Glycerol rhizotomy and radiofrequency thermocoagulation for trigeminal neuralgia in multiple sclerosis

Efficacy and Challenges: Minimally Invasive Procedures for Trigeminal Neuralgia Treatment in Multiple Sclerosis - A Systematic Review and Meta-Analysis

INTRODUCTION

Trigeminal neuralgia (TGN) poses a therapeutic challenge, particularly within the context of multiple sclerosis (MS). This study aimed to conduct a comprehensive meta-analysis and systematic review of four less-invasive treatment modalities for TGN in MS patients, namely, gamma knife radiosurgery (GKRS), glycerol rhizotomy (GR), balloon compression (BC), and radiofrequency ablation (RFA).

METHODS

Single-armed meta-analyses were employed to assess the overall efficacy of each treatment, while double-armed analyses compared the efficacy between different treatment options in double-armed studies. Outcome evaluations included acute pain relief (within 1 month post-procedure), recurrence rates throughout 18 months of follow-up, and reported complication rates.

RESULTS

The meta-analysis revealed diverse outcomes for each intervention. GKRS demonstrated favorable outcomes, achieving a 77% success rate in alleviating pain among a pooled cohort of 863 patients, reinforcing its status as a viable therapeutic option. Additionally, GR, BC, and RFA exhibited efficacy, with success rates of 77%, 71%, and 80%, respectively, based on outcomes observed in 611, 385, and 203 patients. Double-armed analyses highlighted distinctions between the treatments, providing nuanced insights for clinical decision-making.

CONCLUSION

This meta-analysis provides a comprehensive overview of less-invasive treatments for TGN in MS patients. GKRS emerges as a leading option with comparable efficacy and fewer complications. However, the study underscores the nuanced efficacy and considerations associated with GR, BC, and RFA. The findings offer valuable insights for clinicians navigating treatment choices in this challenging patient population, considering acute pain relief, recurrence rates, and complication profiles.

Pharmacological and Non-pharmacological Approaches for the Management of Neuropathic Pain in Multiple Sclerosis

Multiple sclerosis is a chronic inflammatory disease that affects the central nervous system and can cause various types of pain including ongoing extremity pain, Lhermitte's phenomenon, trigeminal neuralgia, and mixed pain. Neuropathic pain is a major concern for individuals with multiple sclerosis as it is directly linked to myelin damage in the central nervous system and the management of neuropathic pain in multiple sclerosis is challenging as the options available have limited efficacy and can cause unpleasant side effects. The literature search was conducted across two databases, PubMed, and Google Scholar. Eligible studies included clinical trials, observational studies, meta-analyses, systematic reviews, and narrative reviews. The objective of this article is to provide an overview of literature on pharmacological and non-pharmacological strategies employed in the management of neuropathic pain in multiple sclerosis. Pharmacological options include cannabinoids, muscle relaxants (tizanidine, baclofen, dantrolene), anticonvulsants (benzodiazepines, gabapentin, phenytoin, carbamazepine, lamotrigine), antidepressants (duloxetine, venlafaxine, tricyclic antidepressants), opioids (naltrexone), and botulinum toxin variants, which have evidence from various clinical trials. Non-pharmacological approaches for trigeminal neuralgia may include neurosurgical methods. Non-invasive methods, physical therapy, and psychotherapy (cognitive behavioral therapy, acceptance and commitment therapy and mindfulness-based stress reduction) may be recommended for patients with neuropathic pain in multiple sclerosis. The choice of treatment depends on the severity and type of pain as well as other factors, such as patient preferences and comorbidities. There is a pressing need for healthcare professionals and researchers to prioritize the development of better strategies for managing multiple sclerosis-induced neuropathic pain.

Preoperative Characteristics and Postoperative Pain Outcomes in Trigeminal Neuralgia With Concomitant Autoimmune Disease

BACKGROUND AND OBJECTIVES

Although the association between multiple sclerosis and trigeminal neuralgia (TN) is well established, little is known about TN pain characteristics and postoperative pain outcomes after microvascular decompression (MVD) in patients with TN and other autoimmune diseases. In this study, we aim to describe presenting characteristics and postoperative outcomes in patients with concomitant TN and autoimmune disease who underwent an MVD.

