The long-term outcome of microvascular decompression for trigeminal neuralgia

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.

Preoperative Opioid Use and Postoperative Outcomes in Patients Undergoing Microvascular Decompression for Trigeminal Neuralgia

BACKGROUND AND OBJECTIVES

The prescription of opioid analgesics for trigeminal neuralgia (TN) is controversial, and their effect on postoperative outcomes for patients with TN undergoing microvascular decompression (MVD) has not been reported. We aimed to describe the relationship between preoperative opioid use and postoperative outcomes in patients with TN undergoing MVD.

METHODS

We reviewed the records of 920 patients with TN at our institution who underwent an MVD between 2007 and 2020. Patients were sorted into 2 groups based on preoperative opioid usage. Demographic information, comorbidities, characteristics of TN, preoperative medications, pain and numbness outcomes, and recurrence data were recorded and compared between groups. Multivariate ordinal regression, Kaplan-Meier survival analysis, and Cox proportional hazards were used to assess differences in pain outcomes between groups.

RESULTS

One hundred and forty-five (15.8%) patients in this study used opioids preoperatively. Patients who used opioids preoperatively were younger ( P = .04), were more likely to have a smoking history ( P < .001), experienced greater pain in modified Barrow Neurological Institute pain score at final follow-up ( P = .001), and were more likely to experience pain recurrence ( P = .01). In addition, patients who used opioids preoperatively were more likely to also have been prescribed TN medications including muscle relaxants and antidepressants preoperatively ( P < .001 and P < .001, respectively). On multivariate regression, opioid use was an independent risk factor for greater postoperative pain at final follow-up ( P = .006) after controlling for variables including female sex and age. Opioid use was associated with shorter time to pain recurrence on Kaplan-Meier analysis ( P = .005) and was associated with increased risk for recurrence on Cox proportional hazards regression ( P = .008).

CONCLUSION

Preoperative opioid use in the setting of TN is associated with worse pain outcomes and increased risk for pain recurrence after MVD. These results indicate that opioids should be prescribed cautiously for TN and that worse post-MVD outcomes may occur in patients using opioids preoperatively.

Trigeminal and Glossopharyngeal Neuralgia

Trigeminal neuralgia and glossopharyngeal neuralgia are craniofacial pain syndromes characterized by recurrent brief shock-like pains in the distributions of their respective cranial nerves. In this article, the authors aim to summarize each condition's characteristics, pathophysiology, and current pharmacotherapeutic and surgical interventions available for managing and treating these conditions.

Bibliometric Analysis of the Top 100 Cited Articles and Author H-Indexes on the Surgical Treatment of Trigeminal Neuralgia

INTRODUCTION

Medically refractory cases of trigeminal neuralgia often require treatment escalation. Surgical options include microvascular decompression and percutaneous ablation. This paper provides a bibliometric analysis of the most influential articles on the surgical management of trigeminal neuralgia.

METHODS

The Web of Science database was queried to identify the top 100 cited articles concerning surgical treatment of trigeminal neuralgia. The search terms used included ALL=(("trigeminal neuralgia" OR "tic douloureux" OR "Fothergill's disease" OR "Trifacial neuralgia") AND ("surgical treatment" OR "surgical management" OR "surgery" OR "neurosurgery") NOT ("radiosurgery" OR "gamma knife")). The extracted variables included the first and senior author names, journal, publication year, institution, and surgical modality.

RESULTS

Our bibliometric search yielded 2104 studies, with 41,502 citations overall. Within the top 100 articles, Zakrzewska had the most first author papers (n = 5), and Burchiel had the most senior author papers (n = 6). The Massachusetts General Hospital was the most represented institution (n = 5). The United States was the most represented country (51%). Microvascular decompression was the most studied surgical strategy (51%), followed by percutaneous radiofrequency coagulation (9%), balloon/nerve compression (7%), and glycerol rhizolysis (7%). Some studies assessed multiple treatment modalities (22%). The types of studies included retrospective articles (58%), prospective articles (26%), reviews (10%), anatomic studies (2%), and basic science (1%). Neurosurgery (35%) and the Journal of Neurosurgery (33%) were the most represented journals.

CONCLUSIONS

The current literature consists of retrospective reviews and mostly describes microvascular decompression for trigeminal neuralgia. Future studies should include further characterization of other surgical modalities such as percutaneous radiofrequency thermocoagulation, glycerol injection, and balloon compression.

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.

Proteomic Analysis to Identify Prospective Biomarkers of Treatment Outcome After Microvascular Decompression for Trigeminal Neuralgia: A Preliminary Study

Trigeminal neuralgia (TN) is a severe neuropathic facial pain disorder, often caused by vascular or neuronal compression of the trigeminal nerve. In such cases, microvascular decompression (MVD) surgery can be used to treat TN, but pain relief is not guaranteed. The molecular mechanisms that affect treatment response to MVD are not well understood. In this exploratory study, we performed label-free quantitative proteomic profiling of plasma and cerebrospinal fluid samples from patients undergoing MVD for TN, then compared the proteomic profiles of patients graded as responders (n = 7) versus non-responders (n = 9). We quantified 1,090 proteins in plasma and 1,087 proteins in the cerebrospinal fluid, of which 12 were differentially regulated in the same direction in both sample types. Functional analyses of differentially regulated proteins in protein-protein interaction networks suggested pathways of the immune system, axon guidance, and cellular stress response to be associated with response to MVD. These findings suggest potential biomarkers of response to MVD, as well as possible mechanisms of variable treatment success in TN patients. PERSPECTIVE: This exploratory study evaluates proteomic profiles in plasma and cerebrospinal fluid of patients undergoing microvascular decompression surgery for trigeminal neuralgia. Differential expression of proteins between surgery responders versus non-responders may serve as biomarkers to predict surgical success and provide insight into surgical mechanisms of pain relief in trigeminal neuralgia.

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

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

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.

The role of artificial intelligence in the management of trigeminal neuralgia

Trigeminal neuralgia (TN) is the most frequent facial pain. It is difficult to treat pharmacologically and a significant amount of patients can become drug-resistant requiring surgical intervention. From an etiologically point of view TN can be distinguished in a classic form, usually due to a neurovascular conflict, a secondary form (for example related to multiple sclerosis or a cerebello-pontine angle tumor) and an idiopathic form in which no anatomical cause is identifiable. Despite numerous efforts to treat TN, many patients experience recurrence after multiple operations. This fact reflects our incomplete understanding of TN pathogenesis. Artificial intelligence (AI) uses computer technology to develop systems for extension of human intelligence. In the last few years, it has been a widespread of AI in different areas of medicine to implement diagnostic accuracy, treatment selection and even drug production. The aim of this mini-review is to provide an up to date of the state-of-art of AI applications in TN diagnosis and management.

