Neuropelveology: New possibilities for the diagnosis and treatment of neuropathic pelvic pain

Neuropelveology is an emerging speciality focusing on the pathologies of the pelvic nervous system. Pathology of the pelvic nerves and plexuses may explain such “unknown sciatic pain conditions” and associated pelvic organ dysfunctions. Pathologies of the pelvic somatic nerves may produce neuropathic pain in the lower back, the genito-anal areas and the lower extremities but also pelvic organ dysfunction. The concept of “neuropelveology”, the first medical practice focused on the pathologies of the pelvic nervous system was introduced more than ten years ago. Neuropelveology combines the knowledge required for a proper neurological diagnosis for intractable Sciatic Pain, and offers patients not only an etiological diagnosis but also a possible curative treatment.

Introduction – “neuropathic pain”

Chronic pelvic pain syndrome (CPPS), Sciatic Pain (SP) and Chronic Low Lumbar Pain (LLP) are conditions, which have a high prevalence in the general population. All these pain conditions are commonly encountered in clinical practice with a high prevalence, varying between 10 and 39% of the population. Most patients have a variety of further ”associated” problems, including bladder or bowel dysfunction, sexual dysfunction and other systemic or constitutional symptoms. Because of the stigma and social isolation of these patients, it is not surprising that other associated problems may co-exist, such as depression, anxiety and drug addiction. These pain conditions present a major challenge to healthcare providers because of their often-unclear etiology, complex natural history and poor response to therapy. These patients often approach several new physicians with an off-putting combination of unrealistic hopes for a cure and suspicion related to past diagnosis and treatment failures. The goal of treatment is then to reduce pain and other symptoms without a real search for a potential etiologic treatment. Such conditions are usually classified depending on the specialty perspective of the physician as “Idiopathic Sciatic Pain or Back Pain”, “Chronic Prostatodynia”, “Interstitial Cystitis”, “Vulvodynia” or “Irritable Bowel Syndrome”. With such diagnoses, patients are often sidelined and have to accept medical pain management and antidepressants, with their known side effects and risk of dependency for the rest of their lives.

Idiopathic sciatic pain is commonplace: Idiopathic sciatica describes pain, tingling, numbness and weakness in the lower back, buttocks and legs, which has not been positively identified as coming from a verified spinal source. This scenario is rather common, with many patients not being able to achieve an accurate diagnosis of why they have pain. Idiopathic pseudo-sciatica is diagnosed when there are definitely no spinal sources responsible for enacting the symptoms, yet a chronic expression is present. In these circumstances, no structural or non-structural cause has been verified as the source process for sciatica to occur.
In undiagnosed or idiopathic sciatica pain syndromes, pathologies of the endopelvic portion of the sciatic nerve and/or of the sacral nerve roots may explain such “unknown pain conditions” and ”associated” pelvic organ dysfunctions. However, this in-depth approach is still omitted in modern medical practice and education. This is all the more surprising if one considers the number of pelvic pathologies and invasive procedures in proximity to the pelvic nerves that could potentially induce neuronal compression, entrapment or damage. The incidence of pelvic nerve pathologies is widely underestimated, mainly because of lack of awareness that such lesions may exist, lack of diagnosis and acceptance, as well as declaration and report of such lesions. Neurosurgical procedure techniques are well established in nerve lesions of the upper limbs but surgical exploration of the pelvic retroperitoneal area and the pelvic nerves are still unusual for neurosurgeons. The only well-investigated pelvic nerve pathology is pudendal neuralgia (Alcock´s Canal Syndrome) because the nerve is easily accessible for neurophysiological explorations, infiltrations and surgical decompression. By contrast, the endopelvic nerves are difficult to access and have been less well investigated in the past. Nevertheless, pathologies of the endopelvic portion of the sciatic nerve may explain many cases of Sciatic Pain. Because management of the pelvic nerve pathologies requires good integration and knowledge of all pelvic organ systems, neuro-functional pelvic anatomy and the musculoskeletal, neurological and psychiatric aspects, no current specialty is appropriate for a global management of SP at all. Based on recent findings in pelvic neurofunctional anatomy and the introduction of laparoscopy in the visualization and dissection of the pelvic nerves, Marc Possover developed -more than ten years ago- the concept of “Neuropelveology”, the first medical practice focused on the pathologies of the pelvic nervous system. Neuropelveology combines all the knowledge required for a proper neurological diagnosis for intractable Sciatic Pain and other Chronic Pelvic Pain Syndromes of “unknown genesis” _{(Possover M, Forman A, Rabischong B, Lemos N, Chiantera V. Neuropelveology: New Groundbreaking Discipline in Medicine. J Minim Invasive Gynecol 2015;22(7):1140-1).}