METHODS

A retrospective review of all patients who underwent an MVD at our institution between 2007 and 2020 was conducted. The presence and type of autoimmune disease were recorded for each patient. Patient demographics, comorbidities, clinical characteristics, postoperative Barrow Neurological Institute (BNI) pain and numbness scores, and recurrence data were compared between groups.

RESULTS

Of the 885 patients with TN identified, 32 (3.6%) were found to have concomitant autoimmune disease. Type 2 TN was more common in the autoimmune cohort ( P = .01). On multivariate analysis, concomitant autoimmune disease, younger age, and female sex were found to be significantly associated with higher postoperative BNI score ( P = .04, <0.001, and <0.001, respectively). In addition, patients with autoimmune disease were more likely to experience significant pain recurrence ( P = .009) and had shorter time to recurrence on Kaplan-Meier analysis ( P = .047), although this relationship was attenuated on multivariate Cox proportional hazards regression.

CONCLUSION

Patients with concomitant TN and autoimmune disease were more likely to have Type 2 TN, had worse postoperative BNI pain scores at the final follow-up after MVD, and were more likely to experience recurrent pain than patients with TN alone. These findings may influence postoperative pain management decisions for these patients and support a possible role for neuroinflammation in TN pain.

The role of multiple sclerosis subtype in microvascular decompression outcomes for patients with trigeminal neuralgia

OBJECTIVES

While patients with concomitant trigeminal neuralgia (TN) and multiple sclerosis (MS) are understood to experience a more intractable pain phenotype, whether TN pain outcomes differ by the presenting MS subtype is not well characterized. This study's objective is to compare post-operative pain and numbness outcomes following microvascular decompression (MVD) in TN patients with either relapsing-remitting MS (RRMS) or progressive MS.

METHODS

We retrospectively reviewed all TN patients who underwent MVDs at our institution from 2007 to 2020. Of the 1044 patients reviewed, 45 (4.3%) patients with MS were identified. Patient demographics, procedural characteristics, and post-operative pain and numbness scores were recorded and compared. Factors associated with pain recurrence were assessed using survival analyses and multivariate regressions.

RESULTS

Of the resulting 45 MS patients, 34 (75.6%) patients presented with the RRMS subtype, whereas 11 (24.4%) patients exhibited progressive MS. Using an adjusted multivariate ordinal regression, the subtype of MS was not significantly associated with the Barrow Neurological Institute (BNI) pain score at final follow-up. Using a Kaplan-Meier survival analysis and a multivariate Cox proportional hazards regression, respectively, RRMS was significantly associated with a shorter post-operative pain-free interval (p = 0.04) as well as a greater risk for pain recurrence (p = 0.02).

CONCLUSIONS

Although the degree of pain at final follow-up may not differ, RRMS patients are at increased risk for pain recurrence following MVD for TN. These results align with a growing understanding that neuroinflammation may play a significant role in TN pain.

Clinical features of herpes simplex virus reactivation after microvascular decompression for trigeminal neuralgia: Experience of 200 patients and a literature review

Background:

Herpes simplex virus (HSV) reactivation occasionally develops in the early postoperative period after microvascular decompression (MVD) for trigeminal neuralgia (TN). Therefore, the present study investigated the clinical features of this phenomenon.

Methods:

The study cohort comprised 200 patients with 125 women aged between 17 and 90 years (median age, 66 years) who underwent MVD for TN between January 2010 and December 2020. Characteristics were compared between patients with and without HSV reactivation and clinical features were analyzed.

Results:

Twenty patients had HSV reactivation: herpes labialis in 18 and herpes zoster (final diagnosis) in 2. A multivariate analysis revealed independent correlations between postoperative HV reactivation and a previous history of herpes labialis (odds ratios [OR]: 6.32, P = 0.0003) and reoperation for recurrent or persistent pain (OR: 5.06, P = 0.0211). No significant differences were observed in pain relief, postoperative facial numbness, or Barrow Neurological Institute Pain Intensity/Facial Numbness Scores in the past follow-up between patients with and without HSV reactivation. HSV reactivation manifested at a median of the 4^th postoperative day (1–10 days) and its location was not related to the preoperative distribution of facial pain. All patients were treated with local acyclovir and were completely cured within 1–2 weeks.

