Radiofrequency stimulation of intervertebral discs

The etiology of discogenic pain is poorly understood. The most accepted theory has been that nociceptors in the outer one-third of the annulus fibrosis are responsible for transmitting pain secondary to internal disc disruptions. The concept of "neoneuralization" after disc injury has been disseminated. It has been noted that disc degeneration and injury are associated with ingrowth of neural fibers into the disc annulus. One mechanism of Intradiscal Electrodothermal Therapy (IDET) has been thought to be lesioning of these nociceptors. Five consecutive patients were studied using an intraannular electrode. The Radionics discTRODE was used. It was found impossible to selectively stimulate axial pain fibers using this system. Radicular stimulation was noted in all patients at all levels studied. The implication of these findings concerning the concept of neoneuralization, mechanism of IDET, and possible strategies to decrease discogenic pain are discussed.