When all else has failed and chronic pain persists many have turned to a spinal cord stimulator. This is a medical device that has thin wire electrodes attached to a battery pack. The electrodes are placed between the spinal cord and veterbral body where the pain begins. The battery is usually tucked into a skin fold near the buttock or abdomen. This allows a patient to direct how much of an impulse is created to block pain signals.
Pain is usually protective. A way to alert us to potential injury or illness. Without it we wouldn’t remove our hand when it accidentally touches a hot stove. But in some cases the protective origin of pain turns into a prolonged debilitating condition that doesn’t resolve, even after the inciting event is over.
Chronic pain changes how our brain and nervous system react to stimuli. As a result it can:
- Create pathways that cause pain signals to be sent for issues that shouldn’t be painful.
- Cause the pain signals being sent to hurt more severely (hyperalgesia)
- Decide to randomly or constantly emit pain for no specific reason
Our nervous system is a remarkable and intricate network that provides communication between the brain and body. When its disrupted pain ensues. Spinal cord stimulators create a mild electrical current to flow along the damaged nerve fibers causing the disruptive pain. Depending on the unit, these new signals can either mask the pain signals, preventing them from reaching the brain, or turn them into a mild tingling feeling.
Spinal cord stimulators are used after conventional treatments have failed for:
- Chronic back pain especially for those who failed surgery
- spinal cord injuries
- Neuropathic pain
- Peripheral vascular disease
- Other chronic pain conditions
- Complex regional pain syndrome
- Pain after an amputation
- Post herpetic neuralgia
- Abdominal/pelvic pain
- Arachnoiditis- pain around the thin membrane that covers the brain and spinal cord
- heart pain e.g. angina, refractory to other treatments
It starts with a trial run:
A temporary device is implanted along the epidural space of the spine determined by the location of your pain. Only the electrodes are placed, the battery pack is carried on a belt for now. If there’s at least 50% reduction in pain after a week or so the test is considered a success and a permanent one is placed.
There are two types:
- Conventional implantable pulse generator (IPG) is a great option for those who have pain in only one body part because it generates a lower electrical output. These require a surgery to replace the battery pack when it runs out.
- Rechargeable IPGs can be recharged without another surgery and can put out more electricity. Often a better choice in those with low back pain that radiates into one or both legs since the signal can reach further.
After the permanent one is placed:
- The goal is to reduce pain by 50-70%. Or enough to improve daily function.
- A handheld programmer allows it to be turned on and off at the user’s discretion as well as select different programs that can adjust the strength and duration of the stimulation e.g. for a few hours or all day long if necessary. The remote programmer has settings that an individual can adjust at any time to determine:
- The frequency or number of times stimulation is delivered per second.
- How much area it will cover
- The amplitude of the pulse which affects the perception of pain.
- It has a non- rechargeable battery that must be surgically replaced every 2-5 years depending on the frequency of use.
Living with a spinal cord stimulator
It allows patients to be far more active and pain free. But there are some restrictions that must be honored:
- It will set off airport security. Your surgeon can provide a card that explains the device you have implanted, but always turn it off before you go through the detector.
- CT scans and X-rays should be done when the unit is turned off.
- Only some newer MRI scanners are compatible with a neurostimulator. It must be cleared first to prevent harm.
- Never drive with the stimulator on. Different levels of stimulation can be a distraction and lead to accidents.
- Once the permanent unit is placed, swimming, showering and bathing are not an issue.
Does it work?
Spinal cord stimulators are often a treatment of last resort, when nothing else has helped. Success often depends on the issue being treated. On average, studies show more than 50% get relief.
But those results can diminish over time due to:
- Electrode placement migrates so that the wrong area is stimulated.
- The unit breaks or malfunctions.
- Infections occur. These happen more commonly at the site where the battery pack is implanted than at the leads.
- The body acclimates and no longer responds as it should to the stimulation.
In a large study of over 500,000 patients treated with a spinal cord stimulator from 2015 to 2021, it was unclear if it decreased opioid use in long-term users, but it was associated with decreasing those from starting.
If at any time it isn’t right for you the stimulator can be removed.
Not everyone will benefit from a spinal cord stimulator. Investigate thoroughly before you commit.