Conclusion:

HSV reactivation occurred in 10% of patients after MVD including 1% of herpes zoster. A previous history of herpes labialis and reoperation was identified as risk factors for reactivation. Symptoms were completely cured by antiviral drugs within 1–2 weeks. It is important to note that cases of herpes zoster may be confused with cases of HSV after MVD.

Trigeminal Neuralgia: Current Approaches and Emerging Interventions

Trigeminal neuralgia (TN) has been described in the literature as one of the most debilitating presentations of orofacial pain. This review summarizes over 150 years of collective clinical experience in the medical and surgical treatment of TN. Fundamentally, TN remains a clinical diagnosis that must be distinguished from other types of trigeminal neuropathic pain and/or facial pain associated with other neuralgias or headache syndromes. What is increasingly clear is that there is no catch-all medical or surgical intervention that is effective for all patients with trigeminal neuralgia, likely reflective of the fact that TN is likely a heterogenous group of disorders that jointly manifests in facial pain. The first-line treatment for TN remains anticonvulsant medical therapy. Patients who fail this have a range of surgical options available to them. In general, microvascular decompression is a safe and effective procedure with immediate and durable outcomes. Patients who are unable to tolerate general anesthesia or whose medical comorbidities preclude a suboccipital craniectomy may benefit from percutaneous methodologies including glycerol or radiofrequency ablation, or both. For patients with bleeding diathesis due to blood thinning medications who are ineligible for invasive procedures, or for those who are unwilling to undergo open surgical procedures, radiosurgery may be an excellent option-provided the patient understands that maximum pain relief will take on the order of months to achieve. Finally, peripheral neurectomies continue to provide an inexpensive and resource-sparing alternative to pain relief for patients in locations with limited economic and medical resources. Ultimately, elucidation of the molecular mechanisms underlying trigeminal neuralgia will pave the way for novel, more effective and less invasive therapies.

Comparison of first-time microvascular decompression with percutaneous surgery for trigeminal neuralgia: long-term outcomes and prognostic factors

Objective

Common surgical treatments for trigeminal neuralgia (TN) include microvascular decompression (MVD) and percutaneous procedures (glycerol rhizolysis; thermocoagulation; and balloon compression). Although the efficacy of each procedure has been documented, direct comparisons of their relative efficacies for TN are lacking. We aimed to directly compare long-term outcomes after first-time MVD with percutaneous surgery in primary (idiopathic and classical) TN and identify predictors of outcome.

Methods

We conducted a retrospective analysis of prospectively collected data on 185 patients undergoing MVD and 129 undergoing percutaneous surgery. Procedures were performed by one of two neurosurgeons in a single centre; an independent observer collected long-term follow-up data by interviews, using the same outcome measures for all procedures.

Results

MVD patients were younger than those undergoing percutaneous surgery (P <.001). MVD provided superior initial pain relief (P <.001): 87.0% had Barrow Neurological Institute class I or II pain scores after MVD compared with 67.2% after percutaneous surgery. The complication rate for percutaneous procedures was 35.7% and for MVDs was 24.9% (P =.04), including minor and transient complications. Kaplan-Meier analysis demonstrated that MVD provided longer pain relief than percutaneous procedures (P <.001); 25% of patients had recurrence at 96 months following MVD compared with 12 months after percutaneous surgery. Subgroup analysis showed that balloon compression provided more durable relief amongst percutaneous procedures. Multivariate analysis revealed that post-operative numbness and age were prognostic factors for percutaneous procedures (P =.03 and .01, respectively).

Conclusions

MVD provides better initial pain relief and longer durability of relief than percutaneous surgery, although carrying a small risk of major complications. Amongst percutaneous procedures, balloon compression gave the most durable relief from pain. Older age and post-operative numbness were predictors of good outcome from percutaneous surgery. These results can help clinicians to counsel patients with primary TN on neurosurgical treatment selection for pain relief.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00701-021-04793-4.

