Trigeminal Neuralgia

Exploring long-term outcomes following CyberKnife robotic radiosurgery for trigeminal neuralgia

Background and purpose

Radiosurgery has been extensively studied for its efficacy and safety in the management of trigeminal neuralgia (TN). However, among the plethora of relevant studies in the literature, only a restricted number have been conducted targeting an elongated trigeminal nerve segment with the CyberKnife radiosurgery (CKRS) system. Herein, we report long-term clinical outcomes of TN patients treated with CKRS.

Materials and methods

Fifty patients treated with CKRS for medically refractory TN were analyzed. Pain response and sensory dysfunction post CKRS were assessed using the Barrow Neurological Institute (BNI) scale. Kaplan-Meier analysis was used to assess the maintenance of pain control and the risk of onset of facial numbness. The Cox proportional hazards regression model was employed for both univariate and multivariate analyses to identify predictive factors among the collected variables.

Results

The median follow-up period was 63 months (range: 12-174 months). The median values of treated nerve volume, prescription dose, and integral dose were 59 mm3, 60 Gy and 3.9 mJ, respectively. Pain control (BNI I-III) was achieved in 37 patients (74%). Among them, the actuarial freedom from pain (FFP) rate was 82%, 78% and 74% at 24, 36 and beyond 48 months post-CKRS, respectively. A correlation of FFP rate with patient gender, treated nerve volume, and mean dose was revealed in multivariate analysis. Twenty-three patients (62%) reported onset of new or aggravation of pre-existing, facial numbness with twenty-one of them (57%) characterizing it as "mild facial numbness, not bothersome" (BNI-II) and two (5%) as "somewhat bothersome" (BNI-III). We did not encounter any case with very bothersome facial numbness (BNI-IV).

Conclusions

Long-term results of this work contribute to the body of evidence supporting the safety and efficacy of CKRS in the treatment of TN patients, in view of excellent pain control for an acceptable toxicity profile.

Advanced neuroimaging of the trigeminal nerve and the whole brain in trigeminal neuralgia: a systematic review

ABSTRACT

For trigeminal neuralgia (TN), a major role of imaging is to identify the causes, but recent studies demonstrated structural and microstructural changes in the affected nerve. Moreover, an increasing number of studies have reported central nervous system involvement in TN. In this systematic review, recent quantitative magnetic resonance imaging (MRI) studies of the trigeminal nerve and the brain in patients with TN were compiled, organized, and discussed, particularly emphasizing the possible background mechanisms and the interpretation of the results. A systematic search of quantitative MRI studies of the trigeminal nerve and the brain in patients with TN was conducted using PubMed. We included the studies of the primary TN published during 2013 to 2023, conducted for the assessment of the structural and microstructural analysis of the trigeminal nerve, and the structural, diffusion, and functional MRI analysis of the brain. Quantitative MRI studies of the affected trigeminal nerves and the trigeminal pathway demonstrated structural/microstructural alterations and treatment-related changes, which differentiated responders from nonresponders. Quantitative analysis of the brain revealed changes in the brain areas associated with pain processing/modulation and emotional networks. Studies of the affected nerve demonstrated evidence of demyelination and axonal damage, compatible with pathological findings, and have shown its potential value as a tool to assess treatment outcomes. Quantitative MRI has also revealed the possibility of dynamic microstructural, structural, and functional neuronal plasticity of the brain. Further studies are needed to understand these complex mechanisms of neuronal plasticity and to achieve a consensus on the clinical use of quantitative MRI in TN.

Preoperative Evaluation of Neurovascular Relationship in Primary Trigeminal Neuralgia(PTN) by Magnetic Resonance Virtual Endoscopy(MRVE) Combined with 3D-FIESTA-c and 3D-TOF-MRA

Objective

This study aims to evaluate the effectiveness of Magnetic Resonance Virtual Endoscopy combined with 3D-FIESTA-c and 3D-TOF-MRA in preoperative assessment of MVD for PTN, with a focus on accurately detecting neuromuscular contact.

Methods

We retrospectively analyzed clinical and imaging data from 240 patients with unilateral primary trigeminal neuralgia undergoing MVD surgery between April 2016 and July 2023. Preoperative scans with 3D-FIESTA-c and 3D-TOF-MRA were performed, and MRVE images were obtained to analyze the relationship between the trigeminal nerve and adjacent vessels. Using the findings during microvascular decompression (MVD) surgery as the gold standard, the diagnostic results of 3D-TOF-MRA + 3D-FIESTA-c were considered as group I, while the combined use of MRVE, 3D-TOF-MRA + 3D-FIESTA-c was considered as group II.

Results

In 240 cases, group I had a positive rate of 96.25% and an accuracy rate of 86.25% for identifying responsible blood vessels, while group II had a positive rate of 98.3% and an accuracy rate of 94.17%. There were no statistically significant differences in positive rates between group I and group II, group I and MVD, or group II and MVD (P > 0.05). However, there were statistically significant differences in accuracy rates (P < 0.05). The accuracy for single and multiple arteries with group I was 99.38% and 80.0%, respectively, while with group II, it was 100% and 95.0%. No statistically significant difference was found in accuracy for single or multiple arteries (P>0.05). The accuracy of evaluating responsibility veins with or without other vessels was 52.73% and 80.0%, respectively, with a statistically significant difference (P<0.05).

Conclusion

MRVE combined with 3D-TOF-MRA + 3D-FIESTA-c significantly improves the accuracy of identifying responsibility vessels, especially veins, in preoperative assessment for MVD. This has important clinical implications for preoperative decision-making and surgical planning.

Neuronavigation-Specific Parameters for Selective Access of Trigeminal Rootlets in Radiofrequency Lesioning: A Cadaveric Morphometric Study

BACKGROUND AND OBJECTIVE

Radiofrequency lesioning (RFL) is a safe and effective treatment for medically refractory trigeminal neuralgia. Despite gaining mainstream neurosurgical acceptance in the 1970s, the technique has remained relatively unchanged, with the majority of series using lateral fluoroscopy over neuronavigation for cannula guidance. To date, there are no studies describing neuronavigation-specific parameters to help neurosurgeons selectively target individual trigeminal rootlets. In this cadaveric study, we sought to provide a neuronavigation-specific morphometric roadmap for selective targeting of individual trigeminal rootlets.

METHODS

Embalmed cadaveric specimens were registered to cranial neuronavigation. Frontotemporal craniotomies were then performed to facilitate direct visualization of the Gasserian ganglion. A 19-gauge cannula was retrofit to a navigation probe, permitting real-time tracking. Using preplanned trajectories, the cannula was advanced through foramen ovale (FO) to the navigated posterior clival line (nPCL). A curved electrode was inserted to the nPCL and oriented inferolaterally for V3 and superomedially for V2. For V1, the cannula was advanced 5 mm distal to the nPCL and the curved electrode was reoriented inferomedially. A surgical microscope was used to determine successful contact. Morphometric data from the neuronavigation unit were recorded.

RESULTS

Twenty RFL procedures were performed (10R, 10L). Successful contact with V3, V2, and V1 was made in 95%, 90%, and 85% of attempts, respectively. Mean distances from the entry point to FO and from FO to the clival line were 7.61 cm and 1.26 cm, respectively.

CONCLUSION

In this proof-of-concept study, we found that reliable access to V1-3 could be obtained with the neuronavigation-specific algorithm described above. Neuronavigation for RFL warrants further investigation as a potential tool to improve anatomic selectivity, operative efficiency, and ultimately patient outcomes.

Gasserian ganglion stimulation for refractory trigeminal neuropathic pain

BACKGROUND AND OBJECTIVE

Painful trigeminal neuropathy is a complex clinical entity due to its severity and refractoriness to pharmacological and interventional management. We describe our experience in treating refractory painful trigeminal neuropathy (RPTN) with gasserian ganglion stimulation (GGS).

MATERIALS AND METHODS

Six patients with RPTN were treated with GGS in our Unit between 2019 and 2022. The following data were collected: socio-demographic characteristics, triggering event, duration of the disease and treatment received prior to surgery, pre- and post-intervention visual analogue scale (VAS) score, follow-up time, and pre- and post-intervention functionality and quality of life.

RESULTS

All patients were women who had received aggressive first-, second-, and third-line pharmacological, non-pharmacological, and interventional management before being referred for GGS. Patients reported a 50%-72% decrease in pain on VAS and improved functionality during follow-up.

CONCLUSIONS

GGS is a promising therapeutic alternative for patients with RPTN. Although the initial outcomes and experience are encouraging, RPTN is recommended on the basis of safety, reproducibility, and trends observed in clinical practice.

Electroacupuncture and carbamazepine for patients with trigeminal neuralgia: a randomized, controlled, 2 × 2 factorial trial

BACKGROUND

Trigeminal neuralgia (TN) is difficult to treat due to its severe pain intensity and recurring episodes, which significantly impact quality of life.

OBJECTIVES

We aimed to assess the effectiveness of electroacupuncture (EA) in alleviating the pain intensity in TN, and to determine whether EA combined with low-dosage carbamazepine (CBZ) has a synergistic effect.

METHODS

A multi-centre, randomized, 2 × 2 factorial trial was conducted. Participants who met the inclusion criteria received active EA or sham EA for 60 min, three times a week for four weeks; CBZ (300 mg per day) or placebo for four weeks. The primary outcome was the change in visual analog scale (VAS) score from baseline to weeks 2, 4, 16, and 28. Secondary outcomes included quality of life and adverse events.

