Trigeminal neuralgia. Non-invasive techniques versus microvascular decompression. It is really available any further improvement?

Neuronavigation-guided Percutaneous Rhizotomies to Trigeminal Neuralgia: A Systematic Review

OBJECTIVE

Neuronavigation improves intraoperative visualization of the cranial structures, which is valuable in percutaneous surgical treatments for patients with trigeminal neuralgia (TN) who are refractory to pharmacotherapy or reluctant to receive open surgery. The objective of this review was to evaluate the available neuronavigation-guided percutaneous surgical treatment modalities with cannulation of foramen ovale to TN, and their relative benefits and limitations.

METHODS

This review was conducted based on the PRISMA statement. An initial search was performed on electronic databases, followed by manual and reference searches. Study and patient characteristics, rhizotomy procedure and neuronavigation details, and treatment outcomes (initial pain relief and pain recurrence within 2 y, success rate of forman ovale cannulation, and complications) were evaluated. The risk of bias was assessed with a quality assessment based on the ROBINS-I tools.

RESULTS

Ten studies (491 operations, 403 participants) were analyzed. Three percutaneous trigeminal rhizotomy modalities identified were radiofrequency thermocoagulation rhizotomy (RFTR), percutaneous balloon compression, and glycerol rhizotomy. Intraoperative computed tomography and magnetic resonance imaging fusion-based RFTR had the highest initial pain relief rate of 97.0%. The success rate of foramen ovale cannulation ranged from 92.3% to 100% under neuronavigation. Facial hypoesthesia and masticatory muscle weakness were the most reported complications.

DISCUSSION

Neuronavigation-guided percutaneous trigeminal rhizotomies showed possible superior pain relief outcomes to that of conventional rhizotomies in TN, with the benefits of radiation reduction and lower complication development rates. The limitations of neuronavigation remain its high cost and limited availability. Higher-quality prospective studies and randomized clinical trials of neuronavigation-guided percutaneous trigeminal rhizotomy were lacking.

Is percutaneous balloon compression better than microvascular decompression to treat trigeminal neuralgia? A systematic review and meta-analysis

BACKGROUND

Trigeminal neuralgia (TN) is a neuropathic pain that affects one or more branches of the trigeminal nerve. Surgical options after pharmacological failure are Microvascular Decompression (MVD) or percutaneous procedures, which include Balloon Compression (PBC). This study aims to describe pain outcomes and complications after PBC and MVD procedures for patients with trigeminal neuralgia.

METHODS

We performed a systematic review and meta-analysis on PubMed, EMBASE, LILACS, and Web of Science databases up to April 2022, following PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and meta-Analysis). Articles that separately describe pain outcome for MVD and PBC were included. MINORS tool was used for bias assessment. Meta-analysis results are presented in forest plot and funnel plot.

RESULTS

853 studies were assessed for screening, and 11 studies met the inclusion criteria for this review. A total of 1046 patients underwent PBC and 1324 underwent MVD. The subgroup analysis for patients without multiple sclerosis shows that MVD was associated with lower number of patients with pain than PBC, with an OR value of 0.54 (95 % CI 0.34-0.84). All other analyses evidenced a tendency for better outcomes after the MVD procedure, but with no statistically significant difference.

CONCLUSION

Considering short and long pain relief, recurrence of pain and total complications for MVD and PBC, our study found that MVD is the best surgical option available for trigeminal neuralgia.

Microvascular Decompression versus Stereotactic Radiosurgery for Trigeminal Neuralgia: A Single-Institution Experience

OBJECTIVE

Microvascular decompression (MVD) is the standard surgical procedure for patients with medically refractory trigeminal neuralgia (TN). Stereotactic radiosurgery (SRS) has gained increasing popularity as a less invasive technique. We report our institution's outcome in the surgical treatment of TN (MVD vs. SRS), taking patient's age and gender into consideration.

METHODS

We retrospectively reviewed a prospectively collected database of patients undergoing MVD or SRS for type 1 idiopathic TN between 2004 and 2019 at the University of Iowa. Standardized data collection focused on preoperative clinical characteristics and postoperative outcomes including the Barrow Neurological Institute (BNI) Pain Intensity Score.

RESULTS

A total of 111 patients underwent MVD and 103 patients underwent SRS for TN. Patients were younger in the MVD (median, 60 years) than SRS (median, 72 years) group. More females (58%) than males (42%) had TN. Multivariate ordinal regression analysis showed that an outcome of BNI score I-II (P = 0.365) and III (P = 0.736) can be achieved with either MVD or SRS; however, BNI score IV (P = 0.031) and V (P = 0.022) were more associated with SRS. Six percent of patients in the MVD group and 26% in the SRS group developed pain recurrence and required a second operation. Nine of 10 patients who underwent MVD after failed SRS had complete pain relief.

