I read a study recently about the reduction of pain scores and opioid usage during the first week after percutaneous peripheral nerve stimulation implantation. It demonstrated that the electrical stimulation is effective in reducing patient pain and the use of narcotics in treating that pain. Therefore, it is looking like PNS might someday be a viable option to discuss for treating severe pain.

So, how does peripheral nerve stimulation work? It is a minimally invasive surgery that places a small electrical device (a thin, wire-like electrode) next to one of your peripheral nerves, in your region of pain. The electrode then delivers rapid electrical pulses, at a set frequency, that feel like a mild tingling sensation, or what is called paresthesias. This stimulation can also be referred to as neuromodulation. Simply put, the idea is that, with this stimulation, over time, it will change how the nervous system works, what is sent by the body as a pain signal and how the brain processes pain. Essentially, the electrical pulses interrupt or change the pain signals sent from the nerve to the brain.

How do you know if you are a candidate?

If you have been living with chronic pain, you likely have tried more medications than you can remember, possibly physical therapy, maybe steroid injections or nerve blocks, all with little-to-no or inconsistent relief. You may have already talked with your doctor about a spinal cord stimulator, or SCS.

Peripheral Nerve Stimulation, or PNS, has been around for over 50 years. However, in the past few years, there has been a mini revolution in the devices delivering the stimulation.

For years, we have used devices designed for spinal cord stimulation (SCS) to stimulate the peripheral nerves. But SCS devices are made to be implanted near the spinal cord, a location larger , and broader, then many peripheral nerve sites a doctor may want, and need, to reach in the body. At this time, the PNS is also, usually temporary and externally located. The SCS is a permanent implant.

Now, thanks to nanotechnology, nerve stimulation implants have shrunk—enabling a new age of potential PNS devices use.  Some PNS are a fraction of the size of a spinal cord stimulator devices, and new PNS devices are easier to implant and can be placed using ultrasound guidance.

PNS devices and their protocols differ, but each has three basic components:

• a battery or power source

• a thin wire connected to electrodes that deliver the pulses to the peripheral nerve

• a remote control-type device that allows the patient to adjust the pulse settings.

The PNS device is implanted by an anesthesiologist, physiatrist, neurologist, or neurosurgeon who has been specially trained to perform the procedure. The implantation is conducted as an outpatient procedure that takes less than an hour.

Because the implant is so small, it can be implanted fairly painlessly. You would be mildly sedated during the procedure and a physician would use local anesthetic on your skin, then making a small incision or use a small needle to insert the device wire under the skin near the targeted peripheral nerve.

Please note, PNS does differ from other electrical stimulation systems, such as SCS and TENS units. For example,

• Spinal cord stimulation delivers electrical impulses to the spinal cord versus directly to the peripheral nerve.

• Transcutaneous electrical nerve stimulation (TENS) delivers stimulation by using pads placed on the skin over painful parts of the body. There is no implant.  

PNS can treat these pain conditions:

• complex regional pain syndrome (CRPS/RSD)

• diabetic peripheral neuropathy

• foot pain

• headache disorders, including episodic cluster headache, chronic migraine, occipital neuralgia

• ilioinguinal neuralgia (pain in lower abdomen and upper thigh)

• intercostal neuralgia (pain in chest wall and upper trunk)

• lateral femoral cutaneous neuropathy (pain in outer thigh)

• low back pain

• neck pain

• pain following hernia surgery or knee surgery

• painful nerve injuries

• peripheral vascular disease neuropathy

• post-amputation (stump) pain or phantom limb pain

• post-herpetic neuralgia (burning pain caused by shingles)

• post-thoracotomy syndrome (pain persists along a thoracotomy incision)

• trigeminal neuralgia (pain in the face)

Note that if you have  severe trunk, abdomen, or lower extremity pain, you will want to talk to your doctor dorsal root ganglion (DRG) stimulation instead. The dorsal nerve root is a cluster of nerve cells near the spinal cord. The dorsal nerves are a sort of an intermediary between the spinal cord and the peripheral nerves. They send pain signals from the peripheral nerves to the spinal cord and are more effective at treating severe pain in this area of the body.

Talk to your pain specialist about the many options available as well as the technologies that are in the works and may be available down the road, as a part of your treatment.