“Nerve Combing” for Trigeminal Neuralgia Without Vascular Compression: Report of 10 Cases

Revisiting the Efficacy of Redo Microvascular Decompression for Trigeminal Neuralgia

BACKGROUND

Microvascular decompression (MVD) is an effective nondestructive neurosurgical procedure for trigeminal neuralgia (TN). However, some patients may undergo surgery failure or experience pain recurrence, sparking debates on the need for reoperation.

METHODS

We conducted a retrospective analysis of 103 cases of patients with primary TN who underwent redo MVD at our center between January 2020 and December 2022. Comparative prognostic assessments were performed by comparing these cases against a cohort of 348 patients who underwent primary MVD during the same study period.

RESULTS

During the redo MVD cases, arachnoid membranes adhesions (80.6%) and Teflon adhesions with/without granuloma (86.4%) as well as remaining vascular compression (36.9%) were observed. After the reoperation, an immediate relief rate of 94.2% was observed. During a mean follow-up period of 17.4 ± 4.4 months, a long-term relief rate of 89.3% was achieved. Postoperative complications included 3 cases of persistent paresthesia, 1 case each of hearing loss, cerebrospinal fluid leak, and facial palsy. Ten cases without evident compression received nerve combing and all experienced immediate complete relief, with only 1 patient experiencing recurrence 9 months after surgery. Compared to the primary MVD group, the reoperation group had a higher average age, longer disease duration, and operating time (P < 0.05). However, there were no significant differences in immediate relief rate, long-term relief rate, or complications between the 2 groups. The main cause of persistent symptom was inadequate decompression, such as missing the offending vessel; while the recurrent was primarily due to Teflon adhesion or granuloma formation.

CONCLUSIONS

The redo MVD for TN is equally efficacious and safe compared to the primary procedure, with an emphasis on meticulous dissection and thorough decompression. Additionally, nerve combing proves to be an effective supplementary option for patients without obvious compression.

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.

Facial Nerve Massage for the Treatment of Hemifacial Spasm Refractory to Microvascular Decompression: Outcomes and Complications

BACKGROUND

After microvascular decompression (MVD) for hemifacial spasm (HFS), a minority of patients realize little to no relief of spasms. In some patients, the absence of relief of spasms results from incomplete or inadequate decompression of vascular compression of the facial nerve, and these patients represent excellent candidates for repeat MVD. However, in other patients, repeat MVD is not appropriate because adequate decompression and resolution of neurovascular compression, as determined by postoperative high-resolution MRI, was achieved with the initial operation.

OBJECTIVE

To present a cohort of patients with a history of HFS refractory to MVD, with no evidence of neurovascular compression on postoperative MRI, who underwent facial nerve massage (FNM) in the posterior fossa in an attempt to relieve spasms.

METHODS

Thirteen patients with a history of incomplete relief of spasms after technically adequate MVD surgery for hemifacial spasm underwent FNM. Immediate and long-term degree of spasm relief and complications after FNM were documented through in-person or telemedicine interview.

RESULTS

At follow-up after FNM, 7 of 12 patients (58.3%) reported complete spasm relief (grade I), 2 of 12 patients (16.7%) reported &gt;75% spasm relief (grade II), 0 patient (0%) reported &gt;50% spasm relief (grade III), 3 of 12 (25.0%) patients reported &lt;50% spasm relief (grade IV), and 1 patient was lost to follow-up. One patient experienced a delayed facial paresis, and another patient experienced high-frequency hearing loss.

CONCLUSION

After FNM, durable and, at least, partial relief of spasms with a relatively low complication rate was observed in most patients with HFS with incomplete relief of spasms after technically adequate prior MVD.

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.

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.

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.

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.

The efficacy and safety of nerve combing for trigeminal neuralgia without neurovascular compression

OBJECTIVE

The purpose of our study was to review and evaluate the efficacy and safety of nerve combing without neurovascular decompression for trigeminal neuralgia.

METHODS

A retrospective review of 298 patients with trigeminal neuralgia between August 2007 and August 2016 was conducted. The patients were divided into two groups: the A group was treated by nerve combing (34 patients) and the B group received microvascular decompression (264 patients). Surgical outcomes and postoperative complications were compared between the two groups.

RESULTS

Pain was completely relieved in 88.2% of group A patients and 92.8% of group B after surgery. The median duration of follow-up was 60 months (range 10-115 months) in group A and 62 months (range 12-118 months) in group B. 72.7% and 86.4% of cases were completely relieved in groups A and B, respectively. There were no statistically significant differences in the surgical outcomes between the two groups. Almost all patients experienced some degree of numbness or hypesthesia (76.5%). The rate of facial numbness in group A was significantly higher than that in group B.