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.

Minimally Invasive Retrosigmoidal Parasterional Burr-Hole Approach: Technique and Neuropathic Pain Amelioration after Microvascular Decompression of the Trigeminal Nerve

BACKGROUND

Trigeminal neuralgia, a common condition in clinical practice, often occurs due to vascular compression caused by aberrant or ectopic arterial or venous vessels. Microvascular decompression through a minimally invasive retrosigmoidal approach has shown high rates of pain control, low complication rates, and excellent therapeutic results.

OBJECTIVE

To describe the surgical technique and clinical outcomes in terms of pain relief after microvascular decompression of the trigeminal nerve through a minimally invasive retrosigmoidal parasterional burr-hole technique.

METHODS

A group of patients with trigeminal neuralgia refractory to medical management who underwent microvascular decompression were examined. The records of the patients were considered retrospectively (2016-2018), and the outcomes were considered based on the Visual Analogue Scale (VAS) and the Barrow Neurological Institute Pain Scale (BNIPS) added to a technical note of the surgical technique for a minimally invasive retrosigmoidal parasterional burr-hole.

RESULTS

Twenty-two patients were evaluated, and clinical assessment after surgical intervention showed a decrease in pain according to the VAS, resulting from an average preoperative state of 9.5 ± 0.37 to a postoperative condition of 1.32 ± 1.28, exhibiting statistically significant changes (p < 0.0001, d = 9.356). On the other hand, in relation to the BNIPS scale, a decrease from an average preoperative status of 4.55 ± 0.25 to a postoperative status at 12 months of 1.73 ± 0.54 was also demonstrated, showing significant changes (p < 0.0001, d = 3.960).

CONCLUSION

Microvascular decompression of the trigeminal nerve through a minimally invasive retrosigmoidal parasterional burr-hole is feasible and can be a safe and effective technique for the management of pain. However, further research employing larger sample sizes and longer follow-up periods is necessary.

Objectively-captured Changes in Trigeminal Fibers before and after Microvascular Decompression Using 3D T2-SPACE MRI Might Relate to Eventual Residual Symptoms

Although microvascular decompression (MVD) is a reliable treatment for trigeminal neuralgia (TN), neurosurgeons sometimes encounter patients whose symptoms do not improve postoperatively or who experience good treatment efficacy but develop other sensory disturbances. This study aims to objectively identify changes in nerve fibers before and after surgery by MRI and to clarify the relationship between the changes and residual postoperative symptoms. We retrospectively analyzed data from 36 consecutive patients who underwent MVD for classical TN at our hospital between November 2019 and November 2020. Cases that fulfilled the diagnostic criteria for multiple sclerosis were excluded. We confirmed the changes on the brainstem side of the trigeminal nerve preoperatively and at seven days postoperatively using 3D T2-SPACE MRI, in which the patients were divided into three groups: preoperative T2 high intensity positive (A), postoperative T2 high intensity positive (B), and no T2 high-intensity region (C). The primary outcome measures were therapeutic efficacy and frequency of postoperative numbness. The results of MVD surgery were evaluated one year postoperatively. The percentage of cases in which treatment outcomes were rated as excellent or good at one year: group A: 0 (0%), group B: 6 (100%), and group C: 25 (96.2%) (p < 0.05); the frequency of numbness: 2 (50%) in group A, 3 (50%) in group B, and 1 (3.8%) in group C, indicating significant differences between the three groups (p < 0.05). 3D T2-SPACE MRI sequences can be used to identify changes in trigeminal nerve fibers before and after MVD, which might correlate with eventual residual symptoms.

Sacrifice or preserve the superior petrosal vein in microvascular decompression surgery: a systematic review and meta-analysis

OBJECTIVE

In microvascular decompression (MVD) surgery through the retrosigmoid approach, the surgeon may have to sacrifice the superior petrosal vein (SPV). However, this is a controversial maneuver. To date, high-level evidence comparing the operative outcomes of patients who underwent MVD with and without SPV sacrifice is lacking. Therefore, this study sought to bridge this gap.

METHODS

The authors searched the Medline and PubMed databases with appropriate Medical Subject Heading (MeSH) terms and keywords. The primary outcome was vascular-related complications; secondary outcomes were new neurological deficit, cerebrospinal fluid (CSF) leak, and neuralgia relief. The pooled proportions of outcomes and OR (95% CI) for categorical data were calculated by using the logit transformation and Mantel-Haenszel methods, respectively.

RESULTS

Six studies yielding 1143 patients were included, of which 618 patients had their SPV sacrificed. The pooled proportion (95% CI) values were 3.82 (0.87-15.17) for vascular-related complications, 3.64 (1.0-12.42) for new neurological deficits, 2.85 (1.21-6.58) for CSF leaks, and 88.90 (84.90-91.94) for neuralgia relief. The meta-analysis concluded that, whether the surgeon sacrificed or preserved the SPV, the odds were similar for vascular-related complications (2.5% vs 1.5%, OR [95% CI] 1.01 [0.33-3.09], p = 0.99), new neurological deficits (1.2% vs 2.8%, OR [95% CI] 0.55 [0.18-1.66], p = 0.29), CSF leak (3.1% vs 2.1%, OR [95% CI] 1.16 [0.46-2.94], p = 0.75), and neuralgia relief (86.6% vs 87%, OR [95% CI] 0.96 [0.62-1.49], p = 0.84).

CONCLUSIONS

SPV sacrifice is as safe as SPV preservation. The authors recommend intentional SPV sacrifice when gentle retraction fails to enhance surgical field visualization and if the surgeon encounters SPV-related neurovascular conflict and/or anticipates impeding SPV-related bleeding.

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.

Efficacy and complications of microvascular decompression in patients over 70 years with trigeminal neuralgia

OBJECTIVE

Treatment of choice for trigeminal neuralgia (TN) by neurovascular conflict in case of failure of medical treatment is microvascular decompression (MVD). It is a safe and effective technique in the short and long term. But what about older patients who are considered more fragile anesthetically and surgically? Our Objective is to demonstrate the efficacy and complication rate of microvascular decompression (MVD) for older and younger patients with trigeminal neuralgia (TN) due to neurovascular conflict.

