The long-term outcome of nerve combing for trigeminal neuralgia

Internal Neurolysis for Trigeminal Neuralgia: A Preliminary Single-institution Experience in Japan

Internal neurolysis (IN) is a surgical procedure in which the trigeminal fibers are separated between the pons and porus trigeminus to relieve trigeminal neuralgia (TN). Recent investigations revealed that the number of nerve bundles made by IN varies, and immediate postoperative hypesthesia exceeded 90% and pain control rate at 1 year was 77%-93.5%. We present the preliminary experience of 18 patients who underwent IN for TN between June 2020 and June 2022. The Barrow Neurological Institute pain scale (BNI-PS) was recorded preoperatively and in June 2023, and the Barrow Neurological Institute hypesthesia scale (BNI-HS) was recorded preoperatively, immediate postoperatively and in June 2023. Intraoperatively, the number of bundles made by IN was reviewed. Preoperative BNI-PS ranged between VI and V. Two patients experienced BNI-HS II due to percutaneous procedure prior to IN. Intraoperatively, 3 bundles were made by IN in 7 patients, 4 bundles in 5, and 5 bundles in 6. Immediate postoperative BNI-HS I was recorded in 6 patients and II in 12 (66.7%). The last follow-up revealed that BNI-PS I and II were recorded in 13 patients (72.2%) and BNI-HS I and II in 6 patients, respectively. Our results demonstrated that the rates of immediate postoperative hypesthesia (66.7%) and pain control (72.2%) at 1 year or later were below those of previous reports. Therefore, we are currently combing to make at least 6 bundles. Detailed surgical technique and cardiac reflex alerts during the procedure are described.

Internal Neurolysis for Trigeminal Neuralgia: Technical Nuances and a Single-Institution Experience

BACKGROUND

Trigeminal neuralgia is a facial pain syndrome most commonly caused by a neurovascular compression (NVC) of the trigeminal nerve. Microvascular decompression (MVD) is the most durable surgical treatment; however, patients without an NVC are not candidates for this procedure. Alternative treatments such as percutaneous rhizotomy and radiosurgery are effective but with higher recurrence rates. Internal neurolysis (IN) is a less frequently used procedure that aims to provide long-term relief to patients without NVC.

OBJECTIVE

We present the surgical techniques for IN developed at our institution. We also discuss the technical nuances related to nerve consistency and present a new classification based on these findings. We provide pain and numbness outcomes for our cohort of patients stratified by the extent of neurolysis and nerve consistency.

METHODS

Patients with medically intractable trigeminal neuralgia eligible for posterior fossa exploration are eligible for MVD and possible IN. If no NVC or a mild NVC is encountered, IN is performed. We have divided the procedure into 4 main steps: opening the outer connective sheath, fascicular dissection, inside-out dissection and the fascicular irrigation technique. Trigeminal nerve consistency has been classified into 3 main types: type 1 is soft and friable; type 2 is intermediate consistency and ideal for neurolysis; and type 3 is firm and presents a more challenging dissection.

CONCLUSIONS

In the absence of microvascular compression, we advocate for a thorough neurolysis using the techniques described in our article.

Internal neurolysis versus intraoperative glycerin rhizotomy for trigeminal neuralgia

OBJECTIVE

Internal neurolysis (IN) and intraoperative glycerin rhizotomy (ioGR) are emerging surgical options for patients with trigeminal neuralgia without neurovascular contact. The objective of this study was to compare the neurological outcomes of patients who underwent IN with those of patients who underwent ioGR.

METHODS

The authors retrospectively reviewed all patients who underwent IN or ioGR for trigeminal neuralgia at our institution. Patient demographic characteristics and immediate postoperative outcomes, as well as long-term neurological outcomes, were compared.

RESULTS

Of 1044 patients who underwent open surgical treatment for trigeminal neuralgia, 56 patients underwent IN and 91 underwent ioGR. Of these 147 patients, 37 had no evidence of intraoperative neurovascular conflict. All patients who underwent IN and 96.7% of patients who underwent ioGR had immediate postoperative pain relief. At last follow-up, patients who underwent IN had lower Barrow Neurological Institute (BNI) pain intensity scores (p = 0.05), better BNI facial numbness scores (p < 0.01), and a greater degree of pain improvement (p = 0.05) compared with those who underwent ioGR. Patients who underwent IN also had significantly lower rates of symptomatic pain recurrence (p < 0.01) at last follow-up over an average of 9.5 months.

CONCLUSIONS

IN appears to provide patients with a greater degree of pain relief, lower rates of facial numbness, and lower rates of pain recurrence compared with ioGR. Future prospective studies will better characterize long-term pain recurrence and outcomes.

Strategies for intraoperative management of the trigeminal nerve and long-term follow-up outcomes in patients with trigeminal neuralgia secondary to an intracranial epidermoid cyst

Background

Epidermoid cysts (ECs) are one of the most common causes of secondary trigeminal neuralgia (TGN). However, most previous studies have primarily focused on whether complete tumor resection was achieved, and few studies have discussed the primary goal of pain relief.

Objective

The present study provides intraoperative strategies for trigeminal nerve (TN) management in patients with TGN secondary to an EC and observed long-term follow-up outcomes.