RESULTS

A total of 120 participants (75 females and 45 males; mean (SD) age, 58.5 (15.3) years) were included. The main effects of EA and CBZ were significant (P < 0.001), and there was a significant interaction was identified between the interventions (P = 0.041). Participants who received EA (mean difference [MD], -0.3 [95% CI, -0.40 to -0.20] at week 2; -1.6 [-1.70 to -1.50] at week 4; -1.1 [-1.31 to -0.89] at week 16; -0.8 [-1.01 to -0.59] at week 28), CBZ (MD, -0.6 [95% CI, -0.70 to -0.50] at week 2; -0.9 [-1.03 to -0.77] at week 4, -0.2 [-0.41 to 0.01] at week 16, 0.2 [-0.01 to 0.41] at week 28), and the combination of both (MD, -1.8 [95% CI, -1.90 to -1.70] at week 2; -3.7 [-3.83 to -3.57] at week 4, -3.4 [-3.61 to -3.19] at week 16, -2.9 [-3.11 to -2.69] at week 28) had a greater reduction in VAS score over the treatment phase than their respective control groups (sham EA, placebo, and sham EA plus placebo). EA-related adverse events (6/59, 10.17%) were lower than that of CBZ (15/59, 25.42%) during the whole phases.

CONCLUSIONS

EA or CBZ alone are effective treatments for TN, while the combination of EA and low-dosage CBZ exerts a greater benefit. These findings in this trial demonstrate that the combination of EA and low-dosage CBZ may be clinically effective under certain circumstances.

TRIAL REGISTRATION

NCT03580317.

OTULIN's influence on neuroinflammation and pain modulation in trigeminal neuralgia

INTRODUCTION

Trigeminal neuralgia (TN), marked by chronic pain from neural damage, is closely associated with inflammation. The role of OTULIN, a key regulator in inflammation and autophagy, is not fully understood in TN. The regulatory mechanism of OTULIN, a key protein involved in modulating inflammatory responses and autophagy processes, remains incompletely elucidated, particularly in the context of TN and neuroinflammation.

METHODS

An infraorbital nerve ligation-induced rat model of TN was used. OTULIN's expression was modulated using adenovirus vectors and short hairpin RNA. The impact on pain and inflammatory responses was assessed via quantitative real-time polymerase chain reaction, western blot, immunofluorescence, and transcriptomic analysis.

RESULTS

Enhanced OTULIN expression significantly increased head withdrawal thresholds and reduced pain sensitivity and neuroinflammatory markers in the model. Conversely, silencing OTULIN exacerbated pain and inflammation. Transcriptomic data revealed OTULINs influence on both inflammatory and autophagy pathways, specifically in suppressing NLR family pyrin domain containing 3 (NLRP3) inflammasome and promoting autophagy. In vitro experiments demonstrated OTULIN's inhibition of inflammatory markers in microglia and neurons.

CONCLUSION

OTULIN is crucial in modulating TN, reducing neuropathic pain and neuroinflammation by activating the autophagy pathway and inhibiting the NLRP3 inflammasome.

Modern Approaches to the Treatment of Acute Facial Pain

PURPOSE OF REVIEW

Acute facial pain presents a complex challenge in medical practice, requiring a comprehensive and interdisciplinary approach to its management. This narrative review explores the contemporary landscape of treating acute facial pain, delving into pharmacological, non-pharmacological, and advanced interventions. The significance of tailored treatment strategies, rooted in the diverse etiologies of facial pain, such as dental infections, trigeminal neuralgia, temporomandibular joint disorders, sinusitis, or neurological conditions like migraines or cluster headaches, is underscored. We particularly emphasize recent advances in treating trigeminal neuralgia, elucidating current treatment concepts in managing this particular acute facial pain.

RECENT FINDINGS

Recent research sheds light on various treatment modalities for acute facial pain. Pharmacotherapy ranges from traditional NSAIDs and analgesics to anticonvulsants and antidepressants. Non-pharmacological interventions, including physical therapy and psychological approaches, play pivotal roles. Advanced interventions, such as nerve blocks and surgical procedures, are considered in cases of treatment resistance. Moreover, we explore innovative technologies like neuromodulation techniques and personalized medicine, offering promising avenues for optimizing treatment outcomes in acute facial pain management. Modern management of acute facial pain requires a nuanced and patient-centric approach. Tailoring treatment strategies to the individual's underlying condition is paramount. While pharmacotherapy remains a cornerstone, the integration of non-pharmacological interventions is essential for comprehensive care. Advanced interventions should be reserved for cases where conservative measures prove inadequate. Furthermore, leveraging innovative technologies and personalized medicine holds promise for enhancing treatment efficacy. Ultimately, a holistic approach that considers the diverse needs of patients is crucial for effectively addressing acute facial pain.

Repeat percutaneous rhizotomy for trigeminal neuralgia is not associated with an increased risk of postoperative complications

BACKGROUND AND OBJECTIVES

Patients undergoing percutaneous rhizotomy for trigeminal neuralgia (TN) may require several procedures to manage their pain. However, it is not fully understood whether repeat procedures influence postoperative complication rates.

METHODS

We retrospectively reviewed patients undergoing rhizotomy at our institution from 2011 to 2022. Patients were included only if they had no history of prior interventions including microvascular decompression (MVD) or radiosurgery. We collected baseline patient information, pain characteristics, and postoperative complications for each patient. Patients were dichotomized into those undergoing primary rhizotomy versus those undergoing a repeat rhizotomy. Potential drivers of postoperative complications were included in a multivariate logistic regression model.

RESULTS

Of the 1904 cases reviewed, 965 met our inclusion criteria. 392 patients underwent primary rhizotomy, and 573 patients underwent repeat rhizotomies. The repeat rhizotomy group was significantly older, p<0.001. Patients in the repeat rhizotomy group expressed higher frequencies of bilateral pain, p=0.01. Patients in the repeat rhizotomy group demonstrated a significantly higher rate of preoperative numbness and postoperative numbness, p<0.001. There were no significant differences in any of the considered complications between the single rhizotomy and repeat rhizotomy groups. On multivariate logistic regression, repeat rhizotomy did not predict an increased risk of any postoperative complications, p=0.14.

CONCLUSIONS

Patients undergoing repeat rhizotomy may be at risk of postoperative numbness but are not at increased risk for postoperative complications. These results are of use to patients who are poor surgical candidates, and thus may require multiple rhizotomies to effectively manage their pain over time.

Exploring biomarkers in trigeminal neuralgia patients operated with microvascular decompression: A comparison with multiple sclerosis patients and non-neurological controls

BACKGROUND

Trigeminal neuralgia (TN) is a severe facial pain condition often associated with a neurovascular conflict. However, neuroinflammation has also been implicated in TN, as it frequently co-occurs with multiple sclerosis (MS).

METHODS

We analysed protein expression levels of TN patients compared to MS patients and controls. Proximity Extension Assay technology was used to analyse the levels of 92 proteins with the Multiplex Neuro-Exploratory panel provided by SciLifeLab, Uppsala, Sweden. Serum and CSF samples were collected from TN patients before (n = 33 and n = 27, respectively) and after (n = 28 and n = 8, respectively) microvascular decompression surgery. Additionally, we included samples from MS patients (n = 20) and controls (n = 20) for comparison.

RESULTS

In both serum and CSF, several proteins were found increased in TN patients compared to either MS patients, controls, or both, including EIF4B, PTPN1, EREG, TBCB, PMVK, FKBP5, CD63, CRADD, BST2, CD302, CRIP2, CCL27, PPP3R1, WWP2, KLB, PLA2G10, TDGF1, SMOC1, RBKS, LTBP3, CLSTN1, NXPH1, SFRP1, HMOX2, and GGT5. The overall expression of the 92 proteins in postoperative TN samples seems to shift towards the levels of MS patients and controls in both serum and CSF, as compared to preoperative samples. Interestingly, there was no difference in protein levels between MS patients and controls.

CONCLUSIONS

We conclude that TN patients showed increased serum and CSF levels of specific proteins and that successful surgery normalizes these protein levels, highlighting its potential as an effective treatment. However, the similarity between MS and controls challenges the idea of shared pathophysiology with TN, suggesting distinct underlying mechanisms in these conditions.

SIGNIFICANCE

This study advances our understanding of trigeminal neuralgia (TN) and its association with multiple sclerosis (MS). By analysing 92 protein biomarkers, we identified distinctive molecular profiles in TN patients, shedding light on potential pathophysiological mechanisms. The observation that successful surgery normalizes many protein levels suggests a promising avenue for TN treatment. Furthermore, the contrasting protein patterns between TN and MS challenge prevailing assumptions of similarity between the two conditions and point to distinct pathophysiological mechanisms.

