2013; 16: 614–617
Erica R. Hope, MD, Daniel D. Gruber, MD
Department of Obstetrics & Gynecology, Division of Female Pelvic Medicine & Reconstructive Surgery, Walter Reed National Military Medical Center, Bethesda, MD, USA
There are many painful syndromes that are often difficult to treat. One option is electrotherapy, also known as neurostimulation. The Gate Control Theory first described by Melzack and Wall (1) in 1965 postulated that nerves carrying painful peripheral stimuli and nerves carrying touch and vibratory sensation both terminate in the dorsal horn, which acts as the gate of the spinal cord. They hypoth esized that input to these nerves could"close the gate" to the painful stimuli, thereby eliminating pain.
Based on the Gate Control Theory, Shealy et al. (2) in 1967 showed success in treatment of chronic pain using the first spinal cord stimulator. Continuing this work, Shimoji et al. (3) in 1993 created epidural spinal cord stimulation (SCS) that displayed analgesic properties.
SCS use has been widespread, and is Food and Drug Administration (FDA) approved for numerous conditions. In addition to cervical, thoracic, and lumber stimulators, there is also sacral neuromodulation.
Sacral neuromodulation (InterStim ®, Medtronic, Minneapolis, MN) has been indicated by the FDA for the treatment of urinary urgency, urinary frequency, and fecal incontinence. It is the only approved sacral neuromodulator. However, very little data exist on its use for chronic pain or lower back pain. We describe a case where InterStim was used to treat urinary urgency/frequency symptoms and incidentally relieved chronic lower back pain from a previous pelvic fracture.
The majority of pain that the sacral neuromodulation has previously treated has been chronic pelvic pain that is refractory to other therapies, which often coexists with urinary incontinence or refractory interstitial cystitis. For these two indications, it appears that the sacral neuromodulation has a significant improvement in pain. No citations were found that described the use of sacral neuromodulation in terms of coccygeal pain; only SCS has previously been used. In conclusion, sacral neuromodulation has the potential for treatment of coccygeal pain.