Vascular Offenders in Trigeminal Neuralgia: A Unified Classification and Assessment of the Outcome of Microvascular Decompression

Endoscopic microvascular decompression versus microscopic microvascular decompression for trigeminal neuralgia: A systematic review and meta-analysis

BACKGROUND

To compare the efficacy and safety of full endoscopic or endoscope-assisted microvascular decompression (E-MVD) and microscopic microvascular decompression (M-MVD) for primary trigeminal neuralgia (TN).

METHODS

We systematically searched the online database, including PubMed, Embase and Cochrane Library. The search terms used included, but were not limited to, "Trigeminal Neuralgia", "Microvascular Decompression Surgery" and "Endoscope". Postoperative facial pain relief and postoperative complications were considered for meta-analysis. All the outcomes were calculated as odds ratios (ORs) with 95% confidence intervals using R language.

RESULTS

A total of three studies involving 442 (E-MVD [218] versus M-MVD [224]) patients were included for analysis in our study. Postoperative facial pain relief (very much improved or much improved) was no difference between the two groups (OR, 0.95;95% CI, 0.57-1.58; I2 = 0%; p = 0.83). In addition, the occurrence of some postoperative complications was not statistically different between the two groups, including CSFleak (OR, 1.35;95% CI, 0.16-11.13; I2 = 0%; p = 0.94), facial paralysis (OR, 0.26;95% CI, 0.03-2.54; I2 = 0%; p = 0.67), hearing loss (OR, 0.87;95% CI, 0.30-2.55; I2 = 32%; p = 0.22), facial numbness (OR, 1.03;95% CI, 0.56-1.87; I2 = 62%; p = 0.10).

CONCLUSIONS

Both endoscopic microvascular decompression and microscopic microvascular decompression for trigeminal neuralgia appear to provide patients with equivalent facial pain relief outcomes. Complication rates were also similar between the groups.

Online dynamic nomogram for predicting pain recurrence after microvascular decompression in trigeminal neuralgia

Trigeminal neuralgia (TN) is one of the most common causes of facial pain. Microvascular decompression (MVD) is the first-choice surgical treatment. The present study aimed to develop a novel practical assessment system based on preoperative clinical and imaging factors for clinicians to predict the likelihood of pain recurrence following MVD in TN. A total of 56 patients with primary unilateral TN who underwent MVD were retrospectively analyzed. Patients were followed up to observe pain recurrence 1 year after MVD. An online dynamic nomogram was constructed for predicting the probability of pain recurrence after MVD in patients with TN based on multivariate logistic model. The concordance index (C-index) and receiver operating characteristic (ROC) were used to measure model discrimination. Bootstrap resampling was used for internal validation of the model and calibration curve was constructed. Decision curve analysis (DCA) was used to assess clinical applicability. Factors such as numeric rating scale (to score pain degree of patients with TN), response to neuroanalgesic drugs and neurovascular contact on magnetic resonance imaging were independent risk factors affecting the pain recurrence rate (all P<0.05). C-index was 0.973 (95%CI, 0.938-1.000) and the area under the ROC was 0.973 (95%CI, 0.938-1.000). Calibration curve with a 1,000 bootstrap resampling showed a good fit between dynamic nomogram prediction and actual observations. The DCA showed that at a threshold probability between 0 and 100%, this model can achieve a greater net benefit than if all patients had surgery or none had surgery. In conclusion, this online dynamic nomogram reliably predicted risk of pain recurrence in patients with TN following MVD.

Efficacy and safety of computed tomography-guided percutaneous balloon compression for trigeminal neuralgia secondary to vertebrobasilar dolichoectasia

Percutaneous balloon compression (PBC) of Gasserian ganglion has been popularly used to treat trigeminal neuralgia (TN), one of the most painful syndromes in human experience. Vertebrobasilar dolichoectasia (VBD) is a rare cause of TN and remains challenging to treat. To our knowledge, no study has reported the therapeutic outcome of PBC for VBD-related TN (VBD-TN). In this retrospective study, we collected and analyzed the medical records of all patients undergoing PBC procedure for VBD-TN under the guidance of CT plus three-dimensional reconstruction at the Pain Management Center of Beijing Tiantan Hospital from January 2017 to December 2022. All 23 patients (15 men and 8 women) had a substantial pain relief as modified Barrow Neurological Institute (BNI) I-IIIb immediately after procedure. The follow-up duration ranged from 2 to 63 months, and at the last follow-up visit, only 3 patients (13%) relapsed (BNI IV-V). The cumulative recurrence-free survival was 95%, 87%, and 74% within 1, 3, and 5 years, respectively. Patients' reported satisfactory rate was 100% as Likert scale 4-5 throughout the whole follow-up period, with no severe complications occurring. Our data revealed promising efficacy and safety of PBC procedure for treatment of VBD-TN, thus suggesting a valuable option for pain control in these rare cases of TN. However, there has been no supporting evidence that PBC treatment is a preferred option to other treatments.

