Paresthesia-free Peripheral Nerve Field Stimulation for Trigeminal Neuralgia (FreeST Trial)

Last updated: February 22, 2024
Sponsor: University Health Network, Toronto
Overall Status: Active - Recruiting

Phase

1/2

Condition

Trigeminal Neuralgia

Pain

Pain (Pediatric)

Treatment

Sham stimulation

Paresthesia-free Peripheral Nerve Field Stimulation

Clinical Study ID

NCT05615714
21-6219
  • Ages > 18
  • All Genders

Study Summary

Study type: Prospective, double-blinded, double arm, cross-over, randomized controlled clinical trial.

Brief protocol:

Postoperative week 0-2 -> Conventional parameters (parameters tested during trial period)

Postoperative week 2-6 -> Sham stimulation (2 weeks) and paresthesia-free stimulation (2 weeks) double-blind crossover design

Postoperative week 6 - month 12 -> Parameters that patients feel more benefit from

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Diagnosis of a medically-refractory unilateral facial pain syndrome as defined by theBurchiel classification but excluding atypical facial pain (somatoform pain disorder)
  • Recent successful PNFS trial and permanent implantation surgery
  • Average preoperative episodic/constant pain intensity of 5 or greater out of 10 cm onthe VAS
  • Capable of providing informed consent and complying with study procedures
  • Patients may or may not use a pain medication at the time of recruitment. Medicationsallowed during the study are long-acting/modulatory analgesics (anticonvulsants suchas carbamezapine, oxcarbazepine, pregabalin, gabapentin, lamotrigine; baclofen, botoxinjections) and short-acting analgesics (non-steroid anti-inflammatory drugs,short-acting opioids, lidocaine or sumatriptan injections)

Exclusion

Exclusion Criteria:

  • Currently in a clinical trial involving an investigational product or non-approved useof a drug or device.
  • Active psychiatric disorder or other known condition that can significantly impactpain perception
  • Patients with a revision surgery of a PNFS system by any reason (history of trigeminalpain surgery of other types (i.e., microvascular decompression, gamma knife,percutaneous rhizotomies) are not exclusion criteria)
  • Pregnant and lactating women

Study Design

Total Participants: 24
Treatment Group(s): 2
Primary Treatment: Sham stimulation
Phase: 1/2
Study Start date:
October 28, 2022
Estimated Completion Date:
October 28, 2024

Study Description

Background:

Peripheral Nerve Field Stimulation (PNFS) has been utilized for the treatment of facial pain for around 60 years, and the commercial devices needed to deliver PNFS have been available for around 30 years. The safety and efficacy of the procedure has been demonstrated by various uncontrolled observational studies. It serves as a part of daily neurosurgical practice for selected patients in UHN Toronto Western Hospital. This therapeutic modality involves subcutaneous implantation of electrodes in the vicinity of trigeminal nerve branches and application of electrical current using a permanently implanted pulse generator (IPG). Similar to other forms of neuromodulation, PNFS is non-ablative, reversible, adjustable and associated with a relatively low risk of severe complications. A meta-analysis of paresthesia-inducing (PI) PFNS studies in the literature revealed a treatment efficacy of 75% decrease in VAS scores (mean difference: -6.32 out of 10) with PNFS utilization for facial pain. (PMID: 35180702)

Study design:

Patients who underwent a successful unilateral PNFS implantation surgery (trial and permanent implantation) for a facial pain syndrome as a standard of care treatment, will be screened for inclusion after permanent implantable pulse generator (IPG) implantation. Upon consent, the investigators will set up participants' IPG to deliver stimulation with parameters tested during the trial period (paresthesia-inducing parameters) for 2 weeks. The participants will come back to hospital at postoperative week 2 and will be randomized (1:1 ratio) between the two arms of the study (Group 1= sham, Group 2= paresthesia-free (PF) stimulation). Each participant will consecutively experience all two stimulation groups by 2-week periods in a crossover design. Both participants and clinical investigators that will assess the pain will be blind during the study period (between postoperative week 2 and 6). After 6 weeks, the treatment arms will be merged and all the participants will receive any stimulation parameter that they feel more benefit from ("best" parameter). Outcomes will be assessed 6 and 12 months post-operatively.

Connect with a study center

  • Toronto Western Hospital, University Health Network

    Toronto, Ontario M5T 2S8
    Canada

    Active - Recruiting

  • Centre hospitalier universitaire de Sherbrooke

    Sherbrooke, Quebec J1H 5N4
    Canada

    Active - Recruiting

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