Chronic Treatment with Oxcarbazepine Attenuates Its Anticonvulsant Effect in the Maximal Electroshock Model in Mice

The objective of this study was to assess the impact of acute and chronic treatment with oxcarbazepine on its anticonvulsant activity, neurological adverse effects, and protective index in mice. Oxcarbazepine was administered in four protocols: once or twice daily for one week (7 × 1 or 7 × 2) and once or twice daily for two weeks (14 × 1 or 14 × 2). A single dose of the drug was employed as a control. The anticonvulsant effect was evaluated in the maximal electroshock test in mice. Motor and long-term memory impairment were assessed using the chimney test and the passive avoidance task, respectively. The concentrations of oxcarbazepine in the brain and plasma were determined via high-performance liquid chromatography. Two weeks of oxcarbazepine treatment resulted in a significant reduction in the anticonvulsant (in the 14 × 1; 14 × 2 protocols) and neurotoxic (in the 14 × 2 schedule) effects of this drug. In contrast, the protective index for oxcarbazepine in the 14 × 2 protocol was found to be lower than that calculated for the control. No significant deficits in memory or motor coordination were observed following repeated administration of oxcarbazepine. The plasma and brain concentrations of this anticonvulsant were found to be significantly higher in the one-week protocols. Chronic treatment with oxcarbazepine may result in the development of tolerance to its anticonvulsant and neurotoxic effects, which appears to be dependent on pharmacodynamic mechanisms.

Three-dimensional printed personalised digital guide plate for greater palatine block in trigeminal neuralgia

The nerve block is a safe and effective method to theat trigeminal neuralgia (TN). In terms of the V2 trigeminal neuralgia, the most difficult procedure in nerve block is accurate and fast greater palatine foramen (GPF) insertion. In this study, we developed a new technique using a personalised digital tooth-supported guide plate to increase insertion accuracy and success rates and reduce the pain of patients during injection. A total of 18 patients with TN (11 female and 7 male) were enrolled and treated between September 2020 and June 2022. Before injection, the guide plate was designed via Mimics three-dimensional (3D) reconstruction technology and printed via 3D printer. Then, all patients underwent maxillary nerve block with a guide plate for each injection. In this study, placement of all guide plates was completed within one minute and all punctures were successful the first time. The depth of the injection needle was over 2.5 cm in all cases and the guide plate was stability-supported by the maxillary teeth. The various pain scores had an obvious improvement. No patients presented symptoms of local anaesthetic toxicity or onset of new neurological sequelae. Using this new technology, we can significantly reduce the difficulty of GPF insertion and decrease patient pain during injection. The enhanced success rate of nerve block can achieve better therapeutic effect. For surgeons, personalised digital tooth-supported guide plates make the operation easier, especially for novice surgeons.

Histochemical Analysis of Altered Arachnoid Tissue in Patients With Paroxysmal Trigeminal Neuralgia With Concomitant Continuous Pain

Background Trigeminal neuralgia (TN) is a craniofacial pain characterized by sudden onset, brief, severe, recurrent shooting pain within one or more branches of the trigeminal nerve (CN V). Based on its clinical presentation, TN may be classified as purely paroxysmal or paroxysmal with concomitant continuous pain (CCP), previously known as typical and atypical, respectively. Microvascular decompression (MVD) surgery for releasing the CN V from a neurovascular conflict is an effective and safe treatment for TN. During MVD of patients manifesting TN with CCP, the involvement of an abnormal arachnoid tissue is a common finding. The etiology and pathophysiology behind the appearance of this tissue are unknown; however, it is more commonly found in this variant of the disease. Methods From January 2015 to December 2016, a total of 330 patients diagnosed with TN were evaluated at our clinic. Among them, 31 individuals (9.4%) presented with paroxysmal TN with CCP, with 16 patients (51.6%) undergoing MVD. During surgery, samples of altered arachnoid tissue were collected from five patients and subjected to Hematoxylin-Eosin staining and immunohistochemistry for S100 and CD2 Results In a long-term follow-up, 80% of patients operated by DMV remains pain free. Analysis of biopsies revealed chronic fibrosis (n=4), hyperplasia of neurothelial cells (n=3), dystrophic calcifications (n=1). Immunohistochemistry was positive for S100 (n=3) and CD20 (n=3) inflammatory markers. Conclusion Chronic inflammation in the arachnoid tissue involved in paroxysmal TN with CCP could be a contributor to the pathophysiology of this variant of the disease.

Efficacy and Safety of Botulinum Toxin Type A in the Treatment of Trigeminal Neuralgia: An Update on Systematic Review With Meta-analyses

OBJECTIVE

Pain management in patients with TN is challenging, as facial pain often does not respond well to conventional therapies. Botulinum toxin type A (BTX-A) has been suggested as a potential treatment option, but there is limited evidence regarding its long-term efficacy. This review aimed to analyze the current data for the use of in the treatment of trigeminal neuralgia (TN) and highlight the evidence for its efficacy and safety.

METHODS

A comprehensive search was conducted in various databases (PubMed, Scopus, Embase, ClinicalTrials, and Cochrane Library) to identify clinical studies evaluating the use of BTX-A in TN until October 2023. Randomized controlled trials (RCTs), single-arm studies, and stratified studies were included in the analysis. The mean difference (MD), effect size (ES), and 95% confidence interval (CI) were estimated for visual analogue scale (VAS) scores, pain episode frequency, and the proportion of responders.

RESULTS

The analysis included 23 studies, including 4 RCTs, 14 single-arm studies, and 5 stratified studies. In the RCTs, BTX-A was found to significantly reduce mean VAS scores compared with baseline (ES: -4.05; 95% CI: -6.13, -1.97; P =0.002). In 19 non-RCTs, the pooled single-arm analysis revealed that BTX-A decreased VAS scores (ES: -5.19, 95% CI: -6.05, -4.33, P <0.001) and pain attack frequency (ES: -17.85, 95% CI: -23.36, -12.34, P <0.001) from baseline to the end of follow-up. The overall proportion of responders to BTX-A treatment was also significant (95% CI: 0.653, 0.761, P =0.003).

DISCUSSION

Current evidence indicates that BTX-A injection is an effective and safe option for patients with refractory TN or not responding to medical or surgical management. However, more high-quality studies are needed to further confirm its efficacy.

Revisiting the Efficacy of Redo Microvascular Decompression for Trigeminal Neuralgia

BACKGROUND

Microvascular decompression (MVD) is an effective nondestructive neurosurgical procedure for trigeminal neuralgia (TN). However, some patients may undergo surgery failure or experience pain recurrence, sparking debates on the need for reoperation.

METHODS

We conducted a retrospective analysis of 103 cases of patients with primary TN who underwent redo MVD at our center between January 2020 and December 2022. Comparative prognostic assessments were performed by comparing these cases against a cohort of 348 patients who underwent primary MVD during the same study period.

RESULTS

During the redo MVD cases, arachnoid membranes adhesions (80.6%) and Teflon adhesions with/without granuloma (86.4%) as well as remaining vascular compression (36.9%) were observed. After the reoperation, an immediate relief rate of 94.2% was observed. During a mean follow-up period of 17.4 ± 4.4 months, a long-term relief rate of 89.3% was achieved. Postoperative complications included 3 cases of persistent paresthesia, 1 case each of hearing loss, cerebrospinal fluid leak, and facial palsy. Ten cases without evident compression received nerve combing and all experienced immediate complete relief, with only 1 patient experiencing recurrence 9 months after surgery. Compared to the primary MVD group, the reoperation group had a higher average age, longer disease duration, and operating time (P < 0.05). However, there were no significant differences in immediate relief rate, long-term relief rate, or complications between the 2 groups. The main cause of persistent symptom was inadequate decompression, such as missing the offending vessel; while the recurrent was primarily due to Teflon adhesion or granuloma formation.

CONCLUSIONS

The redo MVD for TN is equally efficacious and safe compared to the primary procedure, with an emphasis on meticulous dissection and thorough decompression. Additionally, nerve combing proves to be an effective supplementary option for patients without obvious compression.

The Challenges in Clinical Diagnosis of Trigeminal Neuralgia: A Review

The lack of established laboratory tests or biomarkers for trigeminal neuralgia (TN) makes diagnosing this relatively rare condition extremely challenging. Trigeminal nerve compression observable on magnetic resonance imaging may indicate TN, but many patients do not have visible lesions or compression. In particular, TN may be confused with migraine, cluster headache, temporomandibular disorder, and other types of headache. An accurate diagnosis is imperative for proper treatment since these conditions do not respond to the same treatment. Many symptoms of these headaches can be vague or overlap, and clinicians depend in large measure on the subjective reports of their patients. Nevertheless, it is imperative to diagnose TN better, which can cause excruciating pain, reduce the quality of life, and even result in disability. It is possible that TN is underestimated.

Trigeminal neuralgia

Trigeminal neuralgia (TN) is a facial pain disorder characterized by intense and paroxysmal pain that profoundly affects quality of life and presents complex challenges in diagnosis and treatment. TN can be categorized as classical, secondary and idiopathic. Epidemiological studies show variable incidence rates and an increased prevalence in women and in the elderly, with familial cases suggesting genetic factors. The pathophysiology of TN is multifactorial and involves genetic predisposition, anatomical changes, and neurophysiological factors, leading to hyperexcitable neuronal states, central sensitization and widespread neural plasticity changes. Neurovascular compression of the trigeminal root, which undergoes major morphological changes, and focal demyelination of primary trigeminal afferents are key aetiological factors in TN. Structural and functional brain imaging studies in patients with TN demonstrated abnormalities in brain regions responsible for pain modulation and emotional processing of pain. Treatment of TN involves a multifaceted approach that considers patient-specific factors, including the type of TN, with initial pharmacotherapy followed by surgical options if necessary. First-line pharmacological treatments include carbamazepine and oxcarbazepine. Surgical interventions, including microvascular decompression and percutaneous neuroablative procedures, can be considered at an early stage if pharmacotherapy is not sufficient for pain control or has intolerable adverse effects or contraindications.

