Spinal Cord Stimulation

What is Spinal Cord Stimulation?

In the simplest of terms, Spinal Cord Stimulation (SCS), or neuromodulation, refers to the targeted application of electrical signals to the spinal cord. Essentially, electrodes are implanted within the epidural space (area around the spinal cord) which supply an electric pulse from a generator implanted in the lower abdomen.  

After the electrodes are placed, there is an observation period of 5-7 days in order to ensure that pain relief is being achieved. If the individual is happy with the level of pain relief, the generator and accompanying wires are permanently implanted. Patients themselves manage the frequency and amplitude of the electrical impulses, with preferences varying between dull beats and buzzing.

How does it work?

How SCS relieves pain isn’t fully understood. It is thought that the SCS changes the neurochemistry within the central nervous system, helping to suppress the excitability of these neurons. 

Research suggests that SCS is effective in managing peripheral neuropathy. Failed Back Surgery Syndrome is the most common form of neuropathy treated with SCS.   There is low quality, inconclusive evidence around the use of SCS for postherpetic neuralgia, diabetic neuropathy, spinal cord injury and central post-stroke pain. There is currently moderate quality, weak evidence in support of SCS for use in instances of complex regional pain syndrome (type 2). 

Side Effects

There are two parts to the procedure, implanting the test electrode and then permanent implantation of the generator. The technique can vary from place to place. Implanting the leads for the test is often done as a percutaneous epidural procedure, much like inserting an epidural for pain control in labour but using the electrode instead of a plastic catheter. There is some risk of accidental dural puncture, bleeding or infeciton as well as less likely risk of serious complications  including paralysis, nerve injury and death. Total incidence of all complications major and minor over 7 years is 5 – 18% of those receiving SCS.  

Because the stimulators use wire leads, common complications include lead migration, lead breaking and infection. Other complications may include bruising, cerebrospinal fluid leak, post dural puncture headaches, discomfort with generator placement, seroma and passing bouts of paraplegia. Other hardware-relates issues, like shifting or broken electrodes and shifting of generator are, may affect some patients.  

Related evidence

Kumar K, Malik S, Demeria D. Treatment of chronic pain with spinal cord stimulation versus alternative therapies: cost-effectiveness analysis. Neurosurgery. 2002 Jul;51(1):106-15; discussion 115-6.

Kumar K, Taylor RS, Jacques L, Eldabe S, Meglio M, Molet J, Thomson S, O'Callaghan J, Eisenberg E, Milbouw G, Buchser E, Fortini G, Richardson J, North RB. The effects of spinal cord stimulation in neuropathic pain are sustained: a 24-month follow-up of the prospective randomized controlled multicenter trial of the effectiveness of spinal cord stimulation. Neurosurgery. 2008 Oct;63(4):762-70; discussion 770. doi: 10.1227/01.NEU.0000325731.46702.D9.

Kumar K, Toth C, Nath RK. Spinal cord stimulation for chronic pain in peripheral neuropathy. Surg Neurol. 1996 Oct;46(4):363-9.