What is Neuromodulation?
- It is a therapy that has been used since the 80’s
- It works by changing the activity of the nerve activity through targeted delivery of electrical energy
- It uses electrical energy to control pain
Types of Neuromodulation
- Spinal Cord Stimulation (SCS) – most common
- Peripheral Nerve Stimulation (PNS)
- Sacral Nerve Modulation (SNM)
- Dorsal Root Ganglion (DRG)
image - Mayfield Clinic
Spinal Cord Stimulation
How does SCS work?
- Delivers small electrical currents to the spinal cord
- Masks the pain signals before they reach the brain
- Works well in conditions such as Failed Back Surgery Syndrome, Neuropathic (nerve) pain, and Complex Regional Pain Syndrome and other pain syndromes
- Does not eliminate the source of pain and the amount of relief will vary from person to person
- Reserved for individuals who have tried all reasonable, more conservative therapies including injections
Living Day to Day
- The battery (IPG) can be either a rechargeable or non-rechargeable
- Some physical activities involving exaggerated cervical or lumbar flexion and extension may not be allowed
Benefits of SCS
- May provide significant pain relief
- Improve sleep, mood, ability to do physical activities, and quality of life
- Reduce the amount of pain medication you need to take
Risks of SCS
- Possible reduced benefit of SCS (decrease in pain relief) over time
- Allergic reaction to the device materials
- Infection requiring removal of the SCS leads and stimulator
Peripheral Nerve Stimulation
Peripheral neuropathic pain is highly prevalent among chronic pain patients. There are multiple causes of peripheral neuropathic pain including isolated mononeuropathics, nerve entrapment syndromes, phantom limb and stump pain, and complex regional pain syndrome. Unfortunately, peripheral neuropathic pain is difficult to treat.
How does PNS work?
Peripheral nerve stimulators (PNS) are devices that are implanted for peripheral neuropathic pain. PNS therapy requires implantation of a metal lead that sits near the target peripheral nerve. The lead is implanted under ultrasound guidance in a minor surgical procedure. The lead is stimulated externally by a battery using conductive radiofrequency signals. When the lead is stimulated, it in turns stimulates the peripheral nerve resulting in pain relief.
PNS may not always work, even for those with peripheral neuropathic pain. However, when it does help studies have demonstrated that use of peripheral nerve stimulation has resulted in significant pain relief (~75% reduction in pain scores). Patients with PNS devices have also found significant improvements in function, work abilities, sleep, quality of life, and reduction in medication use.
Who is eligible?
- Not all patients are eligible for this therapy. Patients who will benefit include those with a single peripheral nerve issue who have typically responded well to targeted peripheral nerve blocks. This is to identify those who will be likely to respond to PNS therapy, although it is not always possible to predict prior to implantation.
- PNS implant is contraindicated in those who have any active implanted devices such as an implanted demand cardiac pacemaker, implantable cardioverter defibrillator (ICD), other implanted, active devices, or any metallic implant in the immediate area intended for implant.
Benefits of PNS
- A non-pharmacological option for pain relief
- No internalized battery (in contrast to spinal cord stimulation)
- Potentially effective pain relief, reduction in pain medications, improved quality of life
Risks of PNS
- Requires a minor surgical procedure
- Limitations on future MRIs in the area of PNS implant
- Possible need for urgent removal if infection occurs