Peripheral Nerve Stimulator Trials and Implants
Peripheral nerve stimulation, frequently referred to as PNS, is a commonly used approach to treat chronic pain. It involves surgery that places a small electrical device (a wire-like electrode) next to one of the peripheral nerves. (These are the nerves that are located beyond the brain or spinal cord). The electrode delivers rapid electrical pulses that are felt like mild tingles (so-called paresthesias). During the testing period (trial), the electrode is connected to an external device, and if the trial is successful, a small generator gets implanted into the patient’s body. Similar to heart pacemakers, electricity is delivered from the generator to the nerve or nerves using one or several electrodes. The patient is able to control stimulation by turning the device on and off and adjusting stimulation parameters as needed.
A common misconception about PNS is that it is a relatively new method that was just recently introduced. In fact, PNS was invented in the mid-1960s, even before the commonly used spinal cord stimulation (SCS). Since that time, PNS has become established for very specific clinical indications, including certain complex regional pain syndromes, pain due to peripheral nerve injuries, etc. Some of the common applications of PNS include treatment of back pain (recently approved in some parts of the world), occipital nerve stimulation for treatment of migraine headaches, and pudendal nerve stimulation that is being investigated for use in urinary bladder incontinence. Despite its long history, the large body of supporting literature, and its official approval in Europe and Australia, peripheral nerve stimulation for pain is still considered “off-label” in the United States.