Prospective comparison of long-term pain relief rates after first-time microvascular decompression and stereotactic radiosurgery for trigeminal neuralgia

Trigeminal Neuralgia: Disease Characterization and Prediction of Response to Surgical Intervention

PURPOSE OF REVIEW

Trigeminal neuralgia (TN) is a highly heterogeneous condition with a wide choice of successful treatment options. However, differences between subtypes are poorly understood and it remains unknown which patients will respond to different treatments. This review aims to summarize the current state of the TN field and explore the problem of predicting surgical outcomes.

RECENT FINDINGS

Attempts have been made to standardize classification, outcome reporting, and treatment guidelines. Identification of risk factors for poor surgical treatment outcomes has led to the development of prognostic scoring systems to predict outcomes and guide management. Advances in imaging techniques including diffusion tensor imaging show promise in better understanding the underlying pathophysiology and predicting surgical outcomes. Progress is hampered by lack of understanding of the pathophysiology in TN and differences between disease subtypes. Further work needs to be done to create accurate prediction tools for widespread use, including use of advanced imaging and computing tools, multicenter collaboration, and prospective validation.

Altered structure and functional connection of subcortical gray matter in female patients with classical trigeminal neuralgia

The etiology of classical trigeminal neuralgia (CTN) is still unclear. A better understanding of the cerebral structural and functional changes in female patients with CTN may provide important novel insights into the pathophysiologic mechanisms of female CTN. A total 37 female CTN patients were included and referred to MRI scans, comprising with 19 left CTN and 18 right CTN patients. We analyzed the volume and shape of subcortical gray matter (GM), and the functional connectivity (FC) between the accumbens nucleus (NAc) and whole brain in right and left CTN patients respectively. We found left CTN patients had a reduced right NAc volume compared to controls, similarly, the right CTN had the decreased volume in the left NAc. Vertex-wise shapes of right NAc in left CTN patients showed significant regional shape deformation on the anterior, medial and ventroposterior aspects, in contrast, left NAc of right CTN patients showed significant regional shape deformation on the anterior and posterior aspect. Furthermore, patients with left CTN showed significantly lower FC between the right NAc and right orbitofrontal cortex than control subjects. The volume of NAc in all CTN was significantly related to the perception of present pain intensity. The CTN might be majorly caused by volume reduction in NAc. A greater understanding of the neurobiological basis of pain-related changes in NAc will provide the knowledge for the development of novel NAc based therapeutic targets for pain management or even prevention in CTN patients.

Virtual Reality Planning of Microvascular Decompression in Trigeminal Neuralgia: Technique and Clinical Outcome

BACKGROUND

 A neurovascular conflict (NVC) is considered the cause of trigeminal neuralgia (TN) in 75% of cases, and if so, a microvascular decompression (MVD) can lead to significant pain relief. A reliable preoperative detection of NVC is essential for clinical decision-making and surgical planning, making detailed neuroradiologic imaging an important component. We present our experiences and clinical outcomes with preoperative planning of the MVD procedure in a virtual reality (VR) environment, based on magnetic resonance imaging (MRI) including magnetic resonance angiography (MRA) and magnetic resonance venography (MRV) sequences.

METHODS

 We analyzed the data of 30 consecutive MVDs in patients treated for TN, in a retrospective single-surgeon (R.A. Kockro) study. Out of the 30 cases, 26 were included. Preoperatively, MRA/MRV and MRI series were fused and three dimensionally reconstructed in a VR environment. All critical structures such as the trigeminal nerve as well as the arteries and veins of the cerebellopontine angle, the brainstem, the neighboring cranial nerves, and the transverse and sigmoid sinus were segmented. The NVC was visualized and a simulation of a retrosigmoid approach, with varying trajectories, to the NVC was performed. The intraoperative findings were then compared with the data of the simulation. The clinical outcome was assessed by a detailed review of medical reports, and follow-up-interviews were conducted in all available patients (20/26).

RESULTS

 The VR planning was well integrated into the clinical workflow, and imaging processing time was 30 to 40 minutes. There was a sole arterial conflict in 13 patients, a venous conflict in 4 patients, and a combined arteriovenous conflict in 9 patients. The preoperative simulations provided a precise visualization of the anatomical relationships of the offending vessels and the trigeminal nerves as well as the surrounding structures. For each case, the approach along the most suitable surgical corridor was simulated and the exact steps of the decompression were planned. The NVC and the anatomy of the cerebellopontine angle as seen intraoperatively matched with the preoperative simulations in all cases and the MVC could be performed as planned. At follow-up, 92.3% (24/26) of patients were pain free and all the patients who completed the questionnaire would undergo the surgery again (20/20). The surgical complication rate was zero.

CONCLUSION

 Current imaging technology allows detailed preoperative visualization of the pathoanatomical spatial relationships in cases of TN. 3D interactive VR technology allows establishing a clear dissection and decompression strategy, resulting in safe vascular microsurgery and excellent clinical results.

Outcomes of Different Surgical Interventions for Treating Trigeminal Neuralgia: A Review

Trigeminal neuralgia (TN) is a debilitating condition characterized by severe facial pain. Various surgical interventions are employed to manage this condition, including microvascular decompression (MVD), percutaneous radiofrequency rhizotomy (PRR), glycerol rhizotomy, percutaneous balloon compression (PBC), and stereotactic radiosurgery such as Gamma Knife radiosurgery (GKRS). This review synthesizes the outcomes of these interventions to provide an understanding of their efficacy and associated risks. MVD, known for its high initial relief rates, shows substantial long-term effectiveness, with recurrence rates varying based on patient demographics and comorbidities. GKRS offers significant pain relief with a favorable adverse event profile; however, recurrence rates increase over time, necessitating repeat procedures for sustained efficacy. PBC demonstrates high initial success, but pain recurrence is common, especially in patients with atypical TN. PRR provides immediate relief with a manageable recurrence rate and is particularly suitable for elderly patients and those with comorbidities. Glycerol rhizotomy, a cost-effective procedure, yields comparable outcomes to other interventions but requires careful patient selection. This review highlights the importance of tailored treatment approaches based on individual patient profiles, emphasizing the need for precise diagnostic criteria and careful patient selection to optimize outcomes. Long-term follow-up and the potential for repeat interventions are critical considerations in managing TN surgically.

Factors associated with outcomes following microvascular decompression for the treatment of primary trigeminal neuralgia in adults: a systematic review and meta-analysis

This study aimed to evaluate pain assessment strategies and factors associated with outcomes after microvascular decompression for the treatment of primary trigeminal neuralgia in adults. We conducted a systematic review and meta-analysis of English, Spanish, and French literature. We searched three databases, PubMed, Ovid, and EBSCO, from 2010 to 2022 and selected studies including patients with primary trigeminal neuralgia, clear pain assessment, and pain outcomes. Population means and standard deviations were calculated. Studies that included factors associated with postoperative outcomes were included in the meta-analysis. A total of 995 studies involving 5673 patients with primary trigeminal neuralgia following microvascular decompression were included. Patients with arteries compressing the trigeminal nerve demonstrated optimal outcomes following microvascular decompression (odds ratio [OR]= 0.39; 95% confidence interval [CI] = 0.19-0.80; X2 = 46.31; Dof = 15; I2 = 68%; P = < 0.0001). Conversely, when comparing arterial vs venous compression of the trigeminal nerve (OR = 2.72; 95% CI = 1.16-6.38; X2 = 23.23; Dof = 10; I2 = 57%; P = 0.01), venous compression demonstrated poor outcomes after microvascular decompression. Additionally, when comparing single-vessel vs multiple-vessel compression (OR = 2.72; 95% CI = 1.18-6.25; X2 = 21.17; Dof = 9; I2 = 57%; P = 0.01), patients demonstrated unfavorable outcomes after microvascular decompression. This systematic review and meta-analysis evaluated factors associated with outcomes following microvascular decompression (MVD) for primary trigeminal neuralgia (PTN). Although MVD is an optimal treatment strategy for PTN, a gap exists in interpreting the results when considering the lack of evidence for most pain assessment strategies.

Awake neurosurgery: Advancements in microvascular decompression for trigeminal neuralgia

Background

The treatment landscape for trigeminal neuralgia (TN) involves various surgical interventions, among which microvascular decompression (MVD) stands out as highly effective. While MVD offers significant benefits, its success relies on precise surgical techniques and patient selection. In addition, the emergence of awake surgery techniques presents new opportunities to improve outcomes and minimize complications associated with MVD for TN.

Methods

A thorough review of the literature was conducted to explore the effectiveness and challenges of MVD for TN, as well as the impact of awake surgery on its outcomes. PubMed and Medline databases were searched from inception to March 2024 using specific keywords "Awake Neurosurgery," "Microvascular Decompression," AND "Trigeminal Neuralgia." Studies reporting original research on human subjects or preclinical investigations were included in the study.

Results

This review highlighted that MVD emerges as a highly effective treatment for TN, offering long-term pain relief with relatively low rates of recurrence and complications. Awake surgery techniques, including awake craniotomy, have revolutionized the approach to MVD, providing benefits such as reduced postoperative monitoring, shorter hospital stays, and improved neurological outcomes. Furthermore, awake MVD procedures offer opportunities for precise mapping and preservation of critical brain functions, enhancing surgical precision and patient outcomes.

