(087) Why Should Pelvic Floor Physical Therapy be Included in Treatment of Vestibulodynia?
Authors: Stanley E , Connor K , Pope R 
Published: May 2023

Abstract

Introduction
Vestibulodynia, vulvar pain localized to the vestibule without an identifiable cause, has a multifactorial etiology including neurologic, hormonal, inflammatory, psychologic, and musculoskeletal factors. Key pathophysiologic drivers likely vary from patient to patient. Published studies demonstrate that compared to controls, patients with provoked vestibulodynia are more likely to have pelvic floor hypertonicity and decreased pelvic floor strength, as measured by dynamometric speculum and ultrasound. Further, observational studies describe improvement of vestibulodynia symptoms with pelvic floor physical therapy, suggesting a causal relationship between pelvic floor hypertonicity and vestibulodynia.

Objective
To describe the pathophysiologic mechanism by which pelvic floor dysfunction and myofascial trigger point development could cause vestibuoldynia, with a focus on pelvic floor anatomy.

Methods
Literature about vestibulodynia, pelvic floor dysfunction, and pelvic floor anatomy was reviewed and synthesized in conjunction with expert clinical experience of pelvic floor physical therapists and gynecologists.

Results
The pelvic floor consists of the levator ani muscles (iliococcygeus, pubococcygeus, and puborectalis) and ischiococcygeus, which form a basket to support the pelvic organs. The puborectalis inserts in the posterior vestibule, and hypertonicity can cause allodynia in this region. The levator ani are innervated by the levator ani nerve, which originates from S3-S5 and traverses the visceral surface of the muscles. Some cadaveric studies suggest dual innervation of the levator ani by the pudendal nerve, which originates from S2-S4 and courses over the inferior surface of the muscles. Pelvic floor hypertonicity, increased resting tone of the pelvic floor muscles, can result from many factors including stress, bladder and rectum voiding habits, and painful pelvic processes (i.e. interstitial cystitis, endometriosis). Increased muscle tone can promote sensitization of muscle afferent fibers and neuropathic upregulation. This may be perceived as vestibulodynia because the vestibule contains visceral and somatic sensory nerve fibers, whose signals are integrated at the same spinal levels as those from the levator ani. This anatomy allows for somatovisceral convergence of afferent signals, and thus perception of vestibular pain. Hypertonicity of the pelvic floor muscles decreases circulation creating localized hypoxia that can promote development of myofascial trigger points (tender nodules) in the pelvic floor. These trigger points can cause allodynia, perceived in the vestibule. In some cases, vestibulodynia may develop first and promote pelvic floor hypertonicity.

Conclusions
As pelvic floor hypertonicity can contribute to the pathogenesis of vestibulodynia, it is imperative for clinicians to include pelvic floor tone evaluation in their assessment of vestibulodynia. If pelvic floor hypertonicity is present, it should be treated concurrently with vestibular pain through a combination of pelvic floor physical therapy, trigger point injections, and botulinum toxin injections as pelvic floor hypertonicity and vestibulodynia may each perpetuate the other.

Disclosure
Any of the authors act as a consultant, employee or shareholder of an industry for: Johnson & Johnson.