Burden of illness of trigeminal neuralgia among patients managed in a specialist center in England

An update on pharmacotherapy for trigeminal neuralgia

INTRODUCTION

Trigeminal neuralgia is a rare condition that can be effectively treated by carbamazepine or oxcarbazepine but these older drugs are associated with dose-dependent and potentially treatment-limiting adverse effects. Third-generation anticonvulsants, new calcitonin gene-related peptide blockers for migraine, and older drugs such as ketamine and cannabinoids may be promising adjuvants or monotherapeutic options.

AREAS COVERED

The new drugs, their presumed mechanisms of action, safety and efficacy are discussed herein. There is a paucity of robust clinical evidence in support of these drugs for trigeminal neuralgia. New migraine agents are considered as well although migraines and trigeminal neuralgia are distinct, albeit similar, conditions. No new drugs have been released to market in recent years with the specific indication of trigeminal neuralgia.

EXPERT OPINION

In real-world clinical practice, about half of trigeminal neuralgia patients take more than one agent for prevention and combination therapy may be the optimal approach. Combination therapy might allow for lower doses of carbamazepine or oxcarbazepine, thus reducing the number and severity of potential adverse events but the potential for pharmacokinetic drug-drug interactions must be considered. Drug therapy for trigeminal neuralgia involves acute or abortive treatments, often administered in hospital versus long-term preventive therapy, usually involving oral agents.

Neuronavigated percutaneous gasserian radiofrequency thermorhizotomy for trigeminal neuralgia: how I do it

BACKGROUND

Radiofrequency thermorhizotomy (TRZ) is an established treatment for trigeminal neuralgia (TN). TRZ can result risky and painful in a consistent subset of patients, due to the need to perform multiple trajectories, before a successful foramen ovale cannulation. Moreover, intraoperative x-rays are required.

METHOD

TRZ has been performed by using a neuronavigated stylet, before trajectory planning on a dedicated workstation.

CONCLUSION

Navigated-TRZ (N-TRZ) meets the expectations of a safer and more tolerable procedure due to the use of a single trajectory, avoiding critical structures. Moreover, N-TRZ is x-ray free. Efficacy outcomes are similar to those reported in literature.

A cost effectiveness analysis of two treatment strategies for trigeminal neuralgia in Ontario

Background

Trigeminal neuralgia (TN) is a debilitating disease with an annual incidence of approximately 4-27/100,000. In Ontario, over 2000 patients receive interventions for profound pain, including medical and surgical therapies. The global expected cost of these approaches is unknown. This study aims to analyze the cost-effectiveness of one surgical therapy, microvascular decompression (MVD), compared with the best medical therapy (carbamazepine) as first-line therapy.

Methods

Costs were gathered from the Canadian Institute for Health Information, Ontario Drug Benefit Formulary, and Ontario Ministry of Health Schedule of Benefits for Physician Services. Academic literature was used to estimate unavailable items. A cost-benefit Markov model was created for each strategy with literature-based rates for annual cycles from years 1 to 5, followed by a linear recurrent cycle from years 6 to 10. Incremental cost-effectiveness ratios (ICERs) were calculated based on the incremental cost in 2022 Canadian Dollars (CAD) per pain-free year.

Results

Base case cost per patient was $10,866 at 10 years in the "MVD first" group and $10,710 in the "carbamazepine first" group. Ten-year ICER was $1,104 for "MVD first," with strict superiority beyond this time point. One-way deterministic sensitivity analysis for multiple factors suggested the highest cost variability and ICER variability were due to surgery cost, medication failure rate, and medication cost.

Conclusion

Economic benefit is established for a "MVD first" strategy in the Ontario context with strict superiority beyond the 10-year horizon. If a cost-effectiveness threshold of $50,000 per pain-controlled year is used, the benefit is established at 4 years.

Systematic review on the frequency of occurrence in nerve branches and the side of the face involved in trigeminal neuralgia and its clinical implication

Purpose

The purpose of this systematic review is to answer the focused question, "What is the commonly affected nerve branch and the side of the face involved in trigeminal neuralgia?"