Conclusion

The integration of awake surgery techniques, particularly awake MVD, represents a significant advancement in the treatment of TN. Future research should focus on refining awake surgery techniques and exploring new approaches to optimize outcomes in MVD for TN.

Pain Outcomes Following Endoscopic Microvascular Decompression for Trigeminal Neuralgia Based on Vascular Compression Type

Background  Arterial compression of the trigeminal nerve at the root entry zone has been the long-attributed cause of compressive trigeminal neuralgia despite numerous studies reporting distal and/or venous compression. The impact of compression type on patient outcomes has not been fully elucidated. Objective  We categorized vascular compression (VC) based on vessel and location of compression to correlate pain outcomes based on compression type. Methods  A retrospective video review of 217 patients undergoing endoscopic microvascular decompression for trigeminal neuralgia categorizing VC into five distinct types, proximal arterial compression (VC1), proximal venous compression (VC2), distal arterial compression (VC3), distal venous compression (VC4), and no VC (VC5). VC type was correlated with postoperative pain outcomes at 1 month ( n  = 179) and last follow-up (mean = 42.9 mo, n  = 134). Results  At 1 month and longest follow-up, respectively, pain was rated as "much improved" or "very much improved" in 89 69% of patients with VC1, 86.6 and 62.5% of patients with VC2, 100 and 87.5% of patients with VC3, 83 and 62.5% of patients with VC4, and 100 and 100% of patients with VC5. Multivariate analysis demonstrated VC4 as a significant negative of predictor pain outcomes at 1 month, but not longest follow-up, and advanced age as a significant positive predictor. Conclusion  The degree of clinical improvement in all types of VC was excellent, but at longest follow-up VC type was not a significant predictor out outcome. However distal venous compression was significantly associated with worse outcomes at 1 month.

Analyzing the Effect of Intraoperative Stimulation Voltage on Facial Numbness Following Radiofrequency Thermocoagulation in the Treatment of Idiopathic Trigeminal Neuralgia

INTRODUCTION

Radiofrequency thermocoagulation (RFT) effectively alleviates idiopathic trigeminal neuralgia (ITN); however, postoperative facial numbness poses a significant challenge. This issue arises due to the close proximity of high-temperature thermocoagulation, which not only ablates pain-related nociceptive fibers but also affects tactile fibers. Intraoperative sensory stimulation voltage (SV), which reflects the distance between the RFT cannula and the target nerve, potentially possesses the ability to prevent tactile fiber injury. This study aimed to investigate the influence of SV on postoperative facial numbness and provide valuable insights to mitigate its occurrence.

METHODS

A retrospective analysis was performed on 72 ITN patients with maxillary division (V2) pain who underwent RFT between 2020 and 2022. Among them, 13 patients with SV ≤ 0.2 V constituted the low SV group. Subsequently, a matched-cohort analysis was conducted on the remaining 59 patients. The patients paired with the low SV patients were subsequently enrolled in the high SV group, adhering to a 1:1 match ratio. The primary outcome was the facial numbness scale assessment at 3 days, 3 months and 6 months post-surgery. The pain intensity and medication burden served as the secondary outcomes.

RESULTS

We successfully matched a cohort consisting of 12 patients in the low SV group and 12 patients in the high SV group. Each patient experienced various degrees of facial numbness at 3 days post-RFT. Notably, the low SV group exhibited a higher incidence of moderate numbness (66.7% vs. 16.67%, P = 0.036), whereas the high SV group had more cases of mild numbness at the 6-month follow-up (25% vs. 83.3%, P = 0.012). Both groups demonstrated significant decreases in pain intensity and medication burden compared to before the operation.

CONCLUSIONS

SV proved to be a reliable parameter for mitigating the degree of postoperative facial numbness in RFT treatment for ITN. A relatively high sensory SV ranging from 0.3 to 0.6 V during the RFT procedure results in less facial numbness in the treatment of ITN.

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.

Functional alterations of the brain default mode network and somatosensory system in trigeminal neuralgia

Mapping the localization of the functional brain regions in trigeminal neuralgia (TN) patients is still lacking. The study aimed to explore the functional brain alterations and influencing factors in TN patients using functional brain imaging techniques. All participants underwent functional brain imaging to collect resting-state brain activity. The significant differences in regional homogeneity (ReHo) and amplitude of low frequency (ALFF) between the TN and control groups were calculated. After familywise error (FWE) correction, the differential brain regions in ReHo values between the two groups were mainly located in bilateral middle frontal gyrus, bilateral inferior cerebellum, right superior orbital frontal gyrus, right postcentral gyrus, left inferior temporal gyrus, left middle temporal gyrus, and left gyrus rectus. The differential brain regions in ALFF values between the two groups were mainly located in the left triangular inferior frontal gyrus, left supplementary motor area, right supramarginal gyrus, and right middle frontal gyrus. With the functional impairment of the central pain area, the active areas controlling memory and emotion also change during the progression of TN. There may be different central mechanisms in TN patients of different sexes, affected sides, and degrees of nerve damage. The exact central mechanisms remain to be elucidated.

Comparison of microvascular decompression, percutaneous radiofrequency rhizotomy, and stereotactic radiosurgery in the treatment of trigeminal neuralgia: A long term quasi-experimental study

BACKGROUND

Microvascular decompression (MVD), radiofrequency rhizotomy (RFR), and stereotactic radiosurgery (SRS) are surgical techniques frequently used in the treatment of idiopathic trigeminal neuralgia (TN), although the results reported for each of these are diverse.

OBJECTIVE

This study aimed to compare long-term pain control obtained by MVD, SRS, and RFR in patients with idiopathic TN.

METHODS

To compare the results obtained by MVD, SRS, and RFR we chose a quasi-experimental, ambispective design with control groups but no pretest. A total of 52 participants (MVD n = 33, RFR n = 10, SRS n = 9) were included. Using standardized outcome measures, pain intensity, pain relief, quality of life, and satisfaction with treatment were assessed by an independent investigator. The TREND statement for reporting non-randomized evaluations was applied. Clinical outcomes were evaluated at the initial postoperative period and at 6 months, 1, 2, 3, 4, and 5 years postoperatively.

RESULTS

MVD has shown better results in pain scales compared to ablative procedures. Significant differences between groups were found regarding pain intensity and pain relief at the initial postoperative period (p < 0.001) and 6 months (p = 0.022), 1 year (p < 0.001), 2 years (p = 0.002), and 3 years (p = 0.004) after the intervention. Those differences exceeded the thresholds of the minimal clinically important difference. A higher percentage of patients free of pain was observed in the group of patients treated by MVD, with significant differences at the initial postoperative period (p < 0.001) and 6 months (p = 0.02), 1 year (p = 0.001), and 2 years (p = 0.04) after the procedure. Also, a higher risk of pain recurrence was observed in the RFR and SRS groups (HR 3.15, 95% CI 1.33-7.46; p = 0.009; and HR 4.26, 95% CI 1.77-10.2; p = 0.001, respectively) compared to the MVD group. No significant differences were found in terms of quality of life and satisfaction with treatment. A higher incidence of complications was observed in the MVD group.

CONCLUSION

Concerning pain control and risk of pain recurrence, MVD is superior to RFR and SRS, but not in terms of quality of life, satisfaction with treatment, and safety profile.

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.

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.

Microvascular decompression for trigeminal neuralgia: a single-center experience with 516 cases, including 32 patients with multiple sclerosis

BACKGROUND AND OBJECTIVES

To evaluate the effectiveness and long-term pain relief of microvascular decompression (MVD) for "typical" trigeminal neuralgia (TN), including patients affected by multiple sclerosis (MS).

METHODS

Between January 2011 and December 2022, 516 consecutive patients presenting with trigeminal neuralgia and a diagnosed neurovascular conflict at MRI underwent microvascular decompression surgery in our neurosurgery department. Ten surgeons with different ages and experiences performed the surgical procedures. Pain improvement, re-operation rate, and complication rates were retrospectively collected and analyzed.

RESULTS

516 patients were included (214 males 302 females, ranging from 12 to 87 years), including 32 patients with multiple sclerosis. Neurovascular compression was found in all cases during surgery. Barrow Neurological Institute pain intensity scale with a score of I was achieved in 404 patients (78,29%), a score II or III was obtained in 100 cases (19,37%) and a score of IV and V in 12 patients (2,32%). In the multiple sclerosis subset of patients, a BNI score of I was achieved in 21/32 (65.62%). The pain recurrence rate of our series was 15.11%. The follow-up for all patients was at least of 13 months, with a mean follow-up of 41.93 months (± 17.75 months, range 13-91 months). Neither intraoperative mortality nor major intra-operative complications occurred in the analyzed series. The re-operation rate was 12.98%. Thermorhizotomy, percutaneous balloon compression, cyber-knife radiosurgery, or new MVD were the surgical techniques utilized for re-operations.