Predictive and prognostic factors for outcome of microvascular decompression in trigeminal neuralgia

BACKGROUND

Trigeminal neuralgia (TN) is a disease characterized by recurring, short-lived, electric shock-like pain experienced on one side of the face. Microvascular decompression (MVD) is one of the most effective surgical interventions for resolving TN caused by neurovascular compression. This study aimed to determine the predictive and prognostic factors of surgical outcomes.

METHODS

This retrospective cohort study enrolled patients diagnosed with TN who underwent MVD at our hospital during 2013-2019. The demographic information, pain character, peri-operative Barrow Neurological Institute (BNI) scale, medication, operative finding were recorded. And the outcome was Outcomes were divided into drug-free and drug-dependent group. Predisposing factors for each outcome were analyzed by one-way analysis of variance, followed by a Mann-Whitney U test or Kruskal-Wallis test.

RESULTS

A total of 104 consecutive patients received MVD to treat TN, and 88 patients were enrolled in this study. The overall postoperative drug-free outcome was 72.7%. A significant difference in drug-free outcomes was observed for patients with typical TN (80.8%) compared with patients with atypical TN (33.33%, p = 0001). When severe venous compression was encountered during MVD, the drug-free outcome fell to 50% (10/20, p = 0.009). The Mann-Whitney U test indicated typical TN as a positive predictive factor of a drug-free outcome, whereas severe venous compression was a negative predictive factor. The patients with preoperative BNI score of 4 had better improvement than others (p = 0.045). Age, onset duration, and arterial loop had no specific difference in this study.

CONCLUSION

In our study, atypical TN and severe venous compression were associated with poor outcomes. Regrouping atypical TN into precise diagnosis represents an immediate priority according to our result. The preoperative BNI score could be used as an effective predictive tool for the outcome of MVD surgery.

Radiologic and Neurosurgical Diagnosis of Arterial Neurovascular Conflict on Magnetic Resonance Imaging for Trigeminal Neuralgia in Routine Clinical Practice

OBJECTIVE

The most common cause of trigeminal neuralgia is neurovascular conflict, particularly arterial compression of the trigeminal nerve (ACTN). It is possible to show this condition preoperatively on fine-cut constructive interference in steady state magnetic resonance imaging (MRI), supplemented by time-of-flight magnetic resonance angiography. We have noticed significant variability in the interpretation of these studies between radiologists and the treating neurosurgeon. We have assessed the sensitivity and specificity of these 2 styles of interpretation compared with the intraoperative observations.

METHODS

We studied 68 patients who underwent de novo microvascular decompression from 2011 to 2018 under the care of a single neurosurgeon in Melbourne, Australia. Data was recorded prospectively in the radiology reports, operation reports, hospital admission records and neurosurgeon correspondence from the perioperative clinic reviews. In particular, the surgical interpretation of the MRI was clearly described prospectively and preoperatively in the correspondence. The presence or absence of ACTN was recorded prospectively in the operation report. These data were collated retrospectively by the first author.

RESULTS

Of patients, 83.8% (57/68) had clear ACTN confirmed at surgery. Radiologists detected this abnormality in 50.9% (29/57) of these patients, with a sensitivity of 50.9% and specificity of 81.8%. The operating neurosurgeon detected ACTN in 87.7% (50/57) of the positive cases with a sensitivity of 87.7% and a specificity of 72.7%. Statistical analysis showed a significant disagreement between both styles of interpretation, with a radiologic accuracy of 55.9% compared with 85.3% neurosurgically (P < 0.0001). Follow-up review of the patient's response to surgery further supported the neurosurgical diagnosis of ACTN.

CONCLUSIONS

There was a strong tendency for radiologists to underreport ACTN on the preoperative MRI compared with the intraoperative findings. In this series, the neurosurgeon was able to accurately detect ACTN in 88% of patients preoperatively. However, the diagnosis of absent ACTN was still associated with a false-negative rate of 46.7% when the neurosurgeon performed the interpretation. At the current standard of fine-cut constructive interference in steady state MRI in Melbourne, underdetection of ACTN remains common. Clinicians using this test need to be acutely aware of its limitations in deciding whether to proceed to microvascular decompression.

Trigeminal Neuralgia from an Arteriovenous Malformation of the Trigeminal Root Entry Zone with a Flow-Related Feeding Artery Aneurysm: The Role of a Combined Endovascular and "Tailored" Surgical Treatment

Idiopathic trigeminal neuralgia (TN) due to an embedded arteriovenous malformation (AVM) on the trigeminal root entry zone (REZ) is rare but a potentially challenging condition to manage. Herein, we report such a case with an additional unruptured aneurysm on the feeding artery and highlight the role of a multimodality approach to their management. A 50-year-old female presented with drug-resistant right-sided trigeminal neuralgia for one year. The magnetic resonance imaging (MRI) suggested a possibility of AVM, the angiographic study showed an AVM nidus with feeders from the right anterior inferior cerebellar artery (AICA) and a dilated right intrinsic pontine artery, the latter showing a flow-related aneurysm towards its brainstem end. The flow-related aneurysm, as well as the dilated intrinsic pontine artery feeder, was embolized at first. During surgery, the AVM was found embedded inside the root entry zone. Parts of the AVM and its draining vein were partially coagulated followed by microvascular decompression of the AICA loop as well as a feeder emanating from it following which the patient recovered completely. She subsequently received gamma knife surgery (GKS) for the residual AVM and remained asymptomatic after 3.5 years of GKS. AVM-related TN are rare, and the additional presence of a feeding artery aneurysm increases the management complexity. Endovascular management of the aneurysm followed by microvascular decompression (MVD) and tailored AVM coagulation represent a prompt and effective means of pain control. Subsequent GKS is necessary to obliterate the AVM nidus.