Types of studies reviewed

This systematic review included studies reporting commonly affected trigeminal nerve branches and the side of the face involved in trigeminal neuralgia. To find the potential studies published, the authors utilized specific search databases such as PubMed, and Google scholar.

Results

Among 132 published studies, the authors selected only 11 to be included for this systematic review. The sample size ranged from 50 to 43,518 study subjects. This review identified that the mandibular branches of the trigeminal nerve were the most affected, followed by the maxillary branch. The review also identified that the right side of the face was predominantly affected.

Conclusion and practical implications

The authors of this review identified a higher occurrence of trigeminal neuralgia in the mandibular division of the nerve, commonly affected on the right side of the face. Further prospective-based research and meta-analysis are required to validate the commonly occurring trigeminal nerve branch and sidedness of the face involved with its clinical implications in trigeminal neuralgia.

Trigeminal Neuralgia as a Primary Demyelinating Disease: Potential Multimodal Evidence and Remaining Controversies

Trigeminal neuralgia is a heterogeneous disorder with likely multifactorial and complex etiology; however, trigeminal nerve demyelination and injury are observed in almost all patients with trigeminal neuralgia. The current management strategies for trigeminal neuralgia primarily involve anticonvulsants and surgical interventions, neither of which directly address demyelination, the pathological hallmark of trigeminal neuralgia, and treatments targeting demyelination are not available. Demyelination of the trigeminal nerve has been historically considered a secondary effect of vascular compression, and as a result, trigeminal neuralgia is not recognized nor treated as a primary demyelinating disorder. In this article, we review the evolution of our understanding of trigeminal neuralgia and provide evidence to propose its potential categorization, at least in some cases, as a primary demyelinating disease by discussing its course and similarities to multiple sclerosis, the most prevalent central nervous system demyelinating disorder. This proposed categorization may provide a basis in investigating novel treatment modalities beyond the current medical and surgical interventions, emphasizing the need for further research into demyelination of the trigeminal sensory pathway in trigeminal neuralgia. PERSPECTIVE: This article proposes trigeminal neuralgia as a demyelinating disease, supported by histological, clinical, and radiological evidence. Such categorization offers a plausible explanation for controversies surrounding trigeminal neuralgia. This perspective holds potential for future research and developing therapeutics targeting demyelination in the condition.

The Therapeutic Effect of Botulinum Toxin Type A on Trigeminal Neuralgia: Are There Any Differences between Type 1 versus Type 2 Trigeminal Neuralgia?

BACKGROUND

Botulinum toxin type A is an effective treatment for trigeminal neuralgia. Moreover, its efficacy in type 2 trigeminal neuralgia and comparative studies between type 1 and type 2 trigeminal neuralgia (TN) still need to be improved.

METHODS

We treated 40 TN patients with onabotulinumtoxinA; 18 had type 1 TN, and 22 had type 2 TN. We compared the baseline pain score with the Visual Analogue Scale (VAS) and paroxysm frequency (number per week) at the baseline with those obtained at 1-month and 3-month follow-ups. Nonetheless, we compared the baseline Penn Facial Pain Scale with the scores obtained at the 1-month follow-up.

RESULTS

BoNT/A effectively reduced pain intensity and frequency at the 1-month and 3-month follow-ups. Moreover, the type 1 TN and type 2 TN groups had baseline pain scores of 7.8 ± 1.65 and 8.4 ± 1.1, respectively. Pain significantly improved (p < 0.001) in both groups to 3.1 ± 2.3 (type 1 TN) and 3.5 ± 2.3 (type 2 TN) at the 1-month follow-up and to 3.2 ± 2.5 (type 1 TN) and 3.6 ± 2.5 (type 2 TN) at the 3-month follow-up. There was no difference between the two groups (p 0.345). The baseline paroxysm frequencies (number per week) were 86.7 ± 69.3 and 88.9 ± 62.2 for the type 1 and type 2 TN groups, respectively; they were significantly reduced in both groups at the 1-month and 3-month follow-ups without significant differences between the two groups (p 0.902). The Pain Facial Pain Scale improved at the 1-month follow-up, and no significant differences were found between the two groups. There was a strong correlation between background pain and paroxysm pain intensity (r 0.8, p < 0.001).