CONCLUSIONS

MVD may be considered an effective and safe surgical technique for TN, and in patients affected by multiple sclerosis, it may be proposed even if a less favorable outcome has to be expected with respect to classic TN patients. Larger studies focusing on the relation of multiple sclerosis with neurovascular compression are required.

Microvascular decompression for trigeminal neuralgia: A retrospective analysis of long-term outcomes and prognostic factors

INTRODUCTION

Microvascular decompression is considered to be the most effective and only etiological surgical treatment for classical trigeminal neuralgia, relieving the neurovascular compression found in up to 95% of cases. This study aims to report the long-term outcomes and to identify prognostic factors in a series of patients with trigeminal neuralgia treated by microvascular decompression.

METHODS

A retrospective observational study of 152 consecutive patients operated by microvascular decompression with at least six months of follow-up. The surgical results, including pain relief according to the Barrow Neurological Institute pain scale, complications and the medical treatment during the follow-up period were reviewed. Binary regression analysis was performed to identify factors associated with a good long-term outcome.

RESULTS

A total of 152 patients with a mean age of 60 years and a mean follow-up of 43 months were included. At the final follow-up visit, 83% of the patients had achieved significant relief of the pain and 63% could reduce the absolute drug doses by 50% or more. The most frequent complications were wound infection (4.5%) and CSF fistula (7%). Being over 70 years of age and having paroxysmal pain were associated with a long-term pain relief.

CONCLUSIONS

Our results support the notion that microvascular decompression is an effective and safe therapy in patients with trigeminal neuralgia. A multidisciplinary approach with an early referral to a neurosurgical unit many be beneficial in patients who are refractory to pharmacological treatment.

Association of concomitant continuous pain in trigeminal neuralgia with a narrow foramen ovale

Background

The pathogenesis of concomitant continuous pain remains unclear and is worthy of further study. In this clinical study, we aimed to explore the potential role of a narrow foramen ovale in the development of concomitant continuous pain.

Methods

A total of 108 patients with classical trigeminal neuralgia affecting the third branch of the trigeminal nerve and 46 healthy individuals were enrolled in this study. Three-dimensional reconstructed computerized tomography images of all participants were collected, and the morphometric features of the foramen ovale were examined by two investigators who were blinded to the clinical data of the patients.

Results

In this cohort, patients with concomitant continuous pain suffered from more sensory abnormalities (18.4% vs. 2.9%, p = 0.015) and responded more poorly to medication (74.3% vs. 91.9%, p = 0.018) than patients without concomitant continuous pain. While no significant differences regarding the mean length (5.02 mm vs. 5.36 mm, p > 0.05) and area (22.14 mm2 vs. 23.80 mm2, p > 0.05) were observed between patients with and without concomitant continuous pain, the mean width of the foramen ovale on the affected side in patients with concomitant continuous pain was significantly narrower than that in patients without concomitant continuous pain (2.01 mm vs. 2.48 mm, p = 0.003).

Conclusion

This neuroimaging and clinical study demonstrated that the development of concomitant continuous pain was caused by the compression of the trigeminal nerve owing to a narrow foramen ovale rather than responsible vessels in classical trigeminal neuralgia.

The role of multiple sclerosis subtype in microvascular decompression outcomes for patients with trigeminal neuralgia

OBJECTIVES

While patients with concomitant trigeminal neuralgia (TN) and multiple sclerosis (MS) are understood to experience a more intractable pain phenotype, whether TN pain outcomes differ by the presenting MS subtype is not well characterized. This study's objective is to compare post-operative pain and numbness outcomes following microvascular decompression (MVD) in TN patients with either relapsing-remitting MS (RRMS) or progressive MS.

METHODS

We retrospectively reviewed all TN patients who underwent MVDs at our institution from 2007 to 2020. Of the 1044 patients reviewed, 45 (4.3%) patients with MS were identified. Patient demographics, procedural characteristics, and post-operative pain and numbness scores were recorded and compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions.

RESULTS

Of the resulting 45 MS patients, 34 (75.6%) patients presented with the RRMS subtype, whereas 11 (24.4%) patients exhibited progressive MS. Using an adjusted multivariate ordinal regression, the subtype of MS was not significantly associated with the Barrow Neurological Institute (BNI) pain score at final follow-up. Using a Kaplan-Meier survival analysis and a multivariate Cox proportional hazards regression, respectively, RRMS was significantly associated with a shorter post-operative pain-free interval (p = 0.04) as well as a greater risk for pain recurrence (p = 0.02).

CONCLUSIONS

Although the degree of pain at final follow-up may not differ, RRMS patients are at increased risk for pain recurrence following MVD for TN. These results align with a growing understanding that neuroinflammation may play a significant role in TN pain.

Outcome after microvascular decompression for trigeminal neuralgia in a single center-relation to sex and severity of neurovascular conflict

BACKGROUND

Trigeminal neuralgia (TN), a severe type of facial pain, is mainly caused by a neurovascular conflict (NVC). The severity of the NVC seems associated with the outcome following microvascular decompression (MVD) surgery. This study aimed to investigate the outcome after MVD and whether it is affected by NVC severity and sex.

METHODS

TN patients (n = 109) were followed for 5 to 10 years after MVD. Barrow Neurology Index (BNI), Patients Global Impression of Change (PGIC), complications, and time to relapse were evaluated. The NVC severity was retrospectively reviewed from presurgical MRI. Demographic and clinical factors and NVC severity were analyzed for potential association with outcome after MVD.

RESULTS

The success rate (BNI ≤ 2) was 80% after 5 to 10 years follow-up for TN patients with severe NVC (grade 2-3) and 56% for TN patients with mild NVC (grade 0-1, P = 0.003). No sex difference was observed in outcome for patients with both mild (P = 0.924) and severe NVC (P = 0.883) respectively. Three patients (2.8%) during the hospital stay, and two patients (1.8%) at 6 weeks, experienced a complication requiring invasive treatment. At long-term 52/109 patients (47.7%) reported some type of persistent adverse event, of which the majority were mild and required no treatment.

CONCLUSIONS

MVD offers an 80% probability of long-term pain relief in TN patients with severe NVC, with low frequency of serious complications. NVC severity significantly affects outcome after MVD, while no sex differences in outcome were found. In consistency with previous work, the results stress the importance of adequate neuroradiological assessment of the NVC for preoperative patient selection.

Contact-free transposition and interposition techniques for trigeminal neuralgia: a systematic review

INTRODUCTION

Surgical treatment for trigeminal neuralgia (TGN), by means of interposition of material between nerve and offending vessel, has been shown to be highly efficient. In recent years, treatment by means of vessel transposition has become more frequent, as in singular cases of recurrence, nerval reactions towards interposed material have been noted. In this review we research the classic microvascular decompression (MVD) techniques (interposition) as well as the more recent transposition and their effectiveness, considering patient outcomes as well as complications and recurrences.

EVIDENCE ACQUISITION

We searched online databases MEDLINE and LIVIVO, using key words trigeminal neuralgia AND transposition/ AND sling/ AND non compressive technique/ AND microvascular decompression.

EVIDENCE SYNTHESIS

We included 8 studies for transposition and 20 studies for the interposition, combining for 2045 patients (302 for transposition and 1743 for interposition). 96.1% of patients in the transposition and 93.1% in the interposition group reported a positive outcome immediately postoperatively. At follow-up, 87.4% in the transposition group (follow-up 51.2 months) and 87.9% of patients in the interposition group (follow-up 36.5 months), reported a positive outcome. 16.2% of patients in the transposition and 13.1% in the interposition group had postoperative complications. Recurrence was reported in 5.6% of patients treated with transposition and 2.3% of patients treated with interposition.

CONCLUSIONS

Transposition presents similar results concerning short- and long-term patient satisfaction for treatment of TGN as well as similar numbers of complications of recurrences as interposition. Yet, current evidence is restricted to a few retrospective studies, thus, evidence is limited so far.

Effects of microvascular decompression on quality-of-life in trigeminal neuralgia patients aged 70 years and older

Background

Trigeminal neuralgia (TN) occasionally affects older adults, frequently worsens, and becomes refractory to medication. Older adult patients with TN may consider microvascular decompression (MVD) for their treatment. No study examines MVD effects on older adult TN patients' health-related quality of life (HRQoL). The present study evaluates the HRQoL of TN patients aged 70 years and older before and after MVD.

Methods

Adult TN patients who underwent MVD evaluated their HRQoL using the 36-Item Short-form (SF-36) Health Survey before and 6 months after MVD. The patients were divided into four groups according to their decade of age. The clinical parameters and operative outcomes were analyzed statistically. The SF-36 physical, mental, and role social component summary scores and eight domain scale scores were analyzed using a twoway repeated-measures analysis of variance (ANOVA) to compare the effects of age group and preoperative and postoperative time points.

Results

Among 57 adult patients (34 women, 23 men; mean age, 69 years; range, 30-89 years), 21 patients were in their seventies, and 11 were in their eighties. The SF-36 scores of patients in all age groups improved after MVD. Two-way repeated-measures ANOVA demonstrated a significant age group effect on the physical component summary and its physical functioning domain. A time point effect was significant on all component summaries and domains. There was a significant interaction between age group and time point effects on the bodily pain domain. These results suggested that patients 70 years and older had significant postoperative HRQoL improvement, but their improvement of physical-related HRQoL and multiple physical pain issues were limited.

