Introduction
Peripheral nerve stimulation (PNS) is a technique for providing relief for chronic ongoing pain associated with a range of medical conditions. It is a relatively new treatment developed in the late 1990s based on the field of neuromodulation, first used in the 1970s for spinal cord stimulation.
Neuromodulation is a mechanism for changing pain signal transmission in the nerves using small electric currents delivered to the nerves using small electrodes.
Research indicates that, although it does not help everyone, on average pain is reduced by around 50%, and around 70% of patients report decreased pain after having a peripheral nerve stimulator implanted.
Indications
Pain associated with the following conditions may be significantly alleviated by PNS…
- Neuropathic pain.
- Certain forms of back pain.
- Complex regional pain syndrome.
- Occipital neuralgia.
- Post-surgical pain.
- Post traumatic pain.
- Shingles.
In some cases, pain may not be completely eliminated, however if it is substantially reduced, it can reduce reliance on pain medication.
Peripheral nerve stimulation is often recommended where other treatments such as nerve blocks or radiofrequency neurotomy have not helped.
Preoperative Instructions
We will ask you to complete a pain chart and a pain diary to record your levels of pain over a 7 day period prior to the procedure. On the pain chart indicate which parts of the body are impacted by pain. The pain diary is a record of levels of pain over the period, noting any changes over each day. There is also a short survey which asks you to describe in a few words the type of pain that you have.
You should avoid undergoing any other medical procedures, such as for example dental treatment or a colonoscopy, within 48 hours of the procedure (before or after).
Do not eat or drink anything, or smoke, in the 6 hours immediately before the procedure (although any medication can continue to be taken with small sips of water). Medication for diabetes should not be taken until after the procedure.
If you are taking any medication containing aspirin (or other blood thinning medication), you should stop taking this at least 11 days before the procedure.
Please also let us know ahead of the procedure if…
- You have any allergies.
- You have high blood pressure.
- You have or have had any bleeding or blood clotting issues (e.g. DVT – deep vein thrombosis or pulmonary emboli in the lungs).
- You are taking any antibiotics.
- You have a pacemaker or defibrillator.
- You are ill (in which case we may need to postpone the procedure).
You should also not drive yourself to or from the appointment.
Procedure
The procedure is in two stages – in the first stage electrodes are implanted along the target nerves with the ends of the wires that connect to the device exposed above the skin. These are then connected to a portable stimulation device for about 10 days after the procedure and the effectiveness of the stimulator is assessed.
If the stimulator is providing a marked reduction in pain levels, stage two involves the permanent insertion under the skin of a miniature stimulator equipped with a battery. Placement is generally in the chest, back or abdominal cavity. This is a permanent installation, with the batteries capable of being recharged without removal, with an overall battery lifespan of 5-15 years (depending on the setting of the stimulator).
Postoperative Instructions
After both stages there will be some pain at the insertion site for around 48 hours. During this time you should not lift anything, and not stretch, twist or bend over further than 45 degrees. The dressing on the incision must be kept dry (i.e. no showers of baths) and you will be checked frequently for any signs of infection at the insertion site.
Where stage one does not result in marked pain reduction, the electrodes will be removed in a short procedure.
Risks
The procedure to test and install a peripheral nerve stimulator is a very low risk procedure, however all medical treatment comes with some level of risk. Possible complications may include…
- Failure of device.
- Electrode failure / displacement.
- Bleeding.
- Infection.
- Pain at insertion site.
- Allergic reaction to anaesthetic.
- Blood clots (i.e. DVT or pulmonary embolism).
- Permanent nerve damage may occur, but is very rare.
If you experience severe pain or weakness, any swelling or infection at the incision site or your temperature is over 38C, you should let us know urgently or visit the nearest emergency department.