Adults ages 18-90 years old who have first been given the standard of care therapy according
to the AUA/EUA guidelines depending on their specific pain modality, first line treatments
based on suspected etiology (for example pelvic floor physical therapy for high tone pelvic
floor muscle dysfunction or amitriptyline for interstitial cystitis) without success will be
defined as refractory. Participants who have plateaued on their response to current
intervention strategies will be offered the TENS unit as an adjunct.
Participation will be offered by mail or in person. If by mail, the investigators will send
the consent with the letter and questionnaires asking participants to call or bring the
material if they would like to enroll. If the investigators speak to the subject over the
phone, the investigators will discuss the study as comprehensively as if they were in the
clinic. This will include explaining the concept of the TENS unit, the study itself, and
clarifying any questions the participant has. Subsequently if they are interested in the
study, the investigators will ask them to sign the consent and return it to us via mail or
email.
Those whose pain symptomatology is above a threshold and who choose TENS therapy will be
included in the study. The participants will be randomized into three groups of 25
participants each. The randomization will occur in blocks so that if the investigators need
to terminate the study early there will be an equal number of participants in each group. The
size of the blocks will also be kept secret for allocation concealment purposes. The
randomization will be stratified by gender so that there is an equal number of participants
from each gender in each group, reducing potential for gender as a confounding variable.
Group 1 will be the low frequency set at 20 Hz. Group 2 will be the medium frequency set at
50 Hz. Group 3 will be the high frequency set 100 Hz. There is no sham group in this study as
it has previously been found that posterior tibial TENS is effective and lasting. As such,
all participants will be treated as a matter of routine medical care for pelvic pain. The
investigators will use a fixed pulse width of 200 microseconds (uS), with continuous rather
than biphasic stimulation. The investigators will aim to recruit 25 participants per group
for a total of 75 participants.
Study Procedures
Screening Day 7/ Week 1 (in clinic or virtual): The first data points (Day 0) will take place
in the clinic during the participant's routine visit or at the time of the participant's
phone call seeking participation. If during a phone call seeking participation, this will be
considered a study phone call, not a billable visit. The participant will fill out the VAS
and GUPI. The participants will be taught how to fill out the pain assessment questionnaires
(the VAS and GUPI, validated tools for measuring genitourinary pain and symptoms
respectively). This can be done via paper to be brought into the office at their next checkup
or via an emailed link through Qualtrics and uploaded to a spreadsheet in a protected AMC
OneDrive. The baseline pain logs will be reviewed for sufficient severity of pain episodes
and the participant will be randomized into the study if their pain is above the designated
threshold: participants who record a pain scale of 4 or higher on any of the VAS scores or
QOL score of 3 or higher on the GUPI question #9 will be eligible for the TENS study.
The GUPI and VAS will be collected at this time; this will record the participant's pain 1
week prior to the study and will be considered Day 7/week 1. The week 1 of screening will be
combined with the first week of baseline measurement (week 2) for a 2-week lead-in.
Participants will be taught how to complete a usage log (stating if the TENS was used each
day and for how long in minutes) and will be asked to repeat this weekly. Participants will
complete an inventory (the Treatment Map) of treatments tried prior to the TENS, throughout
the study, and at the end.
Baseline Day 14/ Week 2: If the participant enrolls, they will be asked to continue logging
pain (VAS and GUPI, on paper or via Qualtrics) for one week, with the week 1 screening and
the week 2 baseline week totaling a 14-day control period. The control period will represent
data (2 weeks of VAS and GUPI) with only baseline treatments and no TENS unit.
At week 2 (the end of the 2-week baseline, in person), participants will hand in scores and
be randomized to a frequency. They will be given a TENS unit and taught how to use the unit.
Teaching will include positioning of electrodes, as well as what buttons they are allowed to
manipulate. The TENS unit settings will be pre-determined at the clinic and measures will be
taken to ensure that the settings cannot be altered at home. The participant will be
instructed not to open the TENS unit during the 2 treatment weeks of the study to ensure the
settings are maintained. They will be instructed to continue only their baseline treatments.
Settings: The TENS unit used is a Compass Health TENS 3000, 3 mode Analog Unit. The
participants' TENS unit will be set at Normal Mode (N), a pulse width of 200 microseconds and
an intensity to be determined in the office based upon when the participant feels sensitive
to the TENS unit. Frequency (pulse rate) will be determined by randomization. The participant
will place the electrodes along the posterior tibial nerve on the medial ankle with a ground
on the inner arch, each day for 30 minutes for a total of 14 days at the time of day
typically associated with the worst pain or at the first opportunity for rest after this
time.
Group 1 will be the low frequency group. This means that the TENS therapy will use a
frequency of 20 Hz.
Group 2 will be the medium frequency group. This means that the TENS therapy will use a
frequency of 50 Hz.
Group 3 will be the high frequency group. This means that the TENS therapy will use a
frequency of 100 Hz.
Participants will be provided the TENS unit, its manual, and enough patches to last the 2
weeks of the treatment period. Participants will be given a weekly usage log, weekly pain VAS
and weekly GUPI questionnaire logs again for 2 weeks they are actively using the TENS, with
the option of paper or Qualtrics. In this log, the rating of pain by VAS and GUPI, the rating
of genitourinary symptoms by GUPI, duration of TENS therapy, usage for every day of the week
and adverse reactions to the TENS unit (rash) will be recorded.
Participants may be called during the 14-day treatment period to keep on track, address any
concerns, questions, or any adverse reactions to TENS therapy by the physician or research
staff. Their phone numbers will be maintained in the master key associated with the
deidentified database in the AMC Onedrive protected research file for this purpose.
At 7 days and the end of the 14-day treatment period the visit can be performed either
virtually or in the office. The 7-day visit will be considered purely a study visit and the
14 day visit a standard of care visit.
The completed week 3 and 4 VAS and GUPI, treatment usage documents will be returned. The
participants will also be asked the question "Will you continue using TENS therapy for your
pelvic pain?" Any persistent issues will be addressed during these visits as well and further
options discussed.
For those who would like to continue the TENS unit, participants will be taught how to adjust
settings and sites at home. Participants will be given repeat VAS and GUPI at 1, 2, and 3
months post-initial phase and seen again at 3 months as part of standard care. Here the
investigators will review logs of what frequency patterns they developed with TENS usage on
their own, if any. In this time participants may increase or decrease the frequency of their
device anywhere in the range of 2 Hz to 150 Hz to see which they prefer most in this part of
the trial. Participants will also be allowed to adjust pulse width (30 to 260 uS), mode (B N
M), time (continuous, 15, 30 minutes), and intensity (1 to 8, 10-80mA) as desired. The only
requests will be that they remove the device if any discomfort occurs and that they log their
settings versus their response.