Conclusion

Impaired HRQoL in TN patients aged 70 years and older can improve after MVD. Careful management of multiple comorbidities and surgical risks enables MVD to be an appropriate treatment for older adult patients with refractory TN.

Clinical outcome after microvascular decompression for trigeminal neuralgia: a systematic review and meta-analysis

Microvascular decompression (MVD) is considered an effective treatment for trigeminal neuralgia (TN). However, the anatomical and clinical variables associated with a better outcome are not fully examined. The authors performed a systematic review and meta-analysis of the literature investigating the immediate and long-term clinical results of MVD for TN, and the impact of the anatomical features of the neurovascular conflict on the outcome. The systematic search of three databases was performed for studies published between January 1990 and November 2021. PRISMA guidelines were followed. Random-effects meta-analysis was used to pool the analyzed outcomes, and random-effect meta-regression was used to examine the association between the effect size and potential confounders. A funnel plot followed by Egger's linear regression was used to test publication bias. A total of 9 studies were included in this analysis, including 2102 patients with trigeminal neuralgia. The immediate post-operative rate of BNI I was 82.9%, whereas surgical failure (BNI IV-V) was reported in approximately 2.6% of patients. CSF leak was the most common postoperative complication (2.4%). The rate of BNI I at last follow up was 64.7% (p < 0.01), showing a significant negative correlation after multiple meta-regression with the rate of patients with isolated venous conflict (p < 0.01). On the other hand, the evidence of an arterial conflict proved is positive association with a favorable outcome (p < 0.01). At the last follow-up, BNI IV-V was reported in 19.2% (95% CI 8.9-29.5%, p < 0.01, I2 = 97.3%). This meta-analysis confirms the safety and efficacy of MVD for TN. The occurrence of serious postoperative complications is very low. The long-term outcome is associated with the type of vascular structure involved, being pure venous conflict associated with a higher risk of surgical failure. These findings should be considered when planning surgery for patients with TN.

Microvascular decompression in trigeminal neuralgia - a prospective study of 115 patients

Background

Trigeminal neuralgia is a severe facial pain disorder. Microvascular decompression is first choice surgical treatment of patients with classical TN. There exist few prospective studies with an independent evaluation of efficacy and complications after MVD.

Objectives

We aimed to assess outcome and complications after microvascular decompression from our center.

Methods

We prospectively recorded clinical characteristics, outcome, and complications from consecutive patients with either classical or idiopathic (only patients with a neurovascular contact) trigeminal neuralgia undergoing microvascular decompression. Neurovascular contact was evaluated by 3.0 Tesla MRI. Patients were assessed before and 3, 6, 12, and 24 months after surgery by independent assessors.

Results

Of 115 included patients, 86% had a clinically significant outcome (i.e., BNI I – BNI IIIb). There was a significant association between an excellent surgical outcome and the male sex (OR 4.9 (CI 1.9–12.8), p = 0.001) and neurovascular contact with morphological changes (OR 2.5 (CI 1.1–6.0), p = 0.036). Significantly more women (12/62 = 19%) than men (2/53 = 4%) had a failed outcome, p = 0.019. The most frequent major complications were permanent hearing impairment (10%), permanent severe hypoesthesia (7%), permanent ataxia (7%), and stroke (6%). Most patients (94%) recommend surgery to others.

Conclusion

Microvascular decompression is an effective treatment for classical and idiopathic (only patients with a neurovascular contact) trigeminal neuralgia with a high chance of a long-lasting effect. The chance of an excellent outcome was highest in men and in patients with classical trigeminal neuralgia. Complications are relatively frequent warranting thorough patient evaluation and information preoperatively.

Trial registration

Clinical.trials.gov registration no. NCT04445766.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10194-022-01520-x.

Microvascular decompression: Diversified of imaging uses, advantages of treating trigeminal neuralgia and improvement after the application of endoscopic technology

Classical trigeminal neuralgia (CTN) is a unilateral and severe facial pain disease, which seriously affects the patient's quality of life. Microvascular decompression (MVD) is currently the most effective surgical method, and it is the only treatment for the etiology of CTN. Imaging for MVD has been increasingly used, and the advantages and disadvantages of endoscopy-assisted vascular decompression surgery have been controversially debated. In this review, we aimed to discuss the advantages of MVD in the treatment of patients with CTN, the importance of using imaging in disease management, and the improvements of vascular decompression surgery through the application and maturity of endoscopic techniques. Compared with other surgical methods, MVD has more prominent short- and long-term treatment effects. Its selection depends on the accurate discovery of neurovascular compression by preoperative imaging. Moreover, magnetic resonance imaging plays a diverse role in MVD, not only in identifying the responsible vessels but also in determining the prognosis and as a tool for scientific research. The use of endoscopic techniques provides improved visualization of the MVD and additional benefits for vascular decompression surgery.

Delayed pain relief in patients with trigeminal neuralgia following microvascular decompression: A single-central retrospective study

Background

Compared to hemifacial spasm after microvascular decompression (MVD), delayed relief (DR) rarely occurs in patients with trigeminal neuralgia (TGN).

Objective

To analyze the characteristics of post-MVD DR in TGN patients to provide useful clues for the clinical differential diagnosis of postoperative DR.

Methods

The clinical data of all patients with TGN who underwent MVD in our center from January 1, 2016, to December 31, 2020, were reviewed retrospectively.

Results

In 272 TGN MVD patients, DR occurred in nine patients (3.3%) during the follow-up periods of 1–6 years. During surgery, all nine DR-TGN patients were identified as having neurovascular conflicts (NVCs), involving the offending artery (OA) in eight patients (two OAs in two patients) and both an artery and a vein in the other patient. The compression site was near the root entry zone (REZ) in most DR patients (7/9). Delayed relief was relieved in seven patients within 5 days after surgery and within 30 days in the other two patients. No recurrence or serious complications were observed within the mean 4 (1-6)-year follow-up duration.

Conclusion

Delayed relief rarely occurs in TGN patients after MVD. Neurovascular conflicts located at the REZ and NVC of grade III may be two important factors contributing to DR in TGN patients. Delayed relief may occur when the pain gradually improves after the operation and responds effectively to a small dose of carbamazepine. The recurrence rate of TGN seems even lower in such patients.

Clinical Efficacy of a Spiral CT-Guided Balloon Compression Day-Surgery Operation for the Treatment of Trigeminal Neuralgia

Objective

This study aimed to investigate the clinical efficacy of a balloon compression day-surgery operation under the guidance of spiral computed tomography (CT) three-dimensional (3D) reconstruction for the treatment of trigeminal neuralgia.

Methods

The clinical efficacy and related indexes of 380 patients with trigeminal neuralgia treated by a spiral CT-guided balloon compression day-surgery operation in the pain department of Beijing TianTan Hospital, from October 2017 to March 2021, were retrospectively analyzed.

Results

Five patients failed due to foramen ovale puncture or in placing the balloon; two patients had ineffective results after the operation and re-entered the hospital for secondary balloon compression. The initial effective rate of the operation in the 380 patients was 98.16%. All patients were discharged on the day of the operation, the average operation time was 26.46 ± 12.15 min, and the average interval from the completion of the operation to discharge was 2.67 ± 0.95 h. During the follow-up period (1-41 months), 12 patients had pain recurrence, and a Kaplan-Meier analysis revealed that the cumulative pain-free recurrence survival rate at 41 months after the operation was 80.64%. No complications related to foramen ovale puncture occurred.

Conclusion

The spiral CT-guided balloon compression day-surgery operation is safe, effective, and worthy of clinical promotion.

Gamma Knife Radiosurgery for Trigeminal Neuralgia : Review and Update

Accurate diagnosis of trigeminal neuralgia (TN) is the starting point for optimal treatment. Gamma knife radiosurgery (GKRS) is currently regarded as one of the first-line treatment options for medically refractory TN. GKRS is a less invasive treatment with a low risk of complications than other surgical procedures that provides a favorable pain control (BNI I–IIIb) rate of >75% at short-term follow-up. Drawbacks of GKRS include the latency period before pain relief and higher recurrence rate compared with microvascular decompression. Therefore, repeat treatment is necessary if the initial GKRS was effective but followed by recurrence. The concept of dose rate and the biologically effective dose of radiation has been actively studied in radiation oncology and is also applied in GKRS for TN to achieve high safety and efficacy by prescribing the optimal dose. Recent progress in functional imaging, such as diffusion tensor imaging, enables us to understand the pathophysiology of TN and predict the clinical outcome after GKRS. Here, we review TN, GKRS, and recent updates, especially in the concepts of radiation dose, diffusion tensor imaging studies, and repeat treatment in GKRS for TN.

Outcomes using linear accelerator stereotactic radiosurgery for the treatment of trigeminal neuralgia: A single-center, retrospective study

Background:

Linear accelerator (LINAC)-based stereotactic radiosurgery (SRS) treatment of trigeminal neuralgia (TN) may have similar efficacy to Gamma Knife SRS (GK-SRS), but the preponderance of data comes from patients treated with GK-SRS. Our objective was to analyze the outcomes for LINAC-based treatment of TN in patients at our institution.