Surgical Removal of Foramen Ovale Osteophyte Completely Relieved Atypical Trigeminal Neuralgia: A Case Report and Literature Review

Atypical trigeminal neuralgia (TN), usually caused by nonvascular compression, lacks a clearly localized trigger and complete remission periods. Although variations of foramen ovale may compress the mandibular nerve branch of the trigeminal nerve, resulting in atypical TN, only a few case reports are reported in the literature. The authors describe a case of a 50-year-old female diagnosed with atypical TN for two months. A high-resolution computed tomography imaging revealed an osteophyte of the left foramen ovale that may compress the mandibular nerve branch of the trigeminal nerve. The patient underwent osteophyte resection, and the pain disappeared completely and immediately after surgery without recurrence in the follow-up to six months. The numbness was also relieved slightly. This case provides a new perspective on the clinical diagnosis and treatment of patients with atypical TN.

Dural arteriovenous fistula presenting as trigeminal neuralgia: Case report and literature review

Background

Trigeminal neuralgia (TN) secondary to a dural arteriovenous fistula (DAVF) is quite rare, and the goal of treatment is to resolve both the fistula and the pain.

Case presentation

We herein report a case of TN secondary to a DAVF in a 64-year-old woman with a 1-year history of right-sided TN. Brain magnetic resonance imaging and digital subtraction angiography showed a right tentorial DAVF. Interventional embolization was performed, but the pain was not relieved after the operation. Six months later, we performed microvascular decompression of the trigeminal nerve. During the operation, we electrocoagulated the tortuous and dilated malformed vein, which was compressing the trigeminal nerve, to reduce its diameter and mitigate the compression on the cisternal segment of the trigeminal nerve. That patient's pain was relieved postoperatively. In addition, we reviewed the literature of TN caused by DAVF and found a total of 30 cases, 22 of which were treated by interventional embolization. Of these 22 cases, the interventional embolization healed the fistula with pain relief in 14 cases and healed the fistula without pain relief in 8 cases. We found that the venous drainage methods of the 8 cases were all classified into the posterior mesencephalic group.

Conclusions

We believe that this drainage pattern contributes to the more common occurrence of unrelieved pain. For such patients, microvascular decompression can be performed with intraoperative coagulation to narrow the dilated veins until the cisternal segment of the trigeminal nerve is no longer compressed. Satisfactory curative effects can be obtained using this technique.

Deciphering the functional role of insular cortex stratification in trigeminal neuropathic pain

Trigeminal neuropathic pain (TNP) is a major concern in both dentistry and medicine. The progression from normal to chronic TNP through activation of the insular cortex (IC) is thought to involve several neuroplastic changes in multiple brain regions, resulting in distorted pain perception and associated comorbidities. While the functional changes in the insula are recognized contributors to TNP, the intricate mechanisms underlying the involvement of the insula in TNP processing remain subjects of ongoing investigation. Here, we have overviewed the most recent advancements regarding the functional role of IC in regulating TNP alongside insights into the IC's connectivity with other brain regions implicated in trigeminal pain pathways. In addition, the review examines diverse modulation strategies that target the different parts of the IC, thereby suggesting novel diagnostic and therapeutic management of chronic TNP in the future.

Palliative Care Aspects in Multiple Sclerosis

CONTEXT

Multiple sclerosis (MS) is an inflammatory, chronic, demyelinating, and neurodegenerative disorder of central nervous system, determined by an auto-immune dysfunction. Severe disability generally occurs in patients with progressive forms of MS that typically develop either after an earlier relapsing phase or less commonly from disease onset. Despite advances in research to slow the progression of MS, this condition remains a life-limiting disease with symptoms impacting negatively the lives of patients and caregivers.

OBJECTIVES

To analyze the difefrent aspects of palliative cae in patients with MS.

METHODS

To analyse selected literature assessing several palliative care aspects in patients with MS.

RESULTS

People with MS have complex symptoms and different needs. These demands include how to deal with the burden of physical disability, how to organise daily life, restructuring social roles in the family and at work, keeping self-sufficiency in personal care, and preserving personal identity and community roles.

CONCLUSION

An early palliative care approach aims to improve the palliative care skills and competencies of health professionals caring for the patients since the early stage of disease, including those who are actively undergoing disease-targeted therapies, rather than merely providing end-of-life care.

Riveting technique in percutaneous balloon compression for trigeminal neuralgia remedy

BACKGROUND

The percutaneous balloon compression (PBC) is a safe and simple treatment for trigeminal neuralgia. It works by compressing the Gasserian ganglion to block pain signals from the trigeminal nerve. To ensure effectiveness, it is important to focus the compression on the lower part of the balloon.

OBJECTIVE

To validate the efficacy of a riveting technique, specifically pulling an inflated balloon, in order to apply enhanced compression on the ganglion.

METHODS

To compare this novel technique with the conventional approach, a retrospective investigation was conducted on consecutive PBCs performed in our department between 2019 and 2022. For postoperative outcome assessment, efficacy was defined as achieving a VAS score of 0 or an improvement exceeding 5 points. Postoperative numbness was graded as none, mild, or severe based on its impact on daily life and tolerance level.

RESULTS

Excluding cases with missed follow-up, a total of 179 participants were included in the study, and their follow-up period ranged up to 40 months. Postoperatively, symptomatic remission was achieved by 98.1% (52/53) of patients in the riveting technique group compared to 87.3% (110/126) in the conventional group (P<0.05). At the last follow-up period, with recurrence observed over time, the long-term efficacy of riveting and conventional groups were 94.3% and 74.6%, respectively (P<0.05). The majority of cases in both groups experienced ipsilateral facial numbness immediately following PBC, which appeared to diminish after 3 months in both groups without significant difference between them (P>0.05).

A novel indicator to predict the outcome of percutaneous stereotactic radiofrequency rhizotomy for trigeminal neuralgia patients: diffusivity metrics of MR-DTI

Magnetic resonance-diffusion tensor imaging (MR-DTI) has been used in the microvascular decompression and gamma knife radiosurgery in trigeminal neuralgia (TN) patients; however, use of percutaneous stereotactic radiofrequency rhizotomy (PSR) to target an abnormal trigeminal ganglion (ab-TG) is unreported. Fractional anisotropy (FA), mean and radial diffusivity (MD and RD, respectively), and axial diffusivity (AD) of the trigeminal nerve (CNV) were measured in 20 TN patients and 40 healthy control participants immediately post PSR, at 6-months, and at 1 year. Longitudinal alteration of the diffusivity metrics and any correlation with treatment effects, or prognoses, were analyzed. In the TN group, either low FA (value < 0.30) or a decreased range compared to the adjacent FA (dFA) > 17% defined an ab-TG. Two-to-three days post PSR, all 15 patients reported decreased pain scores with increased FA at the ab-TG (P < 0.001), but decreased MD and RD (P < 0.01 each). Treatment remained effective in 10 of 14 patients (71.4%) and 8 of 12 patients (66.7%) at the 6-month and 1-year follow-ups, respectively. In patients with ab-TGs, there was a significant difference in treatment outcomes between patients with low FA values (9 of 10; 90%) and patients with dFA (2 of 5; 40%) (P < 0.05). MR-DTI with diffusivity metrics correlated microstructural CNV abnormalities with PSR outcomes. Of all the diffusivity metrics, FA could be considered a novel objective quantitative indicator of treatment effects and a potential indicator of PSR effectiveness in TN patients.

Clinical Depression and Anxiety Are Relieved by Microvascular Decompression in Patients with Trigeminal Neuralgia-A Prospective Patient-Reported Outcome Study

Objective: Patients with idiopathic trigeminal neuralgia (TN) live in constant fear of triggering shock-like pain episodes, which may cause symptoms of depression and a reduction in quality of life. Microvascular decompressive surgery has been demonstrated to achieve satisfactory and stable results. With this study, we wanted to investigate prevalence and risk factors for depression and perceived stress in correlation with symptom relief after surgical treatment. Methods: In this prospective study, patients undergoing microvascular decompression (MVD) for TN were included. The Barrow Neurological Institute Pain Score (BNI), Beck Depression Inventory (BDI), Chronic Pain Acceptance Questionnaire (CPAQ), Perceived Stress Questionnaire (PSQ) and McGill questionnaire were used to evaluate depression, stress and anxiety disorders before and 3 months after MVD. Results: A total of 35 patients (16 male (46%)) with a mean age of 55.4 (SD 15) years were included in this study. The BDI revealed that 24 (68.8%) patients harbored mild-to-extreme depression preoperatively (2.4 ± 1.4), which improved to 1.2 (±0.6, p < 0.0001). Pain acceptance also changed from 64 (±11.3) to 67.7 (±9.3, p = 0.006). Perceived stress decreased from 46.9 (±21.9) to 19.6 (±18.6) (p < 0.0001) postoperatively, and pain decreased from 31.0 (±11.7) to 9.4 (±12.9, p < 0.0001). Microvascular decompression reduced the mean BNI pain score significantly from 4.6 to 1.8 postoperatively (p < 0.00001). Conclusions: Depression and perceived stress are prevalent in patients with idiopathic TN. Adequate treatment not only provides a high rate of satisfaction through pain relief, but also leads to immediate and significant improvements in depression and stress. Thus, in patients with TN who do not reach an adequate and timely pain reduction through medical management and develop signs of depression, early treatment with microvascular decompression should be considered.

