Spinal Cord Stimulators

FDA-approved therapy to treat chronic pain of the trunk and/or limbs Used to treat patients with neuropathic pain SCS is considered a third tier pain therapy SCS is not a cure Spinal Cord Stimulation Therapy

Pain Nociceptive Pain Harmful stimulus is applied to skin, joints, muscles and nociceptive nerve endings are activated Sharp shooting/ dull aching pain Typically lessens over time Responds well to traditional treatments Neuropathic Pain Arise spontaneously without activation of nociceptors Typically Chronic pain Does not respond well to traditional treatments Tactile Hypersensitivity- allodynia and hyperalgesia

How does SCS Therapy work? Stimulator leads placed along the dorsal column of the spinal cord produce paresthesia sensation to help mask pain signals There are 3 types of SCS systems that can be used depending on the patient’s pain Conventional IPG system Rechargeable IPG System Radiofrequency (RF) system

Spinal Cord Stimulator Procedure

Theories Behind SCS Therapy Gate Control Theory By stimulating the large A beta blocks the transmission of pain signals via the small C fibers Stimulating supraspinal pathways sends signals up the dorsal column to the brain stem and is then returned to spinal cord via dorsal Longitudinal fasciculus to mediate the pain pathways Descending Inhibition of Pain pathways Stimulation of the adrenergic sympathetic neurons close the gate Stimulation of Dorsal Nerve root fibers

Benefits of SCS Pain relief Reduction in pain medication intake Improvement of depression symptoms Return to work Return to daily activities Increase quality of life

SCS Candidates SCS is a last resort treatment of chronic pain when other therapies have failed Patients must have a multidisciplinary screening to determine if they would be a good candidate Successful Trial Placement Patients must be motivated and willing to try the treatment

Successful SCS treatments SCS has been used since 1967 for the treatment of chronic pain SCS has successfully treated numerous painful disorders Failed Back Surgery Syndrome/ Arachnoiditis Reflex Sympathetic Dystrophy (Complex Regional Pain Syndrome Angina Stump Pain/ Phantom Limb Pain Peripheral neuropathies Radiculopathies Peripheral Vascular Disease/ Ischemic Pain

Failed Back Surgery Syndrome Pain that persists after one or more surgical procedure on the lumbo-sacral spine Most common diagnosis for patients who receive SCS Etiology is difficult to pinpoint Most common cause of FBSS- improper patient selection 1-10% of patients will be worse after surgery Characteristics: back/ leg pain, numbness/tingling & weakness in legs, stabbing burning and shooting pain

FBSS Results Leveque, J et al. Randomized Controlled Trial of 16 patients with FBSS ANS St. Jude Medical Company Case Study Case Study of a patient with FBSS

Complex Regional Pain Syndrome AKA: Reflex Sympathetic Dystrophy Multi-symptom/ Multi-system Characteristics: Soft tissue injury/ immobilization Temperature difference between affected and unaffected extremity of at least 1°C Tactile hypersensitivity Cutaneous changes

CRPS and SCS Research Results Kemler, M et al. Randomized Control Trial of patients with Chronic Reflex Sympathetic Dystrophy Harney, D et al. Review of case studies with patients with CRPS treated with SCS Overall all SCS groups had a 60-70% success rate, narcotic intake was reduced and improvement in activity and quality of life

SCS and Angina Number 1 Reason for Spinal Cord Stimulator implantation in Europe Main Clinical Symptoms are related to ischemic heart pain Pain in chest, arms, throat and neck Results: Improved Coronary blood flow but no increase in totally flow Altered sympathetic/ parasympathetic balance Research- Ferrero, P et al., De Jongste et al.

Leg pain Characteristics Pain in leg when walking Numbeness/tingling in leg Burning pain that is worse at night Phantom limb sensation- uncontrollable movements Sensitive Pain Research Jivegard et al. Raina, et al.

Questions??

References ANS: St. Jude Medical Company. (n.d.). Spinal Cord Stimulation: A Promising Treatment Option for Your Patients With Chronic Pain [Pamphlet]. Boston Scientific. (2007). Taking Control of Your Pain: The First Step [Pamphlet]. USA: Precision Plus. Cameron, T., Ph.D. (2004, March). Safety and Efficacy of Spinal Cord Stimulation for the Treatment of Chronic Pain: a 20-year Literature Review. Journal of Neurosurgery: Spine, 100, Ferrero, P., MD., Grimaldi, R., MD., Massa, R., MD., & Chiribri, A., MD. (2007, January). Spinal Cord Stimulation for Refractory ANgina in a Patient Implanted with a Cardioverter Defibrillator. PACE, 30, Greenwald, T., RN., & Ryan, B., RN. (2004, June). Spinal Cord Stimulation Overview. In Mayfield Clinic. Retrieved January 15, 2009, from Harney, D., Magner, J. J., & O’Keeffe, D. (2004, June). Complex Regional Pain Syndrome: the case for Spinal Cord Stimulation (a Brief Review). Injury: International Journal of the Care of the Injured, (36),

References Continued… Kemler, M. A., MD., Barendse, G. A., MD., & Van Kleef, M., M.D., Ph.D. (2000, August). Spinal Cord Stimulation in Patients with Chronic Reflex Sympathetic Dystrophy. The New England Journal of Medicine, Leveque, J.-C., Villicencio, A. T., & Bulsara, K. R., MD. (2008, October). Spinal Cord Stimulation for Failed Back Surgery Syndrome. Neuromodulation, 4(1), 1-9. North, R., MD. (2007). Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Chronic Neuropathic Pain. American Academy of Pain Medicine, 8(S4), S20-S275. Raina, G. B., Piedimonte, F., & Micheli, F. (2007). Posterior Spinal Cord Stimulation in a Case of Painful Legs and Moving Toes. Stereotactic and Functional Neurosurgery, (85),