TSEP + Rhizotomy for Trigeminal Neuralgia

Overseen By Danielle Carlson, MD

Age: 18+

Sex: Any

Trial Phase: Phase < 1

Sponsor: University of Minnesota

Disqualifiers: Facial pain, Migraine, Fibromyalgia, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 2 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

Duration: 1 day

30 Participants Needed

Trial Summary

What is the purpose of this trial?

Trigeminal neuralgia (TGN) is a debilitating pain syndrome where electrical, shock- like jolts of pain affect the face. Trigeminal somatosensory evoked potentials (TSEPs) provide a promising modality for measuring the trigeminal sensory and nociceptive pathway by using peripheral stimulation of the trigeminal nerve (on the skin) and measuring low latency evoked potentials on the scalp (contralateral sensory cortex). While TSEPs have been measured in the past, it is not clear if implementing TSEPs into a routine neurosurgical rhizotomy procedure will be feasible. This is a prospective cohort study examining the feasibility of routinely performing TSEPs during rhizotomies for TGN.

Do I need to stop my current medications for this trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment TSEP + Rhizotomy for Trigeminal Neuralgia?

The research indicates that percutaneous stereotaxic rhizotomy (PSR), a similar procedure to the rhizotomy part of the treatment, has shown good long-term results in treating trigeminal neuralgia, with 61% of patients experiencing excellent outcomes. Additionally, trigeminal somatosensory evoked potentials (TSEPs) have been useful in diagnosing and managing trigeminal nerve issues, suggesting they could help guide effective treatment. ^{1 2 3 4 5}

Is TSEP + Rhizotomy generally safe for humans?

The safety of TSEP + Rhizotomy for trigeminal neuralgia shows that while complications can occur, they are mostly mild and non-disabling, though some long-lasting side effects have been reported. TSEPs are non-invasive and have been used to assess nerve function, suggesting a level of safety in their application. ^{1 6 7 8 9}

How is the TSEP + Rhizotomy treatment for trigeminal neuralgia different from other treatments?

The TSEP + Rhizotomy treatment for trigeminal neuralgia is unique because it combines trigeminal somatosensory evoked potentials (TSEPs), which help assess nerve function, with rhizotomy, a surgical procedure that targets nerve roots to relieve pain. This approach may offer a more precise and objective method to guide the surgical intervention compared to traditional rhizotomy alone. ^{1 3 4 5 10}

Research Team

David Darrow, MD MPH

Principal Investigator

University of Minnesota

Eligibility Criteria

This trial is for adults over 18 who are scheduled for rhizotomy surgery to treat severe facial pain known as trigeminal neuralgia. It's not suitable for individuals with a history of migraines, functional pain disorders like fibromyalgia or IBS, recent chronic pain, unclear facial pain origins, or those whose procedure is canceled.

Inclusion Criteria

I am 18 years old or older.

I am scheduled for a procedure to treat facial pain.

Exclusion Criteria

I have never had facial pain like TMD or TGN.

I have facial pain that hasn't been diagnosed as trigeminal neuralgia, or my rhizotomy was canceled.

I have experienced chronic pain in the last month.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo rhizotomy surgery with TSEPs measurement for TGN patients and TSEPs recording in a lab setting for healthy volunteers

1 day

Follow-up

Participants are monitored for safety and effectiveness after the procedure

4 weeks

Treatment Details

Interventions

• TSEP + rhizotomy surgery
• TSEPs recording only

Trial Overview The study tests if measuring brain responses (TSEPs) during rhizotomy surgery can help in treating trigeminal neuralgia. Participants will either have TSEP measurements taken alongside their surgery or just the standard surgical procedure without TSEP recording.