The solution: the Medicine of the pelvic nerves – the Neuropelveology

Due to growing interest from the medical community, the International Society of Neuropelveology (ISoN) (www.theison.org) was founded in 2014 with one major objective; to provide universal access to education in Neuropelveology. The neuropelveological approach to pelvic neuropathies may not only explain many cases of idiopathic Sciatic Pain Syndrome but also enable new therapeutic options from non-invasive treatments to laparoscopic neurofunctional procedures. Advances in video endoscopy and microsurgical instruments enable good access to all areas in the retroperitoneal pelvic space_{(Zanatta A, Rosin MM, Machado RL, Cava L, Possover M. Laparoscopic dissection and anatomy of sacral nerve roots and pelvic splanchnic nerves. J Minim Invasive Gynecol 2014;21(6):982-3),} providing the necessary visibility with magnification of the structures and possibility to work with appropriate instruments for adequate neurofunctional procedures such as nerve decompression and neurolysis _{(Possover M, Forman A. Pelvic neuralgias by neurovascular entrapment: anatomical findings in a series of 97 consecutive patients treated by laparoscopic nerve decompression. Pain Physician 2015;18(6):1139-43. - Lemos N., Possover M. Laparoscopic approach to intrapelvic nerve entrapments. J Hip Preserv Surg 2015; 2:92-8. - Possover M, Schneider T, Henle KP. Laparoscopic therapy for endometriosis and vascular entrapment of sacral plexus. Fertil Steril 2011;95:756-8).}
Laparoscopic neuropelveological procedures may be reserved for experienced surgeons in laparoscopic retroperitoneal pelvic surgery; however, diagnosis of pelvic nerve pathologies is accessible for all physicians! It is just essential to adopt a “neurological way of thinking.” Standard medical training imparts the concept that the location of the pain and its etiology correspond to the same area. In pathologies of the pelvic nerves, however, the location of the patient’s pain (dermatomes) and the senso-motor dysfunctions of the pelvic organs and the lower extremities reveal which nerves are involved in the pain process, whereas the etiology is mostly located on the path from the dermatome to the brain. A neuropelveological workup aims to determine which nerves, at which level, are involved in pain generation and always follows five steps in the following subsections: _{(Possover M, Forman A. Neuropelveological assessment of neuropathic pelvic pains. Gyneco Surg 2014; 11: 139-144):}

1. Determination whether the pain is visceral or somatic
2. Determination of the nerve pathways involved in the relay of pain information to the brain
3. Evaluation of the neurological level of pain (Central vs Pelvic vs Peripheral)
4. Establishment of a potential etiology
5. Confirmation of and therapy for a potential etiology.

Steps 1 to 3 are achieved by looking at the patient`s history while the neurological examination with the direct transvaginal/rectal digital palpation of the pelvic somatic nerves may confirm the diagnosis. Modern imaging and/or laparoscopic visualization may offer an effective etiologic diagnosis and, in most cases, the corresponding etiologic treatment.
Since Neuropelveology is now accessible for all physicians, it is no longer acceptable to ignore the pathologies of the pelvic nerves as a potential etiology for CPPS, SP and LLP.