Methods

A total of 69 patients with TGN secondary to an EC at our hospitals were included (January 2011–June 2021). The same surgical team performed all surgeries using a retrosigmoid approach. After EC removal, different methods for TN management were used, including microvascular decompression (MVD), sharp capsulectomy, nerve combing and embedded cholesterol crystal excision. The epidemiological, clinical, and surgical data were extracted.

Results

The total EC removal rate was 92.8% (64/69). All patients achieved initial pain relief postoperatively, and 12 patients (17.4%) experienced varying degrees of hemifacial hypesthesia, which was relieved within 3–6 months. Three patients (4.3%) reported partial pain recurrence within a median follow-up period of 5.5 (0.5–10.5) years, which was relieved completely after low-dose carbamazepine administration.

Conclusion

The primary goal of surgical tumor removal for patients with TGN secondary to an EC is relief of the main symptom of tormenting pain. The selection of an appropriate strategy for TN, including MVD, sharp capsulectomy, nerve combing or embedded cholesterol crystal excision, should depend on the patient's situation.

Internal neurolysis: 'nerve combing' for trigeminal neuralgia without neurovascular conflict - early UK outcomes

INTRODUCTION

Internal neurolysis (INL) is a surgical procedure where trigeminal nerve fibres are separated between the pons and porus trigeminus to relieve trigeminal neuralgia (TN). We report pain and functional outcomes to evaluate its safety and efficacy.

MATERIALS AND METHODS

Prospective cohort of all patients undergoing retrosigmoid craniotomy and INL between 2015 and 2017 at University Hospital Southampton. Patients with type I (6) or type II (2) refractory TN and no clear neurovascular conflict were offered INL as an alternative to partial sensory rhizotomy. Barrow Pain Intensity Scale (BNI) and Brief Pain Inventory Facial scores (BPI-Facial) were assessed. Minimum follow-up was 2 years'.

RESULTS

Eight patients (7F:1M) underwent INL. Two had MS. Pre-operatively, all had severe pain (BNI grade V) and the median BPI-Facial score was 115 (range 79-123).. There were no unexpected complications. On last follow-up, six (75%) had no pain (BNI grade I), while two (25%) had recurred (at 5 and 27 months). Median BPI-Facial score for all patients on the last follow-up was 20 (range 18-91) reflecting dramatically improved quality of life and activities.

CONCLUSIONS

INL is a potentially safe and effective treatment for refractory TN. Long-term efficacy is unknown, but early results are promising.

The Molecular Basis and Pathophysiology of Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a complex orofacial pain syndrome characterized by the paroxysmal onset of pain attacks in the trigeminal distribution. The underlying mechanism for this debilitating condition is still not clearly understood. Decades of basic and clinical evidence support the demyelination hypothesis, where demyelination along the trigeminal afferent pathway is a major driver for TN pathogenesis and pathophysiology. Such pathological demyelination can be triggered by physical compression of the trigeminal ganglion or another primary demyelinating disease, such as multiple sclerosis. Further examination of TN patients and animal models has revealed significant molecular changes, channelopathies, and electrophysiological abnormalities in the affected trigeminal nerve. Interestingly, recent electrophysiological recordings and advanced functional neuroimaging data have shed new light on the global structural changes and the altered connectivity in the central pain-related circuits in TN patients. The current article aims to review the latest findings on the pathophysiology of TN and cross-examining them with the current surgical and pharmacologic management for TN patients. Understanding the underlying biology of TN could help scientists and clinicians to identify novel targets and improve treatments for this complex, debilitating disease.

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.

Neurapraxia in patients with trigeminal neuralgia but no identifiable neurovascular conflict during microvascular decompression: a retrospective analysis of 26 cases

Background

Microvascular decompression (MVD) is the first choice in patients with classic trigeminal neuralgia (TGN) that could not be sufficiently controlled by pharmacological treatment. However, neurovascular conflict (NVC) could not be identified during MVD in all patients. To describe the efficacy and safety of treatment with aneurysm clips in these situations.

Methods

A total of 205 patients underwent MVD for classic TGN at our center from January 1, 2015 to December 31, 2019. In patients without identifiable NVC upon dissection of the entire trigeminal nerve root, neurapraxia was performed using a Yasargil temporary titanium aneurysm clip (force: 90 g) for 40 s (or a total of 60 s if the process must be suspended temporarily due to bradycardia or hypertension).

Results

A total of 26 patients (median age: 64 years; 15 women) underwent neurapraxia. Five out of the 26 patients received prior MVD but relapsed. Immediate complete pain relief was achieved in all 26 cases. Within a median follow-up of 3 years (range: 1.0–6.0), recurrence was noted in 3 cases (11.5%). Postoperative complications included hemifacial numbness, herpes labialis, masseter weakness; most were transient and dissipated within 3–6 months.

Conclusions

Neurapraxia using aneurysm clip is safe and effective in patients with classic TGN but no identifiable NVC during MVD. Whether this method could be developed into a standardizable method needs further investigation.

