Chronic pelvic pain (CPP) is defined as persistent pain perceived to originate from pelvic structures lasting greater than 6 months in duration [1]. This condition is common, ranging from 5.7-26.6% amongst females and accounting for upwards of 40% of laparoscopies annually [2]. CPP can be overwhelming to the patient, as the vast differential diagnosis crosses many specialties and the root cause can be difficult to determine. Importantly, approximately 80% of CPP is non-gynecological in nature and is associated with a myriad of neurological, visceral, musculoskeletal, sexual, and psychological symptoms. The mechanism of CPP is multifactorial in nature, involving central sensitization and viscero-viscero pain theory. Neural pathways are shared between visceral and somatic structures within the pelvis, likely explaining the difficulty in differentiating sources of pelvic pain [1]. 

Primary management of CPP stems from screening for, identifying, and addressing its underlying etiologies. Therefore, emphasis should be placed on recognizing the prevalence of CPP contributors. We have previously demonstrated a high prevalence of small fiber polyneuropathy (SFN or SFPN) in patients with complex CPP [3]. However, there is little literature examining the prevalence of other neurological conditions in the setting of CPP. In this study, we actively screened CPP patients within our urology/urogynecology specialty referral pain clinics for neurologic symptoms and, if present, conducted a combined evaluation with a neuropathic pain specialist in a multidisciplinary clinic approach.

Study criteria included patients over the age of 18 with CPP who underwent a combined workup with a urologist and neuropathic pain specialist. A standardized, systematic neurological evaluation was provided if the patient screened positive for any of the following:  
- Pain radiating from the spine  
- Combination of bladder, bowel, sexual or pain symptoms referable to the lower spine  
- Pain within a dermatome referable to a specific nerve/root  
- Balance or gait alteration  
- Abnormal reflexes  
- Upper motor neuron (UMN) findings on urodynamics (neurogenic detrusor overactivity/DESD) or some cases of hypotonic bladder  
- History suggesting neurologic contributors (e.g. related to spine surgery)  
- Multiple autonomic symptoms  
- Chronic overlapping pain syndromes  

Subsequent workup was tailored to the presenting complaints and neurological examination. In the case of multisystem pain associated with a nonfocal examination, electromyography (EMG) to rule out neuropathic disease and labs associated with neural function (e.g. vitamin b12, Lyme disease) were typically employed. A skin biopsy was then offered seeking SFN. In certain cases (e.g. history of coagulopathy or miscarriage) methylenetetrahydrofolate reductase (MTHFR) mutation was tested for those negative for SFN. UMN findings on physical exam were pursued with magnetic resonance imaging (MRI) of the central nervous system. Any focal neuropathies radiating from the lumbosacral spine were again imaged with MRI. Video urodynamic testing was offered to those with bladder dysfunction associated with their CPP.

A total of 188 patients underwent combined evaluation, with 181 (96%) undergoing formal neurological examination. 51 (27%) patients had UMN findings (e.g. hyperreflexia, spasticity, Hoffman’s sign, Babinski reflex) on exam, while 17 (9%) had lower motor neuron findings (diminished reflexes, muscle atrophy, decreased tone), and 103 (54%) had nonfocal examinations. 82 patients (44%) were evaluated via EMG, 48 (26%) by skin biopsy, 111 (59%) with MRI, and 100 (53%) with laboratory studies. 62 (33%) patients are still undergoing workup.  Of the 126 patients who have completed evaluation, 92 (73%) were found to possess a neurological disorder. The most common diagnoses included SFN, large fiber neuropathy, lumbosacral radiculopathy, and severe spinal stenosis, among others (table 1).

Our findings demonstrate that in patients with CPP who screen positive for neurological symptoms, two thirds have objective evidence of neurological disease. This indicates that those who manage patients with CPP should include a neurological review of systems, akin to those reported in this article during routine evaluation. This is especially important in patients whose pain symptoms have been refractory to first-line therapy. Therefore, we suggest that patients presenting with CPP should be screened for neurological diagnoses and arrange for combined urologic and neurologic management, implementing a multidisciplinary approach to care.

Neurologic disease is prevalent, present in 73% of subspecialty CPP patients who screen positive for neurologic symptoms. Most of the diagnoses in this study were de novo and patients had experienced diagnostic delay for up to years. Utilization of multispecialty clinics and screening for neurological conditions is recommended in urological and gynecological patients with CPP to facilitate appropriate diagnosis and management.

Lamvu G, Carrillo J, Ouyang C, Rapkin A. Chronic Pelvic Pain in Women: A Review.?JAMA. 2021;325(23):2381-2391. doi:10.1001/jama.2021.2631
Ahangari A. Prevalence of chronic pelvic pain among women: an updated review. Pain Physician 2014;17: E141–7.
Chen A, De E, Argoff C. Small Fiber Polyneuropathy Is Prevalent in Patients Experiencing Complex Chronic Pelvic Pain. Pain Med. 2019 Mar 1;20(3):521-527. doi: 10.1093/pm/pny001. PMID: 29447372.