CONCLUSIONS

Factoring in patients' age and gender, both MVD and SRS can achieve a favorable outcome for medically refractory TN, although BNI scores of IV and V were more common with SRS.

Absence of neurovascular conflict during microvascular decompression while treating essential trigeminal neuralgia. How to proceed? Systematic review of literature

INTRODUCTION

Neurovascular conflict is the most accepted hypothesis for the cause for trigeminal neuralgia. Microvascular decompression of the trigeminal nerve is the most common surgical treatment for these patients. However, despite advances in diagnostic techniques, neurovascular conflict is sometimes not detected during surgery. The aim of this paper is to systematically review all the options available to best manage this scenario.

RESULTS

Several techniques that could be used during microvascular decompression for trigeminal neuralgia in the absence of neurovascular conflict have been described. The success rates of these techniques, pain recurrence rates and rates of complications are also reported. Finally, we provide suggestions based on our experience.

CONCLUSIONS

There is no gold standard, but several techniques could be successfully used in the absence of neurovascular conflict. The use of destructive techniques, such as PSR, should be held as treatments of last resort.

The role of radiosurgery in trigeminal neuralgia

A short review of clinical use of radiosurgery in trigeminal neuralgia is offered.

Sensory abnormalities and masticatory function after microvascular decompression or balloon compression for trigeminal neuralgia compared with carbamazepine and healthy controls

OBJECT

Idiopathic trigeminal neuralgia (iTN) is a neurological condition treated with pharmacotherapy or neurosurgery. There is a lack of comparative papers regarding the outcomes of neurosurgery in patients with iTN. The objective of this study was to investigate sensory thresholds and masticatory function in 78 patients with iTN who underwent microvascular decompression (MVD) or balloon compression (BC), and compare these treatments with carbamazepine and 30 untreated healthy controls.

METHODS

The authors conducted a case-controlled longitudinal study. Patients were referred to 1 of 3 groups: MVD, BC, or carbamazepine. All patients were evaluated before and after treatment with a systematic protocol composed of a clinical orofacial questionnaire, Research Diagnostic Criteria for temporomandibular disorders, Helkimo indices, and a quantitative sensory-testing protocol (gustative, olfactory, cold, warm, touch, vibration, superficial, and deep pain thresholds).

RESULTS

Both MVD and BC were effective at reducing pain intensity (p = 0.012) and carbamazepine doses (p < 0.001). Myofascial and articular complaints decreased in both groups (p < 0.001), but only the patients in the MVD group showed improvement in Helkimo indices (p < 0.003). Patients who underwent MVD also showed an increase in sweet (p = 0.014) and salty (p = 0.003) thresholds. The sour threshold decreased (p = 0.003) and cold and warm thresholds increased (p < 0.001) in patients after MVD and BC, but only the patients who underwent BC had an increase in touch threshold (p < 0.001).

CONCLUSIONS

Microvascular decompression and BC resulted in a reduction in myofascial and jaw articular complaints, and the impact on masticatory function according to Helkimo indices was greater after BC than MVD. MVD resulted in more gustative alterations, and both procedures caused impairment in thermal thresholds (warm and cold). However, only BC also affected touch perception. The sensorial and motor deficits after BC need to be included as targets directly associated with the success of the surgery and need to be assessed and relieved as goals in the treatment of iTN.

Factors Influencing Decision-making and Outcome in the Surgical Management of Trigeminal Neuralgia

Objectives The aim was to optimize the algorithm of operative intervention for trigeminal neuralgia (TN). Design A multivariate analysis was undertaken to determine factors that had influenced both the initial choice of surgical intervention and the subsequent outcomes. Setting The study was undertaken with patients who underwent microvascular decompression (MVD) or percutaneous glycerol injection (PGI) for TN between 2007 and 2009. Participants Seventy-one consecutive patients (43 female) were selected. Main Outcome Measures Data were prospectively recorded and included demographics, etiology, and presentation of TN, duration of symptoms, neurovascular contact, and the outcomes of surgery. Results The response rates for MVD and PGI were 96.2% and 87.5%, respectively. The recurrence rates were 9.8% following MVD and 33.3% following PGI. Multivariate analyses confirmed multiple sclerosis and the identification of neurovascular contact as the only factors predictive of the choice of surgical intervention and the risk of recurrence following MVD. Conclusions Our approach to choosing an operative intervention has been validated. The presence of neurovascular contact and the diagnosis of multiple sclerosis influenced the choice of surgery and were predictive of subsequent outcome. Both MVD and PGI offer effective treatment options for TN. Surgery should be offered early when medical management fails.

