Chronic Pelvic Pain: The Neuropathic Pain Basis

Abstract

Chronic pelvic pain (CPP) in both genders has been chiefly the province of surgical subspecialists. Morphologic end-organ processes have been studied for decades without significant advances in understanding the etiology of CPP or developing adequate therapeutic outcomes. The neurogenic basis of CPP has received little attention. Several peripheral nerves may be the source. The largest of these is a pudendal nerve and is the most important because it is a mixed nerve and affects sensory and motor symptoms in both the somatic and autonomic nervous systems. Nerve compression and stretch are the two most important etiologic factors. Practitioners can diagnose these painful neuropathies by a careful symptom history and physical examination. The most important diagnostic tool is sensory examination of the pudendal territory using pinprick. Various neurophysiologic tests can confirm pudendal neuropathy. The smaller peripheral nerves affect CPP. Because pudendal neuropathy is a tunnel syndrome related to cumulative, repetitive microtrauma, it can be treated accordingly. Treatment options include nerve protection, medications (analeptics, tricyclic amines), perineural infiltrations of local anesthetics with or without corticosteroids, and, in a significant minority, decompression of the pudendal nerves. The smaller nerves often respond to a program of postural correction and perineural anesthetic blockades. All patients require attention to central sensitization. Treatment success depends on the duration of symptoms, etiology, and severity of nerve damage. The last item can only be evaluated at surgery. Complete cures of CPP, treated using each modality, can be measured by validated symptom scores for as long as 13 years. To progress in the diagnosis and treatment of CPP, interspecialty studies are needed that distinctly separate neurogenic from nonneurogenic CPP. To date, this has not been done. Thus, diagnostic, etiologic, and treatment conclusions are quite limited. CPP provides a rich foundation for clinical research for neurologists. Key Words: abdominal cutaneous neuropathy, chronic pelvic pain, interstitial cystitis, irritable bowel syndrome, middle cluneal neuropathy, neurogenic pelvic pain, pudendal neuropathy, sexual dysfunction, thoracolumbar junction syndrome