Peripheral Nerve Stimulation (PNS)

Peripheral nerve stimulators are medical devices. They manage chronic pain by stimulating peripheral nerves that transmit pain with mild electrical impulses. This stimulation disrupts pain signals before they reach the brain.

These specialized devices can help relieve pain when other treatment options have failed.


What is peripheral nerve stimulation?

Peripheral nerve stimulation (PNS) is similar to traditional spinal cord stimulation (SCS). Both use a neuromodulation medical device rather than prescriptive medicine for pain management. Neuromodulation technology uses mild electrical stimulation to mask pain signals before they reach the brain.

The two differ in terms of the positioning of their components. Peripheral nerve stimulation places stimulating leads directly over the nerves at the peripheral region where the pain originates.

Spinal cord stimulation places stimulating leads at specific nerves behind the spinal cord. A doctor will have identified these nerves as the potential carriers of problem chronic pain signals to the patient’s brain.

Depending on the specific device, a peripheral nerve stimulation system’s small stimulator is positioned outside the body or implanted. Usually, the peripheral nerve stimulator system locates the battery outside the body.

Spinal cord stimulation systems implant a stimulator and battery under the skin in the buttocks area.

What are peripheral nerves?

The nervous system of our body has two parts.

The central nervous system includes the brain and spinal cord. The peripheral nervous system branches off the spinal cord and provides for the remainder of the body.

Peripheral nerve stimulation can target peripheral areas such as the knees, shoulders, back, SI joints, foot, and ankle.

Are there different peripheral nerve stimulators that are available?

Multiple FDA-approved peripheral nerve stimulator systems from different companies are currently available. Each system has three major components: a pulse generator (a neurostimulator), a battery, and lead electrodes.

There are three primary differences between each of the systems:

  • Some systems implant the pulse generator in the body. Other systems place it outside the body.
  • Some pulse generators connect wirelessly to an implanted stimulator. Other pulse generators connect directly to the implanted stimulating leads.
  • The uses that the FDA has approved vary with each model of peripheral nerve stimulator.

On a high level, however, all the peripheral nerve stimulation systems work similarly.

Neurostimulation Medical Devices

Two additional classes of neurostimulation systems operate similarly to peripheral nerve stimulation. They are spinal cord stimulators (SCS) and dorsal root ganglion (DRG) stimulation.

How does a peripheral nerve stimulator work?

A patient’s doctor places leads targeted at specific peripheral nerves where the extremity pain occurs. The neurostimulator, when activated, delivers small pulses of mild electric current through the leads to those peripheral nerves. These impulses mask pain signals traveling to the brain.

A patient can control their peripheral nerve stimulator with a remote. The remote can turn the peripheral nerve stimulator on or off and increase or decrease the stimulation level. It can also activate different custom programs to help them handle their pain.

A peripheral nerve stimulator does not eliminate what is causing a patient’s pain. But it does change the way that the brain perceives the pain.

What does peripheral nerve stimulation feel like?

Different peripheral nerve stimulation devices and configurations will handle pain slightly differently. Some may use a slight tingling, called paresthesia, to replace the pain.

Prospective patients should discuss what they should expect with a specific peripheral nerve stimulator with their doctor.

Procedure Details

What are the two stages of the peripheral nerve stimulator implant procedure?

There are two stages involved in the peripheral nerve stimulator procedure.

The first is a trial stage, which is temporary. It helps confirm a patient’s experience in how well a peripheral nerve stimulator may relieve their pain during different activities.

The second is a surgical implant procedure. A decision to proceed will depend on the patient and their doctor’s assessment of the trial’s effectiveness.

How is a peripheral nerve stimulator trial procedure performed?

A peripheral nerve stimulator trial usually occurs at an outpatient surgery center.

  1. Temporary Leads Placed. Using a small insertion device, a doctor will place temporary leads at a patient’s peripheral extremity. The doctor will use a local anesthetic.
  2. Optimal Lead Locations Identified. The doctor will then apply test stimulation. They will ask the patient how they feel to determine the best lead locations. For some device models, there will only be a single lead used.
  3. External Peripheral Nerve Stimulator Connected. The doctor will then connect the leads to a temporary external peripheral nerve stimulator. This device will provide stimulation therapy during the trial.
  4. Trial Peripheral Nerve Stimulator Programmed. The medical team will then program the trial stimulation device. They will customize it specifically for the patient.

How long does a peripheral nerve stimulator trial last?

A peripheral nerve stimulator trial period usually lasts 3 to 5 days.

  • A patient’s doctor will instruct them to try activities that have been difficult because of their pain.
  • The doctor will provide instructions on limits for physical activity to prevent the trial leads from dislodging.
  • Most peripheral nerve stimulation trial systems are not waterproof. The patient must protect the external trial neurostimulator from water during showering or bathing.
  • The benefits of a screening trial may be immediate, or they may take a few days.

After the trial period, a medical professional can remove the trial stimulator leads in a simple office procedure.

How is the permanent peripheral nerve stimulator surgery performed?

Following a successful trial, a patient and their doctor will decide if a permanent implant is a good option.

The permanent implant procedure is similar to a trial procedure. Generally, it occurs at an outpatient surgery center using a local anesthetic before lead insertion.

A doctor places the lead or leads near the nerves they have chosen. They then connect the lead or leads to a small wearable stimulator outside the body.

A small control unit lets a patient turn the stimulator on and off and adjust the stimulation intensity.

There are variations in this procedure according to the specific peripheral nerve stimulator model used.

Risks / Benefits

Are there any adverse side effects associated with a peripheral nerve stimulator?

Each different stimulator model may have its own unique possible adverse side effects. These may include skin irritation, itching, inflammation, pain, and infection at the electrode lead exit site.

Patients should discuss all potential risks with their doctor before undergoing any procedure.

What are the benefits of a peripheral nerve stimulator?

Peripheral nerve stimulators can provide pain relief when other treatment options have failed. They can reduce or even eliminate the need for oral pain medications.

Peripheral nerve stimulators can provide neurostimulation pain relief:

  • Without the need for permanent implants.
  • Without requiring incisions during implantation.
  • Without tissue destruction or nerve damage.
Recovery and Outlook

When happens immediately after the peripheral nerve stimulator implant procedure?

Patients may go home immediately after the procedure and resume normal activities in all but the most unusual cases.

What should you expect when using a peripheral nerve stimulator?

Patients should have realistic expectations about results when deciding to use peripheral nerve stimulation therapy. Some patients will experience significant relief during the trial, while others won’t. Similarly, some patients will experience great results with a permanent implant, while others won’t.

The medical community is still developing screening criteria about which patients may respond best to this therapy. However, this new class of devices enables doctors to do things for patients that were only recently possible.

When To Consider It

Who is a good candidate for a peripheral nerve stimulator?

Suitable candidates for peripheral nerve stimulation have tried conservative treatments without adequate improvement. They are suffering from chronic pain in a peripheral extremity where using a fully implanted spinal cord stimulator isn’t appropriate.

And these candidates also have:

  • Back pain
  • Shoulder joint pain
  • Knee joint pain
  • Head and neck pain
  • Post-amputation pain
  • Pain due to nerve trauma
  • Chronic and acute postoperative pain

Video Overview: Wireless Peripheral Nerve Stimulation

The following video summarizes wireless peripheral nerve stimulation. Other PNS models use a direct wired connection to the leads. However, most of the concepts in this video apply to all models.

Those considering a peripheral nerve stimulator should discuss the pros and cons of these different PNS model approaches with their doctor.