High-resolution 3D-constructive interference in steady-state MR imaging and 3D time-of-flight MR angiography in neurovascular compression: a comparison between 3T and 1.5T

BACKGROUND AND PURPOSE

High-resolution MR imaging is useful for diagnosis and preoperative planning in patients with NVC. Because high-field MR imaging promises higher SNR and resolution, the aim of this study was to determine the value of high-resolution 3D-CISS and 3D-TOF MRA at 3T compared with 1.5T in patients with NVC.

MATERIALS AND METHODS

Forty-seven patients with NVC, trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia were examined at 1.5T and 3T, including high-resolution 3D-CISS and 3D-TOF MRA sequences. Delineation of anatomic structures, overall image quality, severity of artifacts, visibility of NVC, and assessment of the SNR and CNR were compared between field strengths.

RESULTS

SNR and CNR were significantly higher at 3T (P < .001). Significantly better anatomic conspicuity, including delineation of CNs, nerve branches, and assessment of small vessels, was obtained at 3T (P < .02). Severity of artifacts was significantly lower at 3T (P < .001). Consequently, overall image quality was significantly higher at 3T. NVC was significantly better delineated at 3T (P < .001). Six patients in whom NVC was not with certainty identifiable at 1.5T were correctly diagnosed at 3T.

CONCLUSIONS

Patients with NVC may benefit from the higher resolution and greater sensitivity of 3T for preoperative assessment of NVC, and 3T may be of particular value when 1.5T is equivocal.

Pharmacological versus microvascular decompression approaches for the treatment of trigeminal neuralgia: clinical outcomes and direct costs

In idiopathic trigeminal neuralgia (TN) the neuroimaging evaluation is usually normal, but in some cases a vascular compression of trigeminal nerve root is present. Although the latter condition may be referred to surgery, drug therapy is usually the first approach to control pain. This study compared the clinical outcome and direct costs of (1) a traditional treatment (carbamazepine [CBZ] in monotherapy [CBZ protocol]), (2) the association of gabapentin (GBP) and analgesic block of trigger-points with ropivacaine (ROP) (GBP+ROP protocol), and (3) a common TN surgery, microvascular decompression of the trigeminal nerve (MVD protocol). Sixty-two TN patients were randomly treated during 4 weeks (CBZ [n = 23] and GBP+ROP [n = 17] protocols) from cases of idiopathic TN, or selected for MVD surgery (n = 22) due to intractable pain. Direct medical cost estimates were determined by the price of drugs in 2008 and the hospital costs. Pain was evaluated using the Numerical Rating Scale (NRS) and number of pain crises; the Hospital Anxiety and Depression Scale, Sickness Impact Profile, and satisfaction with treatment and hospital team were evaluated. Assessments were performed at day 0 and 6 months after the beginning of treatment. All protocols showed a clinical improvement of pain control at month 6. The GBP+ROP protocol was the least expensive treatment, whereas surgery was the most expensive. With time, however, GBP+ROP tended to be the most and MVD the least expensive. No sequelae resulted in any patient after drug therapies, while after MDV surgery several patients showed important side effects. Data reinforce that, (1) TN patients should be carefully evaluated before choosing therapy for pain control, (2) different pharmacological approaches are available to initiate pain control at low costs, and (3) criteria for surgical interventions should be clearly defined due to important side effects, with the initial higher costs being strongly reduced with time.

Foramen ovale cannulation guided by intra-operative computed tomography with integrated neuronavigation for the treatment of trigeminal neuralgia

BACKGROUND

Radiofrequency rhizotomy of the Gasserian ganglion for the treatment of trigeminal neuralgia via percutaneous cannulation of the foramen ovale is facilitated by various localization modalities. In our preliminary study, we described the feasibility of computed tomography (CT) using an integrated neuronavigation system to cannulate the foramen ovale.

METHODS

Analysis was performed on 42 consecutive patients who underwent cannulation of the foramen ovale for radiofrequency trigeminal rhizotomy guided by CT using an integrated neuronavigation system. The reproducibility and safety of the neuronavigation-guided procedure were evaluated.

RESULTS

Overall, the average dimension of the foramen ovale was 7.1 (1.5)  ×  4.7 (1.1) mm, and it was successfully cannulated by neuronavigation guidance in 31 (73.8%) patients with a mean cannulation time of 3.1 (0.7) min and an overall procedure time of 68.2 (16.4) min. The remaining 11 (26.2%) patients required subsequent CT guidance for successful puncture of the foramen ovale.

CONCLUSIONS

These data demonstrate that neuronavigation-guided cannulation of the foramen ovale can be executed both quickly and safely on an outpatient basis. Additionally, the use of CT with integrated neuronavigation technology provides superior visual-spatial information compared to conventional fluoroscopy, the process of CT scanning, object planning, and neuronavigation-guided intervention can be completed in the same locale, and its application is easy to master and has the potential to enhance procedure tolerability of awake patients.