Methods:

We retrospectively analyzed data for patients who underwent LINAC-based SRS for TN from 2006 to 2018. Data were collected from the patients’ medical records. Nonparametric statistics were used for the analysis.

Results:

Of the 41 patients treated with LINAC-based SRS (typically 90 Gy dosed using a 4 mm collimator for one fraction) during that time, follow-up data of >3 weeks post-SRS were available for 32 patients. The median pretreatment Barrow Neurological Institute (BNI) pain score was 5 (range 4–5). The follow-up period ranged from 0.9 to 113.2 months (median 5 months). There was significant improvement in postradiation BNI pain score (P < 0.001), with 23 (72%) patients who improved to a BNI pain score of 1–3. One patient had bothersome hypoesthesia postradiation. Approximately 38% of patients who had initial pain control had recurrence of symptoms (BNI > 3). Survival analysis showed a median time to pain recurrence of 30 months. There was no relationship between prior microvascular decompression (MVD) surgery and change in BNI pain score pre- to posttreatment.

Conclusion:

The results demonstrate that LINAC-based SRS is an effective means to treat TN. Prior MVD surgery did not affect efficacy of SRS in lowering the BNI score from pre- to posttreatment in this patient cohort.

The impact of needle location on clinical outcome of radiofrequency rhizotomy for trigeminal neuralgia

BACKGROUND

Radiofrequency thermocoagulation trigeminal rhizotomy (RT-TR) through the foramen ovale is a minimally invasive treatment for trigeminal neuralgia. Navigation of magnetic resonance imaging (MRI) and CT fusion imaging is a well-established method for cannulation of the Gasserian ganglion. In this study, we use the inline measurements from fusion image to analyze the anatomical parameters between the actual and simulation trajectories and compare the short- and intermediate-term outcomes according to determinable factors.

METHODS

The study included thirty-six idiopathic neuralgia patients who had undergone RT-TR with MRI and CT fusion image as a primary modality or repeated procedures.

RESULTS

Among thirty-six treated patients, the inline length of the trigeminal cistern was longer for the simulated trajectory (8.4 ± 2.4 versus 6.5 ± 2.8 mm; p < 0.05), and the predominant structure at risk extrapolated from the inline trajectory was the brainstem, which signified a more medially directed route, in contrast with the equal weighting of temporal lobe and brainstem for the actual trajectory. The preoperative visual analogue scale (VAS) was 9.3 ± 1.0, which decreased to 2.5 ± 2.6 and 2.9 ± 3.1 at first (mean, 3 months) and second (mean, 14 months) postoperative follow-up, respectively. The postoperative VAS scores at the two follow-ups were not statistically significant without a covariate analysis. After adjustment for covariate risk factors, the second follow-up sustained therapeutic benefit was evident in patients with no prior history of related treatment, an ablation temperature greater than 70 °C, and needle location within or adjacent to the trigeminal cistern.

CONCLUSIONS

This preliminary study demonstrated that the needle location between cistern and ganglion also plays a significant role in better intermediate-term results.

Treatment of redo-microvascular decompression or internal neurolysis plus microvascular decompression for recurrent trigeminal neuralgia: a review of long-term effectiveness and safety

Objective

We examined the clinical characteristics and outcomes of patients with recurrent trigeminal neuralgia (TN) and assessed the long-term efficacy and safety of microvascular decompression (MVD) to treat typical recurrent TN.

Methods

We identified 3024 patients who underwent MVD for treatment of TN at the China-Japan Friendship Hospital from March 2009 to December 2020. We retrospectively analyzed the data and outcomes of 137 patients who underwent redo-MVD and 74 patients who did not undergo redo-MVD as the control group. These outcomes were evaluated using the Barrow Neurological Institute scoring system.

Results

Recurrence in 68 of the 137 patients was due to incomplete or absent decompression or new responsible vessels. To ensure thorough pain relief, redo-MVD should include decompression of both the trigeminal root entry zone and the peripheral nerve segments, where blood vessels can cause symptoms. Factors associated with reduced effectiveness of redo-MVD were no period of initial pain relief after the first MVD and a longer duration of symptoms before the first MVD.

Conclusions

Redo-MVD should not be excluded as a treatment option for patients with refractory TN who develop recurrent pain after a first MVD procedure.

Bone Cement Cranioplasty Reduces Cerebrospinal Fluid Leak Rate after Microvascular Decompression: A Single-Institutional Experience

Background  Microvascular decompression (MVD) is a common surgical treatment for cranial nerve compression, though cerebrospinal fluid (CSF) leak is a known complication of this procedure. Bone cement cranioplasty may reduce rates of CSF leak. Objective  To compare rates of CSF leak before and after implementation of bone cement cranioplasty for the reconstruction of cranial defects after MVD. Methods  Retrospective chart review was performed of patients who underwent MVD through retrosigmoid craniectomy for cranial nerve compression at a single institution from 1998 to 2017. Study variables included patient demographics, medical history, type of closure, and postoperative complications such as CSF leak, meningitis, lumbar drain placement, and ventriculoperitoneal shunt insertion. Cement and noncement closure groups were compared, and predictors of CSF leak were assessed using a multivariate logistic regression model. Results  A total of 547 patients treated by 10 neurosurgeons were followed up for more than 20 years, of whom 288 (52.7%) received cement cranioplasty and 259 (47.3%) did not. Baseline comorbidities were not significantly different between groups. CSF leak rate was significantly lower in the cement group than in the noncement group (4.5 vs. 14.3%; p  < 0.001). This was associated with significantly fewer patients developing postoperative meningitis (0.7 vs. 5.2%; p  = 0.003). Multiple logistic regression model demonstrated noncement closure as the only independent predictor of CSF leak (odds ratio: 3.55; 95% CI: 1.78-7.06; p  < 0.001). Conclusion  CSF leak is a well-known complication after MVD. Bone cement cranioplasty significantly reduces the incidence of postoperative CSF leak and other complications. Modifiable risk factors such as body mass index were not associated with the development of CSF leak.

The effectiveness and safety of neurosurgical treatment via retrosigmoid approach in elderly patients with trigeminal neuralgia

OBJECTIVE

The purpose of this study was to evaluate the effectiveness and safety of retrosigmoid approach in treating older patients with trigeminal neuralgia (TN).

METHODS

In this retrospective study, 49patients (65 and over, elderly group) and 85 patients (under 65, young group) underwent MVD, MVD + PSR or PSR for idiopathic TN from July 2009 to December 2018. The two groups were compared for immediate, long-term pain outcome and postoperative complications. All perioperative data were collected from medical records and telephone interviews. The pain outcomes were assessed with the Barrow Neurological Institute (BNI) pain score.

RESULTS

The length of follow-up was 13.2 to 124.8 months. 91.8% of the elderly patients and 89.4% of the young patients achieve "Good" immediate pain outcome (BNI I-II), the proportion were 73.5% and 60.0%, respectively, in long-term pain outcome. No statistically significant differences existed in the immediate and long-term pain outcome between the elderly and young patients (P = 0.768 and P = 0.116, respectively). In the grouping analysis, whether in the pure MVD group or the PSR-related group, the immediate and long-term pain outcomes of elderly patients were not significantly different from those of younger patients. Meanwhile, there was no significant difference in the incidence of neurological and non-neurological complications between two groups.

CONCLUSIONS

Compared with young patients, the treatment for TN in elderly patients via retrosigmoid approach has the same favorable pain outcome. The safety of this procedure for elderly TN patients is similar to that in young patients.

Classifier Using Pontine Radial Diffusivity and Symptom Duration Accurately Predicts Recurrence of Trigeminal Neuralgia After Microvascular Decompression: A Pilot Study and Algorithm Description

BACKGROUND

Preprocedure diffusion tensor magnetic resonance imaging (MRI) may predict the response of trigeminal neuralgia (TN) patients to Gamma Knife (Elekta AB) and microvascular decompression (MVD).

OBJECTIVE

To test this hypothesis using pontine-segment diffusion tensor MRI radial diffusivity (RD), a known biomarker for demyelination, to predict TN recurrence following MVD.

METHODS

RD from the pontine segment of the trigeminal tract was extracted in a semiautomated and blinded fashion and normalized to background pontine RD. Following validation against published results, the relationship of normalized RD to symptom duration (DS) was measured. Both parameters were then introduced into machine-learning classifiers to group patient outcomes as TN remission or recurrence. Performance was evaluated in an observational study with leave-one-out cross-validation to calculate accuracy, sensitivity, specificity, and receiver operating characteristic curves.

RESULTS

The study population included 22 patients with TN type 1 (TN1). There was a negative correlation of normalized RD and preoperative symptom duration (P = .035, R2 = .20). When pontine-segment RD and DS were included as input variables, 2 classifiers predicted pain-free remission versus eventual recurrence with 85% accuracy, 83% sensitivity, and 86% specificity (leave-one-out cross-validation; P = .029) in a cohort of 13 patients undergoing MVD.