Participant Groups

Group I: TGN patients Experimental Treatment 1 Intervention

Patients with TGN who will undergo rhizotomy surgery as the standard of care

Group II: Healthy volunteers Active Control 1 Intervention

Healthy volunteers for whom TSEPS will be recorded in a lab setting

TSEP + rhizotomy surgery is already approved in United States, European Union for the following indications:

Approved in United States as Rhizotomy for:

• Trigeminal Neuralgia

Approved in European Union as Rhizotomy for:

• Trigeminal Neuralgia

Who Is Running the Clinical Trial?

University of Minnesota

Lead Sponsor

Trials

1,459

Recruited

1,623,000+

Findings from Research

Trigeminal somatosensory-evoked potentials (TSEPs) provide a non-invasive and objective way to assess neuronal function in patients experiencing oro-facial sensory impairment after procedures like third molar extractions and maxillo-facial trauma.

The increasing popularity of TSEP recording in the last decade highlights its potential clinical applications in oral and maxillo-facial surgery, making it a valuable tool for evaluating sensory nerve function.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Trigeminal somatosensory evoked potentials. A review of the literature as applicable to oral dysaesthesias. Bennett, AJ., Wastell, DG., Barker, GR., et al.[2019]

A new method for mapping the trigeminal nerve root during surgery was tested on 15 patients, using electrophysiological techniques to improve surgical precision.

This technique helps identify specific fiber subdivisions of the trigeminal nerve, aiding in safer and more effective microsurgical procedures for conditions like trigeminal neuralgia.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Intraoperative mapping of the trigeminal nerve root: technique and application in the surgical management of facial pain. Stechison, MT., Møller, A., Lovely, TJ.[2019]

Trigeminal somatosensory evoked potentials (TSEPs) can accurately predict the prognosis of patients with unilateral trigeminal nerve lesions, as demonstrated in two case studies.

In one case, TSEPs indicated a positive outcome with the patient regaining sensation, while in another case, TSEPs suggested a poor prognosis, highlighting their potential utility in guiding treatment decisions like nerve grafting.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Applications of trigeminal somatosensory evoked potentials in the investigation of unilateral lesion of the inferior dental nerve: report of 2 cases. Fagade, OO.[2016]

In a study involving 43 patients with trigeminal neuralgia, atypical facial pain, and cancer pain, trigeminal somatosensory evoked potentials (TSEP) were analyzed as a potential diagnostic tool for pain classification.

The results showed that changes in TSEP latency periods correlated with patients' pain sensations, but no specific pathological peaks were identified, indicating that TSEP results should be interpreted alongside clinical symptoms rather than as standalone diagnostic indicators.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Possibilities of trigeminal somatosensory evoked potentials in diagnosing neuralgiform facial pain]. Krischek-Bremerich, P., Bremerich, A.[2006]

In a study of 1000 patients with classic trigeminal neuralgia, 90% initially responded to medical therapy, but 75% did not achieve long-term relief, leading to surgical interventions for many.

Both percutaneous stereotaxic rhizotomy (PSR) and posterior fossa exploration (PFE) showed similar effectiveness in treating trigeminal neuralgia, with PSR being preferred due to its less invasive nature and easier repeatability, achieving excellent outcomes in 61% of patients after 6 years.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

a 10-year experience in the treatment of trigeminal neuralgia. Comparison of percutaneous stereotaxic rhizotomy and posterior fossa exploration. van Loveren, H., Tew, JM., Keller, JT., et al.[2022]

In a study of 139 patients undergoing retrogasserian glycerol rhizotomy for trigeminal neuralgia, technical difficulties were encountered in 47.3% of cases, leading to interruptions in 8.1% of procedures due to serious complications like vasovagal reactions or cardiac arrest.

While 67.3% of patients experienced complications, most were mild sensory deficits; however, 28.1% faced more serious issues, including dysesthesia and moderate to severe sensory loss, highlighting the need for thorough preoperative patient education about potential risks.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Technical difficulties and perioperative complications of retrogasserian glycerol rhizotomy for trigeminal neuralgia. Blomstedt, PC., Bergenheim, AT.[2017]

Descending trigeminal tractotomy effectively relieved pain in 7 patients with medically untreatable trigeminal neuralgia who did not respond to previous surgical treatments, with pain cessation observed immediately after surgery.