CONCLUSION

This study demonstrated that nerve combing without neurovascular decompression is a safe and effective treatment for trigeminal neuralgia. However, a majority of patients treated with nerve combing experienced some degree of facial numbness.

Retrosigmoid approach for glycerin rhizotomy in the treatment of trigeminal neuralgia without overt arterial compression: updated case series

OBJECTIVE

Trigeminal neuralgia (TN) is a neuropathic pain disorder characterized by severe, lancinating facial pain that is commonly treated with neuropathic medication, percutaneous rhizotomy, and/or microvascular decompression (MVD). Patients who are not found to have distinct arterial compression during MVD present a management challenge. In 2013, the authors reported on a small case series of such patients in whom glycerin was injected intraoperatively into the cisternal segment of the trigeminal nerve. The objective of the authors' present study was to report their updated experience with this technique to further validate this novel approach.

METHODS

The authors performed a retrospective analysis of data obtained in patients in whom glycerin was directly injected into the inferior third of the cisternal portion of the trigeminal nerve. Seventy-four patients, including 14 patients from the authors' prior study, were identified, and demographic information, intraoperative findings, postoperative course, and complications were recorded. Fisher's exact test, unpaired t-tests, and Kaplan-Meier survival curves using Mantel log-rank test were used to compare the 74 patients with a cohort of 476 patients who received standard MVD by the same surgeon.

RESULTS

The 74 patients who underwent MVD and glycerin injection had an average follow-up of 19.1 ± 18.0 months, and the male/female ratio was 1:2.9. In 33 patients (44.6%), a previous intervention for TN had failed. On average, patients had an improvement in the Barrow Neurological Institute Pain Intensity score from 4.1 ± 0.4 before surgery to 2.1 ± 1.2 after surgery. Pain improvement after the surgery was documented in 95.9% of patients. Thirteen patients (17.6%) developed burning pain following surgery. Five patients developed complications (6.7%), including incisional infection, facial palsy, CSF leak, and hearing deficit, all of which were minor.

CONCLUSIONS

Intraoperative injection of glycerin into the trigeminal nerve is a generally safe and potentially effective treatment for TN when no distinct site of arterial compression is identified during surgery or when decompression of the nerve is deemed to be inadequate.

Herpes Simplex Reactivation After Surgical Treatment of Trigeminal Neuralgia: A Retrospective Cohort Study

BACKGROUND

Herpes simplex virus (HSV) reactivation after surgery for trigeminal neuralgia has long been recognized. Only a few studies to date have focused on this complication, and its actual incidence remains unknown. The aim of this study was to investigate the incidence of postoperative herpes labialis (HL) in a cohort of patients treated with either percutaneous balloon compression or microvascular decompression to identify potentially significant differences between different treatments.

METHODS

A total of 92 patients who were operated on for TN with microvascular decompression (group A) or percutaneous balloon compression (group B) in the period 2010-2017 were retrospectively evaluated. The 2 subgroups of patients were compared according to history of previous HL and incidence of postoperative HL.

RESULTS

The final cohort comprised 56 male and 36 female patients. Average age was 58.50 years; 30 male patients belonged to group A and 26 male patients belonged to group B. Lifetime incidence of episodes of HL before surgery in 18/58 patients in group A (31.0%) and 12/34 patients in group B (35.3%), with no statistically significant difference among subgroups. Postoperatively, 1/56 patients in group A (1.7%) experienced HL compared 5/34 patients in group B (14.7%), with a strongly statistically significant difference between the 2 subgroups.

CONCLUSIONS

In our clinical experience, herpes simplex virus reactivation after surgery for trigeminal neuralgia is not so rare and is still not completely understood. Postoperative herpes simplex virus reactivation could be due to a direct mechanical injury on gasserian ganglion neurons, which is more common after percutaneous balloon compression.

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).

Management of veins during microvascular decompression for idiopathic trigeminal neuralgia

OBJECT

To summarize our experience in treating veins during microvascular decompression (MVD) procedures for idiopathic trigeminal neuralgia (TN).

METHODS

A total of 210 patients who underwent single MVD for idiopathic TN were retrospectively studied. The offending vessels were summarized. The treatment choices for veins during the operation were reviewed. Postoperative long-term outcomes were determined by follow-up.