Efficacy and safety of radiofrequency in the treatment of trigeminal neuralgia: a systematic review and meta-analysis

To assess the effectiveness of radiofrequency (RF) versus other percutaneous strategies (balloon compression, glycerol rhizotomy [GR], and microvascular decompression [MVD]) in patients with trigeminal neuralgia. We systematically searched the electronic databases of PubMed, Embase, and the Cochrane Library to identify eligible studies throughout October 2020. The odds ratio (OR) with 95% confidence interval (CI) was applied to assess effect estimates using the random-effects model. Eighteen retrospective cohort studies that enrolled 6391 patients with trigeminal neuralgia were included. We noted that RF was associated with an increased incidence of immediate pain relief compared with GR (OR 2.65; 95% CI 1.29-5.44; P = 0.008). Moreover, RF was associated with an increased risk of pain recurrence compared with MVD (OR 3.80; 95% CI 2.00-7.20; P < 0.001). Furthermore, RF was associated with an increased incidence of postoperative anesthesia compared with GR (OR 3.01; 95% CI 1.11-8.13; P = 0.030) or MVD (OR 4.62; 95% CI 2.15-9.93; P < 0.001). This study found that RF was superior to GR for the improvement in immediate pain relief; whereas, RF yielded an excess risk of pain recurrence compared with MVD. Moreover, the incidence of postoperative anesthesia in patients treated with RF significantly increased compared with the incidence after treatment with GR and MVD.

Peripheral nerve field stimulation in medically refractory trigeminal neuralgia attributed to multiple sclerosis

OBJECTIVE

Case reports and small patient series have suggested peripheral nerve field stimulation (PNFS) as a treatment for refractory trigeminal neuralgia attributed to multiple sclerosis (MS). Here, the authors aimed to assess the effects of this technique on long-term pain severity.

METHODS

Data were prospectively collected on patients with refractory trigeminal neuralgia attributed to MS who underwent PNFS between July 2013 and August 2017 at the authors' neurosurgical department. Patients were evaluated before and after the first treatment as well as at follow-up at least twice a year. Patients underwent assessment of their pain severity using the Barrow Neurological Institute (BNI) Scale before treatment and at follow-up and were questioned about adverse events following cranial MRI performed after implantation of a permanent PNFS system.

RESULTS

Eight patients (3 women) underwent PNFS trials and their median age was 61 years (IQR 73.75 - 46.5 years). Seven patients proceeded to permanent implantation of the stimulation system. At a median follow-up of 33 months (IQR 42 - 24 months), pain severity decreased from baseline to the last follow-up (BNI score decrease from V [IQR V - V] to III [IQR V - III], p = 0.054). Four patients experienced long-lasting benefit (at 48, 33, 24, and 15 months' follow-up, respectively), while in 3 patients the treatment eventually failed after an initially successful period. One patient had an infection, requiring system removal and subsequent reimplantation. No other complications occurred. No adverse events were noted in the patients undergoing MRI postimplantation.

CONCLUSIONS

This analysis indicates a possibly beneficial long-term effect of PNFS on refractory trigeminal neuralgia attributed to MS in some patients.

Operative findings and outcome of microvascular decompression/adhesiolysis for trigeminal neuralgia in multiple sclerosis without demyelinating brain stem lesions

OBJECTIVE

Trigeminal neuralgia (TN) in multiple sclerosis (MS) poses several challenges for treatment. Although these patients often have typical attacks, they may not be considered as candidates for microvascular decompression (MVD). Here we report on surgical findings and long term follow-up of MVD/ adhesiolysis in a series of patients with multiple sclerosis but without demyelinating brain stem lesions.

METHODS

Fifteen patients with MS-related TN underwent MVD/ adhesiolysis. Demyelinating brain stem lesions were excluded radiologically. Outcome of the intervention was assessed according to the Barrow Neurological Institute (BNI) pain intensity score at 3, 12, 24 months follow-up and at the last available follow-up (mean 88.2 months, range 38-146).

RESULTS

All 15 patients benefited from MVD/adhesiolysis and were pain free on the first day of surgery. Intraoperative findings included arterial contact in 7/15 (47 %) patients, venous contact in 9/15 (60 %), and prominent arachnoid thickening in 12/15 (80 %). The distribution of the BNI pain intensity scores showed marked improvement at all follow-up evaluations. Five patients underwent repeat MVD/adhesiolysis for pain recurrence at a mean of 43 months after the first surgery. Long term evaluation at the last available follow-up demonstrated favorable outcome in 13/15 patients (BNI I-IIIa) (87 %), while 2/15 patients had limited benefit (BNI IV).