Analyzing the risk factors of unilateral trigeminal neuralgia under neurovascular compression

Background

This study aimed to explore the risk factors and potential causes of unilateral classical or idiopathic trigeminal neuralgia (C-ITN) by comparing patients and healthy controls (HCs) with neurovascular compression (NVC) using machine learning (ML).

Methods

A total of 84 C-ITN patients and 78 age- and sex-matched HCs were enrolled. We assessed the trigeminal pons angle and identified the compressing vessels and their location and severity. Machine learning was employed to analyze the cisternal segment of the trigeminal nerve (CN V).

Results

Among the C-ITN patients, 53 had NVC on the unaffected side, while 25 HCs exhibited bilateral NVC, and 24 HCs showed unilateral NVC. By comparing the cisternal segment of CN V between C-ITN patients on the affected side and HCs with NVC, we identified the side of NVC, the compressing vessel, and certain texture features as risk factors for C-ITN. Additionally, four texture features differed in the structure of the cisternal segment of CN V between C-ITN patients on the unaffected side and HCs with NVC.

Conclusion

Our findings suggest that the side of NVC, the compressing vessel, and the microstructure of the cisternal segment of CN V are associated with the risk of C-ITN. Furthermore, microstructural changes observed in the cisternal segment of CN V on the unaffected side of C-ITN patients with NVC indicate possible indirect effects on the CN V to some extent.

Fully Endoscopic Microvascular Decompression for Trigeminal Neuralgia Caused by Vertebrobasilar Artery: A Case Series Review: 2-Dimensional Operative Video

BACKGROUND AND OBJECTIVE

Microvascular decompression (MVD) is the most definitive and preferred surgical treatment for trigeminal neuralgia (TN). Treatment of TN caused by the vertebrobasilar artery (VBA) has been reported to be challenging and less satisfactory in complications and recurrence. Endoscopy has been implemented to provide a comprehensive view of neurovascular conflicts and minimize brain tissue stretch injury while exploring the trigeminal nerve. However, there are few retrospective studies on the treatment of TN caused by VBA by fully endoscopic microvascular decompression (E-MVD). This article aimed to illustrate the safety and efficacy of E-MVD for TN caused by the VBA.

METHODS

Clinical data for 26 patients with TN caused by the VBA who underwent E-MVD from 2019 to 2022 were retrospectively analyzed. The characteristics of vertebrobasilar-associated TN were summarized. The safety and efficacy of E-MVD for vertebrobasilar-associated TN were estimated based on the analysis of intraoperative manipulation, postoperative symptom relief, and complications.

RESULTS

Intraoperatively, the vertebrobasilar artery was regarded as a direct offending vessel in all 26 patients with TN, the vertebral artery in 18 (69.23%) and the basilar artery in 10 (38.46%). In addition to the vertebrobasilar artery, other vessels involved included the superior cerebellar artery in 12 patients, anterior inferior cerebellar artery in 9, posterior inferior cerebellar artery in 1, and veins in 4. All patients underwent E-MVD, and TN was entirely resolved in 26 (100%) patients immediately postoperatively. During the follow-up period of 12-45 months, no recurrence or serious complications were found. There were no serious postoperative complications, such as cerebellar swelling, intracranial hemorrhage, or death.

CONCLUSION

E-MVD for vertebrobasilar-associated TN is effective and safe.

Complementary and Integrative Medicine for the Treatment of Trigeminal Neuralgia and Trigeminal Autonomic Cephalalgia

PURPOSE OF REVIEW

Trigeminal neuralgia (TN) and trigeminal autonomic cephalalgias (TACs) are both painful diseases which directly impact the branches of the trigeminal nerve, which supply the face. Patients who have experienced adverse effects, have not responded to mainstream treatments, or have a personal preference for nonmedication options, often turn to complementary and integrative medicine (CIM). The aim of this review is to discuss the efficacy and safety of CIM therapies available for the treatment of TN and TACs.

RECENT FINDINGS

Not only are there limited therapeutic options for TN and TAC patients, but also is there a proportion of patients who are intolerant to standard medical treatments. Recent findings have illustrated that 86% of patients with headache disorders utilize CIM modalities in combination with mainstream medical therapy. CIM modalities can be helpful for these diseases and have primarily been studied in combination with standard medical therapy. There is limited evidence for CIM and behavioral therapies in managing these conditions, and more research is needed to confirm which therapies are safe and effective.

Frame navigation guided percutaneous balloon compression for intractable trigeminal neuralgia secondary to multiple sclerosis

Background

Patients with multiple sclerosis (MS) are more likely to develop trigeminal neuralgia (TN) compared to the regular population, due to scarring of the nerve and development of a demyelination plaque. Despite treatment, approximately 10% of MS patients treated for TN experience symptom recurrence, including the development of MS-like symptoms such as optic neuritis and bilateral facial pain.

Methods

A computed tomography (CT) scan was performed preoperatively on two patients diagnosed with multiple sclerosis (MS) who experienced secondary trigeminal neuralgia (TN). A precise reference frame was strapped firmly to the patient's forehead during the intraoperative procedure. Preliminary CT images were registered using the navigation system and the bony landmarks were set.

Case description

Two patients diagnosed with multiple sclerosis (MS) who experienced refractory trigeminal neuralgia (TN) underwent percutaneous balloon compression. Initial conservative treatment and one dosage of Gamma Knife Radiosurgery (GKR) resulted in symptom control for a few weeks. Both patients had an acute recurrence of pain; thus, percutaneous retrogasserian balloon compression was performed. During follow-up, the patients reported a 70% decrease in pain after the procedure, with minimal recurrence of shooting episodes.

Conclusion

Management of trigeminal neuralgia secondary to drug-resistant multiple sclerosis presents a persistent challenge. The percutaneous technique for retrogasserian balloon compression may offer a solution for some patients, but it presents unique challenges for neurosurgeons. Given the complexity of the pathogenesis, target identification, and the potential absence of neurovascular conflict, microvascular decompression remains a debated approach for this patient population. While stereotactic radiosurgery may be a promising alternative.

Altered trends of local brain function in classical trigeminal neuralgia patients after a single trigger pain

OBJECTIVE

To investigate the altered trends of regional homogeneity (ReHo) based on time and frequency, and clarify the time-frequency characteristics of ReHo in 48 classical trigeminal neuralgia (CTN) patients after a single pain stimulate.

METHODS

All patients underwent three times resting-state functional MRI (before stimulation (baseline), after stimulation within 5 s (triggering-5 s), and in the 30th min of stimulation (triggering-30 min)). The spontaneous brain activity was investigated by static ReHo (sReHo) in five different frequency bands and dynamic ReHo (dReHo) methods.

RESULTS

In the five frequency bands, the number of brain regions which the sReHo value changed in classical frequency band were most, followed by slow 4 frequency band. The left superior occipital gyrus was only found in slow 2 frequency band and the left superior parietal gyrus was only found in slow 3 frequency band. The dReHo values were changed in midbrain, left thalamus, right putamen, and anterior cingulate cortex, which were all different from the brain regions that the sReHo value altered. There were four altered trends of the sReHo and dReHo, which dominated by decreased at triggering-5 s and increased at triggering-30 min.

CONCLUSIONS

The duration of brain function changed was more than 30 min after a single pain stimulate, although the pain of CTN was transient. The localized functional homogeneity has time-frequency characteristic in CTN patients after a single pain stimulate, and the changed brain regions of the sReHo in five frequency bands and dReHo complemented to each other. Which provided a certain theoretical basis for exploring the pathophysiology of CTN.

A nomogram based on radiomics and clinical information to predict prognosis in percutaneous balloon compression for the treatment of trigeminal neuralgia

OBJECTIVE

To develop a clinical-radiomics nomogram based on clinical information and radiomics features to predict the prognosis of percutaneous balloon compression (PBC) for the treatment of trigeminal neuralgia (TN).

METHODS

The retrospective study involved clinical data from 149 TN patients undergoing PBC at Zhongnan Hospital, Wuhan University from January 2018 to January 2022. The free open-source software 3D Slicer was used to extract all radiomic features from the intraoperative X-ray balloon region. The relationship between clinical information and TN prognosis was analyzed by univariate logistic analysis and multivariate logistic analysis. Using R software, the optimal radiomics features were selected using the least absolute shrinkage and selection operator (Lasso) algorithm. A prediction model was constructed based on the clinical information and radiomic features, and a nomogram was visualized. The performance of the clinical radiomics nomogram in predicting the prognosis of PBC in TN treatment was evaluated using the area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA).

RESULTS

A total of 149 patients were eventually included. The clinical factors influencing the prognosis of TN in univariate analysis were compression severity score and TN type. The lasso algorithm Max-Relevance and Min-Redundancy(mRMR) was used to select two predictors from 13 morphology-related radiomics features, including elongation and surface-volume ratio. A total of 4 predictors were used to construct a prediction model and nomogram. The AUC was 0.886(95% confidence interval (CI), 0.75 to 0.96), indicating that the model's good predictive ability. DCA demonstrated the nomogram's high clinical applicability.