CONCLUSIONS

Botulinum toxin type A effectively reduced the pain, paroxysm frequency, and PFPS scores of type 1 and type 2 trigeminal neuralgia patients without statistically significant differences. Facial asymmetry was the only adverse event.

Neuropathic Pain in the Emergency Setting: Diagnosis and Management

Neuropathic pain, traditionally considered a chronic condition, is increasingly encountered in the emergency department (ED), accounting for approximately 20% of patients presenting with pain. Understanding the physiology and key clinical presentations of neuropathic pain is crucial for ED physicians to provide optimal treatment. While diagnosing neuropathic pain can be challenging, emphasis should be placed on obtaining a comprehensive medical history and conducting a thorough clinical examination. Patients often describe neuropathic pain as a burning or shock-like sensation, leading them to seek care in the ED after ineffective relief from common analgesics such as paracetamol and NSAIDs. Collaboration between emergency medicine specialists, neurologists, and pain management experts can contribute to the development of evidence-based guidelines specifically tailored for the emergency department setting. This article provides a concise overview of the common clinical manifestations of neuropathic pain that may prompt patients to seek emergency care.

Surgical and Clinical Outcomes of Microvascular Decompression: A Comparative Study between Young and Elderly Patients

Microvascular decompression (MVD) is the only etiological technique for the treatment of trigeminal neuralgia (TN). Whilst there is a consensus MVD is likely effective regardless of age, the elderly population is thought to be more prone to have a higher rate of surgical complication, morbidity, and mortality. The main objective of our single-center, retrospective study was to analyze the surgical and clinical outcomes of MVD in TN elderly patients. From a surgical series of patients with TN who had undergone MVD from April 2018 to April 2022, 76 patients who matched the inclusion criteria were divided into two groups: twenty-five (32.9%) patients were older than 65 years and included in the elderly group, while the remaining fifty-one (61.1%) patients were below 65 years included in the non-elderly one. There were no differences between the groups in terms of acute pain relief (APR), Barrow Neurological Index (BNI) at follow-up, complications, and recurrence rate. In multivariate analysis (Cox proportional hazards regression analysis) the presence of an offending artery with nerve root distortion/indentation emerged as the only independent prognostic factor for pain-free survival (p = 0.0001). Our data endorse MVD as a safe and effective surgical procedure also for elderly patients with TN.

Long term evaluation of a multidisciplinary trigeminal neuralgia service

Background

Trigeminal neuralgia is an episodic severe neuralgic pain and can be managed both medically and surgically. If possible, this should be directed by a Multidisciplinary Team (MDT) of specialised surgeons, physicians, dentists, psychologists and specialist nurses with access to all treatment modalities, which enables patients to make an informed decision about their future management.

Objective

The aim of this study was to review the outcomes of patients managed by an MDT clinic, in a single institute over an eleven-year period.

Methods

A prospective database was used to identify patients with trigeminal neuralgia or its variants who had attended a joint MDT clinic. The electronic notes were examined for demographics, onset and duration of trigeminal neuralgia, medications history, pain scores and details of surgical procedures if any by two independent assessors.

Results

Three hundred thirty-four patients attended the MDT between 2008–2019. Forty-nine of them had surgery before being referred to the service and were included but analysed as a subgroup. Of the remaining patients, 54% opted to have surgery following the MDT either immediately or at a later date. At the last reported visit 55% of patients who opted to have surgery were pain free and off medications, compared to 15.5% of medically managed patients. Surgical complications were mostly attributable to numbness and in the majority of cases this was temporary. All patients who were not pain free, had complications after surgery or opted to remain on medical therapy were followed up in a facial pain clinic which has access to pain physicians, clinical nurse specialists and a tailored pain management program. Regular patient related outcome measures are collected to evaluate outcomes.

Conclusion

An MDT clinic offers an opportunity for shared decision making with patients deciding on their personal care pathway which is valued by patients. Not all patients opt for surgery, and some continue to attend a multidisciplinary follow up program. Providing a full range of services including psychological support, improves outcomes.

