Trigeminal neuralgia and glossopharyngeal neuralgia

Orofacial Pain

OBJECTIVE

This article explores the multiple etiologies, diagnosis, and management of orofacial pain.

LATEST DEVELOPMENTS

Published in 2019, the International Classification of Orofacial Pain has become the internationally accepted classification system for primary and secondary facial pain. New discoveries in temporomandibular disorders have demonstrated that they are far more complex than the traditional dental mechanistic point of view. A 2020 consensus report released by the National Academies of Sciences, Engineering, and Medicine entitled "Temporomandibular Disorders: Priorities for Research and Care" highlighted this paradigm shift and its importance for patient care, education, and research.

ESSENTIAL POINTS

Orofacial pain comprises many disorders with different etiologies and pathophysiologies. The subjectivity of the pain experience and the interrelated anatomy and physiology of the craniofacial area add to the complexity of diagnosis when the source and etiology of pain are not clear. As orofacial pain straddles the expertise of multiple disciplines, a multidisciplinary approach combining medication, physical therapy, and procedural and psychological strategies is essential in treating patients with orofacial pain.

The Challenges in Clinical Diagnosis of Trigeminal Neuralgia: A Review

The lack of established laboratory tests or biomarkers for trigeminal neuralgia (TN) makes diagnosing this relatively rare condition extremely challenging. Trigeminal nerve compression observable on magnetic resonance imaging may indicate TN, but many patients do not have visible lesions or compression. In particular, TN may be confused with migraine, cluster headache, temporomandibular disorder, and other types of headache. An accurate diagnosis is imperative for proper treatment since these conditions do not respond to the same treatment. Many symptoms of these headaches can be vague or overlap, and clinicians depend in large measure on the subjective reports of their patients. Nevertheless, it is imperative to diagnose TN better, which can cause excruciating pain, reduce the quality of life, and even result in disability. It is possible that TN is underestimated.

Concurrent glossopharyngeal neuralgia and oromandibular dystonia resolved after microvascular decompression of the trigeminal and glossopharyngeal nerve: A rare presentation

Background

This type of pain syndrome occurs suddenly and briefly, beginning unilaterally from one side of the face. Modestly stimulating speech can provoke it, affecting the ear, tongue, throat, and jaw angle. Interestingly, it is the sensory distribution of the auricular and the pharyngeal branches of the cranial nerves IX and X. People have not had a confirmed case of glossopharyngeal neuralgia (GPN), along with oromandibular dystonia (OMD). Nevertheless, usually in the medical literature, this case report supplies information about a patient who has concurrent GPN and OMD.

Case Description

A 36-year-old male patient presented with a history of sudden onset of increasing electric pains, which were centered in the middle of the forehead to the depth of the throat and accompanied by uncontrolled movements, repetitive tongue protrusions, jaw movements, and recurrent pervasive gagging reflexes. Magnetic resonance imaging showed that a vascular loop of the superior cerebellar and anterior inferior cerebellar artery on the left side had crossed over and compressed those nerves. Decompression surgery in the left glossopharyngeal and trigeminal nerves cured all the symptoms.

Conclusion

The simultaneous occurrence of GPN and OMD is rare, complex, and challenging from the clinician's viewpoint in the management of similar but different pathologies. A detailed history was taken, and a radiological investigation was called to devise a management plan in the context of understanding the pathology of both disorders.

Long-Term Follow-Up of Ultrasound-Guided Glossopharyngeal Nerve Block Treatment for Glossopharyngeal Neuralgia: A Retrospective Clinical Study of 43 Cases

Background

Glossopharyngeal neuralgia (GPN) is a rare chronic neuropathic pain disorder that significantly impacts quality of life. Ultrasound-guided glossopharyngeal nerve blocks (UGPNB) have gained popularity due to their various advantages. However, there have been no studies reporting the long-term outcomes of UGPNB in a larger cohort of GPN patients.

Aim

This study aims to evaluate the efficacy and safety of UGPNB in patients with GPN.