CONCLUSION

Clinical-radiomics nomogram constructed by combining clinical information and morphology-related radiomics features have good potential in predicting the prognosis of TN for PBC treatment. However, this needs to be further studied and validated in several independent external patient populations.

Daily olive oil intake is feasible to reduce trigeminal neuralgia facial pain: A pilot study

Extra virgin olive oil (EVOO) is thought to contribute to neuroprotection and, thus, may influence pain symptoms experienced by adults with demyelination-related trigeminal neuralgia (TN). This study aimed to determine the feasibility of daily intake of EVOO and its potential to alleviate facial pain of TN. Adults, self-reporting as female and affected by TN, were enrolled in a 16-week nonblinded, parallel study. After a 4-week baseline, participants were randomized to 60 mL/day EVOO or control (usual diet and no supplemental EVOO) for 12 weeks. Participants completed a daily questionnaire on pain intensity and compliance, the Penn Facial Pain Scale weekly, the 36-Item Short Form Survey monthly, and dietary assessment during baseline and intervention. Participants (n = 52; 53.3 ± 12.9 years) were recruited nationally; 42 completed the study. The EVOO group, with 90% intake compliance, showed significant decreases in the Penn Facial Pain Scale items of interference with general function, interference with orofacial function, and severity of pain from baseline, whereas the control group showed no improvements. EVOO benefit, compared with control, trended for the interference with orofacial function (P = .05). The 36-Item Short Form Survey items of role limitations resulting from emotional problems and role limitations from physical health favored EVOO. The EVOO group significantly improved their Healthy Eating Index 2015 component scores of fatty acids (primarily from increased oleic acid), sodium, and refined grains. EVOO intake of 60 mL/day was feasible for participants experiencing TN and may mitigate pain and improve quality of life. This trial was registered at clinicaltrials.gov (NCT05032573).

Trigeminal Neuralgia after Hyaluronic Acid and Botox Injection

A rare case of trigeminal neuralgia following injections of Hyaluronic Acid and Botox was documented. In addressing the severe pain and swelling caused by the injection, a novel combination therapy was employed, notably including 5-fluorouracil. The significant improvement observed in this case not only provided clinical insights but also spurred further investigation into the underlying mechanisms linking trigeminal nerve damage to local dermal filler injections. The aim was to glean new medical perspectives and develop practical preventive strategies to mitigate such complications in future cases. This approach highlights the importance of understanding and addressing the potential neurological impacts of cosmetic procedures. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .

Surgical management of nervus intermedius neuralgia: A report of 4 cases and literature review

BACKGROUND

Nervus intermedius neuralgia (NIN) is characterized by paroxysmal episodes of sharp, lancinating pain in the deep ear. Unfortunately, only a few studies exist in the literature on this pain syndrome, its pathology and postoperative outcomes.

METHOD

We conducted a retrospective review of four cases diagnosed with NIN who underwent a neurosurgical intervention at our center from January 2015 to January 2023. Detailed information on their MRI examinations, intraoperative findings and other clinical presentations were obtained, and the glossopharyngeal and vagus nerves were isolated for immunohistochemistry examination.

RESULTS

A total of 4 NIN patients who underwent a microsurgical intervention at our institution were included in this report. The NI was sectioned in all patients and 3 of them underwent a microvascular decompression. Of these 4 patients, 1 had a concomitant trigeminal neuralgia (TN), and 1 a concomitant glossopharyngeal neuralgia (GPN). Three patients underwent treatment for TN and 2 for GPN. Follow-up assessments ranged from 8 to 99 months. Three patients reported complete pain relief immediately after the surgery until last follow-up, while in the remaining patient the preoperative pain gradually resolved over the 3 month period. Immunohistochemistry revealed that a greater amount of CD4+ and CD8+ T cells had infiltrated the glossopharyngeal versus vagus nerve.

CONCLUSIONS

NIN is an extremely rare condition showing a high degree of overlap with TN/GPN. An in depth neurosurgical intervention is effective to completely relieve NIN pain, without any serious complications. It appears that T cells may play regulatory role in the pathophysiology of CN neuralgia.

Transplantation of olfactory ensheathing cells can alleviate neuroinflammatory responses in rats with trigeminal neuralgia

Trigeminal neuralgia (TN) is a common form of facial pain, which primarily manifests as severe pain similar to facial acupuncture and electric shock. Olfactory ensheathing cells (OECs) are glial cells with high bioactivity; these cells are essential for the periodic regeneration of the olfactory nerve and have been utilized for the repair of nerve injuries. A member of the P2X receptor family, P2X7R, is an ion channel type receptor that has been confirmed to participate in various pain response processes. In this study, we transplanted OECs into trigeminal nerve-model rats with distal infraorbital nerve ligation to observe the therapeutic effect of transplanted OECs in rats. Additionally, we utilized the P2X7R-specific inhibitor brilliant blue G (BBG) to study the therapeutic mechanisms of cell transplantation. The facial mechanical pain threshold of these rats significantly increased following cell transplantation. The immunohistochemistry, immunoblotting, and RT-qPCR results demonstrated that the levels of P2X7R, (NOD)-like receptor protein-3 (NLRP3), nuclear factor-κB (NF-κB), interleukin (IL)-1β, and IL-18 in the trigeminal ganglion of rats treated with OEC transplantation or BBG treatment were significantly lower than those in the injured group without treatment. Overall, our results demonstrate that OEC transplantation can alleviate TN in rats, and it can reduce the expression of P2X7R related inflammatory factors in TN rats, reducing neuroinflammatory response in TG.

Clival-Meckel's Cave Angle: A Predictor of Glycerol Displacement in Percutaneous Glycerol Rhizotomy for Trigeminal Neuralgia

BACKGROUND AND OBJECTIVES

Percutaneous glycerol rhizotomy successfully treats trigeminal neuralgia although failure rates and durability of the procedure are variable. Some of this variability in clinical outcome might be due to egress of glycerol from Meckel's cave (MC) because of surgical positioning and individual patient anatomy. In this article, we quantitatively analyzed the anatomic variances that affect glycerol fluid dynamics to better predict patients more amenable for percutaneous glycerol injections.

METHODS

Computed tomography imaging of 11 cadaveric heads was used to calculate bilateral Clival-Meckel's cave (CMC) and sella-temporal (ST) angles. Twenty-two cadaveric percutaneous injections of dyed glycerol into the Meckel's cave were performed using Härtel's approach, and the fluid movement was documented at prespecified intervals over 1 hour. The relationship between the angles and glycerol migration was studied.

RESULTS

Specimens with basal cistern involvement by 60 minutes had significantly greater CMC angles (median [IQR]: basal cistern involvement = 74.5° [59.5°-89.5°] vs no basal cistern involvement = 58.0° [49.0°-67.0°]), U = 6.0, P < .001. This model may predict which patients will experience glycerol migration away from the Gasserian ganglion (area under the curve: 0.950, SE: 0.046, CI: 0.859-1.041, P < .001). Increased ST angle was associated with lateral flow of glycerol (r s = 0.639, P = .001), and CMC angle was associated with total area of dispersion (r s = -0.474, P = .026).

CONCLUSION

Anatomic variation in skull base angles affects glycerol migration. Specifically, a more obtuse CMC angle was associated with a higher risk of posterior migration away from the Gasserian ganglion. This may be a reason for differing rates of surgical success. These results suggest that anterior head flexion for 60 minutes may prevent percutaneous glycerol rhizotomy failures and some patients with large CMC angles are more likely to benefit from postinjection head positioning. However, this clinical effect needs validation in vivo.

Trigeminal neuralgia and trigeminal neuropathic pain

It is very important that the dental team are aware of the varied presentations of pain in the mouth, face and other parts of the trigeminal region which are not directly caused by teeth or oral structures. Our understanding of underlying causes in this complex area is evolving. Ultimately, patients who present with what may at first seem to be oral or dental problems will require specialist input in secondary care with potential for use of systemic medications. This article reviews the common non-dental pains encountered in the orofacial region related to dysfunction of the trigeminal nerve.

Causal association between adiponectin and risk of trigeminal neuralgia: A Mendelian randomization study

OBJECTIVE

To determine whether adiponectin levels and the risk of trigeminal neuralgia (TN) were causally related, a two-sample Mendelian Randomization (MR) study design was used.

METHODS

We obtained data regarding adiponectin from the UK Biobank genome wide association studies (GWAS) (n = 39,883) as the exposure and TN, using GWAS summary statistics generated from FinnGen, (total n = 195 847 159; case = 800, control = 195 047) as the outcome. We conducted a two-sample Mendelian randomization analysis employing inverse variance-weighted (IVW), MR-Egger regression, weighted median, and weighted mode analyses.

