Is Low Level Laser Therapy (LLLT) Effective for Reducing Pain Experienced by Women With Provoked Vestibulodynia?
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Ottawa
- Enrollment
- 28
- Locations
- 2
- Primary Endpoint
- Pain rating during the tampon test
Study Overview
Brief Summary
Provoked vestibulodynia (PVD) is one major subtype of vulvar pain, affecting close to one in ten women and resulting in pain during attempts at vaginal intercourse and/or attempts to insert a digit, device or tampon into the vagina. Management involves a multidisciplinary approach, through physicians, psychologists, sex therapists and physiotherapists. Low Level Laser Therapy (LLLT) is a therapeutic modality involving irradiation of injured or diseased tissue with a combination of red and infrared light. This process is thought to initiate a series of physiological reactions within the cells exposed to light at these wavelengths, leading to the restoration of normal cell structure and function. The investigators hypothesize that LLLT will be effective at reducing pain and improving sexual function among women with PVD.
The purpose of this double-blind randomized controlled trial is to assess the feasibility of using a LLLT intervention for the management of PVD in women. The aim is to determine whether there is evidence of a positive effect of LLLT, delivered using a BioFlexTM laser system (Health Canada Licence No. 7931) and a semi-standardized protocol, in terms of self-reported pain and sexual functioning, physiological responses to pressure applied at the vulvar vestibule, tonic and phasic activation of the PFM and/or corticomotor excitability to the PFMs in women with PVD with or without concurrent vaginismus (VAG) when compared to an identical treatment schedule where sham LLLT is delivered.
Women will be recruited from among eighty women with confirmed PVD and PVD+VAG who participate in a cross sectional study investigating pelvic floor muscle involvement in PVD. If they are interested in participating in this intervention study, they will be asked to consent to having their data from the cross sectional study used for the purposes of this concurrent study.
Women will be evaluated before the intervention using a battery of physical assessments and questionnaires, re-evaluated on primary outcome measures 3 weeks after initiating the intervention and then re-evaluated using the complete battery of physical assessment and questionnaires at the end of the intervention period. If we secure further funding, a medium term (12 weeks later) follow-up will be added. Physical assessment will include evaluation of pressure-pain threshold, temporal summation of pain, electromyographic (EMG) evaluation of PFM activity, responses of the PFMs to pressure applied at the vulvar vestibule using a custom electronic vulvalgesiometer, motor evoked potential threshold, amplitude, latency and the duration of cortically mediated silent period recorded from the PFMs following transcranial magnetic stimulation. The questionnaires will include the The Vulvar Pain Assessment Questionnaire (VPAQ), the Female Sexual Functioning Index, the Pain Catastrophizing Scale, the Depression Anxiety Stress Scales and the Central Sensitization Inventory. Three weeks and 12 weeks after the first start of treatment, the Global Perception of Improvement and Global patient satisfaction with treatment questionnaires will be administered. These will be repeated 12 weeks after completing treatment if funding becomes available.
Detailed Description
Vulvar pain affects the psychological and sexual health of more than one in five Canadian women, yet its pathophysiology is poorly understood. Provoked vestibulodynia (PVD) is one major subtype of vulvodynia, affecting close one in ten women and resulting in sharp, burning pain during attempts at vaginal intercourse and/or attempts to insert a digit, device or tampon into the vagina. Hypersensitivity of the vulvar vestibule is one of the key defining characteristics of PVD and, while its pathogenesis is unknown, it has been primarily attributed to inflammatory processes and hyperinnervation. Pelvic floor muscle (PFM) dysfunction has also been implicated in many forms of dyspareunia, yet the nature of this involvement also remains largely unknown.
Low Level Laser Therapy (LLLT), or photobiomodulation, is a therapeutic resource involving irradiation of injured or diseased tissue with a combination of red and infrared light. This laser is thought to initiate a series of physiological reactions within the cells exposed to light at these wavelengths, leading to the restoration of normal cell structure and function.
The purpose of this randomized controlled trial is to assess the feasibility of using a comprehensive LLLT intervention for the management of PVD in women with PVD alone (PVD) or with concurrent vaginismus (PVD+VAG). True and sham LLLT will be delivered by the BioFlexTM laser system (Health Canada License No. 7931). The aim is to determine whether there is evidence of a positive effect of LLLT delivered using a semi-standardized protocol delivered by the BioFlexTM laser in terms of primary outcomes including pain, sexual functioning and overall symptoms and secondary outcomes including changes in physiological responses to pressure applied at the vulvar vestibule, corticomotor excitability to the PFMs, and tonic activation and motor control of the PFMs.