CONCLUSION

Pontine-segment RD and DS accurately predict MVD outcomes in TN1 and provide further evidence that diffusion tensor MRI contains prognostic information. Use of a classifier may allow more accurate risk stratification for neurosurgeons and patients considering MVD as a treatment for TN1. These findings provide further insight into the relationship of pontine microstructure, represented by RD, and the pathophysiology of TN.

Microvascular Decompression for Trigeminal Neuralgia: Experience of a Tertiary Care Center in India and a Brief Review of Literature

Background

Trigeminal neuralgia (TN) is a devastating condition causing significant patient discomfort and morbidity hampering quality of life. Of the many treatment options available, microvascular decompression (MVD) of the trigeminal nerve is widely performed. However, the procedure is not risk-free.

Objective

The study aimed to describe our experience of treating TN via MVD and long-term follow-up of the patients treated by this modality.

Materials and Methods

It is a 5-year retrospective analysis of the database of patients with idiopathic TN treated with MVD at our institute. A total of 106 patients fulfilling the criteria of idiopathic TN by International Classification of Headache Disorders, 3^rd ed.ition and available for follow-up for at least 1-year post-procedure were included in the study.

Results

Of the 106 patients, 58 (54.7%) were female and 48 (45.3%) were male with a mean age of 55 years (range 22-75 years). Vascular compression of the trigeminal nerve was seen in all cases; arterial compression in 82%, both artery and vein 14.5% while unidentified vessels were the culprit in 3.8% of the patients. There were no intra- or post-operative deaths. The best response was achieved at 1 month following the procedure where 85% of the patients achieved excellent outcomes.

Conclusion

In experienced hands, MVD is still a safe and cost-effective modality over a myriad of treatment options available for TN in patients of all ages. The absence of adhesions, indentations, and distortion of the trigeminal nerve are positive predictors of excellent outcomes in the long run.

Comparison of first-time microvascular decompression with percutaneous surgery for trigeminal neuralgia: long-term outcomes and prognostic factors

Objective

Common surgical treatments for trigeminal neuralgia (TN) include microvascular decompression (MVD) and percutaneous procedures (glycerol rhizolysis; thermocoagulation; and balloon compression). Although the efficacy of each procedure has been documented, direct comparisons of their relative efficacies for TN are lacking. We aimed to directly compare long-term outcomes after first-time MVD with percutaneous surgery in primary (idiopathic and classical) TN and identify predictors of outcome.

Methods

We conducted a retrospective analysis of prospectively collected data on 185 patients undergoing MVD and 129 undergoing percutaneous surgery. Procedures were performed by one of two neurosurgeons in a single centre; an independent observer collected long-term follow-up data by interviews, using the same outcome measures for all procedures.

Results

MVD patients were younger than those undergoing percutaneous surgery (P <.001). MVD provided superior initial pain relief (P <.001): 87.0% had Barrow Neurological Institute class I or II pain scores after MVD compared with 67.2% after percutaneous surgery. The complication rate for percutaneous procedures was 35.7% and for MVDs was 24.9% (P =.04), including minor and transient complications. Kaplan-Meier analysis demonstrated that MVD provided longer pain relief than percutaneous procedures (P <.001); 25% of patients had recurrence at 96 months following MVD compared with 12 months after percutaneous surgery. Subgroup analysis showed that balloon compression provided more durable relief amongst percutaneous procedures. Multivariate analysis revealed that post-operative numbness and age were prognostic factors for percutaneous procedures (P =.03 and .01, respectively).

Conclusions

MVD provides better initial pain relief and longer durability of relief than percutaneous surgery, although carrying a small risk of major complications. Amongst percutaneous procedures, balloon compression gave the most durable relief from pain. Older age and post-operative numbness were predictors of good outcome from percutaneous surgery. These results can help clinicians to counsel patients with primary TN on neurosurgical treatment selection for pain relief.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-021-04793-4.

Microvascular decompression for trigeminal neuralgia: A retrospective analysis of long-term outcomes and prognostic factors

INTRODUCTION

Microvascular decompression is considered to be the most effective and only etiological surgical treatment for classical trigeminal neuralgia, relieving the neurovascular compression found in up to 95% of cases. This study aims to report the long-term outcomes and to identify prognostic factors in a series of patients with trigeminal neuralgia treated by microvascular decompression.

METHODS

A retrospective observational study of 152 consecutive patients operated by microvascular decompression with at least six months of follow-up. The surgical results, including pain relief according to the Barrow Neurological Institute pain scale, complications and the medical treatment during the follow-up period were reviewed. Binary regression analysis was performed to identify factors associated with a good long-term outcome.

RESULTS

A total of 152 patients with a mean age of 60 years and a mean follow-up of 43 months were included. At the final follow-up visit, 83% of the patients had achieved significant relief of the pain and 63% could reduce the absolute drug doses by 50% or more. The most frequent complications were wound infection (4.5%) and CSF fistula (7%). Being over 70 years of age and having paroxysmal pain were associated with a long-term pain relief.

CONCLUSIONS

Our results support the notion that microvascular decompression is an effective and safe therapy in patients with trigeminal neuralgia. A multidisciplinary approach with an early referral to a neurosurgical unit many be beneficial in patients who are refractory to pharmacological treatment.

Balloon compression vs radiofrequency for primary trigeminal neuralgia: a randomized, controlled trial

ABSTRACT

Surgical procedures are necessary in up to 50% of trigeminal neuralgia patients. Although radiofrequency (RF) is more widely used, it is associated with high intraprocedural costs and long technical learning time. Other simpler procedures such as balloon compression (BC) require a lower training period and have significant lower costs. We evaluated the effects of BC and RF in pain control in primary trigeminal neuralgia in a randomized, double-blinded, head-to-head trial. Individuals were randomly allocated in 1 of 2 groups: BC and RF. Throughout pain, psychological and quality of life measurements were performed at baseline and after surgery. The main outcome was the worst pain in the last 24 hours (0-10) at 6 months postoperatively. After the inclusion of half of the estimated sample, a preplanned interim analysis was performed when 33 patients (62.1 ± 9.4 y.) completed the study. Pain intensity (confidence interval [CI] 95% 0.6 to 3.8, and -0.6 to 2.2, for BC and RF) did not significantly differ. Complications, interference of pain in daily life (CI 95% -0.1 to 2.3 and -0.4 to 2.3, for BC and RF), neuropathic pain symptoms (CI 95% 1.7 to 3.6 and 3.0 to 5.7, for BC and RF), mood (CI 95% 4.8 to 11.5 and 5.5 to 15.1, BC and RF, respectively), medication use, and quality of life (CI 95% 80.4 to 93.1 and 83.9 to 94.2, for BC and RF) were also not different. Radiofrequency presented more paresthetic symptoms than BC at 30 days after intervention. Based on these results, the study was halted due to futility because BC was not superior to RF.

Trigeminal neuralgia recurrence: a comparison of microvascular decompression and percutaneous balloon compression: a five years follow-up study

BACKGROUND

About 50% of patients that suffer from trigeminal neuralgia do not experience sustained benefit from the use of oral medication. For their adequate management, a few surgical procedures are available. Of these, percutaneous balloon compression (PBC) and microvascular decompression (MD) are two of the most performed worldwide. In this retrospective study, we present the outcomes of these techniques through estimation of initial pain relief and subsequent recurrence rate.

METHODS

Thirty-seven patients with medically refractory trigeminal pain surgically treated at Hospital Cajuru, Curitiba, Brazil, with PBC, MD or both between 2013 and 2018 were enrolled into this retrospective study. The post-procedural rate for pain relief and recurrence and associations between patient demographics and outcomes were analyzed.

RESULTS

MD had an earlier recurrence time than balloon compression. Of the 37 patients, the mean age was 61.6 years, approximately one third were male and most had type I neuralgia. The most affected branch was the maxillary (V2). The time for recurrence after surgery was on average 11.8 months for PBC and 9.0 months for MD. Complications were seen only with microsurgery.

CONCLUSIONS

MD presented with a more precocious recurrence of pain than PBC in this article. Moreover, it had a higher recurrence rate than described in the literature as well, which is possibly explained by the type of graft (muscle) that was used to separate the neurovascular structures.

Value of Partial Sensory Rhizotomy in the Microsurgical Treatment of Trigeminal Neuralgia Through Retrosigmoid Approach

Purpose

Microvascular decompression (MVD) is the most effective surgical procedure for the treatment of refractory primary trigeminal neuralgia (TN), but due to the presence of non-neurovascular compression (NVC), the application of MVD is limited. In some cases, partial sensory rhizotomy (PSR) is required. The purpose of this study was to compare the outcome of MVD and MVD+PSR in the treatment of primary TN and to evaluate the application value of PSR in the treatment of TN.

Patients and Methods

We retrospectively analyzed the postoperative outcomes of patients who received MVD or MVD+PSR for the first time from the same surgeon in the neurosurgery department of China-Japan Friendship Hospital from March 2009 to December 2017. A total of 105 patients were included in the data analysis, including 40 in the MVD group and 65 in the MVD+PSR group.