METHODS

102 patients with TN due to neurovascular conflict were included (June 2005-December 2016) in a single Regional hospital. 25 were included in the group composed of ≥ 70-year-old patients (G1), while 77 were included in the < 70-year-old group (G2). The patients were operated on by the same surgical team using a retro-sigmoid approach to access the neurovascular conflict. The epidemiologic, clinical, anesthetic, and surgical data were extracted.

RESULTS

The immediate efficacy of surgical treatment (BNI pain intensity = I) was 96% in G1 and 96.10% in the G2 group (p = 0.71). At 3-year follow-up, the efficacy rate was 89% and 86%, respectively (p = 0.93). At 5 years, it was 92% and 92% (p = 0.98). Complication rates were comparable between the two groups (20% versus 27%; p = 0.47) and no deaths occurred despite the fact that G1 group had worst preoperative anesthetic score (ASA-NYHA).

CONCLUSION

MVD is a durable procedure in patients over 70 years of age diagnosed with essential TN. The complication rate and immediate-, medium-, and long-term efficacy were similar to those of younger patients.

Autologous conditioned serum (Orthokine) injection for treatment of classical trigeminal neuralgia: results of a single-center case series

BACKGROUND

Despite some advances, treatment of trigeminal neuralgia remains a significant challenge. This study determines the efficacy and safety of autologous conditioned serum (Orthokine) injection into the foramen oval to treat refractory trigeminal neuralgia.

CASE PRESENTATION

This is a consecutive case series from the Pain and Palliative Care Department of Imam Reza University Hospital, Tabriz, Iran. Eleven Iranian patients, eligible according to the inclusion and exclusion criteria, aged 45.64 ± 11.58 years (Four male and seven female, all Iranian) with established classical trigeminal neuralgia were injected with Orthokine (2 mL per injection) once a week for three consecutive weeks (total of four injections). Numeric rating scale scores for facial pain intensity and also carbamazepine daily dose were confirmed at pretreatment (T0) and at week 1 (T1), week 2 (T2), week 3 (T3), week 4 (T4), and month 2 (T5) posttreatment. Pain intensity was significantly reduced in the first 3 weeks of follow-up in comparison with baseline (T0 to T3) (8.18 ± 1.99 to 2.82 ± 2.13, p < 0.001), an effect that was retained at week 4 (T4) and month 2 (T5) follow-ups (2.82 ± 2.13 to 3.36 ± 2.69, p = 0.886). Carbamazepine consumption was significantly reduced in the first 3 weeks of follow-up in comparison with baseline (T0 to T3) (636.36 ± 307.48 to 200.00 ± 296.64, p = 0.003), an effect that was retained at week 4 and month 2 follow-ups (200.00 ± 296.64 to 200.00 ± 282.84, p = 0.802). There were no serious adverse events in participants.

CONCLUSION

Orthokine injection led to consistent pain relief and reduced carbamazepine dosage in patients with trigeminal neuralgia, with acceptable safety.

Multidata Analysis Based on an Artificial Neural Network Model for Long-Term Pain Outcome and Key Predictors of Microvascular Decompression in Trigeminal Neuralgia

OBJECTIVE

To investigate use of multidata analysis based on an artificial neural network (ANN) to predict long-term pain outcomes after microvascular decompression (MVD) in patients with trigeminal neuralgia (TN) and to explore key predictors.

METHODS

Perioperative and long-term follow-up multidata of 1041 patients with TN who received MVD surgery at Hangzhou First People's Hospital from March 2013 to May 2018 were collected to construct an ANN model for prediction. The prediction results were compared with the actual follow-up outcomes, and the variables in each input layer were changed to test the effectiveness of ANN and explore the factors that had the greatest impact on prediction accuracy.

RESULTS

The ANN model could predict the long-term pain outcomes after MVD in patients with TN with an accuracy rate of 95.2% and area under the curve of 0.862. Four factors contributed the most to the predictive performance of the ANN: whether the neurovascular offending site of the trigeminal nerve corresponded the region of facial pain, immediate postoperative pain remission after MVD, degree of nerve compression by culprit vessels, and the type of culprit vessels. After these factors were sequentially removed, the accuracy of the ANN model decreased to 74.5%, 78.6%, 87.2%, and 90.1%, while the area under the curve was 0.705, 0.761, 0.793, and 0.810.

CONCLUSIONS

The ANN model, constructed using multiple data, predicted long-term pain prognosis after MVD in patients with TN objectively and accurately. The model was able to assess the importance of each factor in the prediction of pain outcome.

Microvascular decompression for pediatric onset trigeminal neuralgia: patterns and variation

OBJECTIVES

Pediatric trigeminal neuralgia has been rarely reported in the literature, which were only 28 cases. Although microvascular decompression (MVD) has been widely accepted as effective therapy for trigeminal neuralgia, the etiology and surgical treatment of pediatric ones are seldom addressed. We report our experience with MVD for pediatric trigeminal neuralgia patients with emphasis on the vascular conflict patterns and surgical skills.

METHODS

This retrospective report included 11 pediatric TN patients, who underwent MVD and were followed for 3-86 months. The data were retrospectively analyzed with emphasis on the clinical features.

RESULTS

This series included 4 boys and 7 girls with average age of 13 ± 3.4 years old, their onset age were from 7 to 18 years old. The singular vein and combined artery/vein conflictions account for 7/11. 9 (81.8%) patients achieved immediate excellent outcomes. One recurrence was observed after 5 months and refused the second surgery.

CONCLUSIONS

The etiology of pediatric onset trigeminal neuralgia is still vascular conflict, whose patterns are different from adults, of which combined artery/vein and singular venous compression patterns have a much more higher proportion. Because of the smaller operative space and fragile-thin venous wall with adhesion to other structures, it is much more difficult to decompress the trigeminal nerve among pediatric patients. Sufficient arachnoid release, full exploration, and decompression along the trigeminal nerve were necessary, which will increase the excellent rate among pediatric patients.

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.

Teflon Granuloma: A Common Cause of Recurrent Trigeminal Neuralgia

BACKGROUND

Trigeminal neuralgia (TN) is a common pain syndrome of the nervous system,. Although about 90% patients who were refractory to medications could be free from pain after microvascular decompression (MVD), some patients did experience recurrence. The study aimed to analyze clinical characteristics of patients with recurrent TN, recurrence factors of TN, and prognosis after re-do MVD.

METHODS

Clinical data and at least 12 months follow-up of patients with recurrent TN who underwent re-do MVD in our hospital from 2005 to 2020 were collected and analyzed.