Internal Neurolysis for the Treatment of Trigeminal Neuralgia: A Systematic Review

INTRODUCTION

Trigeminal neuralgia (TN) remains a challenging disease with debilitating symptoms and variable efficacy in terms of treatment options. Microvascular decompression (MVD) with internal neurolysis (IN) is an alternative treatment that might benefit patients but has limited understanding. We performed a systematic review of IN for the treatment of TN.

METHODS

Studies from 2000 to 2021 that had assessed IN for TN were aggregated and independently reviewed.

RESULTS

A total of 520 patients in 12 studies were identified, with 384 who had undergone IN (mean age, 53.8 years; range, 46-61.4 years; mean follow-up, 36.5 months). Preoperative symptoms had been present for ∼55.0 months before treatment, and pain was predominantly in V2 and V3 (26.8%), followed by other distributions. Of the patients, 83.7% (range, 72%-93.8%) had had an excellent to good outcome (Barrow Neurological Institute pain scale score [BNI-PS], I-II). The pain outcomes at 1 year were excellent for 58%-78.4%, good or better for 77%-93.75%, and fair or better for 80%-93.75% of the patients. On average, facial numbness after IN was experienced by 96% of the patients. However, at follow-up, facial numbness remained in only 1.75%-10%. Most of the remaining numbness was not significantly distressing to the patients. Subgroup comparisons of IN versus recurrent MVD, IN versus radiofrequency ablation, the effects of IN in the absence of vascular compression, and IN with and without MVD were also evaluated.

CONCLUSIONS

IN represents a promising surgical intervention for TN in the absence of vascular compression and for potential cases of recurrence. Complications were limited in general but require further study.

Long Time Efficacy and Safety of Microvascular Decompression Combined with Internal Neurolysis for Recurrent Trigeminal Neuralgia

Objective

To explore the clinical efficacy and safety of microvascular decompression (MVD) combined with internal neurolysis (IN) in the treatment of recurrent trigeminal neuralgia (TN) after MVD.

Methods

Sixty-four patients with recurrent TN admitted to the hospital from January 2014 to December 2017 were divided into two groups according to the surgical method. Twenty-nine patients, admitted from January 2014 to December 2015, were treated with MVD alone, whereas 35 admitted from January 2016 to December 2017 were treated with MVD+IN. The postoperative efficacy, complications, and pain recurrence rate of the two groups were analyzed.

Results

The efficacy of the MVD+IN and MVD groups were 88.6% and 86.2%, and the cure rates were 77.1% and 65.5% respectively. There was no statistically significant difference between the two groups (p>0.05). The cure rate (83.3%) of patients in the MVD+IN group, who were only found thickened arachnoid adhesions during the operation that could not be fully released, was significantly higher than that of the MVD group (30.0%) (p<0.05), while the efficacy (91.7% vs. 70%) of the two groups was not statistically different (p>0.05). For patients whose arachnoid adhesions were completely released, there had no significant difference (p>0.05) in the efficacy (87% vs. 94.7%) and recurrence rate (5.0% vs. 11.1%). The incidence of postoperative facial numbness (88.6%) in the MVD+IN group was higher than that in the MVD group (10.3%) (p<0.01). The long-term incidence of facial numbness was not statistically significant (p>0.05). In the 18–36 months follow-up, the recurrence rate of patients in the MVD+IN group (9.7%) and in the MVD group (16%) were not statistically different (p>0.05).

Conclusion

A retrospective comparison of patients with recurrent TN showed that both MVD and MVD combined with IN can effectively treat recurrent TN. Compared with MVD alone, MVD combined with IN can effectively improve the pain cure rate of patients with recurrent TN who have only severe arachnoid adhesions. The combination does not increase the incidence of long-term facial numbness and other complications.

External Neurolysis in Microvascular Decompression for Magnetic Resonance Imaging-Negative Idiopathic Trigeminal Neuralgia

OBJECTIVE

Internal neurolysis has been proposed as an alternative to microvascular decompression in patients with idiopathic trigeminal neuralgia (TN) in whom neurovascular compression is not confirmed by magnetic resonance imaging (MRI). External neurolysis, which straightens and realigns the trigeminal nerve root axis by dissecting the arachnoid membranes around the nerve, was reported 20 years ago in the context of so-called negative exploration when MRI did not confirm the absence of the offending vessel, but is not currently used.

METHODS

External neurolysis was performed in 4 patients with idiopathic TN with typical evoked neuralgic pain despite the absence of suspected offending vessels on MRI. The surgical findings that caused TN were summarized and the outcomes were evaluated using the Barrow Neurological Institute Pain Intensity Scale (BNI-PS).

RESULTS

Tethering and distortion of the nerve root by surrounding arachnoid membranes were commonly found. All 4 patients showed complete pain relief immediately after surgery. During the follow-up period of 26.5 ± 16.92 months (±standard deviation), 3 of 4 patients had no pain (score I, BNI-PS). One patient received a score of IIIa on the BNI-PS assessment. There was no instance of recurrence or side effects associated with the surgery.

CONCLUSIONS

Idiopathic TN can be induced by individual variation of the surrounding inner arachnoid membranes supporting the trigeminal nerve root, and the condition cannot be identified by MRI. Intradural external neurolysis may be considered an effective treatment for MRI-negative idiopathic TN.