RESULTS

Veins accounted for 26.7% of the total 262 offending vessels. Neurovascular conflicts were caused by veins alone in 23 patients (11.2%), and they were caused by arteries and veins together in 47 patients (22.8%). The offending veins were cut (15.7%) or saved (84.3%) during the operation. Excellent long-term outcomes were acquired in 78.3% of the patients with venous type TN.

CONCLUSION

There are no acknowledged principles guiding the treatment of veins during MVD. Our primary treatment principle is to retain veins as often as possible.

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.

Endoscopic versus microscopic microvascular decompression for trigeminal neuralgia: equivalent pain outcomes with possibly decreased postoperative headache after endoscopic surgery

OBJECTIVE

Endoscopic surgery has revolutionized surgery of the ventral skull base but has not yet been widely adopted for use in the cerebellopontine angle. Given the relatively normal anatomy of the cerebellopontine angle in patients with trigeminal neuralgia (TN), the authors hypothesized that a fully endoscopic microvascular decompression (E-MVD) might provide pain outcomes equivalent to those of microscopic MVD (M-MVD) but with fewer complications.

METHODS

The authors conducted a single-institution, single-surgeon retrospective study with patients treated in the period of 2006–2013. Before surgery, all patients completed a questionnaire that included a validated multidimensional pain-outcome tool, the Penn Facial Pain Scale (PFPS, formerly known as Brief Pain Inventory–Facial), an 11-point scale that measures pain intensity, interference with general activities of daily living (ADLs), and facial-specific ADLs. Using a standardized script, independent research assistants conducted follow-up telephone interviews.

RESULTS

In total, 167 patients were available for follow-ups (66.5% female; 93 patients underwent M-MVD and 74 underwent E-MVD). Preoperative characteristics (i.e., TN classification, PFPS components, and medication use) were similar for the 2 surgical groups except for 2 variables. Patients in the M-MVD group had slightly higher incidence of V3 pain, and the 2 groups differed in the date of surgery and hence in the length of follow-up (2.4 years for the M-MVD group and 1.3 years for the E-MVD group, p < 0.05). There was a trend toward not finding neurovascular conflict at the time of surgery more frequently in the M-MVD than in the E-MVD group (11% vs 7%, p = 0.052). Internal neurolysis was more often performed in the E-MVD group (26% vs 7%, p = 0.001). The 2 groups did not significantly differ in the length of the MVD procedure (approximately 2 hours). Self-reported headaches at 1 month postoperatively were present in 21% of the patients in the M-MVD group versus 7% in the E-MVD group (p = 0.01). Pain outcomes at the most recent followup were equivalent, with patients reporting a 5- to 6-point (70%–80%) improvement in pain intensity, a 5-point (85%) improvement in pain interference with ADLs, and a 6-point (85%) improvement in interference with facial-specific ADLs. Actuarial freedom from pain recurrence was equivalent in the 2 groups, with 80% pain control at 3 years.

CONCLUSIONS

Both the fully endoscopic MVD and the conventional M-MVD appear to provide patients with equivalent pain outcomes. Complication rates were also similar between the groups, with the exception of the rate of headaches, which was significantly lower in the E-MVD group 1 month postoperatively.

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.

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.

Occurrence of Herpes Simplex Virus Reactivation Suggests a Mechanism of Trigeminal Neuralgia Surgical Efficacy

Common to the types of surgery that are effective for the treatment of trigeminal neuralgia (TN) is reactivation of herpes simplex virus (HSV). It is likely that such HSV reactivation following surgery indicates altered trigeminal ganglion neuron function, which was caused by the surgery. It is not thought that HSV infection is related to the cause of TN or that HSV reactivation is important for surgical treatment efficacy. Rather, it is thought that HSV reactivation is a marker of altered trigeminal ganglion neuron function resulting from the TN surgery. It is suggested that HSV reactivation is a surrogate marker of ganglion neuron injury. The correlation between effective types of surgery and evidence that they alter ganglion neuron function suggests that altered trigeminal ganglion neuron function may be the basis of the surgical efficacy.

Trigeminal neuralgia without neurovascular compression presents earlier than trigeminal neuralgia with neurovascular compression

OBJECT

Trigeminal neuralgia (TN) occurs and recurs in the absence of neurovascular compression (NVC). To characterize what may be distinct patient populations, the authors examined age at onset in patients with TN with and without NVC.