Methods

We reviewed the electronic medical records of patients with GPN who received UGPNB at the Department of Pain Medicine of the First Medical Center, PLA General Hospital between June 1, 2011, and June 1, 2022. The effect of UGPNB was evaluated using the Barrow Neurological Institute (BNI) scale. Improvement was defined as a reduction in pain category by comparing pain categories before and after therapy. Recovery was defined as achieving BNI I after treatment. Patients who responded to treatment but then regressed to the category before therapy were considered to have experienced pain relapse.

Results

A total of 43 patients with GPN who received UGPNB were included in the analysis. At discharge, 35 (81.4%) patients experienced pain improvement after treatment, and among them, 13 (30.2%) patients achieved recovery. After discharge, 13 patients (37.1%) out of the 35 effective patients experienced pain relapse at different time intervals: 0.5, 0.7, 1, 1, 3, 3, 4, 12, 15, 36, 45, 63, and 96 months. The cumulative recurrence-free survival rates were 88.85% at month 1, 82.83% at month 3, 77.04% at month 12, 70.31% at month 36, and 54.66% at month 120. Among the 13 patients who experienced relapse, four patients received a second UGPNB treatment, and pain improved in two patients (50%). No severe adverse reactions were documented.

Conclusion

UGPNB is an effective, repeatable, safe, and minimally invasive treatment for patients with GPN. It may be preferable to consider UGPNB before undergoing invasive intracranial surgery or neurodestructive methods.

Glossopharyngeal and vagoglossopharyngeal neuralgia: Long-term surgical outcomes in a single institution

BACKGROUND

Glossopharyngeal neuralgia (GPN) and vagoglossopharyngeal neuralgia (VGPN) are infrequent syndromes that can have great negative impact on a patient's quality of life. The objective of this study is to describe the characteristics and long-term results of patients with GPN-VGPN who are treated surgically with microvascular decompression (MVD) in one institution.

METHODS

This is a retrospective series of 20 patients with the diagnosis of GPN-VGPN who underwent MVD. Demographic characteristics, surgical results, complications, and long-term follow-up were analyzed.

RESULTS

The mean age of symptom onset was 51.25 years and the majority of patients were women (60%). The posterior inferior cerebellar artery was the main offending vessel (75%). The immediate MVD success rate was 100%, but during follow-up, two patients (10%) were diagnosed with VGPN and both cases presented pain recurrence. The mean follow-up was 120.4 (25-333) months. VGPN (P = 0.005) and a ≥5 day hospital stay (P = 0.032) were associated with unsuccessful outcomes. Two complications were documented, which resolved without sequelae. There was no surgical mortality.

CONCLUSION

MVD is an effective and safe treatment for long-term pain relief of GPN-VGPN. VGPN and a prolonged hospital stay were associated with poor outcomes. More studies are required to confirm these findings.

The Superior Cerebellar Artery: Variability and Clinical Significance

The superior cerebellar artery (SCA) arises from the distal part of the basilar artery and passes by the oculomotor, trochlear, and trigeminal nerves. SCA is known to play a crucial role in the development of trigeminal neuralgia. However, due to its anatomical variability, it may also trigger other neurovascular compression (NVC), including hemifacial spasm, oculomotor nerve palsy, and ocular neuromyotonia. Additionally, it may be associated with ischemic syndromes and aneurysm development, highlighting its clinical significance. The most common anatomical variations of the SCA include duplication, a single vessel origin from the posterior cerebral artery (PCA), and a common trunk with PCA. Rarely observed variants include bifurcation and origin from the internal carotid artery. Certain anatomical variants such as early bifurcation and caudal course of duplicated SCA trunk may increase the risk of NVC. In this narrative review, we aimed to examine the impact of the anatomical variations of SCA on the NVCs based on papers published in Pubmed, Scopus, and Web of Science databases with a snowballing approach. Our review emphasizes the importance of a thorough understanding of the anatomical variability of SCA to optimize the management of patients with NVCs associated with this artery.

CSF neuron-specific enolase as a biomarker of neurovascular conflict severity in drug-resistant trigeminal neuralgia: a prospective study in patients submitted to microvascular decompression

BACKGROUND

Although neurovascular conflict (NVC) is the most widely accepted cause of trigeminal neuralgia (TN), few articles have analyzed molecular and biochemical mechanisms underlying TN. In the present study, we dosed neuron-specific enolase (NSE) on serum and CSF samples of 20 patients submitted to microvascular decompression (MVD) and correlated these findings with the type of NVC.