Recent Advances in Trigeminal Neuralgia and Its Management: A Narrative Review

Trigeminal neuralgia (TN) is a chronic facial pain condition that affects one or more divisions of the trigeminal nerve (5th cranial nerve). It can be idiopathic, primary, or secondary. The cornerstone of the therapy has been antiepileptic medications, peripheral nerve blocks with various neurolytic agents, and surgical procedures. With the advent of newer technologies, minimally invasive neurolytic techniques like low-level laser therapy and ozone injection have revolutionized the management of TN. Novel drugs like vixotrigine and eslicarbazepine have been promising in reducing the frequency and severity of attacks. Inhaled carbon dioxide too has shown promising results in initial trials. Neuromodulation has given robust data in controlling neuralgic pain especially refractory to medical management. Pulsed radiofrequency has been used with increasing success and the side effects like dysesthesia and paresthesia are less. Cryotherapy, neural prolotherapy, and fiber knife techniques have helped us believe that TN can be controlled and cured. The need of the hour is to develop and explore newer modalities for trigeminal neuralgia treatment with minimum side effects. In this narrative review, we have tried to shed light into the newer modalities of treatment of TN along with new clinical classification for better disease recognition and management.

Efficacy of Internal Neurolysis for Trigeminal Neuralgia without Vascular Compression

BACKGROUND AND OBJECTIVE

 Trigeminal neuralgia is a common neurologic disease that seriously impacts a patient's quality of life. We retrospectively investigated the efficacy and safety of internal neurolysis (nerve combing) for trigeminal neuralgia without vascular compression.

PATIENTS AND METHODS

 This study was a retrospective review of all patients with trigeminal neuralgia who were admitted between January 2014 and February 2019. A subgroup of 36 patients had no vascular compression at surgery and underwent internal neurolysis. Chart review and postoperative follow-up were performed to assess the overall outcomes of internal neurolysis.

RESULTS

 Thirty-six patients were identified, with a mean age of 44.89 ± 7.90 (rang: 31-65) years and a disease duration of 5.19 ± 2.61 years. The immediate postoperative pain relief (Barrow Neurological Institute [BNI] pain score of I or II) rate was 100%. The medium- to long-term pain relief rate was 91.7%. Three patients experienced recurrence. Facial numbness was the primary postoperative complication. Four patients with a score of III on the BNI numbness scale immediately after surgery had marked improvement at 6 months. No serious complications occurred.

CONCLUSION

 Internal neurolysis is a safe and effective treatment for trigeminal neuralgia without vascular compression or clear responsible vessels.

Virtual reality-based evaluation of neurovascular conflict for the surgical planning of microvascular decompression in trigeminal neuralgia patients

OBJECTIVE

Trigeminal neuralgia (TN) is a lightning bolt of violent, electrifying, and stinging pain, often secondary to the neurovascular conflict (NVC). The vessels involved in NVC are mostly arteries and rarely veins. Evaluation of NVC in the deep infratentorial region is inseparably connected with cranial imaging. We retrospectively analyzed the potential influence of three-dimensional (3D) virtual reality (VR) reconstructions compared to conventional magnetic resonance imaging (MRI) scans on the evaluation of NVC for the surgical planning of microvascular decompression in patients with TN.

METHODS

Medical files were retrospectively analyzed regarding patient- and disease-related data. Preoperative MRI scans were retrospectively visualized via VR software to detect the characteristics of NVC. A questionnaire of experienced neurosurgeons evaluated the influence of VR visualization technique on identification of anatomical structures involved in NVC and on surgical strategy.

RESULTS

Twenty-four patients were included and 480 answer sheets were evaluated. Compared to conventional MRI, image presentation using 3D-VR modality significantly influenced the identification of the affected trigeminal nerve (p = 0.004), the vascular structure involved in the NVC (p = 0.0002), and the affected side of the trigeminal nerve (p = 0.005).

CONCLUSIONS

In patients with TN caused by NVC, the reconstruction of conventional preoperative MRI scans and the spatial and anatomical presentation in 3D-VR models offers the possibility of increased understanding of the anatomy and even more the underlying pathology, and thus influences operation planning and strategy.

Internal Neurolysis with and without Microvascular Decompression for Trigeminal Neuralgia: Case Series

OBJECTIVE

Microvascular decompression (MVD) has remained the first-line surgical treatment of trigeminal neuralgia when an offending vessel can be identified that is causing neurovascular compression. However, patients without neurovascular compression can either develop trigeminal neuralgia or recurrence after MVD. In addition, patients with venous and less severe arterial compression have been shown to have reduced efficacy after MVD. Internal neurolysis is a surgical technique used to separate the fascicles of the trigeminal nerve and might be a good option for patients with trigeminal neuralgia but without vascular compression.

METHODS

A retrospective, institutional review board-approved medical record review was performed of adult patients with trigeminal neuralgia who had undergone internal neurolysis. The search resulted in 32 patients who had been treated from 2016 to 2019. The Barrow Neurological Institute (BNI) pain intensity scale and hypesthesia scale (HS) were used to determine the outcomes.

