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

Sphenopalatine ganglion stimulation for the treatment of trigeminal neuropathic pain

Introduction

Unlike idiopathic trigeminal neuralgia, which can be treated with conventional neurosurgical methods such as microvascular decompression, radiofrequency rhizotomy of the Gasser ganglion, or stereotactic radiosurgery, trigeminal neuropathic pain (TNP) presents a major challenge for neurosurgeons. Injury to the trigeminal system resulting in chronic refractory pain can be treated with neuromodulation methods, such as peripheral nerve stimulation, motor cortex stimulation, or deep brain stimulation. Sphenopalatine ganglion (SPG) stimulation has been successfully applied in patients with cluster headaches and migraine. This study aimed to evaluate the response of patients with TNP to permanent percutaneous SPG stimulation.

Methods

We studied six patients treated with SPG stimulation for TNP. All patients had previously been treated with RF rhizotomy, microvascular decompression, or stereoradiosurgery without a satisfactory long-term therapeutic effect and had recurrent, mostly constant TNP. An electrode lead was implanted in the pterygopalatine fossa of all patients to stimulate the SPG under guidance of neuronavigation with an implantable pulse generator inserted after a two-week trial period.

Results

Preoperatively, the mean visual analog scale score was 9. Two weeks after the trial stimulation, it decreased to 3.6 in six patients. In four patients, the score further decreased to 3.0 after 6 months and 2.25 after 12 months, accompanied by an improvement in health status, as measured by the 36-Item Short Form Health Survey questionnaire. In two patients, the electrodes were externalized through eroded skin after 3 months, and stimulators were removed.

Discussion

The preliminary results of this pilot study are encouraging. Pain relief after the trial stimulation was found to be notable. The treatment procedure was safe, and the stimulation effect was durable. SPG stimulation is an attractive alternative to other neuromodulation methods.

Efficacy and clinical outcomes of percutaneous treatments for trigeminal neuralgia secondary to multiple sclerosis

BACKGROUND

People with Multiple Sclerosis (MS) have a 20-fold higher risk of developing trigeminal neuralgia compared to the general population. Treating trigeminal neuralgia in these patients is particularly challenging due to reduced tolerance and increased side effects from medications. When no neurovascular conflict exist, percutaneous treatments are usually the first option after drug therapy. According to the literature, treatment outcomes for MS-associated trigeminal neuralgia show higher relapse rates and lower rates of sustained pain relief compared to primary trigeminal neuralgia, often necessitating multiple procedures.

METHODS

We conducted a retrospective cohort study of patients who underwent percutaneous procedures for trigeminal neuralgia between 2010 and 2021 at Rouen University Hospital. The patients were divided into two groups based on the presence or absence of multiple sclerosis. The primary endpoint was the postoperative Barrow Neurological Institute (BNI) pain score, categorized as favourable (I-III) or unfavourable (IV-V) at 3 months postoperatively and at the last date of follow-up.

RESULTS

Patients with multiple sclerosis were younger, had fewer comorbidities, and experienced more bilateral trigeminal pain compared to those without multiple sclerosis. BNI score evaluations at 3 months and at the last follow-up did not differ significantly between the two groups, with 81 % and 77 % of patients, showing favourable outcomes. However, the recurrence of pain after percutaneous procedures was significantly higher in patients with multiple sclerosis (p < 0.05).

CONCLUSION

Percutaneous rhizotomies achieve satisfactory clinical outcomes in patients with MS, despite a higher incidence of recurrences and subsequent percutaneous procedures compared to the general population.

[Surgical treatment of trigeminal pain]

Surgical procedures for treating neuropathic pain, including trigeminal neuralgia (TGN), are categorized into three groups: decompression, ablation, and neuromodulation. Microvascular decompression is the only causal therapy for TGN, applicable favorably in cases of classical TGN due to a vascular nerve conflict. Ablative procedures include both percutaneous and radiosurgical methods, which are mainly used for idiopathic trigeminal neuralgia. For irreversible neuropathies of the trigeminal nerve, the algorithm for other neuropathic pain conditions should be considered, along with the potential use of neuromodulatory techniques. When selecting a therapy, diagnosis, medication side effects, individual patient risks, and treatment outcomes must all be taken into account (current S1 guideline from the German Society of Neurology).

