, and mobility
- Review of MRI, X-ray, CT, or other imaging when appropriate
- Electrodiagnostic testing when neurological symptoms warrant further evaluation
- Review of previous pain treatments
This information helps determine whether PENS, another interventional procedure, rehabilitation, or a combination of approaches may be appropriate.
How does PENS fit into interventional pain management?
Chronic pain treatment often requires more than one approach. PENS may be used as part of an individualized treatment strategy rather than as an isolated solution.
Depending on the diagnosis, pain management treatment may also include:
- Medication management when appropriate
- Physical therapy and rehabilitation
- Epidural injections
- Nerve blocks
- Radiofrequency ablation
- Other advanced interventional procedures when medically appropriate
The objective is to select treatment based on the underlying pain generator and individual patient needs.
PENS vs. injections and nerve blocks
PENS, injections, and nerve blocks are different procedures with different mechanisms and purposes.
For example, an epidural injection may be considered when inflammation around a spinal nerve root contributes to radicular pain. A nerve block may target a particular nerve or group of nerves for diagnostic or therapeutic purposes. PENS instead uses electrical stimulation to influence pain signaling.
These treatments are therefore not interchangeable. A specialist can determine which approach is most appropriate based on the patient’s diagnosis and clinical findings.
When should you see a specialist for chronic pain?
Chronic pain generally warrants further evaluation when it persists for months, interferes with daily activities, or does not respond adequately to initial treatment.
Specialized evaluation may be appropriate when:
- Pain continues despite conservative treatment
- Pain significantly limits movement, sleep, work, or daily activities
- Numbness, tingling, burning, or weakness occurs with pain
- The source of persistent pain remains unclear
- Previous treatments have provided only temporary or inadequate improvement
- A patient is being evaluated for advanced or minimally invasive pain management options
The purpose of specialist evaluation is to identify the source of symptoms and determine which treatment options are medically appropriate.
PENS and minimally invasive chronic pain treatment
For patients dealing with persistent pain, PENS represents one of several minimally invasive approaches that may be considered when clinically appropriate. Its use of percutaneous electrical stimulation distinguishes it from surface-based electrical therapies such as TENS.
At Allied Neurology & Interventional Pain Practice, chronic pain treatment begins with determining the source of symptoms and developing an individualized strategy. Depending on the patient’s diagnosis, this may involve rehabilitation, neurological pain management, injections, nerve blocks, radiofrequency procedures, or other advanced treatments.
With more than 35 years of experience and triple board certification, Dr. Dariusz Nasiek, MD, provides neurological and interventional pain care for patients with chronic and complex pain conditions in New Jersey and New York.