METHODS

Blood samples were obtained preoperatively and 48 h after MVD. CSF from trigeminal cistern was intraoperatively obtained. NSE levels were measured using the Diasorin kit (LIAISON®NSE). NVC was classified as "contact" or "trigeminal nerve distortion/indentation" or "trigeminal root atrophy" based on MRI and intraoperative findings. Clinical outcome was measured by acute pain relief (APR) and Barrow Neurological Institute (BNI) scale at last available follow-up (FU; 6.40 ± 5.38 months).

RESULTS

APR was obtained in all patients. A statistically significant BNI reduction was obtained at latest FU (p < 0.0001). Serum NSE levels significantly decreased following MVD (from 12.15 ± 3.02 ng/mL to 8.95 ± 2.83 ng/mL, p = 0.001). The mean CSF NSE value was 48.94 ng/mL, and the mean CSF/serum NSE rate was 4.18 with a strong correlation between these two variables (p = 0.0008). CSF NSE level in "trigeminal root atrophy" group was significantly higher compared to "contact" (p = 0.0045) and "distortion/indentation" (p = 0.010) groups.

CONCLUSION

NSE levels seem to be related to the etiopathology and severity of NVC. A significant reduction of serum NSE levels could be related to the resolution of the NVC and clinical TN improvement.

Puncture approaches and guidance techniques of radiofrequency thermocoagulation through foramen Ovale for primary trigeminal neuralgia: Systematic review and meta-analysis

Objective

Trigeminal neuralgia (TN) is one of the leading causes of facial pain and seriously affects patients' quality of life. Foramen ovale (FO) radiofrequency thermocoagulation is a classic approach for the treatment of TN that has failed pharmacological therapy. This study summarized the safety and efficacy of transforaminal radiofrequency thermocoagulation for TN by comparing puncture approaches or guidance techniques, thereby providing higher-quality clinical evidence.

Methods

Databases including PubMed, Embase, Cochrane Library, CNKI, and Wanfang were searched for relevant studies published before May 2022. Relevant data were extracted for analysis to compare methodological variables and clinical outcomes.

Results

This meta-analysis included 27 studies with a total of 1,897 patients. In terms of puncture approaches, FO had a significant advantage in reducing VAS at 12 months postoperatively (P = 0.019) and efficacy (P = 0.043). However, FO performed poorly on complications (P < 0.001), operation time (P < 0.001), and the number of needle adjustments (P < 0.001). Regarding the guidance techniques, the adjunctive use of guidance techniques could reduce patients' 6-month VAS (P < 0.001) and 12-month VAS (P < 0.001), improve the efficacy (P = 0.032), reduce recurrence rates (P = 0.001), shorten operation times (P < 0.001), decrease times of intraoperative fluoroscopy (P < 0.001), and improve the success of the first puncture (P < 0.001).

Conclusion

FO radiofrequency thermocoagulation has advantages in efficacy it can still better relieve the pain of patients 12 months postoperatively. However, FO has disadvantages in complications, recurrences, and operation time. The adjunctive use of guidance techniques has a positive effect on treatment efficacy and safety during FO radiofrequency thermocoagulation. However, the results still require large samples and high-quality randomized clinical trials to confirm.

Glossopharyngeal Neuralgia

Glossopharyngeal neuralgia (GPN) is a rare disease that must be differentiated from trigeminal neuralgia. The purpose of this article is to provide a comprehensive review of anatomy, pathophysiology, diagnostic criteria, and several options of treatment for GPN. Lessons learned through our experience of treating GPN are presented in detail, as well as cases of misdiagnosis and diagnostic pitfalls. Microvascular decompression (MVD) should be primarily considered for medically intractable GPN. Techniques employed in MVD for GPN are categorized and described. Especially, we underscore the advantages of the 'transposition' technique where insulating material is positioned 'off' the root entry zone (REZ), instead of 'on' it. We believe this 'off-the-REZ' technique can fundamentally prevent recurrence, if applicable. In addition, Gamma Knife radiosurgery can be an alternative option when a patient is ineligible for MVD, though it is categorized as a destructive procedure.

