When more conservative therapies have failed, the cost and risks of managing pain rise. Increasingly, many healthcare providers are employing a multi-modal approach to pain that includes various forms of neurostimulation.
Neurostimulation is a therapy provided by electrical devices implanted on the nervous system to try to stop or correct the excessive pain signals.
An implantable system delivers electrical pulses via a lead to various parts of the nervous system. Pain signals are inhibited before they reach the brain and replaced with a tingling sensation (parasthesia) that covers the specific areas where the pain was felt. A neurostimulation system consists of 2 implanted components:
Neurostimulator (Pacemaker, IPG)– Rechargeable or non-rechargeable implanted power source that generates electrical pulses according to programmable neurostimulation parameters and features. It contains the lithium battery as well as the electronic circuitry;
Lead – A set of thin wires with a protective coating and electrodes near the tip (percutaneous lead) or on a paddle (surgical lead). The electrodes transmit the electrical pulses to the stimulation site. Percutaneous leads, also known as cylindrical leads, are usually inserted through a needle. Paddle leads, which are like small flat ribbons, instead, require to be placed through an open surgical procedure. There are advantages and disadvantages to each type of lead as well as different indications. These will be discussed with you by the team;
Two external components to a spinal cord stimulation system allow the therapy to be customized for each patient:
Clinician Programmer – Used by the company representatives to program the implanted neurostimulator
Patient Programmer – Patients are given a “downscaled” version of the programmer so that they can, within preset physician parameters, optimize outcomes by adjusting the stimulator.
The electrodes (leads) can be placed on several different structures of the nervous system : the peripheral nerves (usually in the arms or legs), the small nerve fibers under the skin, the spinal cord and/or nerve roots (inside of the spine) and the brain. The electrodes are not placed inside of the nervous structures, but next to them.
The various target areas are not necessarily mutually exclusive, and sometimes more than one area is targeted by the implant.
The decision of where to implant the electrodes as well as what type of electrodes is made by the physician at the time of the evaluation of the patient. The decision is usually made based on the distribution and characteristics of the pain.
The neurostimulator (IPG) is usually implanted under the skin in an area that has some adipose tissue. The most common implant areas are the buttock, the flank, the abdomen and the pectoral area, just under the collarbone.
The wires are then passed under the skin from the electrode implant site to the neurostimulator implant site. At the end of the implant procedure, no wires can be seen outside of the body.