All patients remained pain-free during follow-up periods ranging from 9 months to 15 years, indicating the long-term efficacy of this surgical intervention for this challenging condition.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Descending trigeminal tractotomy for trigeminal neuralgia after surgical failure. Morita, M., Hosobuchi, Y.[2018]

In a study of 99 patients undergoing carotid endarterectomy, stable intra-operative trigeminal scalp-induced somatosensory-evoked potentials (T-SSEP) were reliably recorded, demonstrating a mean latency of 12.4 ms and an amplitude of 5.7 μV.

The findings indicate that T-SSEP recordings are not affected by muscle activity, confirming their reliability and suggesting they originate from non-muscular sources, which is important for monitoring during surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Recordings of long-latency trigeminal somatosensory-evoked potentials in patients under general anaesthesia. Malcharek, MJ., Landgraf, J., Hennig, G., et al.[2011]

Percutaneous radiofrequency rhizotomy (PSR) is a safe and effective surgical option for treating trigeminal neuralgia, with low rates of pain recurrence.

The recurrence rates of pain after PSR are lower than those seen with other percutaneous procedures and are comparable to the rates following microvascular decompression, highlighting its efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Treatment of trigeminal neuralgia by percutaneous radiofrequency rhizotomy. Taha, JM., Tew, JM.[2005]

The novel peroral trigeminal rhizotomy method using a 3D-printed patient-specific guidance tool was successfully performed on 18 patients, with all procedures completed on the first attempt and an average surgery time of just 19 minutes.

The procedure resulted in significant pain relief, with 8 patients achieving complete analgesia and 6 experiencing pain relief, while only 4 patients had persistent trigeminal pain after follow-up of up to 20 months, indicating both efficacy and safety of the technique.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Peroral Trigeminal Rhizotomy Using a Novel 3-Dimensional Printed Patient-Specific Guidance Tool. Oertel, MF., Sarnthein, J., Regli, L., et al.[2022]

References

1. Denmark pubmed.ncbi.nlm.nih.gov

Trigeminal somatosensory evoked potentials. A review of the literature as applicable to oral dysaesthesias. [2019]

2. United States pubmed.ncbi.nlm.nih.gov

Intraoperative mapping of the trigeminal nerve root: technique and application in the surgical management of facial pain. [2019]

3. Nigeria pubmed.ncbi.nlm.nih.gov

Applications of trigeminal somatosensory evoked potentials in the investigation of unilateral lesion of the inferior dental nerve: report of 2 cases. [2016]

4. Germany pubmed.ncbi.nlm.nih.gov

[Possibilities of trigeminal somatosensory evoked potentials in diagnosing neuralgiform facial pain]. [2006]

5. United States pubmed.ncbi.nlm.nih.gov

a 10-year experience in the treatment of trigeminal neuralgia. Comparison of percutaneous stereotaxic rhizotomy and posterior fossa exploration. [2022]

6. Switzerland pubmed.ncbi.nlm.nih.gov

Technical difficulties and perioperative complications of retrogasserian glycerol rhizotomy for trigeminal neuralgia. [2017]

7. Switzerland pubmed.ncbi.nlm.nih.gov

Descending trigeminal tractotomy for trigeminal neuralgia after surgical failure. [2018]

8. Netherlands pubmed.ncbi.nlm.nih.gov

Recordings of long-latency trigeminal somatosensory-evoked potentials in patients under general anaesthesia. [2011]

9. United States pubmed.ncbi.nlm.nih.gov

Treatment of trigeminal neuralgia by percutaneous radiofrequency rhizotomy. [2005]

10. United States pubmed.ncbi.nlm.nih.gov

Peroral Trigeminal Rhizotomy Using a Novel 3-Dimensional Printed Patient-Specific Guidance Tool. [2022]