The role of biomarkers in drug-resistant trigeminal neuralgia: a prospective study in patients submitted to surgical treatment

BACKGROUND

Molecular mechanisms underlying trigeminal neuralgia (TN) have been poorly understood. Recently, different biomarkers have been studied in several chronic neuropathic diseases or in neuronal damage, but their role in TN has not yet been investigated. Here, we firstly analyzed the serum levels of the neuron-specific enolase (NSE) (as an index of neuronal tissue damage) in TN patients submitted to surgical treatment. Different cytokines and interleukins related to inflammation were also studied.

METHODS

Blood samples from 40 patients were prospectively collected preoperatively and after the surgical procedure, namely microvascular decompression (MVD) and percutaneous balloon compression (PBC). Serum levels of uric acid, NSE, ferritin, CRP, IL-2R, and IL-6 were studied. The acute pain relief (APR) and the pre- and postoperative BNI were used to evaluate the clinical outcome.

RESULTS

Overall, we obtained an APR in 87.5% of patients and a significant reduction of BNI after surgery (p < 0.0001). We observed a significant reduction of postoperative NSE values in the group of patients undergoing MVD (p = 0.0055) and a significant increase of postoperative NSE values in patients undergoing PBC (p < 0.05). Furthermore, in the group of patients undergoing MVD, we found a significant postoperative increase of CRP (p < 0.0001), ferritin (p = 0.001), and IL-6 (p = 0.01) values. The only patient who did not respond to MVD had NSE levels unchanged.

CONCLUSION

Our results suggest the hypothesis that TN would be related to the neural damage instead of the systemic inflammatory status and indicate NSE as a possible biomarker of response in patients submitted to MVD.

Glossopharyngeal Neuralgia: Epidemiology, Risk factors, Pathophysiology, Differential diagnosis, and Treatment Options

Purpose of Review

This is a comprehensive review of the most recent literature on glossopharyngeal neuralgia (GPN), a relatively rare form of neuropathic facial pain. It covers the epidemiology, risk factors, pathophysiology, and differential diagnosis given that glossopharyngeal neuralgia can often be confused with other facial pain syndromes. Finally, we extensively review recent findings regarding medical or conservative measures, minimally invasive, and surgical options for potentially treating and managing glossopharyngeal neuralgia.

Recent Findings

An in-depth analysis of the recent literature indicates that glossopharyngeal neuralgia is not only rare but its etiology and pathophysiology are complex and are often secondary to other disease processes. Regardless, current management options are shown to be effective in controlling pain. Conservatively, first-line management of GPN is carbamazepine, but gabapentin and eslicarbazepine acetate are suitable alternatives. In terms of current minimally invasive pain management techniques, pulsed radiofrequency ablation, nerve blocks, or percutaneous radiofrequency thermocoagulation are effective. Finally, surgical management involves microvascular decompression and rhizotomy.

Summary

While there are currently many viable options for addressing glossopharyngeal neuralgia pain ranging from conservative to surgical management, the complex nature of GPN etiology, pathophysiology, and involved anatomical structures prompts further research for more effective ways to treat the disease.

Pharmacologic Management of Neuropathic Pain

This article aims to provide the practitioner with therapeutic options to treat a broad spectrum of acute and chronic orofacial pain syndromes. The focus will be nonsurgical that the oral health care physician can implement to treat this population of patients. The World Health Organization estimated that more than 1 in every 3 people suffers from acute or chronic pain. This article is primarily devoted to medication management once the diagnosis of neuropathic pain, a true trigeminal neuralgia, or a variant of trigeminal neuralgia often referred to as traumatic neuropathic pain or traumatic trigeminal neuralgia.

Epidemiology of trigeminal neuralgia: an electronic population health data study in Korea

BACKGROUND

Trigeminal neuralgia (TN) is one of the most painful disorder in the orofacial region, and many patients have suffered from this disease. For the effective management of TN, fundamental epidemiologic data related to the target population group are essential. Thus, this study was performed to clarify the epidemiological characteristics of TN in the Korean population. This is the first national study to investigate the prevalence of TN in Korean patients.