Results

The MVD group had an effectiveness rate of 60% and a recurrence rate of 31.4% after an average follow-up of 49.4 months. The MVD+PSR group had an average effectiveness rate of 69.2% and a recurrence rate of 28.6% after an average follow-up of 71.4 months. There was no statistically significant intergroup difference in long-term effectiveness (p=0.333) or recurrence rates (p=0.819). The incidence of facial numbness was significantly higher in the MVD+PSR group than in the MVD group (83.1% vs 7.5%; p<0.001). However, facial numbness had no significant effect on the patients’ daily life.

Conclusion

MVD+PSR and MVD have the same effectiveness in the treatment of primary TN. MVD+PSR is associated with a higher incidence of facial numbness than MVD, but the difference does not affect the patients’ daily life. PSR should have a place in the treatment of TN by posterior fossa microsurgery.

Dexmedetomidine Combined With Butorphanol or Sufentanil for the Prevention of Post-operative Nausea and Vomiting in Patients Undergoing Microvascular Decompression: A Randomized Controlled Trial

Background: Patients undergoing microvascular decompression are often accompanied with high risk of post-operative nausea and vomiting (PONV). In this study, we compare the antiemetic efficacy of butorphanol or sufentanil combined with dexmedetomidine in patients undergoing microvascular decompression.

Methods: Patients undergoing microvascular decompression were randomized into two groups. The primary outcome was the occurrence and severity of PONV during the 72 h after surgery. Secondary outcomes included levels of pain intensity and sedation and consumption of opioids at 1, 2, 6, 12, 24, 48, and 72 h after surgery. We also recorded the intraoperative hemodynamics, consumption of narcotic drugs, operation and anesthesia time, estimated blood loss, infusion volume and urine output, requirements of rescue antiemetics or analgesics, the satisfaction scores of patients and surgeons, complications, and length of stay.

Results: The overall incidence rates of nausea and vomiting during the 72 h after surgery were significantly reduced in group DB (76.00 and 44.00% in group DS vs. 54.17% and 22.92% in group DB, P < 0.05). Patients in group DB had a lower incidence of nausea than those in group DS at intervals of 1–6 and 6–24 h (P < 0.05). However, patients in group DB had a lower incidence of vomiting than those in group DS only at intervals of 1–6 h (P < 0.05). Similarly, the number of patients requiring rescue antiemetics was also significantly reduced in group DB compared with that in group DS at intervals of 1–6 h (P < 0.05). The number of patients experiencing moderate to severe PONV was comparable between the two groups during 72 h after surgery (P > 0.05). The consumption of opioid morphine equivalent was significantly reduced in group DB (P < 0.05). Compared with those in group DS, the satisfaction scores of both patients and surgeons were significantly increased in group DB (P < 0.05).

Conclusion: Butorphanol combined with dexmedetomidine could reduce early PONV and the number of patients requiring rescue antiemetics, especially at intervals of 1–6 h, while the satisfaction scores of both patients and surgeons were significantly increased.

Long-term pain outcomes in elderly patients with trigeminal neuralgia: comparison of first-time microvascular decompression and stereotactic radiosurgery

OBJECTIVE

Common surgical treatments for trigeminal neuralgia (TN) include microvascular decompression (MVD) and stereotactic radiosurgery (SRS). The use of MVD in elderly patients has been described but has yet to be prospectively compared to SRS, which is well-tolerated and noninvasive. The authors aimed to directly compare long-term pain control and adverse event rates for first-time surgical treatments for idiopathic TN in the elderly.

METHODS

A prospectively collected database was reviewed for TN patients who had undergone treatment between 1997 and 2017 at a single institution. Standardized collection of preoperative demographics, surgical procedure, and postoperative outcomes was performed. Data analysis was limited to patients over the age of 65 years who had undergone a first-time procedure for the treatment of idiopathic TN with at least 1 year of follow-up.

RESULTS

One hundred ninety-three patients meeting the study inclusion criteria underwent surgical procedures for TN during the study period (54 MVD, 24 MVD+Rhiz, 115 SRS). In patients in whom an artery was not compressing the trigeminal nerve during MVD, a partial sensory rhizotomy (MVD+Rhiz) was performed. Patients in the SRS cohort were older than those in the MVD and MVD+Rhiz cohorts (mean ± SD, 79.2 ± 7.8 vs 72.9 ± 5.7 and 70.9 ± 4.8 years, respectively; p < 0.0001) and had a higher mean Charlson Comorbidity Index (3.8 ± 1.1 vs 3.0 ± 0.9 and 2.9 ± 1.0, respectively; p < 0.0001). Immediate or short-term postoperative pain-free rates (Barrow Neurological Institute [BNI] pain intensity score I) were 98.1% for MVD, 95.8% for MVD+Rhiz, and 78.3% for SRS (p = 0.0008). At the last follow-up, 72.2% of MVD patients had a favorable outcome (BNI score I-IIIa) compared to 54.2% and 49.6% of MVD+Rhiz and SRS patients, respectively (p = 0.02). In total, 0 (0%) SRS, 5 (9.3%) MVD, and 1 (4.2%) MVD+Rhiz patients developed any adverse event. Multivariate Cox proportional hazards analysis demonstrated that procedure type (p = 0.001) and postprocedure sensory change (p = 0.003) were statistically significantly associated with pain control.

CONCLUSIONS

In this study cohort, patients who had undergone MVD had a statistically significantly longer duration of pain freedom than those who had undergone MVD+Rhiz or SRS as their first procedure. Fewer adverse events were seen after SRS, though the MVD-associated complication rate was comparable to published rates in younger patients. Overall, the results suggest that both MVD and SRS are effective options for the elderly, despite their advanced age. Treatment choice can be tailored to a patient's unique condition and wishes.

Comparison of Stereotactic Radiosurgery and Radiofrequency Ablation for Trigeminal Neuralgia in Multiple Sclerosis Patients

<b><i>Background:</i></b> The optimal treatment for medically refractory trigeminal neuralgia in multiple sclerosis (MS-TN) patients is unknown. <b><i>Objective:</i></b> To compare treatment outcomes between stereotactic radiosurgery (SRS) and radiofrequency ablation (RFA). <b><i>Methods:</i></b> We performed a retrospective study of MS-TN patients treated with SRS or RFA between 2002 and 2019. Outcomes included degree of pain relief, pain recurrence, and sensory changes, segregated based on initial treatment, final treatment following retreatment with the same modality, and crossover patients. <b><i>Results:</i></b> Sixty surgical cases for 42 MS-TN patients were reviewed. Initial pain freedom outcomes and rates of retreatment were similar (SRS: 30%; RFA: 42%). RFA resulted in faster onset of pain freedom (RFA: &#x3c;1 week; SRS: 15 weeks; <i>p</i> &#x3c; 0.001). SRS patients with pain relief had longer intervals to pain recurrence at 2 years (<i>p</i> = 0.044). Final treatment outcomes favored RFA for pain freedom/off-medication outcomes (RFA: 44%; SRS: 11%; <i>p</i> = 0.031), though RFA resulted in more paresthesia (RFA: 81%; SRS: 39%; <i>p</i> = 0.012). Both provided at least 80% of adequate pain relief. Crossover patients did not have improved pain relief. <b><i>Conclusions:</i></b> SRS and RFA are both valid surgical options for MS-TN. Discussion with providers will need to balance patient preference with their unique treatment characteristics.

Clinical efficacy of MVD combined with PSR in the treatment of primary trigeminal neuralgia

Clinical efficacy of microvascular decompression (MVD) combined with percutaneous stereotactic radiofrequency rhizotomy (PSR) in the treatment of primary trigeminal neuralgia was investigated. The medical records of 141 patients with primary trigeminal neuralgia admitted to Shandong Provincial Hospital from May 2011 to June 2013 were collected. Among them, 63 patients received MVD surgery and were set as group A, while the other 78 received MVD combined with PSR and were as group B. The efficacy and complication of the two treatment methods were compared. Multivariate logistic regression was performed to analyze the risk factors for treatment efficacy. The total effective rate was 96.15% in group B, higher than that in group A (88.89%), but the difference was not statistically significant (P>0.05). The complications in group B were statistically less than that in group A (P<0.05). Risk factors for the onset of primary trigeminal neuralgia included the degree of decompression, duration of disease, degree of compression, and clinical symptoms. Patients treated with MVD combined with PSR had a better quality of life and lower 5-year recurrence rate than patients treated with MVD (both P<0.05). In conclusion, MVD combined with PSR treatment has good clinical efficacy in primary trigeminal neuralgia and low incidence of complications. The possible risk factors for the onset of primary trigeminal neuralgia include the degree of decompression, duration of disease, degree of compression, and clinical symptoms.

Radiosurgery to the spinal dorsal root ganglion induces fibrosis and inhibits satellite glial cell activation while preserving axonal neurotransmission

OBJECTIVE

Stereotactic radiosurgery (SRS) has been used to treat trigeminal neuralgia by targeting the cisternal segment of the trigeminal nerve, which in turn triggers changes in the gasserian ganglion. In the lumbar spine, the dorsal root ganglion (DRG) is responsible for transmitting pain sensitivity and is involved in the pathogenesis of peripheral neuropathic pain. Therefore, radiosurgery to the DRG might improve chronic peripheral pain. This study evaluated the clinical and histological effects of high-dose radiosurgery to the DRG in a rodent model.