RESULTS

We selected 14 single nucleotide polymorphisms (SNPs) with genome-wide significance from the GWAS on adiponectin as instrumental variables. Based on the IVW method, a causal association between adiponectin levels and TN was evidenced (OR= 0.577, 95 %CI: 0.393-0.847). MR-Egger regression revealed that directional pleiotropy was unlikely to be biasing the result (intercept = -0.01; P = 0.663), but it showed no causal association between adiponectin and TN (OR=0.627, 95 %CI: 0.369-1.067). However, the weighted median (OR=0.569, 95 %CI: 0.353-0.917) and Weighted mode (OR= 0.586, 95 %CI: 0.376-0.916) approach yielded evidence of a causal association between adiponectin and TN. Cochran's Q-statistics and funnel plots indicated no evidence of heterogeneity or asymmetry, indicating no directional pleiotropy.

CONCLUSION

The results of the MR analysis suggested that adiponectin may be causally associated with an increased TN risk.

Distinctive cortical morphological patterns in primary trigeminal neuralgia: a cross-sectional clinical study

PURPOSE

The characteristics of surface-based morphological patterns to primary trigeminal neuralgia (PTN) are still not well understood. This study aims to screen the useful cortical indices for the prediction of PTN and the quantification of pain severity.

METHODS

Fifty PTN patients and 48 matched healthy subjects enrolled in the study from March 2016 to August 2021. High-resolution T1 data were performed at 3.0 Tesla scanner and were analyzed with FreeSurfer software to detect the abnormalities of cortical mean curve (CMC), cortical thickness (CT), surface area (SA), and cortical volume (CV) in PTN patients compared to healthy controls. Logistic regression analysis was conducted to determine whether certain morphological patterns could predict PTN disorder. Then, the relationships of cortical indices to the pain characteristics in patient group were examined using linear regression model.

RESULTS

Distinctive cortical alterations were discovered through surface-based analysis, including increased temporal CMC, decreased insular CT and fusiform SA, along with decreased CV in several temporal and occipital areas. Moreover, the difference of temporal CMC was greater than other cortical parameters between the two groups, and the combination of certain morphological indices was of good value in the diagnosis for PTN. Besides, CT of left insula was negatively associated with the pain intensity in PTN patients.

CONCLUSION

The patients with PTN demonstrate distinctive morphological patterns in several cortical regions, which may contribute to the imaging diagnosis of this refractory disorder and be useful for the quantification of the orofacial pain.

CLINICAL TRIALS

The registry name of this study in https://clinicaltrials.gov/ : Magnetic Resonance Imaging Study on Patients with Trigeminal Neuralgia (MRI-TN) https://clinicaltrials.gov/ ID: NCT02713646 A link to the full application: https://clinicaltrials.gov/ct2/results?cond=&term=NCT02713646&cntry=&state=&city=&dist= The first patient with primary trigeminal neuralgia was recruited on November 28, 2016.

The CSF1-CSF1R pathway in the trigeminal ganglion mediates trigeminal neuralgia via inflammatory responses in mice

BACKGROUND

Trigeminal neuralgia (TN) is the most severe type of neuropathic pain. The trigeminal ganglion (TG) is a crucial target for the pathogenesis and treatment of TN. The colony-stimulating factor 1 (CSF1) - colony-stimulating factor 1 receptor (CSF1R) pathway regulates lower limb pain development. However, the effect and mechanism of the CSF1-CSF1R pathway in TG on TN are unclear.

METHODS

Partial transection of the infraorbital nerve (pT-ION) model was used to generate a mouse TN model. Mechanical and cold allodynia were used to measure pain behaviors. Pro-inflammatory factors (IL-6, TNF-a) were used to measure inflammatory responses in TG. PLX3397, an inhibitor of CSF1R, was applied to inhibit the CSF1-CSF1R pathway in TG. This pathway was activated in naïve mice by stereotactic injection of CSF1 into the TG.

RESULTS

The TN model activated the CSF1-CSF1R pathway in the TG, leading to exacerbated mechanical and cold allodynia. TN activated inflammatory responses in the TG manifested as a significant increase in IL-6 and TNF-a levels. After using PLX3397 to inhibit CSF1R, CSF1R expression in the TG declined significantly. Inhibiting the CSF1-CSF1R pathway in the TG downregulated the expression of IL-6 and TNF-α to reduce allodynia-related behaviors. Finally, mechanical allodynia behaviors were exacerbated in naïve mice after activating the CSF1-CSF1R pathway in the TG.

CONCLUSIONS

The CSF1-CSF1R pathway in the TG modulates TN by regulating neuroimmune responses. Our findings provide a theoretical basis for the development of treatments for TN in the TG.

Altered brain function in classical trigeminal neuralgia patients: ALFF, ReHo, and DC static- and dynamic-frequency study

The present study aimed to clarify the brain function of classical trigeminal neuralgia (CTN) by analyzing 77 CTN patients and age- and gender-matched 73 healthy controls (HCs) based on three frequency bands of the static and dynamic amplitude of low-frequency fluctuation, regional homogeneity, and degree centrality (sALFF, sReHo, sDC, dALFF, dReHo, and dDC). Compared to HCs, the number of altered brain regions was different in three frequency bands, and the classical frequency band was most followed by slow-4 in CTN patients. Cerrelellum_8_L (sReHo), Cerrelellum_8_R (sDC), Calcarine_R (sDC), and Caudate_R (sDC) were found only in classical frequency band, while Precuneus_L (sALFF) and Frontal_Inf_Tri_L (sReHo) were found only in slow-4 frequency band. Except for the above six brain regions, the others overlapped in the classical and slow-4 frequency bands. CTN seriously affects the mental health of patients, and some different brain regions are correlated with clinical parameters. The static and dynamic indicators of brain function were complementary in CTN patients, and the changing brain regions showed frequency specificity. Compared to slow-5 frequency band, slow-4 is more consistent with the classical frequency band, which could be valuable in exploring the pathophysiology of CTN.

The long-term outcome of CT-guided radiofrequency ablation of the peripheral branches of the trigeminal nerve in trigeminal neuralgia

Radiofrequency thermocoagulation (RFTC) of the peripheral branches of the trigeminal nerve has been used for trigeminal neuralgia. However, the long-term outcomes of radiofrequency thermocoagulation have not been established. To evaluate the long-term efficacy of RFTC of peripheral branches in patients with refractory trigeminal neuralgia. A retrospective cohort study was conducted in a comprehensive medical center in China. Patients who underwent radiofrequency thermocoagulation of peripheral branches for refractory trigeminal neuralgia from May 2014 to March 2021 were included for analysis. A total of 84 patients with refractory trigeminal neuralgia underwent 105 procedures. BNI I-II which represents treatment success was achieved in 76/84 (90%) patients and 93/105 (89%) procedures. During follow-up, BNI I and II were maintained in 64/76 (84%), 40/73 (55%), 20/67 (30%), 17/65 (26%), 12/61 (20%), and 8/58 (14%) of patients at 1, 2, 3, 4, 5, and 6 years, after the first procedure, respectively. For all the 105 procedures, BNI I and II were maintained in 68/93 (73%), 41/89(46%), 22/82(27%), 15/79 (19%), 8/74 (11%), and 3/72 (4%) at 1, 2, 3, 4, 5, and 6 years, respectively. There is no significant difference between the first and repeat thermocoagulation in terms of immediate (90% vs. 81%, P=0.140) and long-term efficacies (24 months vs.18 months, P=0.266). Radiofrequency thermocoagulation resulted in better long-term outcomes in patients with typical purely paroxysmal pain (24 months vs. 11 months, P=0.033). Radiofrequency ablation of the peripheral branches of the trigeminal nerve might be a safe and effective method in the treatment of refractory trigeminal neuralgia.

Application of Sequential Thresholding-Based Automated Reconstruction of the Trigeminal Nerve in Trigeminal Neuralgia

OBJECTIVE

High-resolution magnetic resonance imaging (MRI) of the trigeminal nerve is indispensable for workup of trigeminal neuralgia (TN) before microvascular decompression; however, the evaluation is often subjective and prone to variability. We aim to develop and assess sequential thresholding-based automated reconstruction of the trigeminal nerve (STAR-TN) as an algorithm for segmenting the trigeminal nerve and contacting structures that will allow for a structured method for assessing neurovascular conflict.

METHODS

A total of 42 patients with TN who underwent high-resolution MRI before microvascular decompression in 2022 were included in our study. Segmentation of the trigeminal nerve and contacting structures was performed on preoperative MRI scans using STAR-TN. The segmentations were then evaluated for neurovascular conflict and compared to the preoperative radiology and operative notes. Geometric features, including the area of contact and distance to conflict, were extracted.

RESULTS

Of the 42 patients, 32 (76.2%) were found to show neurovascular conflict based solely on their STAR-TN segmentations and 10 (23.8%) were found to not show neurovascular conflict. Compared with the intraoperative findings, this resulted in a sensitivity of 78.0% and specificity of 100%. In contrast, assessments of neurovascular conflict by radiologists using only 2-dimensional MRI views had a sensitivity of 68.3% and specificity of 100%. Of the 32 patients with neurovascular conflict, 29 (90.9%) had conflict within the root entry zone. Overall, the patients had a median area of contact of 10.66 mm2.

CONCLUSIONS

STAR-TN allows for 3-dimensional visualization and identification of neurovascular conflict with improved sensitivity compared with neuroradiologist assessments from MRI slices.

Microvascular Decompression and Trigeminal Neuralgia: Patient Sentiment Analysis Using Natural Language Processing

OBJECTIVE

Microvascular decompression (MVD) as a treatment for trigeminal neuralgia (TGN) has high success rate but is associated with risks of complication. This study analyzes Twitter to provide insights into discussions surrounding MVD for patients with TGN.