RESULTS

The average follow-up was 20 months (range, 3-40 months). The postoperative outcomes showed a BNI pain intensity scale score of I for 50%, with excellent control in 56%, successful control in 78%, adequate control in 94%, and poor control in 6%. Significantly more patients without previous treatment had had successful pain control (95% vs. 54%). Six patients (19%) experienced pain recurrence and were significantly more likely to experience pain recurrence compared with patients without a previous procedure (39% vs. 5%). The overall BNI-HS score postoperatively was I for 28%, II for 69%, and III for 3%.

CONCLUSIONS

Internal neurolysis with and without MVD has shown efficacy in treating trigeminal neuralgia in carefully selected patients.

Treatment of Trigeminal Neuralgia with "Microvascular Decompression Plus" Technique

Objective  Although microvascular decompression (MVD) has been widely accepted as an effective treatment of trigeminal neuralgia (TN), some patients have not been cured. To improve the postoperative outcome, the surgical procedure should be further refined. Design  This is a retrospective study. Setting  Present study conducted at a cranial nerve disorder center. Participants  Clinical data were collected from patients with TN who had undergone surgery in our center, including 685 who had undergone traditional MVD and 576 who had undergone the "MVD plus" procedure, in which any vessel attached to the trigeminal nerve was freed away ("nerve-combing"), which was followed by intraoperative neurolysis. Main Outcome Measures  Postoperative outcomes and complications in the two groups were compared. Results  Among patients who underwent traditional MVD, the rates of immediate relief and 1-year relief were 89.9 and 86.9%, respectively; among patients who underwent MVD plus group, these rates were 95.1 and 94.6%, respectively ( p  = 0.05). Patients who underwent MVD plus initially exhibited a higher rate of facial numbness ( p  < 0.05), but this finding decreased over time and reached the same level as that in the traditional MVD group within 3 months ( p  > 0.05). Conclusion  Sufficient MVD with nerve-combing for the treatment of TN may produce a high rate of cure with less recurrence.

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.

Relationship Between Arterial Blood Pressure During Trigeminal Nerve Combing and Surgical Outcome in Patients with Trigeminal Neuralgia

INTRODUCTION

Changes in blood pressure during trigeminal combing have been discussed in recent years. In this study, a retrospective analysis of patients with trigeminal neuralgia (TN) requiring microvascular decompression (MVD) with nerve combing was carried out to investigate fluctuation in arterial blood pressure during trigeminal nerve combing and its surgical effect and corresponding pathogenesis.

METHODS

A total of 70 cases of MVD with nerve combing performed during the treatment of primary TN patients were selected between January 2017 and January 2018 at Peking University People's Hospital. The degree of pain and prognosis of the patients were evaluated according to the visual analog scale. Postoperative facial numbness of the 2 groups were assessed by the Barrow Neurological Institute facial numbness score. Arterial blood pressure changes before and while combing the trigeminal nerve during MVD were dynamically monitored, and the patients were divided into responders and nonresponders. Total adrenaline (AD), norepinephrine (NE), and dopamine values were measured before and during trigeminal nerve combing.

RESULTS

Increased arterial blood pressure during the combing of the trigeminal nerve in MVD had a significant correlation with the prognosis of patients, with patients with higher arterial blood pressure having a better prognosis (P < 0.05). In the increased arterial blood pressure patients, precombing total AD and NE means were dramatically improved (P < 0.05).

CONCLUSIONS

This study shows that changes in arterial blood pressure during trigeminal nerve combing in MVD were correlated with the prognosis of patients. Further research is necessary to clarify the mechanism of increased arterial blood pressure.

Pain and Psychological Distress: Effect of Microvascular Decompression on Sleep Disorders and Obsessions in Trigeminal Neuralgia

Objective  This study was aimed to investigate the effects of microvascular decompression (MVD) on sleep disorders and obsessions in trigeminal neuralgia. Methods  Clinical data from 115 patients with trigeminal neuralgia treated with MVD from August 1, 2017 to May 31, 2018 at Jining First People's Hospital were analyzed retrospectively. The preoperative and postoperative risk factors for sleep disorders and obsessions, as well as the effects of MVD on sleep disorders and obsessions, were examined. Results  In 115 patients, there were significant differences in preoperative sleep disorders associated with sex, monthly household income, pain in multiple branches, visual analog scale (VAS) score, and Self-Rating Depression Scale (SDS) score ( p  < 0.05). Preoperative obsessions were significantly different according to age, gender, pain in multiple branches, monthly household income, VAS score, and Self-Rating Anxiety Scale (SAS) score groups ( p  < 0.05). A 1-year recurrence was positively correlated with sleep disturbance (odds ratio = 3.829) and obsessions (odds ratio = 4.507). In addition, the results revealed a negative correlation between the manipulation of trigeminal neuralgia and postoperative sleep disorders ( B  ≥ 1.043). Moreover, there was a significant difference in sleep disorders and obsessions before and 1 year after MVD ( p  < 0.05). Conclusion  For patients with trigeminal neuralgia, pain caused by sleep and obsession disorders should be examined early to identify an effective solution. Moreover, MVD, as a first treatment, is valuable for improving the physiological and psychological prognosis of patients.