RESULTS

A total of 14 patients with recurrent TN were enrolled eventually; adhesive arachnoid membranes were found in all patients. Teflon granuloma was found in 10 patients, new neurovascular compression (NVC) in 3 patients, and vascular displacement in 1 patient. Pain disappeared in 12 patients and relieved in 2 patients, but 4 patients experienced mild facial numbness and 1 patient suffered from incision infection after re-do MVC. No serious surgery-related complications and pain recurrences were recorded.

CONCLUSIONS

Teflon granuloma was the most common cause of TN recurrence in current study, new NVC was also saw in some patients. Patients with recurrent TN could get satisfactory results from re-do MVD.

Chinese expert consensus on minimally invasive interventional treatment of trigeminal neuralgia

BACKGROUND AND PURPOSE

Trigeminal neuralgia is a common condition that is associated with severe pain, which seriously affects the quality of life of patients. When the efficacy of drugs is not satisfactory or adverse drug reactions cannot be tolerated, minimally invasive interventional therapy has become an important treatment because of its simple operation, low risk, high repeatability and low cost. In recent years, minimally invasive interventional treatments, such as radiofrequency thermocoagulation (RF) of the trigeminal nerve and percutaneous microcompression (PMC), have been widely used in the clinic to relieve severe pain in many patients, however, some related problems remain to be addressed. The Pain Association of the Chinese Medical Association organizes and compiles the consensus of Chinese experts to standardize the development of minimally invasive interventional treatment of trigeminal neuralgia to provide a basis for its clinical promotion and application.

MATERIALS AND METHODS

The Pain Association of the Chinese Medical Association organizes the Chinese experts to compile a consensus. With reference to the evidence-based medicine (OCEBM) system and the actual situation of the profession, the Consensus Development Committee adopts the nominal group method to adjust the recommended level.

RESULTS

Precise imaging positioning and guidance are the keys to ensuring the efficacy and safety of the procedures. RF and PMC are the most widely performed and effective treatments among minimally invasive interventional treatments for trigeminal neuralgia.

CONCLUSIONS

The pain degree of trigeminal neuralgia is severe, and a variety of minimally invasive intervention methods can effectively improve symptoms. Radiofrequency and percutaneous microcompression may be the first choice for minimally invasive interventional therapy.

A Systematic Review of Repeat Microvascular Decompression for Recurrent or Persistent Trigeminal Neuralgia

OBJECTIVE

When conservative therapy fails, microvascular decompression (MVD) has been the preferred treatment of primary trigeminal neuralgia (TN). However, the management of recurrent or persistent TN after MVD can often be difficult. The purpose of the present systematic review was to objectively analyze and summarize the reported literature regarding the feasibility of repeat MVD.

METHODS

We conducted a database search using the MEDLINE and PubMed databases until July 2020. The search terms used for title and abstract screening were as follows: "recurrent trigeminal neuralgia," "persistent trigeminal neuralgia," "repeat microvascular decompression," and "reexploration." The inclusion criteria for the systematic review were as follows: clinical studies (excluding case studies), repeat MVD treatment of TN, and studies that had recorded the pain relief outcomes, operative findings, and complications (if any).

RESULTS

Of the 1771 initial results obtained, we performed a full text screening of 43 studies, and, ultimately, 19 were deemed eligible. A total of 2247 patients had undergone MVD for TN, of whom, 311 had experienced recurrence (13.84%). Of the 311 patients, 178 had undergone repeat MVD. The average pain-free interval was 27.75 months after the first MVD. The effective rate of repeat MVD was 91.66%, and 71.48% of the patients had had obvious compression found at repeat MVD. The postoperative complication rate after repeat MVD was 37.31% and was due to postoperative adhesions around the nerve and nerve injury caused by partial sensory rhizotomy. The most common complication after repeat MVD was facial numbness (21.89%), although the incidence of other complications was <5%.

CONCLUSIONS

For patients with recurrent or persistent pain after MVD, the findings from our systematic review support that repeat MVD remains a feasible treatment for recurrent or persistent TN.

Microvascular decompression in trigeminal neuralgia: predictors of pain relief, complication avoidance, and lessons learned

OBJECTIVE

To analyze characteristics associated with long-term pain relief after microvascular decompression (MVD) for trigeminal neuralgia (TGN). Description of associated morbidity and complication avoidance.

METHODS

One hundred sixty-five patients with TGN underwent 171 MVD surgeries at the authors' institution. Patient characteristics and magnetic resonance imaging (MRI) datasets were obtained through the hospital's archiving system. Patients provided information about pre- and post-operative pain characteristics and neurologic outcome. Favorable outcome was defined as a Barrow Neurological Institute (BNI) pain intensity score of I to III with post-operative improvement of I grade.

RESULTS

Type of TGN pain with purely paroxysmal pain (p = 0.0202*) and TGN classification with classical TGN (p = 0.0372*) were the only significant predictors for long-term pain relief. Immediate pain relief occurred in 90.6% of patients with a recurrence rate of 39.4% after 3.5 ± 4.6 years. MRI reporting of a neurovascular conflict had a low negative predictive value of 39.6%. Mortality was 0% with major complications observed in 8.2% of patients. Older age was associated with lower complication rates (p = 0.0009***). Re-MVD surgeries showed improved long-term pain relief in four out of five cases.

CONCLUSIONS

MVD is a safe and effective procedure even in the elderly. It has the unique potential to cure TGN if performed on a regular basis, and if key surgical steps are respected. Early MVD should be offered in case of medical treatment failure and paroxysmal pain symptoms. The presence of a neurovascular conflict on MRI is not mandatory. In case of recurrence, re-MVD is a good treatment option that should be discussed with patients.

HIGHLIGHTS

• Long-term analysis of pain relief after MVD. • Positive predictors for outcome: classical TGN and purely paroxysmal pain. • Presence of neurovascular conflict in MRI is not mandatory for MVD surgery. • Analysis of complications and surgical nuances for avoidance. • MVD is a safe procedure also in the elderly.

Comparison of Prognostic Scoring Systems to Predict Durable Pain Relief After Microvascular Decompression for Trigeminal Neuralgia

BACKGROUND

Microvascular decompression (MVD) is an effective treatment for trigeminal neuralgia, but pain recurs in a substantial minority of patients. Two recently published scoring systems by Hardaway et al. and Panczykowski et al. use simple preoperative clinical and imaging features to predict durable pain relief following MVD, but their predictive performance has not been independently validated. This study aimed to compare predictive performance of the Hardaway et al. score (HS) and Panczykowski et al. score (PS) for 1-year, 3-year, and long-term pain-free outcomes after MVD for trigeminal neuralgia.