CONCLUSIONS

MS-related TN in patients without demyelinating brain stem lesions may be related either to vascular conflicts or to focal arachnoiditis at the trigeminal nerve entry zone. MVD/ adhesiolysis may be considered as a useful treatment option in this subgroup of patients with regard to long term outcome.

Comparison of Stereotactic Radiosurgery and Radiofrequency Ablation for Trigeminal Neuralgia in Multiple Sclerosis Patients

<b><i>Background:</i></b> The optimal treatment for medically refractory trigeminal neuralgia in multiple sclerosis (MS-TN) patients is unknown. <b><i>Objective:</i></b> To compare treatment outcomes between stereotactic radiosurgery (SRS) and radiofrequency ablation (RFA). <b><i>Methods:</i></b> We performed a retrospective study of MS-TN patients treated with SRS or RFA between 2002 and 2019. Outcomes included degree of pain relief, pain recurrence, and sensory changes, segregated based on initial treatment, final treatment following retreatment with the same modality, and crossover patients. <b><i>Results:</i></b> Sixty surgical cases for 42 MS-TN patients were reviewed. Initial pain freedom outcomes and rates of retreatment were similar (SRS: 30%; RFA: 42%). RFA resulted in faster onset of pain freedom (RFA: &#x3c;1 week; SRS: 15 weeks; <i>p</i> &#x3c; 0.001). SRS patients with pain relief had longer intervals to pain recurrence at 2 years (<i>p</i> = 0.044). Final treatment outcomes favored RFA for pain freedom/off-medication outcomes (RFA: 44%; SRS: 11%; <i>p</i> = 0.031), though RFA resulted in more paresthesia (RFA: 81%; SRS: 39%; <i>p</i> = 0.012). Both provided at least 80% of adequate pain relief. Crossover patients did not have improved pain relief. <b><i>Conclusions:</i></b> SRS and RFA are both valid surgical options for MS-TN. Discussion with providers will need to balance patient preference with their unique treatment characteristics.

Percutaneous glycerol rhizotomy for trigeminal neuralgia in patients with multiple sclerosis: a long-term retrospective cohort study

OBJECTIVE

The prevalence of trigeminal neuralgia (TN) in patients with multiple sclerosis (MS-TN) is higher than in the general population (idiopathic TN [ITN]). Glycerol rhizotomy (GR) is a percutaneous lesioning surgery commonly performed for the treatment of medically refractory TN. While treatment for acute pain relief is excellent, long-term pain relief is poorer. The object of this study was to assess the efficacy of percutaneous retrogasserian GR for the treatment of MS-TN versus ITN.

METHODS

A retrospective chart review was performed, identifying 219 patients who had undergone 401 GR procedures from 1983 to 2018 at a single academic institution. All patients were diagnosed with medically refractory MS-TN (182 procedures) or ITN (219 procedures). The primary outcome measures of interest were immediate pain relief and time to pain recurrence following initial and repeat GR procedures. Secondary outcomes included medication usage and presence of periprocedural hypesthesia.

RESULTS

The initial pain-free response rate was similar between groups (p = 0.726): MS-TN initial GR 89.6%; MS-TN repeat GR 91.9%; ITN initial GR 89.6%; ITN repeat GR 87.0%. The median time to recurrence after initial GR was similar between MS-TN (2.7 ± 1.3 years) and ITN (2.1 ± 0.6 years) patients (p = 0.87). However, there was a statistically significant difference in the time to recurrence after repeat GR between MS-TN (2.3 ± 0.5 years) and ITN patients (1.2 ± 0.2 years; p < 0.05). The presence of periprocedural hypesthesia was highly predictive of pain-free survival (p < 0.01).

CONCLUSIONS

Patients with MS-TN achieve meaningful pain relief following GR, with an efficacy comparable to that following GR in patients with ITN. Initial and subsequent GR procedures are equally efficacious.