A novel scoring system as a preoperative predictor for pain-free survival after microsurgery for trigeminal neuralgia

OBJECTIVE

Pain relief following microvascular decompression (MVD) for trigeminal neuralgia (TN) may be related to pain type, degree of neurovascular conflict, arterial compression, and location of compression. The objective of this study was to construct a predictive pain-free scoring system based on clinical and radiographic factors that can be used to preoperatively prognosticate long-term outcomes for TN patients following surgical intervention (MVD or internal neurolysis [IN]). It was hypothesized that contributing factors would include pain type, presence of an artery or vein, neurovascular conflict severity, and compression location (root entry zone).

METHODS

At the authors' institution 275 patients with type 1 or type 2 TN (TN1 or TN2) underwent MVD or IN following preoperative high-resolution brain MRI studies. Outcome data were obtained retrospectively by chart review and/or phone follow-up. Characteristics of neurovascular conflict were obtained from preoperative MRI studies. Factors that resulted in a probability value of < 0.05 on univariate logistic regression analyses were entered into a multivariate Cox regression analysis in a backward stepwise fashion. For the multivariate analysis, significance at the 0.15 level was used. A prognostic system was then devised with 4 possible scores (0, 1, 2, or 3) and pain-free survival analyses conducted.

RESULTS

Univariate predictors of pain-free survival were pain type (p = 0.013), presence of any vessel (p = 0.042), and neurovascular compression severity (p = 0.038). Scores of 0, 1, 2, and 3 were found to be significantly different in regard to pain-free survival (log rank, p = 0.005). At 5 and 10 years there were 36%, 43%, 61%, and 69%, and 36%, 43%, 56%, and 67% pain-free survival rates in groups 0, 1, 2, and 3, respectively. While TN2 patients had worse outcomes regardless of score, a subgroup analysis of TN1 patients with higher neurovascular conflict (score of 3) had significantly better outcomes than TN1 patients without severe neurovascular conflict (score of 1) (log rank, p = 0.005). Regardless of pain type, those patients with severe neurovascular conflict were more likely to have arterial compression (99%) compared to those with low neurovascular conflict (p < 0.001).

CONCLUSIONS

Pain-free survival was predicted by a scoring system based on preoperative clinical and radiographic findings. Higher scores predicted significantly better pain relief than lower scores. TN1 patients with severe neurovascular conflict had the best long-term pain-free outcome.

Surgical treatment of trigeminal neuralgia with no neurovascular compression: A retrospective study and literature review

The objective of the current study is to summarize the experiences of 360-degree circumferential arachnoid dissection for TN in patients without NVC. Clinical data from 19 TN patients without NVC who underwent 360-degree circumferential arachnoid dissection were retrospectively analyzed. All patients underwent preoperative examinations of three-dimensional time-of-flight magnetic resonance angiography (3D-TOF-MRA) and three-dimensional nuclear magnetic resonance of constructive interference in steady state (3D-CISS) to identify the neurovascular structures around the trigeminal nerve. Surgical outcomes were evaluated based on the Barrow Neurological Institute (BNI) Pain Intensity Scale, and severity of pain was determined using the visual analogue scale (VAS) score. Preoperative imaging showed that no patients had NVC compression. The preoperative BNI pain score was IV among 9 patients and V among other 10 patients. The preoperative VAS score was 7.89 ± 0.658. After the operation, pain disappeared in all 19 patients, and transient facial numbness occurred in 3 patients. During follow-up, pain in 2 of 19 patients (10.5%) recurred at postoperative 20 and 23 months. This study demonstrated that 360-degree circumferential arachnoid dissection is an alternative treatment for trigeminal neuralgia in patients with no neurovascular compression, especially when a thickened arachnoid, angulation, or torsion of the trigeminal nerve root was found during the operation. However, further study is needed to compare the outcomes of different surgical strategies and prove the efficacy of 360-degree circumferential arachnoid dissection in cases without neurovascular compression (NVC).

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.

Postherpetic Neuralgia and Trigeminal Neuralgia

Postherpetic neuralgia (PHN) is an unpredictable complication of varicella zoster virus- (VZV-) induced herpes zoster (HZ) which often occurs in elderly and immunocompromised persons and which can induce psychosocial dysfunction and can negatively impact on quality of life. Preventive options for PHN include vaccination of high-risk persons against HZ, early use of antiviral agents, and robust management of pain during the early stage of acute herpes zoster. If it does occur, PHN may persist for months or even years after resolution of the HZ mucocutaneous eruptions, and treatment is often only partially effective. Classical trigeminal neuralgia is a severe orofacial neuropathic pain condition characterized by unilateral, brief but recurrent, lancinating paroxysmal pain confined to the distribution of one or more of the branches of the trigeminal nerve. It may be idiopathic or causally associated with vascular compression of the trigeminal nerve root. The anticonvulsive agents, carbamazepine or oxcarbazepine, constitute the first-line treatment. Microvascular decompression or ablative procedures should be considered when pharmacotherapy is ineffective or intolerable. The aim of this short review is briefly to discuss the etiopathogenesis, clinical features, and treatment of PHN and classical trigeminal neuralgia.