Analysis of recurrence factors after balloon compression for trigeminal neuralgia and the relationship between pear-shaped balloon and guidewire path

BACKGROUND

Percutaneous balloon compression (PBC) is widely used to treat trigeminal neuralgia due to its significant efficacy and low treatment cost. However, there is considerable variation in postoperative pain recurrence among patients. Currently, the factors influencing pain recurrence after PBC are under discussion. This study aims to explore the impact of individual patient parameters and surgical parameters on postoperative pain recurrence following PBC. The goal is to provide clinicians with a reference for preoperative assessment of pain recurrence risk and to offer insights for effectively intervening in controllable influencing parameters.

METHODS

A analysis was conducted on 114 patients who underwent PBC in the Department of Neurosurgery at Hebei General Hospital. Univariate Kaplan-Meier analysis and multivariate Cox regression analysis were performed on the general and surgical data of the patients to identify factors potentially associated with postoperative pain recurrence.

RESULTS

The results of the multivariate Cox regression analysis showed that a history of hypertension, MRI indicating trigeminal nerve compression and a non-ideal pear-shaped balloon were statistically significant factors for pain recurrence after PBC. Additionally, the guidewire path during the procedure had a statistically significant impact on the rate of achieving a pear-shaped balloon (P<0.05).

CONCLUSION

A history of hypertension, MRI indicating trigeminal nerve compression and a non-ideal pear-shaped balloon shape are independent risk factors for pain recurrence after PBC. Additionally, to avoid pain recurrence due to an unfavorable balloon shape, it is recommended to use 3D-slicer for preoperative guidewire path simulation and 3D reconstruction of Meckel's cavity.

Abnormal electromyographical trigeminal activation through stimulation of the offending artery (Z-L response): An intraoperative tool during microvascular decompression for trigeminal neuralgia

BACKGROUND

There are currently no intraoperative neurophysiological tools to assess the effectiveness of trigeminal nerve decompression during microvascular decompression surgery for drug-resistant trigeminal neuralgia. In microvascular decompression surgery for hemifacial spasm, an abnormal electromyographic activation of facial muscles after stimulation of the offending vessel was identified and named 'Z-L response'.

METHODS

We adapted a neurophysiological protocol to elicit a Z-L response during microvascular decompression surgery for trigeminal neuralgia and applied it to a prospective series of 18 surgical patients.

RESULTS

Patients had suffered from trigeminal neuralgia for a median 9-year timeframe, and median preoperative Barrow Neurological Institute pain score was 4.5. Through monopolar stimulation, using rising amplitudes starting from 0.1 mA, we confirmed intraoperatively the true culprit vessel before decompression. In 4/18 cases, multiple offending vessels were identified (22 conflicts overall). After decompression, a significant increase in activation threshold (p < 0.0001) confirmed the effectiveness of the maneuver; in 10 cases, Z-L response was abolished. Using this technique, we obtained excellent or good outcome (Barrow Neurological Institute 1-3) in all patients, with a significant reduction in postoperative Barrow Neurological Institute score as compared with preoperative one (median Barrow Neurological Institute 1; p = 0.0002).

CONCLUSION

we provide the first evidence on the applicability and clinical usefulness of Z-L response during microvascular decompression surgery for trigeminal neuralgia.

Optimizing surgical technique in microvascular decompression for hemifacial spasm - Results from a surgical series with contemporary use of neuronavigation and intraoperative neuromonitoring

Background

Microvascular decompression (MVD) through a retrosigmoid approach is considered the treatment of choice in cases of hemifacial spasm (HFS) due to neurovascular conflict (NVC). Despite the widespread of neuronavigation and intraoperative neuromonitoring (IONM) techniques in neurosurgery, their contemporary application in MVD for HFS has been only anecdotally reported.