METHODS

From 2014 to 2018, population-based medical data for 51,276,314 subscribers to the National Health Insurance Service of Korea were used for this study.

RESULTS

The incidence of TN was 100.21 per 100,000 person-years in the year of 2018 in Korea, and the male to female ratio was 1:2.14. The age group of 51-59 years had the highest prevalence of TN. Constant increases in medical cost, regional imbalance, and differences in prescription patterns by the medical specialties were showed in the management of TN.

CONCLUSIONS

The results in this study will not only help to study the characteristics of TN, but also serve as an important basis for the effective management of TN in Korea.

Gamma Knife radiosurgery and refractory glossopharyngeal neuralgia: a single-center series with long-term follow-up

We present our experience with Gamma Knife surgery (GKS) and refractory glossopharyngeal neuralgia (GPN), analyzing its usefulness and safety in patients with or without previous surgeries, another concomitant neuralgia, or retreats. In addition, we study some factors that could condition the outcome of this technique. According to our review, our follow-up is the longest in the literature. We performed the prospective study of 8 patients submitted to GKS between 2008 and 2020. We employed the Leksell radiosurgery Gamma Knife system. The cases were evaluated before and after surgery (3, 6, 12 months and then annually). The VAS (Visual Analogue Scale) and BNI (Barrow Neurological Institute) scale were used. The data were assessed with SPSS25. Our series was composed of 6 (75%) women and 2 (25%) men, with an average age of 59.5 ± 14.04 years. Six patients (75%) had one or more than one previous surgeries. The median follow-up time was 7.22 ± 3.66 years (1.08-12.5 years). In the short-term postoperative period (1 year), eight patients (100%) experienced significant pain relief (VAS, p = 0.012; BNI I-IIIb). After the last interview, 5 patients felt pain relief (62.5%) (BNI grade I = 3; BNI grade IIIa = 2); 3 patients (37.5%) (BNI grade IV) were retreated (MVD, 2; GKS, 1). We found no association between patients with long evolution time of disease (p = 0.356), previous surgeries (p = 0.206), or vascular contact (p = 0.673) and worse clinical results after GKS. Both morbidity and mortality were 0%. Our results suggest that GKS for treating drug-resistant GPN with high initial doses is both a minimally invasive and useful and effective therapeutic strategy, without permanent complications. It presents good results even in patients with one or more previous surgical interventions. These findings encourage us to use this non-invasive technique as initial therapy against the invasive options.

Trigeminal Neuralgia Crisis - Intravenous Phenytoin as Acute Rescue Treatment

OBJECTIVE

The aim of this retrospective cohort study was to analyze responses to intravenous (IV) phenytoin (PHT) for trigeminal neuralgia (TN) crisis in a group of patients treated at our institution.

BACKGROUND

TN is one of the most common causes of facial pain. Its treatment relies on preventive therapy with either carbamazepine or oxcarbazepine. During severe pain episodes, patients may be unable to eat, drink, or even swallow oral medication, requiring in-hospital treatment. There is scarce evidence to support IV medication use for TN, making management of this condition difficult.

METHODS

We reviewed clinical records of patients with TN crisis consulting the emergency department at a tertiary neurological referral center in Buenos Aires, Argentina, treated with IV PHT as analgesic strategy, and with at least 1-month posttreatment follow-up. Demographic features, magnetic resonance imaging findings, and therapeutic management were analyzed.

RESULTS

Thirty-nine patients with TN were included, 18 (46.2%) receiving IV PHT more than once (total number of infusions administered, 65). Immediate pain relief was observed in 89.2% (58/65) and 15.4% (10/65) presented side effects.

CONCLUSIONS

We recommend IV PHT as acute rescue treatment in TN crisis.

Prevalence of common causes of neuropathic pain in Korea: population-based observational study

OBJECTIVE

To investigate the prevalence of complex regional pain syndrome (CRPS), post-herpetic neuralgia (PHN), trigeminal neuralgia (TN), and diabetic neuropathy (DN), common causes of neuropathic pain encountered in pain clinics.