METHODS

HS and PS were computed for a retrospective, single-institution cohort of 68 patients with trigeminal neuralgia who underwent MVD. Primary outcome was pain recurrence after MVD. Predictive performance of HSs and PSs was evaluated with area under the curve sensitivity analysis and regression models for survival analyses at 1 year, 3 years, and last follow-up.

RESULTS

Area under the curve for predicting pain-free outcome was higher for PS versus HS at 1 year (0.873 vs. 0.775) and 3 years (0.793 vs. 0.704). Cox proportional hazard models showed that PS better predicted long-term pain-free outcomes compared with HS (P < 0.05). One-year pain-free outcome was best predicted by pain type; longer-term outcomes were better predicted by presence and degree of neurovascular compression on preoperative imaging.

CONCLUSIONS

PS is superior to HS in predicting pain-free outcomes after MVD, which may aid in patient selection and counseling. Overall, more significant neurovascular compression of the trigeminal nerve root, and to a lesser extent classical paroxysmal pain, are good predictors of durable pain relief after MVD.

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.

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.

Does the Surgical Intervention for Trigeminal Neuralgia Refractory to Pharmacotherapy Improve Quality-of-Life? - A Systematic Review

PURPOSE

Trigeminal neuralgia (TN) refractory to pharmacotherapy requires surgical interventions which vary from percutaneous procedure to microvascular decompression (MVD). The aim of the systematic review is to find evidence for the surgical treatment for TN with high success rate and low complications which improves the quality-of-life (QOL).

METHODS

A systematic literature search was made on published studies from MEDLINE, SCOPUS, Science direct, and Cochrane Library databases that report the available surgical treatment for TN up to March 2020 and studies referred in the selected papers. Relevant studies were selected based on predefined eligibility criteria. The primary outcome measured was success rate, pain relief and secondary outcome measured was QOL, recurrence and complication rate.

RESULTS

Ten studies with a sum of 11,154 individuals were included in this qualitative analysis. Seven studies compared MVD whereas 4 studies compared Gamma knife radiosurgery with other techniques like percutaneous balloon compression, percutaneous glycerol rhizotomy etc. The result showed that MVD has a considerable higher rate of initial pain-free outcomes (96.6%) followed by Gamma knife radiosurgery (96.2%), cryotherapy (95.4%), percutaneous balloon compression (87%), percutaneous glycerol rhizotomy (85%) and the lowest rate of cohorts who were never pain-free (1.7%).QOL was improved to 100% as a result of pain relief which was evaluated in only 2 studies . Overall the recurrence rate was 0.45 to 52%. MVD has lower rate of long-term recurrence 0.45 and 6.1% for 2 years and 8 years, respectively, and cryotherapy has the highest rate of 52% at 6 months.

CONCLUSION

Outcomes of the literature search showed that it lacks the knowledge to generally support 1 or the other treatment. Each type of TN requires individualized protocols to treat based on pain response which ultimately improve the QOL. We also propose there should be more reliable data reporting by using a universally acceptable pain scale for better analysis of treatment outcome.

Microvascular decompression for trigeminal neuralgia in the elderly: efficacy and safety

OBJECTIVE

The safety and efficacy of surgical microvascular decompression (MVD) in elderly patients with trigeminal neuralgia (TN) is controversially discussed in the literature. A widespread reluctance to expose this cohort to major intracranial surgery persists. Our aim was to compare the efficacy and safety between older and younger patients with TN.

METHODS

In this cross-sectional study, 139 MVD procedures (103 patients < 70 and 36 patients ≥ 70) were included. Surgical fitness was assessed by the American Society of Anesthesiology (ASA) grade. The pain-free interval was evaluated using Kaplan-Meier analysis only in patients with a recent follow-up visit. Independent risk factors for recurrence in patients with a minimum 12-month follow-up were determined.

RESULTS

Patients ≥ 70 showed a significantly higher number of comorbidities. Pain intensity, affection of trigeminal branches and symptom duration was similar between groups. No significant difference in treatment associated complications and permanent neurological deficits was shown. There was no treatment-related mortality. A tendency towards a lower recurrence rate in patients < 70 did not reach statistical significance (17.6% vs. 28.6%, P = 0.274). Pain-free interval was not different between both cohorts (78.7 vs. 73.5 months, P = 0.391).

CONCLUSION

Despite a higher prevalence of comorbidities in elderly patients, complication rates and neurological deficits after MVD were comparable to younger patients. Rates of immediate and long-term pain relief compared favorably to previous studies and were similar between elderly and younger patients. These data endorse MVD as a safe and effective first-line surgical procedure for elderly patients with TN and neurovascular conflict on MRI.

Outcomes of Treatment for Elderly Patients With Trigeminal Neuralgia: Percutaneous Balloon Compression Versus Microvascular Decompression

OBJECTIVE

The study aimed to evaluate the surgical outcomes of percutaneous balloon compression (PBC) and microvascular decompression (MVD) in the treatment of elderly patients with trigeminal neuralgia (TN).

METHODS

A total of 30 patients who underwent PBC surgery (PBC group) and 30 patients who received MVD surgery (MVD group) were included. The treatment efficacy, Barrow Neurological Institute (BNI) pain intensity score, inflammatory response, the rates of complication and recurrence were analyzed respectively.

RESULTS

The total efficacy was 93.33% in the PBC group and 90.00% in the MVD group (P > 0.05), respectively. The pain relief rate was 90.00% and 86.67% after PBC and MVD surgery, respectively (P > 0.05). The levels of IL-1β, TNF-α, and IL-6 were significantly decreased at post-operative 3 days and 5 days compared with pre-operation in the 2 groups (P < 0.05). The post-operative complication rates regarding masticatory muscle weakness and facial numbness in the PBC group were higher than MVD group (P < 0.05). Nevertheless, the incidences of herpes simplex and keratohelcosis were similar between the 2 groups (P > 0.05). The recurrence rates were also similar between the 3 groups (P > 0.05).

CONCLUSION

Percutaneous balloon compression and MVD are effective in the treatment for elderly TN, which can effectively improve the post-operative cure rate of pain prognosis and reduce the inflammatory response. However, PBC is a minimally invasive, safe and effective method for patients in poor general condition and refused treatment with craniotomy.

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.