METHODS

A retrospective review of patients undergoing posterior fossa surgery for Type I TN at Oregon Health & Science University from 2009 to 2013 was undertaken. Charts were reviewed, and imaging and operative data were collected for patients with and without NVC. Mean, median, and the empirical cumulative distribution of onset age were determined. Statistical analysis was performed using Student t-test, Wilcoxon and Kolmogorov-Smirnoff tests, and Kaplan-Meier analysis. Multivariate analysis was performed using a Cox proportional hazards model.

RESULTS

The charts of 219 patients with TN were reviewed. There were 156 patients who underwent posterior fossa exploration and microvascular decompression or internal neurolysis: 129 patients with NVC and 27 without NVC. Mean age at symptoms onset for patients with and without NVC was 51.1 and 42.6 years, respectively. This difference (8.4 years) was significant (t-test: p = 0.007), with sufficient power to detect an effect size of 8.2 years. Median age between groups with and without NVC was 53.25 and 41.2 years, respectively (p = 0.003). Histogram analysis revealed a bimodal age at onset in patients without NVC, and cumulative distribution of age at onset revealed an earlier presentation of symptoms (p = 0.003) in patients without NVC. Chi-square analysis revealed a trend toward female predominance in patients without NVC, which was not significant (p = 0.08). Multivariate analysis revealed that age at onset was related to NVC but not sex, symptom side or distribution, or patient response to medical treatment.

CONCLUSIONS

NVC is neither sufficient nor necessary for the development of TN. Patients with TN without NVC may represent a distinct population of younger, predominantly female patients. Further research into the pathophysiology underlying this debilitating disease is needed.

Fully endoscopic microvascular decompression for trigeminal neuralgia: technique review and early outcomes

OBJECT

Fully endoscopicmicrovascular decompression (E-MVD) of the trigeminal nerve was initially described more than 1 decade ago, but has not yet gained wide acceptance. The authors present the experience of their first 47 consecutive E-MVDs for trigeminal neuralgia (TN).

METHODS

All surgeries were performed by a single surgeon (J.Y.K.L.) at the Pennsylvania Hospital at the University of Pennsylvania. Patients prospectively completed pain scales before and after surgery by using the Brief Pain Inventory-Facial outcomes tool. All patients were called on the telephone, and the same outcome tool was administered without reference to their preoperative pain status.

RESULTS

Forty-seven patients (17 men) were identified and enrolled. Forty (85%) had Burchiel Type 1 TN. Vascular compression was observed at surgery in 42 patients (89%). No surgery was aborted or converted to microscope. One patient suffered permanent hearing loss, for a permanent neurological morbidity rate of 2%. Overall improvement in pain outcomes was excellent, with a median maximum pain intensity preoperatively of 10 and postoperatively of 0 (p< 0.0001). The mean interference with global function scores were 6.2 preoperatively and reduced to 1.0 at last follow-up (p < 0.0001). The mean interference with facial function was 7.3 preoperatively and reduced to 1.2 at last follow-up (p < 0.0001). The mean follow-up period after surgery was 15 ± 8 months.

CONCLUSIONS

In experienced hands, E-MVD offers superb visualization and illumination and is both safe and effective, at least in the short term. Further longer-term study is needed to compare E-MVD to traditional microscopic MVD.

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.

The long-term outcome of nerve combing for trigeminal neuralgia

BACKGROUND

The purpose of our study was to describe and evaluate the long-term clinical outcome of nerve combing for idiopathic trigeminal neuralgia (TN) with and without vascular compression.

METHODS

The study included 60 trigeminal neuralgia patients, 28 of which (Group A) had no visible vascular compression intraoperatively and 32 of which (Group B) had trigeminal nerve root entry zone (REZ) compressed by vascular structure. All patients were considered medical failures prior to the surgeries. All of them underwent trigeminal nerve combing. The following outcome measures were assessed: pain relief, recurrence, complication and time to pain relief.

RESULTS

The median duration of follow-up was 52 months (range 48-96 months) in group A and 56 months (range 48-96 months) in group B. Excellent relief and good relief were noted in 23 patients (82.1 %) and two patients (7.1 %) from group A, respectively, and in 20 (62.5 %) and eight patients (25 %) from group B. The major complication of both groups was facial numbness. And the total complication rate was 15.8 % in group A and 18.8 % in group B. Recurrence was found in one patient in group A and in two in group B by the end of follow-up.

CONCLUSION

Trigeminal nerve combing is effective in treating TN, but has a much higher pain relief rate in patients without vascular compression than those with vascular compression.