Methods

Here, we report the results of MVD performed with a combination of neuronavigation and IONM, including lateral spread response (LSR) in 20 HFS patients. HFS clinical outcome and different surgical-related factors, such as craniotomy size, surgical duration, mastoid air cell (MAC) opening, postoperative cerebral spinal fluid (CSF) leakage, sinus injury, and other complications occurrence, and the length of hospitalization (LOS) were studied.

Results

Postoperatively, residual spasm persisted only in two patients, but at the latest follow-up (FU) (mean: 12.5 ± 8.98 months), all patients had resolution of symptoms. The mean surgical duration was 103.35 ± 19.36 min, and the mean LOS was 2.21 ± 1.12 days. Craniotomy resulted in 4.21 ± 1.21 cm2 in size. Opening of MAC happened in two cases, whereas no cases of CSF leak were reported as well as no other complications postoperatively and during FU.

Conclusion

MVD for HFS is an elective procedure, and for this reason, surgery should integrate all technologies to ensure safety and efficacy. The disappearance of LSR is a crucial factor for identifying the vessel responsible for NVC and for achieving long-term resolution of HFS symptoms. Simultaneously, the benefits of using neuronavigation, including the ability to customize the craniotomy, contribute to reduce the possibility of complications.

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

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

Trigeminal neuralgia caused by a persistent primitive trigeminal artery variant passing through Meckel's cavity: a case report

BACKGROUND

Persistent primitive trigeminal artery variant (PPTAv) is a rare remnant of the primitive intracranial embryonic anastomotic arteries, and its persistence has an unknown etiology. Trigeminal neuralgia attributed to a PPTAv passing through Meckel's cavity is extremely uncommon.

CASE PRESENTATION

A 73-year-old woman presented with right-sided facial pain for 10 years that had failed to respond to medication. Magnetic resonance angiography suggested the presence of a PPTAv compressing the trigeminal nerve, as the abnormal artery originated from the right internal carotid artery. During microvascular decompression (MVD), the offending vessel was inferred to be a PPTAv, as it continued to become the anterior inferior cerebellar artery after passing through Meckel's cavity. Postoperative computed tomography angiography showed the PPTAv continuing posteriorly as the anterior inferior cerebellar artery and supplying the cerebellar hemisphere, which confirmed the intraoperative judgment. The pain resolved after MVD and has not recurred in 12 months of follow-up.

CONCLUSION

MVD is the best surgical choice for trigeminal neuralgia combined with a PPTAv. For patients with neurovascular conflicts, particularly those with suspected vascular variations, preoperative imaging examinations play a critical role in meticulously evaluating the anatomical locations of the nerves and blood vessels. Semilunar puncture (for radiofrequency ablation or percutaneous balloon compression) is contraindicated in patients with a PPTAv.

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 young onset primary trigeminal neuralgia: a single-center experience

This study aims to explore the causes of primary young onset trigeminal neuralgia (TN) and the clinical outcomes of these patients. From May 2015 to December 2020, 19 primary TN patients with onset age under 30 years underwent microvascular decompression (MVD) in Nanjing Drum Tower Hospital. In this study, the clinical characteristics, surgical outcomes, and postoperative complications of these patients were analyzed retrospectively. Of the 19 patients, 5 were males and 14 were females, and the pain was located on the right side in 10 cases (52.6%). Vascular compression was observed in 17 patients, including 14 cases of superior cerebellar artery (SCA) alone, 2 cases of superior petrosal vein (SPV) alone, and 1 case of SCA and SPV combined. Two patients had no neurovascular conflict, and nerve combing was performed. After surgery, 18 patients got immediate pain relief; 1 patient improved but still had occasional pain. With a mean follow-up of 42.7 ± 22.3 months, one patient was found to have a relapse 45 months after MVD. Surgical complications including mild facial numbness in two patients and hearing impairment in one patient. Neurovascular compression is the main cause of young onset primary TN, and the most commonly encountered vascular was SCA. MVD is a safe and effective treatment for these patients.