Sacral neuromodulation for chronic pain conditions.

Chronic nonmalignant pain syndromes of the pelvis or genitourinary are well described in both the gynecology and urology literature, though the origin and physiology of the pain syndromes are not well understood. Patients frequently have multisystem complaints including voiding dysfunction, chronic pelvic pain, and genitourinary hypersensitivity. Both the patient’s history and physical examination can be a powerful diagnostic tool in unmasking a chronic pain disorder. However, laboratory and imaging studies often are unrevealing, with no physical cause for the pain disorder being identified. This can lead to frustration and depression in these patients, which may lead them to develop complex psychologic adaptive and maladaptive methods of coping with their pain as it affects their lives. Although there are numerous pain syndromes involving the pelvis or sacrum and urogenital tract, syndromes that have had good pain control outcomes with sacral neuromodulation are interstitial cystitis (IC), prostadynia or epididymo-orchalgia, vulvodynia, and coccydynia. Interstitial cystitis is a chronic debilitating condition of the urinary bladder characterized by symptoms of dyspareunia, irritative urinary symptoms, and nocturia. The epidemiology of the disorder is not well established, but there are an estimated 700,000 cases of IC in the United States. It occurs primarily in women. Onset is predominately in adulthood, although IC does occur in childhood. The median age of onset is 40 years; however, there is a bimodal distribution with one peak in the twenties and a later one in the fifties. In general, patients suffer with the symptoms for 3 to 7 years before the correct diagnosis is made [1]. Numerous