Chronic Pain: How Neuromodulation Can Help
Education & Research Experts estimate chronic pain affects 1 in 5 people, but many may not realize that advanced, non-drug treatments could improve both function and quality of life.
Patients with neuropathic pain (caused by damage to the nerves) could be candidates for neurostimulation treatment. Neurostimulation is a type of neuromodulation therapy that, rather than relying on medication, delivers targeted electrical stimulation to nerves to modify their activity and reduce the perception of pain. Stimulation is provided by an implantable pulse generator, similar to a cardiac pacemaker. For that reason, neurostimulators are sometimes referred to as “pain pacemakers.”
Setting the ‘pace’
Neurostimulation has been in common use since the 1980s and continues to evolve. More recent systems may use different stimulation patterns for comfort, or target different structures to address hard-to-treat pain. Some offer flexibility in operation through being wirelessly powered or having conditional MRI compatibility.
The most commonly practiced neurostimulation therapy is spinal cord stimulation, which starts with a trial phase. In a minimally invasive procedure, patients have stimulation leads placed beneath the skin above the spine at the mid-back. A temporary external device worn at the waist powers the stimulation. A patient whose pain is reduced 50 percent or more might consider receiving a fully implanted system. After stimulation parameters are programmed, patients go home with a controller for switching between programs or turning the device on or off.
“While neurostimulation has shown value in helping improve function and quality of life for many chronic pain patients, we continue to hear of patients who have struggled for many years before learning of this option."
Another category of implantable neuromodulation therapy, intrathecal drug delivery, also starts with a trial phase and may be appropriate for some types of pain, including cancer pain. These implanted infusion systems administer micro-doses of medication to the intrathecal space around the spine through a catheter from an implanted reservoir.
In addition to these methods, implantable or non-invasive methods have been studied to address intractable chronic pain through brain stimulation. These include some clinical experience with deep brain stimulation, which is primarily used to treat movement disorder; motor cortex stimulation (which has also been studied in stroke rehabilitation); and transcranial magnetic stimulation (which is FDA-approved for some cases of medication-resistant depression).
Also, methods to stimulate nerves near the head or jaw, such as the occipital nerves or the sphenopalatine ganglion, have been studied as potential interventions for severely disabling head pain, such as cluster headache.
Alim Louis Benabid, M.D., Ph.D., is a key pioneer in developing deep brain stimulation for Parkinson’s disease, is chairman of the board of the Clinatec Institute in Grenoble, France. He remarked, “Since the first applications to the treatment of pain with electrical stimulation, numerous newly developed methods, including direct electrical stimulation and drug infusion…have made it possible to develop new, very powerful therapeutic approaches to serious clinical conditions. Every new branch soon produces its own ramifications and neuromodulation looks like a very fast-growing tree.”
Lawrence Poree, M.D., Ph.D., professor of anesthesiology at the University of California, San Francisco Medical Center, has co-authored studies that present the appropriate use of neurostimulation, and set forth when it should be introduced during treatment. He also contributes to developing explanatory materials for referrers, patients, and practitioners.
“While neurostimulation has shown value in helping improve function and quality of life for many chronic pain patients,” he noted, “we continue to hear of patients who have struggled for many years before learning of this option. My colleagues and I would like to see this approach—which saves medical costs over time and minimizes patients’ reliance on oral pain medication—become as commonly known as hip implants are today.”