Radiofrequency thermoablation of the peripheral branches of trigeminal nerve versus the Gasserian ganglion for treating idiopathic trigeminal neuralgia: A systematic review and meta-analysis

BACKGROUND

Trigeminal neuralgia is characterized by pain at the distribution of one or more of the trigeminal nerve branches and is usually treated with anti-epileptic medication. When first line treatment fails, patients receive other treatment modalities including radiofrequency thermoablation (RFT) of the Gasserian ganglion and peripheral branches of the trigeminal nerve. The aim of this study is to compare RFT of the Gasserian ganglion and peripheral branches of trigeminal nerve in terms of efficacy and rate of complications.

METHODS

This was a systematic review and meta-analysis that searched Medline, Cochrane Central Register of Controlled Trials, and Embase using Medical Subject Headings and the references of the enrolled studies with no restriction on date. We included only RCTs that compared the RFT of the Gasserian ganglion and peripheral branches of trigeminal nerve with one of the following outcomes: pain scales, immediate effective rate, recurrence rate, and complications.

RESULTS

Five articles were eligible for our review and showed that there was no difference between RFT of the peripheral nerves and the Gasserian ganglion in terms of pain scores. There was a non-significant trend for RFT of the peripheral nerve to have higher immediate effect rates and higher recurrence rates. RFT of the Gasserian ganglion group was associated with masticatory weakness, while the other group was associated with facial swelling and numbness of V2.

CONCLUSION

RFT of the peripheral branches is a safe and effective method to treat idiopathic trigeminal neuralgia but leads to a higher recurrence rate when compared with RFT of the Gasserian ganglion.

The Molecular Basis and Pathophysiology of Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a complex orofacial pain syndrome characterized by the paroxysmal onset of pain attacks in the trigeminal distribution. The underlying mechanism for this debilitating condition is still not clearly understood. Decades of basic and clinical evidence support the demyelination hypothesis, where demyelination along the trigeminal afferent pathway is a major driver for TN pathogenesis and pathophysiology. Such pathological demyelination can be triggered by physical compression of the trigeminal ganglion or another primary demyelinating disease, such as multiple sclerosis. Further examination of TN patients and animal models has revealed significant molecular changes, channelopathies, and electrophysiological abnormalities in the affected trigeminal nerve. Interestingly, recent electrophysiological recordings and advanced functional neuroimaging data have shed new light on the global structural changes and the altered connectivity in the central pain-related circuits in TN patients. The current article aims to review the latest findings on the pathophysiology of TN and cross-examining them with the current surgical and pharmacologic management for TN patients. Understanding the underlying biology of TN could help scientists and clinicians to identify novel targets and improve treatments for this complex, debilitating disease.

Characteristics of Patients With Trigeminal Neuralgia Referred to the Indonesian National Brain Center Neurosurgery Clinic

Trigeminal neuralgia (TN) is a debilitating neuropathic pain involving the fifth cranial nerve. There has been no study investigating the clinical and socioeconomical characteristics of patients with TN in Indonesia. A total of 100 patients were included in this study. Symptoms indicating a later stage of the illness, namely, involvement of all the trigeminal nerve branches, numbness, and concomitant persistent pain, were the common presentations found in our cohort. Only one TN diagnosis was made by a general practitioner (GP). None were immediately referred to a neurosurgeon following their diagnosis. Access to our clinic took as long as 4.7 ± 5.1 years (mean ± SD) from the onset. Older age was a significant predictor of an increased likelihood of not knowing their illness upon the referral (21.9%, p = 0.008). Upon their first presentation, 25.5% of patients had experienced drug-related side effects due to prolonged medication. Only 50% of patients were compensated by the universal health coverage (UHC) system. Seven patients spent ≥ 50 million rupiahs and eight patients had already lost their jobs. In conclusion, early contact with a neurosurgeon contributes to better management of TN, both for the patients and healthcare system in Indonesia. A refined understanding of TN nature is still needed in this country.

