Provoked vestibulodynia (PVD) is characterized by severe sharp and/or burning pain felt at the entrance to the vagina (i.e. the vulvar vestibule) when pressure is applied to this area or during attempts at vaginal insertional activities (i.e. provoked).

PVD is sometimes accompanied by intense, involuntary contraction of the PFMs3, termed vaginismus (VAG).

Participants matched by age (within 2 years), parity (parous vs nulliparous) and use of oral contraceptive medications (yes vs no) to women in the PVD group, with no signs and symptoms of PVD.

Dyspareunia

Transcranial magenetic stimulation will be used to probe the excitability of cortical projections to the pelvic floor muscles. The outcomes of interest will include motor evoked potential amplitude and silent period.

Corticomotor excitability to the pelvic floor muscles

Electromyography will be used to determine whether the pelvic floor muscles (PFMs) respond to pressure applied to the vulvar vestibule as anticipatory (i.e. PFMs are active before the pressure is applied) and as behavioural (i.e. PFMs are active after the pressure is applied) responses. The amplitude of the EMG responses will also be recorded.

Pelvic floor muscle response to pressure applied at the vulvar vestibule

A custom vulvalgesiometer will be used to determine the mean pressure at which participants first report pain at the posterior vaginal fourchette.

Pressure pain threshold (PPS)

A custom vulvalgesiometer will be used to apply the same pressure (rated as 4/10 duiring PPS testing as described above) to the vulvar vestibule across 10 repetitions. The difference in pain rated on the tenth application and that rated on the first application will be the outcome.

Temporal summation of pain

Electromyography will be used to measure the mean smoothed, rectified activation amplitude across 1 second of complete rest, across three maximal effort PFM contractions, and across three attempts at a bearing down maneuver.

Tonic, phasic and reflex activation of the pelvic floor muscles (PFMs)

What is the Nature of Pelvic Floor Muscle Involvement in Dyspareunia?

Transcranial magnetic stimulation outcome (i.e. Motor evoked potential peak to peak amplitude - µV) will be determined for all participants and compared among groups.
A Magstim® 200 system coupled with a double cone coil (96 mm loops, P/N 9902) [57] will be used to probe the corticospinal projections to PFMs. MEPs will be ensemble averaged to generate estimates of MEP peak to peak amplitude (µV).

Transcranial magnetic stimulation outcome (i.e. cortical silent period duration - ms) will be determined for all participants and compared among groups.
A Magstim® 200 system coupled with a double cone coil (96 mm loops, P/N 9902) [57] will be used to probe the corticospinal projections to PFMs. MEP cortical silent period (cSP) will be measured from individual trials and then averaged.

The proportion of women in each group who demonstrate anticipatory responses of the PFMs to impending pressure applied at the vulvar vestibule will be determined for each group. Participants will be deemed to have anticipatory responses if electromyographic signals recorded from the PFMs precede the application of pressure. A vulvalgesiometer [58] will be employed using a response-dependent methodology. [59,60] The vulvalgesiometer will be used to apply low (25 g) and moderate (232 g) pressures to the posterior vaginal fourchette or to the posterior thigh, the moderate value having been generated through the team's previous research. [9]

The proportion of women in each group who demonstrate behavioral responses of the PFMs to pressure applied at the vulvar vestibule will be determined for each group. Participants will be deemed to have behavioural if the activation of the PFMs (or other muscles) occurs after the pressure is applied. A vulvalgesiometer [58] will be employed using a response-dependent methodology. [59,60] The vulvalgesiometer will be used to apply low (25 g) and moderate (232 g) pressures to the posterior vaginal fourchette or to the posterior thigh, the moderate value having been generated through the team's previous research. [9]

Surface Electromyography (EMG) recorded using differential suction electrodes (DSEs, developed by Dr. McLean) [54-56] will be used to measure tonic, voluntary and reflex activation of the superficial and deep PFMs. Smoothed peak EMG amplitudes (µV) will be computed as outcomes while women keep their PFMs as relaxed as possible (tonic), contract as strongly as possible (phasic) and perform a straining maneuver (reflex activation).

Women will be instructed to insert and then remove the tampon and they will be instructed to record the degree of pain during the entire insertion/ removal experience on a 0-10 pain numeric rating scale, with 0 meaning no pain, and 10 meaning the worst possible pain.

The pressure at which women report pain on pressure applied through a cotton swab to the region of the posterior vaginal fourchette.
Pressure pain threshold (PPT) will be determined using a custom vulvalgesiometer. PPT will be defined as the average pressure at which women first report pain when the cotton swab tip of the vulvalgesiometer is applied at 6 o' clock of the vaginal introitus [51].

The difference in pain rating (scale 1-10) between the tenth and first application of a pressure applied to the posterior vaginal fourchette through a custom vulvalgesiometer.
The PPT determined at the 6-o-clock position, will be applied ten times at a rate of approximately one per second at the 6 o'clock location on the vestibule. Participants will rate their pain level on the initial and final application of this pressure using a Numeric Rating Scale (0-10). TS will be defined as the difference in pain rating between the final and first application of the pressure [52,53]

This is a 19-item validated questionnaire [43,44] for assessing the key dimension of sexual function in women, considered a gold standard for evaluation of sexual function. It assesses six domains: desire, arousal , lubrification, orgasm, satisfaction, and pain. All scores are totaled for a maximum of 36. Higher scores represents better sexual function. A score ≤26.55 has been set as a cutoff to identify those at risk for sexual dysfunction.

This questionnaire consists primarily of 3 major classes of word descriptors - sensory, affective and evaluative - that are used by patients to specify subjective pain experience. It also contains an intensity scale and other items to determine the properties of pain experience. This questionnaire is composed of 78 words. Respondents choose those that best describe their experience of pain. Scores are tabulated by summing values associated with each word; scores range from 0 (no pain) to 78 (severe pain). Quantitative differences in pain may be reflected in respondents word choice.

The Pain Catastrophizing Scale is a reliable and valid measure of catastrophizing. The scores from this questionnaire is predictors of intensity of physical and emotional distress.
It is a self-report measure, consisting of 13 items scored from 0 to 4, resulting in a total possible score of 52. The higher the score, the more catastrophizing thoughts are present

This is a 42-item self report instrument designed to measure the three related negative emotional states of depression, anxiety and tension/stress [47,48]. Each one contains 14 items, divided into subscales of 2-5 items with similar content. The DASS have been shown to have high internal consistency and to yield meaningful discriminations in a variety of settings.
A higher score on the DASS indicates greater severity or frequency of these negative emotional symptoms. The maximum score is 126.

The Central Sensitisation Inventory (CSI) [49], is a self-report outcome measure designed to identify patients who have symptoms that may be related to central sensitisation (CS) or central sensitivity syndromes (CSS). Part A includes 25 questions related to common CSS symptoms.
Part B determines if the patient has been diagnosed with certain CSS disorders or related disorders, such as anxiety and depression. CSI severity levels have been established for part A: subclinical = 0 to 29; mild = 30 to 39; moderate = 40 to 49; severe = 50 to 59; and extreme = 60 to 100.

Spreadsheets will be provided by email upon request and based on the planned use of the data.

vaginismus/ataxia

What is the Nature of Pelvic Floor Muscle Involvement in Dyspareunia?

Բժշկական դեղաբույսերի ամենալավ տվյալների շտեմարանը, որին աջակցում է գիտությունը