SPINAL CORD STIMULATION IN THE MANAGEMENT OF CHRONIC PAIN

Abstract

SCS has been used in clinical practice in the United States for more than 30 years. A new focus on patient selection, psychological comorbidity, and cost effectiveness has led to a renewed interest among physicians and insurers. When used successfully, SCS provides pain reduction by modulating the pain signal at the spinal cord level. Although many theories exist on the mechanisms involved in pain alleviation, the most widely accepted theory is based on the gate control activation of inhibitory pathways.

The placement of a SCS system involves placing a stimulating electrode or electrodes into the epidural space. This most commonly is performed by the percutaneous approach, with the surgical approach reserved for special circumstances.

In order to place the stimulating electrode, a 15- gauge long beveled Touhy needle is piaced into the epidural space under fluoroscopic guidance. An epidurogram is often obtained to confirm

epidural placement on A-P and lateral views. Creating an electrical field above the neural pathways then produces a paresthesia. The level of sedation is then reduced and the patient is asked to identify the stimulation pattern that produces a paresthesia that is pleasant and covers the area of t5-pical pain complaints. If the area of paresthesia is inadequate a second lead may be added to provide wider a coverage area. Once the lead (or leads) is in an acceptable position an anchoring technique is used to secure the lead to the skin or the supraspinous fascia.

A trial period of stimulation then occurs for periods ranging from two days to three weeks. Subjective and objective improvement should be seen prior to proceeding with a permanent implant.