Clinical Outcome of Percutaneous Trigeminal Nerve Block in Elderly Patients in Outpatient Clinics

Objective

Trigeminal neuralgia (TN) is a severe neuropathic condition that affects several elderly patients. It is characterized by uncontrolled pain that significantly impacts the quality of life of patients. Therefore, the condition should be treated as an emergency. In the majority of patients, pain can be controlled with medication; however, other treatment modalities are being explored in those who become refractory to drug treatment. The use of the trigeminal nerve block with a local anesthetic serves as an excellent adjunct to drug treatment. This technique rapidly relieves the patient of pain while medications are being titrated to effective levels. We report the efficacy and safety of percutaneous trigeminal nerve block in elderly patients with TN at our outpatient clinic.

Methods

Twenty-one patients older than 65 years with TN received percutaneous nerve block at our outpatient clinic. We used bupivacaine (1 mL/injection site) to block the supraorbital, infraorbital, superior alveolar, mental, and inferior alveolar nerves according to pain sites of patients.

Results

All patients reported relief from pain, which decreased by approximately 78% after 2 weeks of nerve block. The effect lasted for more than 4 weeks in 12 patients and for 6 weeks in two patients. There were no complications.

Conclusion

Percutaneous nerve block procedure performed at our outpatient clinic provided immediate relief from pain to elderly patients with TN. The procedure is simple, has no serious side effects, and is easy to apply.

Diffusion tensor imaging reveals microstructural differences between subtypes of trigeminal neuralgia

OBJECTIVE

Trigeminal neuralgia (TN) is an uncommon idiopathic facial pain syndrome. To assist in diagnosis, treatment, and research, TN is often classified as type 1 (TN1) when pain is primarily paroxysmal and episodic or type 2 (TN2) when pain is primarily constant in character. Recently, diffusion tensor imaging (DTI) has revealed microstructural changes in the symptomatic trigeminal root and root entry zone of patients with unilateral TN. In this study, the authors explored the differences in DTI parameters between subcategories of TN, specifically TN1 and TN2, in the pontine segment of the trigeminal tract.

METHODS

The authors enrolled 8 patients with unilateral TN1, 7 patients with unilateral TN2, and 23 asymptomatic controls. Patients underwent DTI with parameter measurements in a region of interest within the pontine segment of the trigeminal tract. DTI parameters were compared between groups.

RESULTS

In the pontine segment, the radial diffusivity (p = 0.0049) and apparent diffusion coefficient (p = 0.023) values in TN1 patients were increased compared to the values in TN2 patients and controls. The DTI measures in TN2 were not statistically significant from those in controls. When comparing the symptomatic to asymptomatic sides in TN1 patients, radial diffusivity was increased (p = 0.025) and fractional anisotropy was decreased (p = 0.044) in the symptomatic sides. The apparent diffusion coefficient was increased, with a trend toward statistical significance (p = 0.066).

CONCLUSIONS

Noninvasive DTI analysis of patients with TN may lead to improved diagnosis of TN subtypes (e.g., TN1 and TN2) and improve patient selection for surgical intervention. DTI measurements may also provide insights into prognosis after intervention, as TN1 patients are known to have better surgical outcomes than TN2 patients.

Neuropathic Pain: From Mechanisms to Treatment

Neuropathic pain caused by a lesion or disease of the somatosensory nervous system is a common chronic pain condition with major impact on quality of life. Examples include trigeminal neuralgia, painful polyneuropathy, postherpetic neuralgia, and central poststroke pain. Most patients complain of an ongoing or intermittent spontaneous pain of, for example, burning, pricking, squeezing quality, which may be accompanied by evoked pain, particular to light touch and cold. Ectopic activity in, for example, nerve-end neuroma, compressed nerves or nerve roots, dorsal root ganglia, and the thalamus may in different conditions underlie the spontaneous pain. Evoked pain may spread to neighboring areas, and the underlying pathophysiology involves peripheral and central sensitization. Maladaptive structural changes and a number of cell-cell interactions and molecular signaling underlie the sensitization of nociceptive pathways. These include alteration in ion channels, activation of immune cells, glial-derived mediators, and epigenetic regulation. The major classes of therapeutics include drugs acting on α₂δ subunits of calcium channels, sodium channels, and descending modulatory inhibitory pathways.

Sensitivity of magnetic resonance tomographic angiography for detecting the degree of neurovascular compression in trigeminal neuralgia

PURPOSE

Neurovascular compression (NVC) is hypothesized to be the main pathogenic factor of trigeminal neuralgia (TN). Microvascular decompression (MVD) has become a popular surgery for TN, and the success rate depends on the degree of NVC. As the routine examination before MVD, magnetic resonance tomographic angiography (MRTA) shows high sensitivity for detecting NVC. However, there are no reports on the sensitivity of MRTA for assessing the degree of NVC.

METHODS

This study aimed to evaluate the sensitivity of MRTA for determining the degree of NVC by comparing preoperative MRTA and intraoperative endoscopy findings. A total of 480 patients who suffered from TN and underwent MVD were included. Their preoperative MRTA and intraoperative endoscopy findings were reviewed. The kappa test was used to identify similarities between the MRTA and endoscopy findings.

RESULTS

The degree of NVC on preoperative MRTA was similar to that on endoscopy (kappa = 0.770). The number of offending vessels according to preoperative MRTA was coincident with that according to endoscopy (kappa = 0.722).

CONCLUSION

MRTA had high sensitivity for detecting not only the presence of NVC but also the degree of NVC.

Treatment Outcomes in Trigeminal Neuralgia-A Systematic Review of Domains, Dimensions and Measures

BACKGROUND

Trigeminal neuralgia (TN) is a painful disorder characterized by sudden electric shock-like pain. It is a rare condition for which multiple treatments are available, including medical and surgical. The best treatment option is yet to be defined, and this is related to the lack of definition in the treatment outcomes and outcome measures. The aim of this systematic review was to summarize all the outcomes and outcomes measures that have been published to date and highlight variability in their use.

METHODS

We have conducted a literature search using a wide range of databases (1946-2019 for medical and 2008-2019 for surgical treatment), for all intervention studies in TN. Four hundred and sixty-seven studies were selected for data extraction on TN classification, data collection method, intervention, and treatment outcomes mapped to the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT guidelines).

RESULTS

Most studies collected data on pain (n = 459) and side effects (n = 386) domains; however, very few collected data on the impact of treatment on physical (n = 46) and emotional functioning (n = 17) and on patient satisfaction (n = 35). There was high variability on outcome measures used for pain relief (n = 10), pain intensity (n = 9), and frequency of pain episodes (n = 3).