Women will be recruited from among eighty women participating in a cross sectional study investigating pelvic floor muscle involvement in PVD. Women will therefore already have been recruited through local physiotherapists and gynecologists who have specific expertise in genital pain disorders and a diagnosis of PVD and PVD+VAG will have been confirmed through screening (Friedrich's Criteria as well as digital palpation assessment) by a gynaecologist, gynaecology resident or pelvic health physiotherapist, all with specific training on the assessment of vulvar pain. Other causes of vulvar pain, including generalized vulvodynia, infection, lichen sclerosis etc. will have been ruled out. Potential participants will be approached by the study protocol officer after they have participated in the cross sectional study and asked if they are interested in participating in this intervention study. If so, they will be asked to consent to having their data from the cross sectional study passed on to the current study.
Women will be evaluated before and after the 12-week intervention on all outcome measures, while primary outcome measures will be also evaluated after 3 weeks of intervention in both groups.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Treatment
- Masking
- Triple (Participant, Investigator, Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to — (Adult, Older Adult)
- Sex
- Female
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- Not provided
Exclusion Criteria
- Not provided
Outcomes
Primary Outcomes
Pain rating during the tampon test
Time Frame: 12 weeks later (if funding becomes available)
The participants will be provided with Original Regular Tampax Tampon and will be instructed to insert and then remove it. After, they will be asked to record the degree of pain during the entire insertion/removal experience in a 11-point numerical rating scale (NRS) with anchors of 0 (no pain at all) to 10 (worst pain imaginable)..
The Vulvar Pain Assessment Questionnaire (VPAQ) Inventory:COMPREHENSIVE (FULL) VERSION
Time Frame: 12 weeks after intervention (if funding becomes available)
Designed to assess: pain quality, the temporal nature of the pain, associated symptoms, pain intensity, emotional/cognitive functioning, physical functioning, coping strategies, and interpersonal functioning. Core Domains: Consists of 63 items:8 questions assessing the onset, location, temporal pattern, degree of burning pain, and associated symptoms of vulvar pain, along with six subscales. Subscales are composed of 55 items rated on 5-point scales with anchors tailored to the nature of the questions being asked: 1. Pain severity 2. Emotional response 3. Cognitive response 4. Life interference 5. Sexual function interference 6. Self-stimulation/penetration interference Each subscale is scored separately and is the average of the items. The lowest possible score is 0 (Not at all) and the highest is 4 (very much). Higher score means worse symptoms
Temporal summation of pain
Time Frame: 12 weeks later (if funding becomes available)
Difference between pain reported on first application of pressure at the vulvar vestibule, delivered through a vulvalgesiometer, and the pain reported after the tenth application of that same pressure
Global perception of improvement
Time Frame: 12 weeks after intervention (if funding becomes available)
The Global perception of improvement is a single question through which participants provide a ordinal rating based on their overall perception of improvement attributed to the intervention. Much Better, Better, About the same, Worse, Much worse. Higher ratings is associated with better outcomes.
The Vulvar Pain Assessment Questionnaire (VPAQ)Inventory:COMPREHENSIVE (FULL) VERSION
Time Frame: 12 weeks (following intervention)
Designed to assess: pain quality, the temporal nature of the pain, associated symptoms, pain intensity, emotional/cognitive functioning, physical functioning, coping strategies, and interpersonal functioning. Core Domains: Consists of 63 items:8 questions assessing the onset, location, temporal pattern, degree of burning pain, and associated symptoms of vulvar pain, along with six subscales. Subscales are composed of 55 items rated on 5-point scales with anchors tailored to the nature of the questions being asked: 1. Pain severity 2. Emotional response 3. Cognitive response 4. Life interference 5. Sexual function interference 6. Self-stimulation/penetration interference Each subscale is scored separately and is the average of the items. The lowest possible score is 0 (Not at all) and the highest is 4 (very much). Higher score means worse symptoms
Pressure pain threshold (PPT) at the posterior vaginal fourchette
Time Frame: 12 weeks after intervention (if funding becomes available)
PPT will be determined using a custom vulvalgesiometer and will be defined as the average pressure at which women first report pain when the cotton swab tip is applied at 6 o' clock position of the vaginal introitus. The vulvalgesiometer will also be used to evaluate TS of pain when the pressure measured before will be applied ten times at a rate of approximately one per second at the same location on the vestibule. Participants will rate their pain level on the initial and final application of this pressure using the same numeric rating scale (0-10).
Secondary Outcomes
- Global Patient satisfaction with treatment(12 weeks after intervention (if funding becomes available))
- Cortical silent period (ms)(12 weeks later (if funding becomes available))
- The Vulvar Pain Assessment Questionnaire - Supplemental Domains(12 weeks after intervention (if funding becomes available))
- Depression Anxiety Stress Scale (DASS)(12 weeks later (if funding becomes available))
- Female Sexual Function Index (FSFI)(12 weeks after intervention (if funding becomes available))
- Motor evoked potential (MEP) peak to peak amplitude (µV)(12 weeks later (if funding becomes available))
- Pain Catastrophizing Scale(12 weeks later (if funding becomes available))
- Central sensitization index(12 weeks later (if funding becomes available))
Investigators
Dr. Linda McLean
Professor in the School of Rehabilitation Sciences at the University of Ottawa.
University of Ottawa