METHODS

Eight Sprague-Dawley rats received either 40- or 80-Gy SRS to the fifth and sixth lumbar DRGs using the Leksell Gamma Knife Icon. Animals were euthanized 3 months after treatment, and the lumbar spine was dissected and taken for analysis. Simple histology was used to assess collagen deposition and inflammatory response. GFAP, Neu-N, substance P, and internexin were used as a measure of peripheral glial activation, neurogenesis, pain-specific neurotransmission, and neurotransmission in general, respectively. The integrity of the spinothalamic tract was assessed by means of the von Frey test.

RESULTS

The animals did not exhibit any signs of motor or sensory deficits during the experimentation period. Edema, fibrosis, and vascular sclerotic changes were present on the treated, but not the control, side. SRS reduced the expression of GFAP without affecting the expression of Neu-N, substance P, or internexin. The von Frey sensory perception elicited equivalent results for the control side and both radiosurgical doses.

CONCLUSIONS

SRS did not alter sensory or motor function but reduced the activation of satellite glial cells, a pathway for DRG-mediated pain perpetuation. Radiosurgery provoked changes equivalent to the effects of focal radiation on the trigeminal ganglion after SRS for trigeminal neuralgia, suggesting that radiosurgery could be successful in relieving radiculopathic pain.

Efficacy and Safety of Percutaneous Ozone Injection Around Gasserian Ganglion for the Treatment of Trigeminal Neuralgia: A Multicenter Retrospective Study

Background

Ozone injection around Gasserian ganglion (OIAGG) has been reported to be an effective treatment for trigeminal neuralgia (TN); however, there remain areas for improvement. To overcome one of these limitations, a multicenter examination of application would be extremely helpful.

Objective

The goal of this report was to assess the efficacy of OIAGG for refractory TN across multiple centers and to explore factors predictive of successful treatment.

Design

A multicenter, retrospective study.

Setting

The study was conducted across 3 pain centers across China.

Patients and Methods

A total of 103 subjects from 3 pain centers were enrolled in the study. An ozone-oxygen mixture gas at a concentration of 30 µg/mL was injected into the area around the Gasserian ganglion performed under C-arm X-ray guidance. Primary outcome measures included a pain assessment using a visual analog scale (VAS) and the Barrow Neurological Institute (BNI) pain intensity scale. Clinical assessment of patients for these outcome measures was performed at pretreatment, post-treatment, 6 months, 1 year and 2 years after the OIAGG.

Results

Successful pain relief was defined as a score within BNI grades I–IIIa. The pain relief rates at post-treatment, 6 months, 1 year and 2 years after the procedure were 88.35%, 86.87%, 84.46% and 83.30%, respectively. The VAS at each observation time point was significantly different from the preoperative levels (P<0.05). Logistic regression analysis showed that previous nerve damage had a significant effect on the treatment results. No significant complications or side effects were found during or after treatment.

Conclusion

This multicenter research confirms our previous single center results that OIAGG is both effective and safe for patients with TN.

Predictors of the Analgesic Efficacy of CT-Guided Percutaneous Pulsed Radiofrequency Treatment of Gasserian Ganglion in Patients With Idiopathic Trigeminal Neuralgia

AIMS

Although pulsed radiofrequency (PRF) has few postoperative adverse reactions, its analgesic efficacy for trigeminal neuralgia (TN) is not always guaranteed. The response rate of PRF targeting the Gasserian ganglion for patients with TN varies. This study aims to identify the predictors of the analgesic efficacy of CT-guided percutaneous PRF in patients with idiopathic TN.

METHODS

The patients with idiopathic TN who failed to respond to conservative treatment and underwent CT-guided percutaneous PRF treatment of the Gasserian ganglion from July 2008 to August 2018 at our pain clinic were screened. A positive response was defined as a ≥50% reduction in the pain numeric rating scale (NRS) score from baseline. The demographics and other pretreatment clinical data were analyzed by logistic regression analysis to identify the predictors of a positive response.

RESULTS

Of the total 102 patients with idiopathic TN who were evaluated in this study, 57 patients (55.9%) were positively responsive to our treatment after 1 year. The binary logistic regression analysis revealed that the positive response to a prior peripheral branch nerve block of the trigeminal nerve with steroid and local anesthetic agents was an independent predictor of the analgesic efficacy of PRF treatment (odds ratio [OR] = 3.685, 95% confidence interval [CI] = 1.583 to 8.577, P = 0.002). The disease duration of TN was also included in the multivariate regression model, although the P value was 0.058 (OR 0.807, 95% CI 0.646 to 1.007).

CONCLUSION

For patients who previously had positive responses to peripheral branch nerve block of the trigeminal nerve, PRF is likely to have better efficacy.

Minimally Invasive Oral Surgery Induction of the FRICT-ION Chronic Neuropathic Pain Model

An easily induced preclinical trigeminal neuropathic nerve injury model is described here for the study of chronic pain, the model acronym FRICT-ION (Foramen Rotundum Inflammatory Constriction Trigeminal InfraOrbital Nerve). In patients, neuropathic pain is thought to be related to vascular alignment or multiple sclerosis along this small trigeminal nerve branch (V2) innervating the maxillary teeth and middle third of the face. With no detectable outward physical signs, the FRICT-ION model is ideal for blinded studies. The acronym FRICT-ION applied relates to the persistence of the trigeminal neuropathic pain model likely due to sliding irritation with normal chewing in the mice. A step-by-step method to induce the mild chronic rodent neuropathic pain model is described here. The surgery is performed orally through a tiny surgical slit inside the cheek crease to align a chromic gut suture irritant along the nerve as it passes into the skull. The model allows testing of non-evoked subjective measures and evoked quantitative mechanical hypersensitivity (allodynia) testing with von Frey filaments through at least 10-14 weeks (100 days). Anxiety and depression behaviors develop within 3-6 weeks relevant to the affective component of chronic pain. While many pain drugs have failed based on testing performed in the acute animal models available, the more stable and easily replicated trigeminal inflammatory compression model is the better suited for understanding both mechanistic and affective components of nerve injury-induced chronic neuropathic pain states as well as the more ideal for preclinical trials of novel non-opioid pain relief therapies.

Prospects of biological and synthetic pharmacotherapies for glioblastoma

Introduction: The field of neuro-oncology has experienced significant advances in recent years. More is known now about the molecular and genetic characteristics of glioma than ever before. This knowledge leads to the understanding of glioma biology and pathogenesis, guiding the development of targeted therapeutics and clinical trials. The goal of this review is to describe the state of basic, translational, and clinical research as it pertains to biological and synthetic pharmacotherapy for gliomas.Areas covered: Challenges remain in designing accurate preclinical models and identifying patients that are likely to respond to a particular targeted therapy. Preclinical models for therapeutic assessment are critical to identify the most promising treatment approaches.Expert opinion: Despite promising new therapeutics, there have been no significant breakthroughs in glioma treatment and patient outcomes. Thus, there is an urgent need to better understand the mechanisms of treatment resistance and to design effective clinical trials.

The Long-Term Outcomes and Predictors of Microvascular Decompression with or without Partial Sensory Rhizotomy for Trigeminal Neuralgia

Purpose

Microvascular decompression (MVD) and MVD combined with partial sensory rhizotomy (PSR) are effective surgical treatments for idiopathic trigeminal neuralgia (TN). The aim of this study was to compare the long-term outcomes of both MVD and MVD+PSR for the treatment of TN and to identify the factors that may influence the long-term outcomes after MVD or MVD+PSR.

Patients and Methods

From March 2009 to December 2017, 99 patients with idiopathic TN who underwent MVD or MVD+PSR in our hospital (40 MVD, 59 MVD+PSR) were included in the study. The indications for MVD+PSR were as follows: vessels only contacted the nerve root, absence of arterial conflict, or failing to completely decompress from the arteries or veins. All patients were treated by one neurosurgeon and were followed up for at least 1 year. The outcomes were assessed with the Barrow Neurological Institute (BNI) Pain Intensity Scale.

Results

The average follow-up duration was 63.0 months (range, 13.2-118.8 months). Patients in the MVD group were younger than those in the MVD+PSR group (55.1 years and 60.5 years, respectively, P=0.012). A total of 62.5% of the patients in the MVD group and 69.5% of the patients in the MVD+PSR group had favorable long-term outcomes. The Kaplan-Meier survival analysis showed no significant difference in long-term outcomes between the two groups (P=0.202). No factors were associated with long-term outcomes after MVD. For MVD+PSR, a long duration of the disease (odds ratio (OR) 6.967, P=0.016) was associated with unfavorable long-term outcomes, whereas pure arterial compression (OR 0.131, P=0.013) was associated with favorable long-term outcomes.

Conclusion

For patients who are not suitable to undergo pure MVD, MVD+PSR can be used as an effective alternative. For MVD+PSR, patients with a long duration of symptoms may have poor long-term outcomes, while patients with pure arterial compression may have favorable long-term outcomes.