METHODS

A Twitter search performed in April 2022 yielded 491 tweets from 426 accounts. Tweets and accounts were classified thematically, and descriptive statistics were used for various social media metrics. Using a natural language processing machine learning algorithm, sentiment analysis (SA) was performed to evaluate patient perspectives before and after surgery, and a multivariate regression model was used to identify predictors of higher engagement metrics (likes, retweets, quote tweets, replies).

RESULTS

Most accounts were patients, caregivers, and other members of the public (70%). The most encountered themes were research (47%) and personal experiences (33.4%). SA of tweets about patient experiences showed that 40.2% of tweets were positive, 31.1% were neutral and 28.7% were negative. Negative tweets decreased significantly in postoperative tweets and mostly discussed complications or failure of surgery (63%). On multivariate analysis, only inclusion of media (photo or video) in a Tweet was associated with higher engagement metrics.

CONCLUSIONS

This study provides a comprehensive review of Twitter use discussing MVD in TGN and is the first to assess patient satisfaction after treatment using SA. The data presented on patient perspectives on social media could help physicians establish direct lines of communication with patients, fostering a more patient-focused care.

Retrosigmoid microvascular decompression as a treatment for trigeminal neuralgia in a patient with osteogenesis imperfecta

Individuals with osteogenesis imperfecta develop pathologic bone due to genetic defects in collagen synthesis. These patients are prone to skull base abnormalities with resultant lower cranial nerve deficits, most common of which is trigeminal neuralgia. Typically, such patients are managed medically, and surgical options are not well explored for those patients, who become refractory to medication management. While microvascular decompression is often recommended for patients with classical trigeminal neuralgia, neurovascular compression by MRI, and normal skull base anatomy, ablative procedures have been described for patients with trigeminal neuralgia and osteogenesis imperfecta. MVD via a retrosigmoid approach has not been described in a patient with trigeminal neuralgia and skull base abnormalities secondary to osteogenesis imperfecta. A 23-year-old man with osteogenesis imperfecta was referred with right-sided classical trigeminal neuralgia. His trigeminal pain had become refractory to a number of medications. High-resolution MRI demonstrated compression of the trigeminal nerve by the superior cerebellar artery. Microvascular decompression of the trigeminal nerve via a retrosigmoid craniectomy was performed, and he remains pain-free 6 months after surgery. Microvascular decompression of the trigeminal nerve through a retrosigmoid approach can be an effective surgical treatment for young patients with trigeminal neuralgia secondary to osteogenesis imperfecta.

Proximal trigeminal nerve atrophy is associated with favourable outcomes and persistent facial numbness following percutaneous balloon compression for primary trigeminal neuralgia

OBJECTIVE

Whether nerve atrophy can affect the prognosis of primary trigeminal neuralgia (PTN) patients undergoing percutaneous balloon compression (PBC) remains unclear. This study aimed to determine the association between nerve characteristics observed on preoperative magnetic resonance imaging (MRI) and PBC outcomes.

METHODS

Between January 2019 and December 2022, a cohort of 58 patients with unilateral PTN treated with PBC were analysed retrospectively and included in this study. The relationship between MRI findings, including the proximal and distal nerve cross-sectional areas (CSAs), and favourable pain outcomes (BNI Grades I-III) was analysed through Kaplan‒Meier analysis.

RESULTS

After a mean follow-up period of 23.8 ± 13.0 months (range, 6-50 months), 48 (82.8%) patients with PTN were pain free with or without medication. A smaller proximal CSA ratio (proximal CSA of the affected nerve/proximal CSA of the unaffected nerve) was significantly associated with favourable outcomes. The Kaplan-Meier survival analysis showed that patients with proximal nerve atrophy (proximal CSA ratio ≤ 87% after receiver operating characteristic curve analysis) had a higher estimated 4-year probability of maintaining a favourable outcome than those without nerve atrophy (94.4% vs. 30.8%, p = 0.005). In addition, patients with proximal nerve atrophy were more likely to suffer from postoperative persistent facial numbness.

CONCLUSIONS

Proximal nerve atrophy is correlated with both favourable outcomes and persistent facial numbness following PBC. Prospective studies are required to determine the optimal duration and pressure of balloon compression in relation to the proximal CSA ratio to achieve better pain outcomes and less facial numbness.

Sex differences in trigeminal neuralgia: a focus on radiological and clinical characteristics

BACKGROUND

It is well established that trigeminal neuralgia is more prevalent in females than in males. Neurovascular compression with morphological changes of the trigeminal root represents the most recognized etiological factor. However, other factors may play a role in the framework of a multi-hit model. The primary aim of this study was to investigate sex differences in radiological and clinical characteristics of trigeminal neuralgia to better understand the multifactorial origin of this peculiar neuropathic pain condition.

METHODS

In this cross-sectional study patients with a definite diagnosis of primary trigeminal neuralgia were consecutively enrolled. Each patient underwent 3T MRI with sequences dedicated to the study of neurovascular compression. Major morphological changes of the trigeminal root were quantitatively assessed. Clinical characteristics were systematically collected through a dedicated questionnaire. A logistic regression model was implemented to predict radiological and clinical characteristics based on sex.

RESULTS

A total of 114 patients with classical (87) or idiopathic trigeminal neuralgia (27) were enrolled. Female sex was predictive for idiopathic trigeminal neuralgia. Male sex was predictive, among the comorbidities and clinical characteristics, for hypertension, the involvement of the left side and the second trigeminal division, alone or with the ophthalmic division.

DISCUSSION

The preponderance of TN in the female sex and the association between idiopathic TN and the female sex suggest the role of additional etiological factors in the framework of a multi-hit model. The identification of clinical variables predicted by sex suggests the possibility that distinct phenotypes, with peculiar pathophysiological and therapeutic aspects, may occur in females and males.

SHED-derived exosomes attenuate trigeminal neuralgia after CCI of the infraorbital nerve in mice via the miR-24-3p/IL-1R1/p-p38 MAPK pathway

BACKGROUND

Microglial activation in the spinal trigeminal nucleus (STN) plays a crucial role in the development of trigeminal neuralgia (TN). The involvement of adenosine monophosphate-activated protein kinase (AMPK) and N-methyl-D-aspartate receptor 1 (NMDAR1, NR1) in TN has been established. Initial evidence suggests that stem cells from human exfoliated deciduous teeth (SHED) have a potential therapeutic effect in attenuating TN. In this study, we propose that SHED-derived exosomes (SHED-Exos) may alleviate TN by inhibiting microglial activation. This study sought to assess the curative effect of SHED-Exos administrated through the tail vein on a unilateral infraorbital nerve chronic constriction injury (CCI-ION) model in mice to reveal the role of SHED-Exos in TN and further clarify the potential mechanism.

RESULTS

Animals subjected to CCI-ION were administered SHED-Exos extracted by differential ultracentrifugation. SHED-Exos significantly alleviated TN in CCI mice (increasing the mechanical threshold and reducing p-NR1) and suppressed microglial activation (indicated by the levels of TNF-α, IL-1β and IBA-1, as well as p-AMPK) in vivo and in vitro. Notably, SHED-Exos worked in a concentration dependent manner. Mechanistically, miR-24-3p-upregulated SHED-Exos exerted a more significant effect, while miR-24-3p-inhibited SHED-Exos had a weakened effect. Bioinformatics analysis and luciferase reporter assays were utilized for target gene prediction and verification between miR-24-3p and IL1R1. Moreover, miR-24-3p targeted the IL1R1/p-p38 MAPK pathway in microglia was increased in CCI mice, and participated in microglial activation in the STN.

CONCLUSIONS

miR-24-3p-encapsulated SHED-Exos attenuated TN by suppressing microglial activation in the STN of CCI mice. Mechanistically, miR-24-3p blocked p-p38 MAPK signaling by targeting IL1R1. Theoretically, targeted delivery of miR-24-3p may offer a potential strategy for TN.

Comparison of the efficacy in improving trigeminal neuralgia in petroclival meningioma between microsurgery and radiosurgery: a meta-analysis

The purpose of this study was to systematically review studies in the literature to assess the superiority between microsurgery and radiosurgery regarding the efficacy in improving petroclival meningioma (PCM)-related trigeminal neuralgia (TN). PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched from the inception until December 08, 2022. The overall proportion of patients with improved TN after treatment in all six included studies was 56% (95% confidence interval [CI], 35-76.9%). Higgins I2 statistics showed significant heterogeneity (I2 = 90%). Subgroup analysis showed that the proportion of improved TN was higher in the microsurgery group than that in the radiosurgery group (89%; 95% CI, 81-96.5% vs. 37%, 95% CI, 22-52.7%, respectively, p < 0.01). Subgroup analysis (for studies that documented the number of posttreatment Barrow Neurological Institute scores 1 and 2) revealed that the proportion of pain-free without medication after treatment was higher in the microsurgery group than that in the radiosurgery group (90.7%; 95% CI, 81-99.7% vs. 34.5%, 95% CI, 21.3-47.7.7%, respectively, p < 0.01). Based on the results of this meta-analysis, we concluded that microsurgery is superior to radiosurgery in controlling PCM-related TN.

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.