When intra-operative exploration is the only option, severe medically refractory trigeminal neuralgia

Introduction: Patients with trigeminal neuralgia (TN) are usually treated on an outpatient basis, and symptoms can be controlled using various medical therapeutic options. We present a case of severe TN with an acute on chronic flare, which was now refractory to a wide variety of medical options, had a prolonged inpatient hospitalization, and ultimately required surgery with excellent results.Case: A 54-year-old Hispanic male was admitted with severe left-sided TN. His symptoms gradually became more pronounced and frequent to a point where he was unable to have a meaningful quality of life. A trial of gabapentin, phenytoin, opioids, and NSAIDs had also been unsuccessful before this hospitalization. He had three ER visits before he was finally hospitalized with intractable pain and unfortunately had begun to have suicidal thoughts. Various therapeutic interventions were tried, including escalating doses of opioids and local nerve blocks, but all non-surgical options failed to provide relief. Neurosurgical route was eventually approached, and patient underwent left retro mastoid suboccipital craniectomy. Intraoperatively, the left superior cerebellar artery was found to adhere to the inferior ventral aspect of the left trigeminal nerve root entry zone. Upon decompression patient's symptoms resolved dramatically. Interestingly this vascular compression was not seen on multiple prior brain imaging.Conclusion: TN can severely affect someone's quality of life. It often leads to severe anxiety and depression. Our case represents the importance of proceeding towards surgical options sooner rather than later. An early multi-disciplinary approach is warranted.

The journeys of patients with trigeminal neuralgia on a background of multiple sclerosis

Aim: Multiple sclerosis (MS) is well recognized as a secondary cause for trigeminal neuralgia (TN). In this case series, we detail the management of all the patients with TN and MS (pwTNMS) presenting to a specialist unit. Materials & methods: A prospective patient database was used to extract key clinical data on pharmacological, psychometric and surgical management of 20 pwTNMS. Results: 65% of pwTNMS underwent surgical interventions for management of their pain.12/20 achieved remission periods, through surgery and/or medication. Significant improvement was noted on the global impression of change illustrated by a p < 0.001. Conclusion: pwTNMS require a multifaceted approach combining polypharmacy, surgical interventions and psychological support. Developing self-management skills is crucial if patients are to live well with pain.

Patient reported outcome measures in trigeminal neuralgia - A systematic review of psychometric performance

BACKGROUND

Trigeminal neuralgia (TN) is a rare condition for which there are multiple treatment options available. To date, there has been difficulty in comparing the outcomes of treatment due to the variety of patient-reported outcome measures (PROMs) and their inadequate psychometric testing. The aim of this review was to assess the psychometric properties of PROMs used to date in TN and make recommendations for their use in future studies.

METHODS

Five electronic databases (MEDLINE, EMBASE, CINAHL Plus, PsycINFO, Health and Psychosocial Instruments) were searched for studies assessing the development of PROMs or their psychometric properties in TN studies. The records obtained were assessed independently by two reviewers for their methodological quality, following guidance from the Consensus-based Standards for the selection of Health Measurement Instruments (COSMIN).

RESULTS

Six studies were identified and information on five PROMs (Brief Pain Inventory Facial (BPI-F), Visual Analogue Scale (VAS), Barrow Neurology Institute Pain Scale (BNI-PS), Penn Facial Pain Scale-Revised (Penn-FPS-R) and Trigeminal Neuralgia Quality of Life Score) were retrieved. The Penn-FPS-R demonstrated moderate quality evidence for sufficient content validity. The BPI-F showed moderate evidence for sufficient internal consistency and structural validity but low evidence for inconsistent content validity. The Trigeminal Neuralgia Quality of Life score showed very low-quality evidence for insufficient content validity, structure validity and responsiveness. No evidence was found on the assessment of any psychometric properties of the VAS and BNI-PS in TN.

CONCLUSION

There is limited evidence of the psychometric performance of patient-reported outcomes for TN and recommendations for their inclusion in future studies cannot be made. The validation of PROMs in TN studies should be a priority in this field of research.

SIGNIFICANCE

This review highlights the knowledge gap in the field of psychometrics of patient reported outcomes measures in the field of TN. Given the unavailability of an objective outcome measure for pain or health related quality of life, psychometrically sound PROMs are essential for assessing medical and surgical treatment outcomes in TN.