Long-Term Efficacy of Nerve Combing for Patients with Trigeminal Neuralgia and Failed Prior Microvascular Decompression

BACKGROUND

Microvascular decompression (MVD) of the trigeminal nerve is the most effective treatment for trigeminal neuralgia (TN). However, many patients respond poorly to initial MVD. For these patients, redo MVD is commonly done. There has been no research regarding the effectiveness of nerve combing (NC) plus MVD in patients with TN and failed prior MVD. We compared the clinical outcome of NC plus MVD and simple redo MVD in patients with TN and failed prior MVD.

METHODS

We performed a retrospective analysis of 148 patients with recurrent or persistent TN symptoms who underwent surgery between January 2007 and December 2015. Simple MVD was performed in 62 patients, and NC plus MVD was performed in 86 patients.

RESULTS

For simple MVD, success rates at 1 day, 7 days, 1 month, 3 months, and 1 year after surgery all were approximately 80%. Success rates of NC plus MVD were significantly (P < 0.05) higher than success rates of simple MVD, by 17.02%, 18.64%, 16.47%, 17.21%, and 14.80% at 1 day, 7 days, 1 month, 3 months, and 1 year. The incidence rates of facial numbness in the simple MVD group were 48.39%, 45.16%, 36.67%, 16.95%, and 1.75% at 1 day, 7 days, 1 month, 3 months, and 1 year; the incidence rates in the NC plus MVD group were 60.47%, 55.81%, 48.24%, 21.69%, and 3.75% (P > 0.05).

CONCLUSIONS

In patients with TN who failed prior MVD, NC plus MVD significantly improved the success rate of the operation compared with simple redo MVD. We obtained good short-term and long-term surgical outcomes with NC combined with MVD.

A retrospective study of neurocombing for the treatment of trigeminal neuralgia without neurovascular compression

BACKGROUND

Microvascular decompression (MVD) is the most effective and non-ablative treatment for trigeminal neuralgia (TN). However, it is not possible when neurovascular compression (NVC) is absent. Neurocombing is a possible treatment option for TN patients without NVC.

AIM

To evaluate and describe the clinical outcome of neurocombing for the treatment of TN when NVC was absent.

METHODS

We retrospectively reviewed the clinical data of the 37 patients of Type 1 TN without NVC who underwent neurocombing in our department between January 2013 and November 2014. The Barrow Neurological Institute (BNI) Pain Intensity scale, the numerical rating scale (NRS) and the quality of life scale (QOL) were evaluated in four stages-presurgical, immediate, at 1 and at 3 years. Pain recurrence was statistically evaluated with Kaplan-Meier analysis.

RESULTS

All the 37 enrolled patients were proved to have no NVC by imaging or exploration in surgery. The mean follow-up duration was 29.50 months. After the procedure, 35 patients (94.6%) experienced immediate pain relief (BNI I) and 2 patients (5.4%) had occasional pain without any medication (BNI II). At 1 year and 3 years, the rates of successful pain relief (BNI I&II) were 86.5 and 83.3%, respectively. 34 patients (91.9%) suffered from mild facial numbness, while it did not exert a harmful impact on their quality of life.

CONCLUSIONS

This study demonstrated that neurocombing is an attractive, effective, safe and durable treatment option for TN when NVC is absent. Further study is needed to explain the complicated and exact mechanism of pain relief by neurocombing.

Trigeminal Neuralgia

Trigeminal neuralgia (TN) is a sudden, severe, brief, stabbing, and recurrent pain within one or more branches of the trigeminal nerve. Type 1 as intermittent and Type 2 as constant pain represent distinct clinical, pathological, and prognostic entities. Although multiple mechanism involving peripheral pathologies at root (compression or traction), and dysfunctions of brain stem, basal ganglion, and cortical pain modulatory mechanisms could have role, neurovascular conflict is the most accepted theory. Diagnosis is essentially clinically; magnetic resonance imaging is useful to rule out secondary causes, detect pathological changes in affected root and neurovascular compression (NVC). Carbamazepine is the drug of choice; oxcarbazepine, baclofen, lamotrigine, phenytoin, and topiramate are also useful. Multidrug regimens and multidisciplinary approaches are useful in selected patients. Microvascular decompression is surgical treatment of choice in TN resistant to medical management. Patients with significant medical comorbidities, without NVC and multiple sclerosis are generally recommended to undergo gamma knife radiosurgery, percutaneous balloon compression, glycerol rhizotomy, and radiofrequency thermocoagulation procedures. Partial sensory root sectioning is indicated in negative vessel explorations during surgery and large intraneural vein. Endoscopic technique can be used alone for vascular decompression or as an adjuvant to microscope. It allows better visualization of vascular conflict and entire root from pons to ganglion including ventral aspect. The effectiveness and completeness of decompression can be assessed and new vascular conflicts that may be missed by microscope can be identified. It requires less brain retraction.

Comparison of nerve combing and percutaneous radiofrequency thermocoagulation in the treatment for idiopathic trigeminal neuralgia

Introduction

Idiopathic trigeminal neuralgia (ITN) is a common pain disease in elderly people. Many methods have been used to alleviate the pain of patients, but few studies in the literature have compared the effect of nerve combing and percutaneous radiofrequency thermocoagulation.

Objective

The purpose of this study was to describe and evaluate the clinical outcome of idiopathic trigeminal neuralgia after nerve combing (NC) and compare them with those obtained using percutaneous radiofrequency thermocoagulation (RF).

