TENS for Testicular Pain (ICO): A Randomized Controlled Trial
Condition: Pain Management
Study type: Interventional

Summary: 
      Idiopathic Chronic Orchialgia (i.e., testicular pain) is a challenging condition to treat,
      with unresolved testicular pain leading to distress, diminished activities of daily living
      and decreased quality of life. Testicular Pain may be caused by a tumor, hernia, infection,
      trauma, vein compression, cysts, and/or postoperative or radiating pain, though is often
      times unknown. Non-pharmacologic, conservative pain reduction interventions include heat,
      ice, scrotal support, physical therapy, and/or counseling, and should often be used as first
      line of defense. More aggressive, invasive, and non-conservative medical treatment options
      include medications, nerve blocks, and/or surgery, each of which may be effective, but may be
      invasive and/or cause serious side effects. However, there is no standard of care for
      managing the testicular pain and many men do not respond to current biomedical or
      nonpharmacologic treatment options. Novel, non-invasive treatment options are needed for ICO
      to improve distress, daily living activities, and quality of life. Transcutaneous electrical
      nerve stimulation (TENS) is a non-pharmacologic intervention for acute and chronic pain. This
      treatment involves the application of electric current through the skin; it is safe, easy to
      use, and inexpensive. Despite the impact and distress associated with Testicular Pain, only
      one known study examined the efficacy of TENS for this condition. A 2018 double-blind,
      randomized controlled study of people with Testicular Pain reported that TENS improved pain
      and quality of life significantly more than the control condition (analgesia only). This 2018
      study lacked a placebo control condition (i.e., unknown whether pain relief was due to the
      placebo effect, where knowing an intervention is happening leads to an expectation that pain
      will decrease, and therefore pain perception decreases independent of the intervention).
      Thus, the aim of this study is to examine the efficacy of TENS on Testicular Pain using a
      randomized, placebo-controlled design. The results of this study will be used to inform a
      larger, federally-funded study.

      i. Primary Aim: To assess the efficacy of TENS for Testicular Pain

      ii. Secondary Aim: To assess the feasibility of TENS for Testicular Pain

      iii. Third Aim: To assess the tolerability of TENS for Testicular Pain

      iii. To assess associations between dispositional pain catastrophizing on responsiveness to
      the TENS intervention.
    

Detailed description: 
      The overall aim of this study is to examine the efficacy of TENS on Testicular Pain using a
      randomized, placebo-controlled design. The results of this study will be used to inform a
      larger, federally-funded study. The study is a prospective, randomized, double-blinded and
      placebo-controlled crossover design (each participant completes all 3 study conditions) with
      randomization to 3 study conditions: 1) Active TENS; 2) Placebo TENS; or 3) No Treatment
      Control. Subjects will be tested 1x/week for 3 weeks. Each subject will receive the 3
      treatments in randomized order. Importantly, the experimenter and subject will be blinded to
      the treatment condition. A second experimenter will administer the Active or Placebo TENS, or
      the Control to ensure appropriate blinding (to ensure no bias from knowing which TENS
      condition is given at each visit).

      Participants. Thirty men with Testicular Pain (lasting >3 months), aged 18-99yrs will be
      recruited. Exclusion criteria includes: pain intensity rating ≤ 3/10, contraindications for
      TENS (pacemaker) or TENS use ≤ 5 years. Participants will provide written informed consent,
      as approved by the University of Iowa Biomedical Institutional Review Board. TENS Treatment.
      All subjects will receive each of the 3 TENS treatment conditions while sitting in an upright
      position. Four adhesive electrodes (2in x 2in) will be placed bilaterally on the: 1) sacrum
      (for pudendal nerve); and 2) groin (ilioinguinal nerve).

      Active TENS includes high frequency TENS delivered for 30mins at a frequency of 100 Hz and
      pulse duration of 100μsec using the EMPI Select TENS unit (calibrated using an oscilloscope
      prior to study). The intensity will be increased until patients feel a "maximally strong but
      comfortable sensation" to ensure an analgesic effect.

      Placebo TENS parameters will be identical to Active TENS (100 Hz and 100 μsec), but a novel
      placebo TENS unit, previously tested and validated will be used. The placebo device provides
      a current for 30sec and ramps off over 15sec to zero output. An indicator light remains on so
      it appears to the subject that the unit is still producing current. This unit has
      demonstrated nearly 100% blinding of investigators such that the investigator applying the
      TENS is unable to distinguish between the active and the placebo unit; approximately ~50% of
      subjects are successfully blinded using this unit.

      The No Treatment Control includes application of TENS electrodes identical to the other 2
      conditions, but the unit remains off. This condition will control for potential effects of
      repeat testing and any placebo effect.

      Patient Measures. Pain will be assessed before and after TENS each session to measure any
      within visit changes in pain from the TENS intervention. Pain change will be measured using
      the: 1) Short-Form McGill Pain Questionnaire 27 with qualitative (i.e., sharp, distressing)
      and quantitative pain scales; and 2) 10-point numeric pain intensity rating scale (NRS)
      ranging from 0 (no pain) to 10 (worst pain imaginable); These pain measures are valid and
      reliable. Pain medication intake will also be assessed. Finally, pain-related catastrophizing
      (i.e., coping) will be measured using the Pain Catastrophizing Scale to determine if any
      responsiveness to TENS intervention is related to dispositional catastrophizing (i.e., their
      general catastrophizing levels prior to initiating the TENS study interventions).
    

Intervention name(s): Transcutaneous Electrical Nerve Stimulation (TENS)
Intervention type(s): Device
Intervention description(s): Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacologic intervention for acute and chronic pain. This treatment involves the application of electric current through the skin; it is safe, easy to use, and inexpensive
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: The study is a prospective, randomized, double-blinded and placebo-controlled crossover design (all participants complete each of the 3 conditions) with randomization to: 1) Active TENS; 2) Placebo TENS; or 3) No Treatment Control. Each subject will receive the 3 TENS treatments in randomized order (one visit per week in three separate weeks). The visits do not have to take place in three consecutive weeks (will depend on participant scheduling preferences), but all three visits must take place within one year
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Transcutaneous electric nerve stimulation; Idiopathic chronic orchialgia; Testicular Pain; Chronic Pain; Testicular; Scrotum