SPINAL CORD STIMULATORS
by Jenna Tabbaa
Neuropathic pain is a chronic pain that exhibits few signs of the original injury. The pain is due to nerves in the peripheral or central nervous systems that have become maladaptive and continue to send pain messages to the brain even through there is no ongoing tissue damage. The nerve damage can be due to traumatic injury or disease, and has been documented in 25% of patients who undergo back surgery for other reasons. (Thomas 1) For some patients, the quality of life with neuropathic pain can be worse than other pain diagnosis such as heart failure and cancer. (Garcia 1) In addition to chronic pain, psychological factors related to pain experience develops overtime, which include depression, anxiety, traumatic stress and cognitive dysfunction. (Garcia 1) Non-invasive treatments of pain, such as opioids and non-steroidal anti-inflammatory drugs (NSAIDs), do not exhibit high efficacy for relieving neuropathic back pain. Spinal cord stimulators (SCS) are a treatment that have demonstrated efficacy to alleviate neuropathic pain. (Thomas 1) Due to the large population with neuropathic pain, SCS are in high demand. To date 400,000 patients have had an SCS implanted with around 40,000 new patients each year. (Deardorff 1) The company has developed a new enhanced SCS to improve treatment for chronic back pain and enhance patient quality of life.
SCS works to alleviate chronic pain by masking pain signals before they reach the brain. There are two components to the device: the small implanted pulse generator (IPG) and one or more thin wires called ‘leads’. (Mayfield) The IPG is an implantable power source inserted just below the skin either in the upper buttock/back or abdominal wall. (Mayfield) This power source is connected to the leads that are inserted in the epidural space above the spinal cord. (Mayfield) These leads carry small electrical contacts along the ends. To decrease their pain, the IPG powers the leads that deliver a mild electrical impulse to specific nerves in the spinal cord to mask the pain signals traveling to the brain. (Thomas 1) The patient’s initial pain should be replaced by a tingling sensation called paresthesia. This sensation varies from patient to patient, but it is common for the patients to experience pain relief. (Thomas 2; Spinal Cord Stimulator Systems) Ultimately, final design of the SCS will have IPG that contains the battery, microprocessor and feed-through connections all sealed within a titanium cover. (Boston Scientific) The device leads will cover 32 contacts and 32 dedicated power sources designed to cover more of the spinal cord. This Precision Spectra system is designed to provide unprecedented pain coverage, a new level of flexibility and advanced control for delivering simulation.
“With 32 contacts and 32 dedicated power sources, the Precision Spectra System lets you cover more of the spinal cord than ever before. Two Infinion™ Leads driven by 32 dedicated power sources provide seamless mediolateral and rostrocaudal coverage over 3 vertebral levels. Precision Spectra provides a monumental 150,000 CPS.” (Boston Scientific Leads)
A multitude of clinical data and tests have shown sustained and a significant reduction of overall back pain with SCS. It was proven that the Precision Spectra SCS system provides sustained and significant reduction after two years post-implantation, as shown in Figure 1 below, with decreased pain of more than 50%. Specifically, for back pain, patient’s demonstrated a 70% increase in response rate compared to the previous generation of SCS with fewer leads (41% to 71%). (Boston Scientific) The study had a patient pool of 213 subjects that underwent Precision Spectra trials that where analyzed over a 24-month period. (Boston Scientific) The patients rated their pain on a 0-10 numeric rating scale for pain (NRS) at 3, 6, 12, and 24-month time-points post-IPG implantation. In this study, patients reported a statically significant difference of 5.34 points between baseline (before implantation) and 24 months after implantation (p<0.0001). (Boston Scientific) This highlights that the spectra SCS has statistically significant impact on relieving patient’s pain. Based on the second study, comparing previous models of SCS, the Precision Spectra after 24 months improved patient’s pain by more than 70% greater than the previous generation system groups. (Boston Scientific) This demonstrates the 32 contact leads/dedicated power sources compared to the sixteen contact leads are more effective at lowering back pain. Overall, this new Precision Spectra SCS described above has longevity and proven statistical significance for relieving back pain.
Thomson, Simon. “Spinal Cord Stimulation.” International Neuromodulation Society, 14 Nov. 2016, www.neuromodulation.com/spinal-cord-stimulation.
Garcia, Nancy. “Spinal cord stimulation for neuropathic pain.” International Neuromodulation Society, www.neuromodulation.com/spinal-cord-stimulation-for-neuropathic-pain.
Deardorff, William W. “Postoperative Pain, Acute Neuropathic Pain.” SpringerReference, 2 Feb. 2017. Spine-Health, doi:10.1007/springerreference_123445.
“Spinal Cord Stimulator Systems.” Spinal Cord Stimulator Systems – Boston Scientific, Veritashealth.com, www.bostonscientific.com/en-US/products/spinal-cord-stimulator-systems.html.
“Boston Scientific Leads.” Percutaneous Leads | Boston Scientific, hcp.controlyourpain.com/products/leads/.
“Boston Scientific.” Clinical Data, 2017, hcp.controlyourpain.com/why-boston-scientific/clinical-data/.
Spine, Mayfield Brain &. “Spinal Cord Stimulation, SCS, Spinal cord stimulators.” Spinal cord stimulator, Spinal Cord Stimulation, relief from chronic back pain, www.mayfieldclinic.com/PE-stim.htm.