One Hundred Eleven Percutaneous Balloon Compressions for Trigeminal Neuralgia in a Cohort of 66 Patients with Multiple Sclerosis

BACKGROUND

Trigeminal neuralgia associated with multiple sclerosis (MS-TN) is comparatively rare and larger series of percutaneous balloon compression (PBC) in such cases are few in the literature.

OBJECTIVE

To evaluate the results after PBC for MS-TN with regards to therapeutic effect, side effects, and complications.

METHODS

One hundred eleven procedures with PBC performed in 66 cases of MS-TN were analyzed. Therapeutic effect was measured as postoperative time to pain recurrence without medication. All complications were compiled and the sensory function was evaluated in a subgroup of cases.

RESULTS

The initial pain free rate was 67% and the median time to pain recurrence was 8 mo. Thirty-six patients were treated with PBC only, and among them, the results were worse if treated 3 to 4 times before, compared to first treatment (P = .009-.034). Patients who had several PBCs had worse results already after the first surgery (P < .001). A significant number of patients had impaired sensation to light touch directly after surgery, which was normalized at the late follow-up. Sensimetric testing showed raised thresholds for perception and pain directly after surgery (P = .004-.03), but these were also normalized at the late follow-up.

CONCLUSION

PBC is a treatment that can be effective for many patients with MS-TN. Repeated previous surgeries is a risk factor for an unsatisfactory outcome. However, the patients with multiple surgeries had less satisfactory results already at the first procedure, indicating that a therapy resistant disease can be predicted after the first two PBCs. Postoperative sensory deficits were common but not lasting.

Microsurgical rhizotomy for trigeminal neuralgia in MS patients: technique, patient satisfaction, and clinical outcomes

OBJECTIVE

Patients with multiple sclerosis (MS)-associated trigeminal neuralgia (TN) have higher recurrence and retreatment rates than non-MS patients. The optimal management strategy and role for microsurgical rhizotomy (MSR) for MS-TN remains to be determined. The aim of this study was to report time to treatment failure (TTF) and pain scores following MSR compared to percutaneous and Gamma Knife procedures.

METHODS

Time to treatment failure was analyzed after MSR (n = 14) versus prior procedures (n = 53) among MS-TN patients. Kaplan-Meier curves and log-rank test were utilized to compare TTF after MSR versus prior procedures using the same cohort of patients as their own control group. Subsequent analysis compared TTF after MSR to TTF after 93 other procedures among a second cohort of 18 MS-TN patients not undergoing MSR. BNI pain scores were compared between MSR and other procedures among the MS-TN cohort using a chi-square test.

RESULTS

TTF was significantly longer after MSR than after other procedures in the MSR cohort (median TTF 79 vs 10 months, respectively, p < 0.0001). Similarly, TTF was longer after MSR than after prior procedures in the non-MSR cohort (median TTF 79 vs 13 months, respectively, p < 0.001). MSR resulted in a higher proportion of excellent pain scores when compared to other procedures in the non-MSR cohort (77% vs 29%, p < 0.001). Probability of treatment survival was higher after MSR than after other procedures at all time points (3, 6, 12, 24, 36, and 48 months). There were no deaths or major complications after MSR.

CONCLUSIONS

TTF was significantly longer following MSR compared to prior procedures in MS-TN patients. Additionally, a higher proportion of patients achieved excellent BNI pain scores after MSR.

The Effectiveness of Percutaneous Balloon Compression, Thermocoagulation, and Glycerol Rhizolysis for Trigeminal Neuralgia in Multiple Sclerosis

BACKGROUND

Balloon compression (BC), thermocoagulation (TC), and glycerol rhizolysis (GR) are percutaneous surgical options for trigeminal neuralgia (TN). Whether the outcomes of these procedures in multiple sclerosis -related TN (MS-TN) are as effective as in idiopathic TN (ITN) is unknown.

OBJECTIVE

To retrospectively compare pain relief, complications, and durability achieved by these 3 types of procedures in MS-TN and ITN.

METHODS

Two hundred and four patients with typical TN were treated percutaneously: 33 had MS-TN (64 procedures) and 171 had ITN (329 procedures). All were performed by 1 of 2 neurosurgeons; interviews enabled long-term data to be gathered by an independent observer.

