Multimodal Vulvar and Peripheral Sensitivity Among Women With Vulvodynia: A Case–Control Study

Abstract

Objective To assess differences in vulvar and peripheral sensitivity between women with and without vulvodynia. Methods Women with vulvodynia (N=41) and age-matched controls (N=43) seen in the outpatient setting were evaluated via surveys, clinical examination, and multimodal sensory testing (pressure, heat, cold, vibration, and electrical stimulation). The relationship between sensitivity to various sensory modalities and case/control status, as well as by vulvodynia subgroups, were assessed using logistic regression. Results Women with vulvodynia were more sensitive to pressure and to electrical stimuli than were control women at the vulva (Median 22 vs 230 grams and 0.495 vs 0.769 mA, respectively, p <0.001 for each) and at the thumb (Median 2500 vs 4250 grams and 0.578 vs 0764 mA, respectively, p=0.006 for pressure, p<0.001 for electrical stimulation). Heat, cold, and vibration detection thresholds did not differ significantly between these groups (p>0.025). Those reporting spontaneous pain versus provoked pain had greater pressure sensitivity to the thumb (Median 1850 vs 2690 grams, p=0.020) and greater electrical sensitivity at the introitus (0.450 vs 0.608 mA, p=0.011), and those with primary versus secondary vulvodynia, had substantially greater pressure sensitivity to the thumb (Median 2438 vs 3125 grams, p=0.004). However, having localized versus generalized vulvodynia was not associated with differences in pressure or electrical sensitivity. Conclusions Sensitivity to pressure and electrical stimuli is greater among vulvodynia cases than among controls, and supports two previously defined subgroups -- those reporting spontaneous pain versus those whose pain only occurred when provoked, and those with primary versus secondary vulvodynia.

Deep Dyspareunia: Review of Pathophysiology and Proposed Future Research Priorities

“…Tenderness of the bladder and pelvic floor, as well as the diagnosis of PBS, have been associated with deep dyspareunia in previous literature as well [92,93]. It should also be emphasized that IC/PBS is associated with vulvodynia [94], and thus is also related to superficial dyspareunia.…”

Experimental pain sensitivity in women with vestibulodynia: a pilot study

“…Reed, et al, assessed differences in vulvar and peripheral sensitivity and similarly found women with vulvodynia were more sensitive to pressure and electrical stimuli than were control women at the vulva and at the thumb. 15 Foster, et al, compared the response to intradermal capsaicin at the forearm and foot of women with vestibulodynia to controls, and found that patients with vestibulodynia demonstrated altered pain processing extending to regions far beyond the vulva. 4 Hampson, et al, found augmented brain activation on fMRI studies in women with vulvodynia…”

Health, obstetric outcomes and reproduction in women with vulvar pain or primary fear of childbirth

“…Studies have found an increased density of nerve fibers in affected vulvar tissue (59) and a lower threshold for pain in extremities which could indicate peripheral and central sensitization (60). Furthermore, other chronic pain conditions such as fibromyalgia and irritable bowel syndrome are more common in women with LPV (51,61).…”

“…• An altered pain-processing in the brain (76), higher gray matter density in painmodulatory and stress-related areas (77) as well as general allodynia to mechanical pressure as measured in the thumb (60) has been observed in women with LPV which could indicate central sensitization (78) .…”