title: Psychophysical properties of female genital sensation.
abstract: Provoked vestibulodynia (PVD) is characterized by the presence of vulvar touch and pain hypersensitivity. Pain with vaginal distension, which motivates treatment seeking and perpetuates distress, is frequently reported with PVD. However, the concordance between the perception of vulvar and vaginal sensation (ie, somatic and visceral genital sensations, respectively) remains unstudied in healthy women, as well as in clinical populations such as PVD. To evaluate the static and dynamic (time-varying) properties of somatic and visceral genital sensation, women with PVD (n=14) and age- and contraceptive-matched healthy controls (n=10) rated varying degrees of nonpainful and painful genital stimulation. Somatic (vulvar) mechanical sensitivity to nonpainul and painful degrees of force were compared to visceral (vaginal) sensitivity to nonpainful and painful distension volumes. Results indicated that healthy women showed substantial individual variation in and high discrimination of vulvar and vaginal sensation. In contrast, PVD was associated with vulvar allodynia and hyperalgesia, as well as vaginal allodynia. Modeling of dynamic perception revealed novel properties of abnormal PVD genital sensation, including temporal delays in vulvar touch perception and reduced perceptual thresholds for vaginal distension. The temporal properties and magnitude of PVD distension pain were indistinguishable from vaginal fullness in healthy controls. These results constitute the first empirical comparison of somatic and visceral genital sensation in healthy women. Findings provide novel insights into the sensory abnormalities that characterize PVD, including an experimental demonstration of visceral allodynia. This investigation challenges the prevailing diagnostic assessment of PVD and reconceptualizes PVD as a chronic somatic and visceral pain condition.
authors.affiliation: Department of Physiology, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave., Chicago, IL 60610, USA Department of Psychology, University of Nevada at Las Vegas, Las Vegas, NV, USA Department of Psychology, Queens University, Kingston, ON, Canada Department of Psychology, McGill University, 1205 Dr. Penfield Ave., Montréal, Canada Alan Edwards Centre for Research on Pain, McGill University, Montréal, Canada Department of Anesthesia, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610, USA Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610, USA Rehabilitation Institute of Chicago, Feinberg School of Medicine, Northwestern University, Chicago, IL 60610, USA Faculty of Dentistry, McGill University, 3640 University Street, Montréal, QC H3A 2B2, Canada.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Farmer
authors.forename: Caroline A
authors.initials: CA
authors.lastname: Maykut
authors.forename: Jackie S
authors.initials: JS
authors.lastname: Huberman
authors.forename: Lejian
authors.initials: L
authors.lastname: Huang
authors.forename: Samir
authors.initials: S
authors.lastname: Khalifé
authors.forename: Yitzchak M
authors.initials: YM
authors.lastname: Binik
authors.forename: Vania A
authors.initials: VA
authors.lastname: Apkarian
authors.forename: Petra
authors.initials: P
authors.lastname: Schweinhardt
mesh_terms: D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000523:psychology; D003075:Coitus / Q000523:psychology; D003430:Cross-Sectional Studies; D005260:Female; D005836:Genitalia, Female / Q000294:innervation / Q000502:physiology*; D006801:Humans; D010147:Pain Measurement / Q000295:instrumentation / Q000379:methods; D017288:Pain Threshold / Q000502:physiology; D010812:Physical Stimulation; D011601:Psychophysics; D012677:Sensation / Q000502:physiology*; D012725:Sexual Behavior; D012959:Socioeconomic Factors; D014621:Vagina / Q000502:physiology; D014844:Vulva / Q000502:physiology; D056650:Vulvodynia / Q000503:physiopathology; D055815:Young Adult
keywords: Distension; Genital sensation; Pain; Provoked vestibulodynia; Psychophysics; Somatic; Visceral