Efficacy and safety of root compression of trigeminal nerve for trigeminal neuralgia without evidence of vascular compression

OBJECTIVE

Trigeminal neuralgia (TN) surgical treatment with microvascular decompression is highly effective and safe, but for a percentage of patients who undergo this procedure, no vascular compression is found. The purpose of this study was to evaluate the long-term efficacy with trigeminal root compression of the trigeminal nerve in patients with TN refractory to medical treatment who underwent neurosurgical management by a retrosigmoid approach of the cerebellopontine angle and were found to be negative for vascular compression.

METHODS

A prospective collection of clinical data on all patients with a diagnosis of idiopathic TN was conducted at our institution. A total of 277 patients with TN were treated by a keyhole retrosigmoid approach for exploration of the cerebellopontine angle between January of 2000 and August of 2010. A total of 44 patients were found to be negative for vascular compression of the trigeminal nerve; all of these patients underwent trigeminal root compression.

RESULTS

We found that all patients were pain free after the procedure. There was a 27% relapse in a mean time of 10 months, but 83% of these patients were adequately controlled by medical treatment, and only 17% needed a complementary procedure for pain relief. We also found that 63% of the patients complained of a partial loss of facial sensitivity, but only 1 patient presented with a corneal ulcer. There was a 6.7% rate of significant complications.

CONCLUSIONS

We concluded that trigeminal root compression is a safe and effective option for patients with primary TN without vascular compression.

Trigeminal neuralgia in young adults

OBJECT

Trigeminal neuralgia (TN) is a form of facial pain that can be debilitating if left untreated. It typically affects elderly adults and is thought to be related to neurovascular compression. It is uncommon in people younger than 30 years of age, with only 1% of cases reportedly occurring in those younger than 20 years of age. The most common cause of compression in young adults is thought to be venous nerve compression either alone or in association with arterial nerve compression. The objective of this study was to review data in cases of TN in which patients were 25 years of age or younger and to identify TN disease characteristics, demographics, clinical features, operative findings, and outcome.

METHODS

The authors retrospectively reviewed the clinical records, surgical treatment, and long-term outcome in patients 25 years of age or younger with TN who underwent surgery performed by the senior author (K.J.B.) at Oregon Health & Science University between 1995 and 2008.

RESULTS

Seven patients (2 males and 5 females) met the inclusion criteria. The average age at symptom onset was 19.6 ± 3.4 years (± SD) and the average age at surgery was 22.9 ± 1.7 years. Six patients had right-sided symptoms and 1 had left-sided symptoms. Pain distribution was the V2 in 3 cases, V2-3 in 3 cases, and V3 in 1 case, with no cases of V1 affliction. A total of 11 procedures were performed in 7 patients, and 4 patients underwent a second procedure. Surgery and imaging revealed venous compression in all cases. The average follow-up period was 35.5 ± 39.9 months (median 12 months). Three patients reported a good outcome (no pain with or without medications) and 4 reported a poor outcome (either no pain relief or mild pain relief after surgery).

CONCLUSIONS

Trigeminal neuralgia is uncommon in young adults. Patients tend to present with symptoms similar to those in adults: long periods of pain and venous compression, but outcome unfortunately is not as good as that reported in the older population.

Facial herpes zoster infection precipitated by surgical manipulation of the trigeminal nerve during exploration of the posterior fossa: a case report

INTRODUCTION

We present a case of herpes zoster infection (shingles) precipitated by surgical manipulation of the trigeminal nerve root during an attempted microvascular decompression procedure. The pathogenesis of this phenomenon, as well as the importance and role of prophylactic acyclovir in its management, are discussed.

CASE PRESENTATION

A 54-year-old Caucasian man with a classical long-standing left-sided V2 and V3 division primary trigeminal neuralgia refractory to medical management, underwent posterior fossa exploration for microvascular decompression via a standard retromastoid craniectomy. The patient had immediate and complete relief from pain. Three days after the operation, he developed severely painful vesicles with V2 and V3 dermatomal distribution. Rather than the classical paroxysmal, lancinating type of trigeminal neuralgia, the pain experienced by the patient was of a constant burning nature. A clinical diagnosis of herpes zoster (shingles) was made after smear confirmation from microbiological testing. The patient was commenced on antiviral treatment with acyclovir. His vesicular rash and pain gradually subsided over the next two weeks. He remains asymptomatic one year later.

CONCLUSIONS

Postoperative shingles precipitated by trigeminal nerve manipulation during surgery for trigeminal neuralgia can be a distressing and demoralizing experience for the patient. A careful preoperative history, early recognition, and prompt antiviral therapy is necessary.