Petrosal Vein Involvement in Neurovascular Conflict in Trigeminal Neuralgia: Surgical Technique and Clinical Outcomes

BACKGROUND

Contact of the main stem of the petrosal vein (PV) to the nerve root is a rare cause of trigeminal neuralgia (TGN). The implication of the PV in relation with neurovascular contact (NVC) is not fully understood.

OBJECTIVE

To assess the operative procedures in microvascular decompression (MVD) in patients with PV involvement in the long-term.

METHODS

We retrospectively reviewed 34 cases (7.0%) in 485 consecutive MVDs for TGN, whose PV main stem had contact with the trigeminal nerve root (PV-NVC). PV-NVCs were divided into 2 groups: concomitant arterial contact or no concomitant arterial contact. Surgical techniques, outcomes, complications, and recurrence were assessed.

RESULTS

The anatomical relationship of the PV with the trigeminal nerve root was consistent with preoperative 3-dimensional imaging in all patients. Pain relief was obtained in most patients immediately after surgery (97.1%) by separating the PV from the nerve root. Postoperative facial numbness was noted in 9 patients (26.5%). Symptomatic venous infarctions occurred in 2 patients (5.9%). Recurrence of facial pain occurred in 3 patients (8.8%) with a median 48 mo follow-up period. Re-exploration surgery revealed adhesion being the cause of recurrence. The statistical analyses showed no difference in the surgical outcomes of the 2 groups.

CONCLUSION

Separating the PV from the nerve root contributes to pain relief in patients with PV conflict regardless of concomitant arteries. Preserving venous flow is crucial to avoid postoperative venous insufficiency.

Invasive and Non-Invasive Electrical Neuromodulation in Trigeminal Nerve Neuralgia: A Systematic Review and Meta-Analysis

BACKGROUND

Trigeminal neuralgia is a chronic disease characterized by intense facial pain that is caused by trigeminal nerve affectation. It usually affects adults from 50 years of age, and is more frequent in women. Additionally, it presents serious psychological effects that often lead to depression, which is why it is considered highly disabling. The therapeutic approach is based on the modification of nerve activity through electrical, surgical or chemical stimulation in specific regions of the nervous system.

OBJECTIVE

To perform a meta-analysis of the scientific literature related to invasive and non-invasive electrical neuromodulation of trigeminal neuralgia, in order to assess their effects over pain and adverse effects.

METHODS

A literature search was conducted in 4 databases, followed by a manual search of articles on invasive or non-invasive electrical neuromodulation to control the pain of trigeminal neuralgia, including the last 15 years.

RESULTS

Regarding non-invasive methods, clinical trials did not present enough results in order to perform a meta-analysis. Regarding invasive methods, clinical trials meta-analysis showed no statistical differences between different treatment methods. In all cases, improvements in patients' pain were reported, although results regarding adverse effects were variable.

CONCLUSION

In the treatment of trigeminal neuralgia, the continuous radiofrequency provides better short and medium-term results, but pulsed radiofrequency shows less adverse effects after treatment, and has better results in the long-term.

Outcomes of microvascular decompression for trigeminal neuralgia with purely venous compression: A systematic review and meta-analysis

OBJECTIVE

Microvascular decompression (MVD) is a commonly-used treatment option for medically-refractory trigeminal neuralgia (TN) with arterial neurovascular compression. Pain control and recurrence rates after MVD in patients with purely venous compression are not well understood. In this systematic review and meta-analysis, we studied outcomes after MVD in patients with purely venous compression and reviewed the operative management in these patients.

METHODS

We performed a systematic review and meta-analysis following the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. We searched PubMed, Google Scholar, and Scopus databases for studies reporting surgical outcomes after MVD for purely venous compression. Pain control and recurrence rates were extracted and summarized. Studies that reported outcomes after mobilization/decompression compared with coagulation/transection of compressive veins were reviewed.

RESULTS

We identified and included 24 studies with a total of 330 patients in this study. 75.6 % of patients achieved a Barrow Neurological Institute (BNI) I pain score with a mean follow-up of 38.0 months. Pain recurred in 23.1 % of patients at a mean follow-up of 51.4 months. There was no significant difference in pain control outcomes between patients with mobilization/decompression and patients with coagulation/transection of compressive veins.

CONCLUSION

After MVD in patients with venous compression alone, pain control rates were similar to those reported for arterial compression, though recurrence rates were higher. There was no difference between vein coagulation/transection compared to mobilization/decompression. Further studies are needed to determine the optimal treatment paradigm for patients with purely venous compression.