CONCLUSIONS

A clear definition of what are the important outcomes for patients with TN is essential. The choice of standardized outcome measures allowing for consistent reporting in TN treatment will allow for comparison of studies and facilitate treatment choice for patients and clinicians thus, improving health outcomes and reducing health care cost.

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.

Nerve Compression Syndromes in the Posterior Cranial Fossa

BACKGROUND

Nerve compression syndromes in the posterior cranial fossa can severely impair patients' quality of life. There is often uncertainty about the best treatment. In this article, we provide an overview of these conditions and the corresponding treatment strategies.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed and on a scientific analysis of the authors' patient collective.

RESULTS

These syndromes are caused by compression of a cranial nerve by an artery or vein at the zone of the nerve's entry to or exit from the brainstem. The best-known neurovascular compression syndrome is trigeminal neuralgia, followed by hemifacial spasm. Less well known are glossopharyngeal neuralgia, nervus intermedius neuralgia, and vestibular paroxysmia. The initial treatment of trigeminal neuralgia is medical: the first line of treatment is with sodium-blocking anticon- vulsants, such as carbamazepine. For patients with hemifacial spasm, botulinum toxin injection is the recommended initial treatment and often leads to a satisfactory regression of the spasms. If these treatments fail, a microvascular decompression operation is indicated. The aim of the procedure is to separate the irritating vessel from the nerve and to keep these structures apart permanently. There is hardly any available evidence on these treatment strategies from randomized controlled trials.

CONCLUSION

Nerve compression syndromes in the posterior cranial fossa can generally be treated nonsurgically at first. Over the course of the condition, however, treatment failure or intolerable side effects may arise. In such cases, a microvascu- lar decompression operation is indicated. This is a causally directed form of treat- ment that generally yields very good results.

Long-term pain outcomes for recurrent idiopathic trigeminal neuralgia after stereotactic radiosurgery: a prospective comparison of first-time microvascular decompression and repeat stereotactic radiosurgery

OBJECTIVE

Microvascular decompression (MVD) and stereotactic radiosurgery (SRS) are common surgical treatments for trigeminal neuralgia (TN). Many patients who receive SRS have pain recurrence; the ideal second intervention is unknown. The authors directly compared pain outcomes after MVD and repeat SRS in a population of patients in whom SRS failed as their first-line procedure for TN, and they identified predictors of pain control.

METHODS

The authors reviewed a prospectively collected database of patients undergoing surgery for TN between 1997 and 2014 at the University of California, San Francisco (UCSF). Standardized data collection focused on preoperative clinical characteristics, surgical characteristics, and postoperative outcomes. Patients with typical type 1, idiopathic TN with ≥ 1 year of follow-up were included.

RESULTS

In total, 168 patients underwent SRS as their first procedure. Of these patients, 90 had residual or recurrent pain. Thirty of these patients underwent a second procedure at UCSF and had ≥ 1 year of follow-up; 15 underwent first-time MVD and 15 underwent repeat SRS. Patients undergoing MVD were younger than those receiving repeat SRS and were more likely to receive ≥ 80 Gy during the initial SRS. The average follow-up was 44.9 ± 33.6 months for MVD and 48.3 ± 45.3 months for SRS. All patients achieved complete pain freedom without medication at some point during their follow-up. At last follow-up, 80% of MVD-treated patients and 33.3% of SRS-treated patients had a favorable outcome, defined as Barrow Neurological Institute Pain Intensity scores of I-IIIa (p < 0.05). Percentages of patients with favorable outcome at 1 and 5 years were 86% and 75% for the MVD cohort and 73% and 27% for the SRS cohort, respectively (p < 0.05). Multivariate Cox proportional hazards analysis demonstrated that performing MVD was statistically significantly associated with favorable outcome (HR 0.12, 95% CI 0.02-0.60, p < 0.01). There were no statistically significant predictors of favorable outcome in the MVD cohort; however, the presence of sensory changes after repeat SRS was associated with pain relief (p < 0.01).

CONCLUSIONS

Patients who received MVD after failed SRS had a longer duration of favorable outcome compared to those who received repeat SRS; however, both modalities are safe and effective. The presence of post-SRS sensory changes was predictive of a favorable pain outcome in the SRS cohort.

On the Surgical Implications of Peritrigeminal Perforating Vessels in Microvascular Decompression

BACKGROUND

Perforating branches arising from the superior cerebellar artery (SCA) or anterior inferior cerebellar artery (AICA) that pierces the brainstem within 5 mm of the trigeminal root may limit offending vessel transposition during microvascular decompression for trigeminal neuralgia.

OBJECTIVE

To investigate the microsurgical anatomy of peritrigeminal perforators and evaluate their effect on the mobility of the SCA and AICA. Additionally, we propose strategies for mitigating the potential complications caused by the presence of short peritrigeminal perforators.

METHODS

Retrosigmoid approaches and exposure of the upper cerebellopontine angle were performed on 11 cadaveric heads (22 sides). The number, origin, and course of perforators were recorded and each was classified as either type I, short straight (<3 mm); type II, long straight perforators (>3 mm); or type III, long circumflex (>3 mm). Transposition of each SCA and AICA away from trigeminal nerve was performed, and degree of mobilization was evaluated and graded.

RESULTS

A total of 123 perforators were identified, of which 44 were considered peritrigeminal. Of these, 19 arose from the AICA, 18 from the SCA, and 7 from the basilar artery. Type I peritrigeminal perforators were the most common at 77.3%. Transposition or interposition of the parent vessel was not possible in 8 (47.1%) instances.

CONCLUSION

Identification of inhibiting perforators is essential before performing microvascular decompression to avoid ischemic injury to the brainstem. The presence of type I perforators may necessitate extensive arachnoid dissection and use of an interpositioning technique with minimal repositioning of the offending vessel.

Microvascular decompression and radiofrequency for the treatment of trigeminal neuralgia: a meta-analysis

PURPOSE

Surgical treatments are used for trigeminal neuralgia (TN) when drug treatment fails. Surgical options can be divided into two categories: ablation (destructive) or non-ablation. Microvascular decompression (MVD) is primarily a non-ablation option, while radiofrequency thermocoagulation/rhizotomy (RF) is an ablation option. The aim of this study was to compare outcomes of MVD versus RF in the treatment of TN.

MATERIALS AND METHODS

This article evaluates the clinical results and economic effectiveness of trigeminal nerve RF and MVD for the treatment of TN. This review was conducted according to the methodological standards described in the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement. The PubMed, Embase and Cochrane libraries were searched in January 2018. We have registered our review at the Review Registry.