Methods

The study included 105 idiopathic trigeminal neuralgia patients with similar symptom, age and underlying disease, which were divided into two groups. One group was treated by nerve combing (50 patients), the other by RF (55 cases). All patients were considered medical failures prior to the surgeries. A questionnaire was used to assess the long-term outcomes: pain relief, recurrence, complication and need for additional treatment.

Results

The median duration of follow-up in both groups was 90 months. Satisfactory relief was noted in 41 patients (82%), 5 patients (10%) initially experienced pain relief, then recurred, and four patients (8%) were designated poor among the group NC. In the group RF, satisfactory relief was noted in 42 patients (76.4%). There were eight “pain free with recurrence patients (14.5%) and 5 poor cases (9.1%). No statistically significant differences existed in the outcomes between both groups (p > 0.05). Postoperative morbidity included dysesthesia, diplopia, partial facial nerve palsy, hearing loss, tinnitus, cerebrospinal fluid leak, meningitis and mortality.

Conclusion

Nerve combing and RF are both satisfactory treatment strategies for patients with ITN. Because of the higher risk of sensory morbidity and surgical risk as open surgery, RF is preferred as the recommended procedure for patients with ITN.

Long-term efficacy and safety of internal neurolysis for trigeminal neuralgia without neurovascular compression

OBJECT Trigeminal neuralgia (TN) occurs and recurs in the absence of neurovascular compression (NVC). While microvascular decompression (MVD) is the most effective treatment for TN, it is not possible when NVC is not present. Therefore, the authors sought to evaluate the safety, efficacy, and durability of internal neurolysis (IN), or "nerve combing," as a treatment for TN without NVC. METHODS This was a retrospective review of all cases of Type 1 TN involving all patients 18 years of age or older who underwent evaluation (and surgery when appropriate) at Oregon Health & Science University between July 2006 and February 2013. Chart reviews and telephone interviews were conducted to assess patient outcomes. Pain intensity was evaluated with the Barrow Neurological Institute (BNI) Pain Intensity scale, and the Brief Pain Inventory-Facial (BPI-Facial) was used to assess general and face-specific activity. Pain-free survival and durability of successful pain relief (BNI pain scores of 1 or 2) were statistically evaluated with Kaplan-Meier analysis. Prognostic factors were identified and analyzed using Cox proportional hazards regression. RESULTS A total of 177 patients with Type 1 TN were identified. A subgroup of 27 was found to have no NVC on high-resolution MRI/MR angiography or at surgery. These patients were significantly younger than patients with classic Type 1 TN. Long-term follow-up was available for 26 of 27 patients, and 23 responded to the telephone survey. The median follow-up duration was 43.4 months. Immediate postoperative results were comparable to MVD, with 85% of patients pain free and 96% of patients with successful pain relief. At 1 year and 5 years, the rate of pain-free survival was 58% and 47%, respectively. Successful pain relief at those intervals was maintained in 77% and 72% of patients. Almost all patients experienced some degree of numbness or hypesthesia (96%), but in patients with successful pain relief, this numbness did not significantly impact their quality of life. There was 1 patient with a CSF leak and 1 patient with anesthesia dolorosa. Previous treatment for TN was identified as a poor prognostic factor for successful outcome. CONCLUSIONS This is the first report of IN with meaningful outcomes data. This study demonstrated that IN is a safe, effective, and durable treatment for TN in the absence of NVC. Pain-free outcomes with IN appeared to be more durable than radiofrequency gangliolysis, and IN appears to be more effective than stereotactic radiosurgery, 2 alternatives to posterior fossa exploration in cases of TN without NVC. Given the younger age distribution of patients in this group, consideration should be given to performing IN as an initial treatment. Accrual of further outcomes data is warranted.

Trigeminal root compression for trigeminal neuralgia in patients with no vascular compression

BACKGROUND

Trigeminal neuralgia (TN) may be present in the absence of vascular compressiom, and surgical treatment in these cases is controversial. Our objective is to evaluate the efficacy and safety of trigeminal root compression in this situation.

METHODS

A prospective collection of clinical data on all patients diagnosed with idiopathic TN in our institution. Cases with no visible offending vessel intraoperatively were included in this study. These patients underwent trigeminal root compression and long-term follow-up. The basic characteristics and outcomes were analyzed.

RESULTS

From February 2005 to November 2010, 381 patients underwent microvascular decompression for TN at our department. Among them, 28(7.3 %) patients (17 female, 11 male) had no visible vascular compression intraoperatively. The median observation period was 46 months (range, 8-60 months). Twenty patients (71.4 %) achieved complete pain relief without medication immediately postoperatively. However, the recurrence rate was 38.4 %, and only 13 patients (46.4 %) achieved complete pain relief without medication at follow-up. Ten patients (35.7 %) developed some degree of facial numbness, which was transient in six cases (21.4 %) and permanent in four (14.3 %).

CONCLUSIONS

Although trigeminal root compression provides good initial pain relief, the long-term efficacy, complication and recurrence rates are far from satisfactory. Further studies are needed to explore the possible mechanisms of underlying pain and to compare the outcomes of various types of interventions in cases without vascular compression.