RESULTS

MS-TN patients (53.1%) had Barrow Neurological Institute pain scores of I or II after a percutaneous procedure, compared with 59.3% in the ITN cohort; there was no difference in initial relief between the 2 groups overall (P = .52). There was a trend toward fewer complications in MS-TN compared with ITN (23.4% vs 33.7%, respectively; P = .058). Kaplan–Meier analysis demonstrated no difference in durability of relief in MS-TN (median 23.0 mo) compared with ITN overall (median 24.0 mo; P = .75). Subgroup analysis demonstrated longer relief from BC and TC compared with GR in MS-TN (P = .013). Multivariate analysis confirmed that although the presence of MS does not predict durability of outcome, postoperative numbness (P = .0046) and undergoing a repeat procedure (P = .037) were significant predictors.

CONCLUSION

BC and TC are safe and effective in MS-TN. Postoperative numbness is the strongest prognostic factor in MS-TN.

A Systematic Review of the Management of Trigeminal Neuralgia in Patients with Multiple Sclerosis

BACKGROUND AND OBJECTIVE

Patients with trigeminal neuralgia (TN) and multiple sclerosis (MS) are often treated with medications or a surgical procedure. However, there is little evidence that such treatments result in 50% pain reduction and improvement in quality of life. The aim of this systematic review is to evaluate the clinical effectiveness of treatments in patients with MS and trigeminal neuralgia.

METHODS

We searched Medline, EMBASE, and the Cochrane Collaboration database from inception until October 2016. Two authors independently selected studies for inclusions, data extraction, and bias assessment.

RESULTS

All studies were of low quality using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. For medical management, 10 studies were included, of which one was a randomized controlled trial. Two studies were on the use of misopropol, unique to patients with MS. For surgical therapy, 26 studies with at least 10 patients and a minimum of 2 years follow-up were included. All types of surgical procedures are reported and the results are poorer for TN with MS, with 50% having a recurrence by 2 years. The main complication was sensory loss. Many patients had to undergo further procedures to become pain free and there were no agreed prognostic factors.

CONCLUSIONS

There was insufficient evidence to support any 1 medical therapy and so earlier surgery may be preferable. A patient with TN and MS has therefore to make a decision based on low-level evidence, beginning with standard drug therapy and then choosing a surgical procedure.

[Experience in the use of high-frequency selective percutaneous rhizotomy in trigeminal neuralgia associated with multiple sclerosis]

OBJECTIVE

the study was aimed at assessment of the efficacy of percutaneous high frequency selective rhizotomy (PHFSR) after failure of conservative treatment of trigeminal neuralgia (TN) in multiple sclerosis (MS).

MATERIAL AND METHODS

A retrospective analysis of 28 patients with TN associated with MS who underwent percutaneous rhizotomy in the period from 2000 to 2014 was performed. All patients were definitely diagnosed with MS according to the McDonald criteria (version of 2001, 2005, and 2010). The patients were divided by age, gender, and the trigeminal nerve branches involved in the process. The patients' condition was evaluated at different times after surgery.

RESULTS

Good outcomes in the form of pain syndrome regression were achieved in 100% of the patients. A disease recurrence was observed in 6 (21%) patients during a follow-up period of 3 months to 14 years. Dysesthesia complications occurred in 4 (14%) patients. There were no deaths and severe complications. The percentage of minor complications was low.

CONCLUSION

These data confirm that PHFSR is a safe, repeatable, and effective method of symptomatic neurosurgical treatment of TN associated with MS and may be recommended in the case of failure/intolerance of medication.

Laser speckle imaging to improve clinical outcomes for patients with trigeminal neuralgia undergoing radiofrequency thermocoagulation

OBJECTIVE

Percutaneous treatments for trigeminal neuralgia are safe, simple, and effective for achieving good pain control. Procedural risks could be minimized by using noninvasive imaging techniques to improve the placement of the radiofrequency thermocoagulation probe into the trigeminal ganglion. Positioning of a probe is crucial to maximize pain relief and to minimize unwanted side effects, such as denervation in unaffected areas. This investigation examined the use of laser speckle imaging during probe placement in an animal model.