RESULTS

Nine studies were included in this review. The sample size was 2163 participants. The results showed that compared with RF, MVD had a lower risk of requiring a secondary procedure. The MVD group also had a lower risk of facial numbness. There was no significant difference in postoperative medication use between the two groups. Compared to RF, MVD was more likely to increase the risk of hypacusis and hypesthesia and to decrease the risk of facial pain and dysesthesia. The total cost of MVD, including the operation, hospital stay and additional procedures, was much higher than that of RF.

CONCLUSION

MVD had a lower risk of requiring a secondary procedure and facial numbness after surgery. RF could be considered in patients who are unfit for MVD or refused invasive treatment.

Adverse Events After Microvascular Decompression: A National Surgical Quality Improvement Program Analysis

BACKGROUND

Although microvascular decompression (MVD) is a durable treatment for medically refractory trigeminal neuralgia, hemifacial spasm, or glossopharyngeal neuralgia attributable to neurovascular conflict, few national studies have analyzed predictors of postoperative complications.

OBJECTIVE

To determine the incidence and risk factors for adverse events after MVD.

METHODS

Patients who underwent MVD were extracted from the prospectively collected National Surgical Quality Improvement Program registry (2006-2017). Multivariable logistic regression identified predictors of 30-day adverse events and unplanned readmission; multivariable linear regression analyzed predictors of a longer hospital stay.

RESULTS

Among the 1005 patients evaluated, the mortality was 0.3%, major neurologic complication rate 0.4%, and 2.8% had a nonroutine hospital discharge. Patient age was not a predictor of any adverse events. Statistically significant independent predictors both of any adverse event (9.2%) and of a longer hospitalization were American Society of Anesthesiologists (ASA) classification III-IV designation and longer operative duration (P ≤ 0.03) The 30-day readmission rate was 6.8%, and the most common reasons were surgical site infections (22.4%) and cerebrospinal fluid leakage (14.3%). Higher ASA classification, diabetes mellitus, and operative time were predictors of readmission (P < 0.04).

CONCLUSIONS

In this National Surgical Quality Improvement Program analysis, postoperative morbidity and mortality after MVD was low. Patient age was not a predictor of postoperative complications, whereas higher ASA classification, diabetes mellitus, and longer operative duration were predictive of any adverse event and readmission. ASA classification provided superior risk stratification compared with the total number of patient comorbidities or laboratory values. These data can assist with preoperative patient counseling and risk stratification.

Radiofrequency Ablation for Treating Headache

PURPOSE OF REVIEW

Examining the efficacy of radiofrequency ablation in treating headache conditions.

RECENT FINDINGS

The efficacy of radiofrequency ablation in treating headache conditions is not well studied. Chronic headache conditions can be difficult to treat with little consensus on management of headaches associated with pericranial neuralgias. In this retrospective study, we found that radiofrequency ablation is an effective and safe treatment for resistant headache conditions. This study is important as it describes a novel treatment for chronic headache which can benefit a large number of patients.

Neurotologic Complications Following Microvascular Decompression: A Retrospective Study

Objective  The main purpose of this article is to determine the frequency of neurotologic complications after posterior fossa microvascular decompression (MVD) surgery. Design  Retrospective case review. Setting  Tertiary care referral center. Participants  A total of 215 consecutive MVD operations by a single surgeon between March 1996 and May 2016 were reviewed with 192 surgeries on 183 patients meeting inclusion criteria. Main Outcome Measures  Neurotologic complications secondary to MVD. Results  The 52 males and 131 females had a mean age of 58.52 years (range, 28-92 years). Indications for MVD were trigeminal neuralgia ( n  = 162), hemifacial spasm ( n  = 23), glossopharyngeal neuralgia ( n  = 13), vagal palsy ( n  = 1), and tinnitus ( n  = 1). The outcomes examined were postoperative hearing loss, tinnitus, vertigo, and hemifacial paresis. At least one of these complications was present in 17.7% of patients. There were 4.17% with permanent hearing loss, 6.77% with transient hearing loss, 5.21% with tinnitus, 5.73% with vertigo, and 0.52% with hemifacial paresis. There was no significant difference in complication rates based on surgical indication. Conclusions  Neurotologic complications are a significant risk when performing MVD. It is important for otolaryngologists as well as neurosurgeons to be aware of such complications. We recommend perioperative audiometry in all patients undergoing MVD and believe there is utility in routine otolaryngologist involvement.

Laryngeal manifestations of cranial nerve IX/X compression at the brainstem

OBJECTIVE

We report an association between lower cranial nerve (CN IX/X) vascular compression at the brainstem with laryngeal symptoms utilizing a stepwise algorithm that systematically evaluates and eliminates all other common etiologies. Our experiences with retromastoid craniectomy with lower cranial nerve (LCN) decompression versus non-neurosurgical treatments are detailed.

STUDY DESIGN

Retrospective chart review at a tertiary care academic medical center with follow-up telephone survey.

METHODS

Baseline demographics, clinical characteristics, quality-of-life surveys, and treatment outcomes were recorded for patients with laryngeal symptoms associated with LCN compression at the brainstem.

RESULTS

Forty-nine patients demonstrated LCN compression at the brainstem on imaging and presented with chief complaints of dysphonia (25 of 49, 51%), chronic cough (19 of 49, 39%), dysphoric breathing (3 of 49, 6%), and dysphagia (2 of 49, 4%). Poor initial scores were noted for Voice-Related Quality of Life (V-RQOL), Reflux Symptom Index, and Glottal Closure Index. Twenty-four patients underwent LCN decompression, of which 21 of 24 (88%) reported partial, near-complete, or complete improvement. Major perioperative complications occurred in four of 24 patients (17%). Patients who had undergone decompression were more likely to obtain complete/near-complete symptom resolution (10 of 24 patients, 42%) compared to those undergoing conservative treatments (2 of 25 patients, 8%) (P = 0.02). V-RQOL scores improved more in surgical patients [mean change score, 33.0 (standard deviation [SD], 31.2) than nonsurgical patients (mean change score 9.6, SD 20.9) (P = 0.03) (mean follow-up 3.0 years, SD 2.0).

CONCLUSION

Lower cranial nerve compression at the brainstem should be considered when all other etiologies are excluded. Retromastoid craniectomy with LCN decompression demonstrates an acceptable safety profile.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:2105-2111, 2019.