Chronic pain conditions are well known but not always understood. This article refers to the use of a spinal cord stimulator for those patients suffering from Chronic Regional Pain Syndrome (CRPS). This condition has previously been referred to as Causalgia, or Reflex Sympathetic Dystrophy. Its symptoms include changes in the skin, sweating, temperature, circulation and pain that increases over time, and it usually occurs after an injury is sustained.
For some chronic pain conditions a spinal cord stimulator may be implanted, if all other treatment options have been exhausted. Usually the patient will have tried physiotherapy, combinations of painkillers and nerve blockers, TENS, desensitisation techniques and any other applicable treatments. If other treatments fail, a spinal cord stimulator can be implanted in some patients, to provide long-lasting pain relief which then allows the patient to enjoy a better quality of life.
The patient must go through medical and psychological testing before a decision is made about implantation. Because the stimulator is often the last option for patients who have exhausted all other pain relief methods, it is important that the patient will be able to deal with the possibility that the device may not work for them. Implantation of the device requires major surgery, and is a decision which must be carefully considered, both by the patient and the medical practitioners involved.
The stimulator consists of a small round electromagnetic device and one or two leads, each with electrodes at the end. The electrodes are attached to the spinal column, although the placement will depend upon where the patient requires pain relief. Usually the electrodes will be placed somewhere along the thoracic spine. A small channel is then created beneath the muscle, and the leads are fed through to the abdomen or buttocks, where they attach to the device.
Pain signals travel from the affected area to the spinal column, from where the brain processes the signal. The purpose of the stimulator (also referred to as a neurostimulator) is to create small electrical impulses between the site of pain and the spinal column, disrupting the brain’s ability to read the pain signal. The patient will feel a slight tingling or buzzing sensation in place of pain. The stimulator is effectively a more advanced, implanted version of a TENS machine, which can be removed if the patient does not experience the desired pain relief, or if they decide it is not right for them.
Currently, the aim of a stimulator is to provide somewhere between a 40–70% reduction in pain, although this is just a guideline. Those patients for whom the treatment is successful can begin to carry out daily activities without experiencing the same level of pain. Chronic pain conditions can be both physically and mentally debilitating, and impact upon physical and mental ability and quality of life. The stimulator can replace much of the medication previously required, and allow the patient to control their own pain relief by way of a small remote control. The implanted device is recharged by way of a belt which contains an electromagnetic disc. Usually recharging is required for about an hour a week, although this is dependent upon the level and frequency of pain relief required.
Stimulators can become more effective over time, by helping the body to create its own natural painkillers, endorphins. Once the stimulator has been in use for some time, the patient will find that each time they turn off the stimulator the pain relief will continue for a little longer after the device is switched off. Ideally, the damaged nerve will eventually begin to react in the same way as the undamaged nerves, thus negating the need for the stimulator. In these cases the device can be removed and the patient can manage without it.
There are several neurostimulators available now; most are rechargeable to negate the need for further surgeries to replace the batteries. The most recent models have a guaranteed battery life of 9 years, although the actual battery life depends on how much the patient uses the device, and how high the stimulation is set. There is a one-in-twenty chance that one or both of the leads can become disconnected, either because the patient pulls them free through excessive movement, or because the muscle and tissue can grow around the cables and pull them out of alignment. If this happens, the surgeon will relocate them within twenty-four hours of displacement.
For those with chronic pain conditions, a spinal cord stimulator can mean a return to normal living and everyday activities. The difference in quality of life can be phenomenal, and reduce the need for painkillers and nerve blockers like Gabapentin and Pregabalin. The fact that the patient can control their pain by a small remote control gives them a sense of greater control and independence.