METHODS

This preclinical safety study used nonhuman primates, Macaca nemestrina (pigtail monkeys), to examine whether real-time imaging of blood flow in the face during the positioning of a coagulation probe could monitor the location and guide the positioning of the probe within the trigeminal ganglion.

RESULTS

Data from 6 experiments in 3 pigtail monkeys support the hypothesis that laser imaging is safe and improves the accuracy of probe placement.

CONCLUSIONS

Noninvasive laser speckle imaging can be performed safely in nonhuman primates. Because improved probe placement may reduce morbidity associated with percutaneous rhizotomies, efficacy trials of laser speckle imaging should be conducted in humans.

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.

Microsurgical Pontine Descending Tractotomy in Cases of Intractable Trigeminal Neuralgia

BACKGROUND

Current treatment strategies in patients with trigeminal neuralgia (TN) include trials of medical therapy and surgical intervention, when necessary. In some patients, pain is not adequately managed with these existing strategies.

OBJECTIVE

To present a novel technique, ventral pontine trigeminal tractotomy via retrosigmoid craniectomy, as an adjunct treatment in TN when there is no significant neurovascular compression.

METHODS

We present a nonrandomized retrospective comparison between 50 patients who lacked clear or impressive arterial neurovascular compression of the trigeminal nerve as judged by preoperative magnetic resonance imaging and intraoperative observations. These patients had intractable TN unresponsive to previous treatment. Trigeminal tractotomy was performed either alone or in conjunction with microvascular decompression. Stereotactic neuronavigation was used during surgery to localize the descending tract via a ventral pontine approach for descending tractotomy.

RESULTS

Follow-up was a mean of 44 months. At first follow-up, 80% of patients experienced complete relief of their pain, and 18% had partial relief. At the most recent follow-up, 74% of patients were considered a successful outcome. Only 1 (2%) patient had no relief after trigeminal tractotomy. Of those with multiple sclerosis-related TN, 87.5% experienced successful relief of pain at their latest follow-up.

CONCLUSION

While patient selection is a significant challenge, this procedure represents an option for patients with TN who have absent or equivocal neurovascular compression, multiple sclerosis-related TN, or recurrent TN.

Percutaneous treatments for trigeminal neuralgia

Trigeminal neuralgia (TN) is a neurologic disorder, defined by paroxysmal electric shocklike painful attacks in 1 or more trigeminal nerve branches. Treatment of TN is diverse and includes minimally invasive percutaneous techniques, which consist of balloon compression, glycerol rhizotomy, and radiofrequency thermocoagulation. Although all 3 techniques are generally safe, efficient, and effective, a clear consensus has not been reached regarding their specific indications and degree of efficacy. The aim of this article is to describe the percutaneous treatments available for TN and outline their characteristics, technique, indications and efficacy.

A prospective study of X-ray imaging combined with skin stimulation potential-guided percutaneous radiofrequency thermocoagulation of the Gasserian ganglion for treatment of trigeminal neuralgia

OBJECTIVE

To investigate the clinical efficacy of X-ray imaging combined with skin stimulation potential-guided percutaneous radiofrequency thermocoagulation of the Gasserian ganglion for treatment of primary trigeminal neuralgia.

DESIGN

This is a prospective, randomized study. Sixty patients with primary trigeminal neuralgia were randomly assigned to a study group or control group. In the study group, the patients underwent X-ray imaging combined with skin stimulation potential-guided percutaneous radiofrequency thermocoagulation of the Gasserian ganglion. The patients in the control group underwent C-arm X-ray-guided puncture through the foramen ovale, and then the puncture needle was microscopically adjusted according to the intensity of the masticatory muscle response and the patients' reactions. Puncture success, postoperative adverse reactions, and short- and middle-term analgesic efficacies were statistically compared between the two surgical approaches.

RESULTS

The incidence of postoperative side effects was significantly reduced, and immediate and mid-term analgesic efficacy was better in patients in the study group comparing with those in the control group (P < 0.01).

CONCLUSION

Using skin stimulation potential-guided puncture may enable more accurate microscopic adjustment of the targets localization damaged by radiofrequency and significantly enhanced clinical efficacy in this study.