Neuroanatomy of the female abdominopelvic region: A review with application to pelvic pain syndromes

Abstract

Pelvic pain can be a life altering disease. Multiple pathologies can affect this region resulting in neurologic issues. Therefore, a thorough understanding of the nerve supply to this region is important for the clinician who treats such patients. The current review outlines the anatomy of the nervous system of the abdominopelvic region with special attention to this anatomy in the female.

New Developments in the Pharmacotherapy of Neuropathic Chronic Pelvic Pain

“…The uterus, bladder and rectum are innervated by the hypogastric plexus, with sensory axons converging at the same dorsal root ganglion T10–L1. The vagina, clitoris and vulva as well as parts of the bladder, cervix and rectum also have sensory input from the sacral nerves (S2–S4) and also share sensory processing in the dorsal root ganglion of S2–S4 [6,7]. These communal information centers increase the risk of neuronal dysfunction in the pelvis, resulting in a unique cross-over effect.…”

Response to the letter to the editor by Barry K. Komisaruk “re: Puppo V, Puppo G. 2014. Anatomy of sex: Revision of the new anatomical terms used for the clitoris and the female orgasm by sexologists”

“…In addition, no anatomy and neurology textbooks contain a vaginal-cervical genitosensory component of the vagus nerve. Shoja et al (2013) have stated, "Noteworthy, the proximal vagina is said to be almost insensitive in it upper portion." Dr. Komisaruk stated: "women with complete spinal cord injury.…”

“…Therefore, sexual medicine experts, sexologists, and psychologists must use the (scientific) term "female orgasm," so women worldwide will not feel inferior or abnormal for not reaching a "vaginal" orgasm or vaginally activated orgasm; and for the few women who report "vaginal" orgasms (they use the term because in the mass-media, and in sexual education, the sexologists use it), the use of "female orgasm" makes no difference. Shoja et al (2013) stated "Interestingly, neither sympathectomies nor vagotomies appear to affect the female genital tract so that normal labor and delivery may occur," "pain from the cervix, vagina, vesical trigone, and rectum returns to the cord via the pelvic splanchnics," "the vagus nerve within the abdominopelvic region does not convey pain information because its brainstem relay center (solitary nucleus) does not convey information to the thalamus and cortex and therefore its information does not reach the level of consciousness." In addition, no anatomy and neurology textbooks contain a vaginal-cervical genitosensory component of the vagus nerve.…”

The effect of spinal cord injury on vagal afferents.

“…Complementary to this understanding, a 2013 review of the female abdominopelvic region indicates this caudal extension of the vagus based upon a drawing from the mid-1800s (Frankenhaüser, 1866), in which the authors additionally state that upon entry into the abdomen, the sympathetic and vagal fibers become "indistinguishably mixed" (Shoja M., 2013). Indirect evidence of a vagal connection to the pelvic viscera in humans is demonstrated from the fact that women with functionally "complete" spinal cord injury (SCI -American Spinal Injury Association criteria) are able to perceive sensations from mechanostimulation to the vagina and cervix and even respond with orgasms (Komisaruk et al, 1997, Komisaruk et al, 2004.…”

“…Vagus nerve stimulation (VNS) has been approved by the Food and Drug Administration for the treatment of refractory epilepsy and depression and more recently, is being studied for its applications in obesity, Alzheimer's disease, heart failure, and inflammatory disease (Tracey, 2002, Li et al, 2004, Groves and Brown, 2005, Milby et al, 2008, Schwartz et al, 129 2008. Given that the vagus nerve would not be distinguishable from sympathetic fibers once it enters the abdominal region (Shoja M., 2013), the most common area of access to the nerve for stimulation would be on the cervical vagus.…”