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

Trigeminal Neuralgia Clinical Trial

— FreeST  

Official title:

Paresthesia-free Peripheral Nerve Field Stimulation for Trigeminal Neuralgia: a Double-blinded, Randomized Trial (FreeST Trial)

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05615714
• Other study ID #: 21-6219
• Status: Recruiting
• Phase: Phase 1/Phase 2
• Start date: October 28, 2022
• Est. completion date: October 28, 2024

Study information

• Verified date: February 2024
• Source: University Health Network, Toronto
• Contact: Jacob Kim
• Phone: +14166035800
• Email: jacob.kim[@]uhn.ca
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 24
• Est. completion date: October 28, 2024
• Est. primary completion date: October 28, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Diagnosis of a medically-refractory unilateral facial pain syndrome as defined by the Burchiel 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 on the 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. Medications allowed during the study are long-acting/modulatory analgesics (anticonvulsants such as carbamezapine, oxcarbazepine, pregabalin, gabapentin, lamotrigine; baclofen, botox injections) and short-acting analgesics (non-steroid anti-inflammatory drugs, short-acting opioids, lidocaine or sumatriptan injections)

Exclusion Criteria:

• Currently in a clinical trial involving an investigational product or non-approved use of a drug or device.

• Active psychiatric disorder or other known condition that can significantly impact pain perception

• Patients with a revision surgery of a PNFS system by any reason (history of trigeminal pain surgery of other types (i.e., microvascular decompression, gamma knife, percutaneous rhizotomies) are not exclusion criteria)

• Pregnant and lactating women

Related Conditions & MeSH terms

• Facial Pain
• Neuralgia
• Paresthesia
• Trigeminal Neuralgia

Intervention

Other:
• Paresthesia-free Peripheral Nerve Field Stimulation
High frequency and sub-paresthesia threshold intensity parameters will be used for paresthesia-free stimulation of trigeminal nerve branches.
• Sham stimulation
Stimulation will be turned off.

Locations

Country	Name	City	State
Canada	Centre hospitalier universitaire de Sherbrooke	Sherbrooke	Quebec
Canada	Toronto Western Hospital, University Health Network	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
University Health Network, Toronto

Country where clinical trial is conducted

Canada, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Visual Analogue Scale (VAS) Score Change	VAS score change between sham condition (postop week 2-4 or postop week 4-6) and Paresthesia-free stimulation condition (postop week 2-4 or postop week 4-6) VAS score ranges from 0 to 100 mm (or 0 to 10 cm). Higher score is worse outcome.	Postoperative week 2 to week 6
Secondary	Visual Analogue Scale (VAS) Score Change	Score changes between sham condition (postop week 2-4 or postop week 4-6), Paresthesia-free stimulation condition (postop week 2-4 or postop week 4-6) and Paresthesia-inducing stimulation condition (postop week 0-2) Non-independent within-group comparison VAS score ranges from 0 to 100 mm (or 0 to 10 cm). Higher score is worse outcome.	Postoperative week 0 to week 6
Secondary	Barrow Neurological Institute (BNI) pain intensity score change	Score changes between sham condition (postop week 2-4 or postop week 4-6), Paresthesia-free stimulation condition (postop week 2-4 or postop week 4-6) and Paresthesia-inducing stimulation condition (postop week 0-2) Non-independent within-group comparison BNI score ranges from 1 to 5. Higher score is worse outcome.	Postoperative week 0 to week 6
Secondary	Brief Pain Inventory (BPI) score change	Score changes between sham condition (postop week 2-4 or postop week 4-6), Paresthesia-free stimulation condition (postop week 2-4 or postop week 4-6) and Paresthesia-inducing stimulation condition (postop week 0-2) Non-independent within-group comparison BPI-Pain Severity Score and BPI-Pain Interference Score range from 0 to 10. Higher score is worse outcome.	Postoperative week 0 to week 6
Secondary	Clinician and Patient Global Impression of Change Scale and Patient satisfaction scale score change	Score changes between sham condition (postop week 2-4 or postop week 4-6), Paresthesia-free stimulation condition (postop week 2-4 or postop week 4-6) and Paresthesia-inducing stimulation condition (postop week 0-2) Non-independent within-group comparison Clinician and Patient Global Impression of Change Scale (range from 1 to 7) and Patient satisfaction scale (range from 1 to 5). Higher score is worse outcome.	Postoperative week 0 to week 6
Secondary	Adverse effect Profile	Adverse effect Profile	Postoperative week 0 to month 12
Secondary	Ratio of patients who chose paresthesia-free or paresthesia-inducing stimulation at week 6, month 6 and 12	paresthesia-free or paresthesia-inducing stimulation	Postoperative week 6, month 6 and 12
Secondary	fMRI BOLD signal change	IPG ON>OFF BOLD signal change (both paresthesia-free and Paresthesia-inducing conditions will be tested)	Between postoperative month 6 and 12
Secondary	Visual Analogue Scale (VAS) Score Change	Score changes between baseline and postoperative 6 and 12 months VAS score ranges from 0 to 100 mm (or 0 to 10 cm). Higher score is worse outcome.	Postoperative month 6 and 12
Secondary	Barrow Neurological Institute (BNI) pain intensity score change	Score changes between baseline and postoperative 6 and 12 months BNI score ranges from 1 to 5. Higher score is worse outcome.	Postoperative month 6 and 12
Secondary	Brief Pain Inventory (BPI) score change	Score changes between baseline and postoperative 6 and 12 months BPI-Pain Severity Score and BPI-Pain Interference Score range from 0 to 10. Higher score is worse outcome.	Postoperative month 6 and 12