METHODS

We investigated the period prevalence rate of CRPS, PHN, TN, and DN using data from a Korean national electronic database from 2009 to 2013.

RESULTS

The prevalence of CRPS decreased slightly throughout the study period, while the prevalence of PHN increased from 2009 to 2013. The prevalence of TN was reduced over the same period. The prevalence of DN increased from 2009 to 2012 but decreased in 2013. All four neuropathic diseases were more prevalent in individuals aged over 70 years. The prevalence of CRPS, PHN, and TN were more common in women than in men, but DN showed no gender difference.

CONCLUSION

While the prevalence of CRPS and TN has decreased in Korea, that of PHN and DN has increased. With the exception of DN, the neuropathic diseases were more prevalent in women. Further studies are necessary to investigate the risk factors and socioeconomic burden for each disease, and national efforts are essential to limit the development of these preventable neuropathic diseases.

Trigeminal Neuralgia: Basic and Clinical Aspects

The trigeminal nerve is the largest of all cranial nerves. It has three branches that provide the main sensory innervation of the anterior two-thirds of the head and face. Trigeminal neuralgia (TN) is characterized by sudden, severe, brief, and stabbing recurrent episodes of facial pain in one or more branches of the trigeminal nerve. Pain attacks can occur spontaneously or can be triggered by non-noxious stimuli, such as talking, eating, washing the face, brushing teeth, shaving, a light touch or even a cool breeze. In addition to pain attacks, a proportion of the patients also experience persistent background pain, which along with autonomic signs and prolonged disease duration, represent predictors of worse treatment outcomes. It is now widely accepted that the presence of a neurovascular compression at the trigeminal root entry zone is an anatomic abnormality with a high correlation with classical TN. However, TN may be related to other etiologies, thus presenting different and/or additional features. Since the 1960s, the anticonvulsant carbamazepine is the drug of choice for TN treatment. Although anti-epileptic drugs are commonly used to treat neuropathic pain in general, the efficacy of carbamazepine has been largely limited to TN. Carbamazepine, however, is associated with dose-limiting side-effects, particularly with prolonged usage. Thus, a better understanding and new treatment options are urgently warranted for this rare, but excruciating disease.

Orofacial neuralgia associated with a middle cerebral artery aneurysm

Chronic orofacial pain of neuropathic origin can present diagnostic and management dilemmas to dental practitioners and also affects the patient's quality of life. Intracranial aneurysms are a potential cause of stroke (e.g. sub-arachnoid haemorrhage) that is usually associated with, high rates of mortality and morbidity. A patient who had been previously managed for symptoms of temporomandibular joint disorder (TMD) presented with sharp, shooting pain of moderate intensity. It was precipitated by swallowing, and radiated to the right throat, posterior border of the mandible, ear and temporomandibular joint. Clinical and radiological investigations ruled out odontogenic pain, TMD and other more common types of facial pain. Magnetic resonance imaging revealed a 7 × 6 mm aneurysm in the right middle cerebral artery (MCA) which was subsequently surgically clipped. Interestingly, the facial pain resolved after this procedure. Compression of the insular region of the brain innervated by the trigeminal, glossopharyngeal and vagus nerves provides a plausible explanation for the pain reported. To our knowledge, this is the first case of facial neuralgia associated with an aneurysm in the MCA which emphasizes the importance of a multidisciplinary approach in the diagnosis and management of unusual cases of chronic orofacial pain.

Stereotactic radiosurgery for idiopathic glossopharyngeal neuralgia: an international multicenter study

OBJECTIVE The goal of this study was to evaluate the outcomes of Gamma Knife stereotactic radiosurgery (SRS) when used for patients with intractable idiopathic glossopharyngeal neuralgia. METHODS Six participating centers of the International Gamma Knife Research Foundation identified 22 patients who underwent SRS for intractable glossopharyngeal neuralgia between 1998 and 2015. The median patient age was 60 years (range 34-83 years). The median duration of symptoms before SRS was 46 months (range 1-240 months). Three patients had unsuccessful prior surgical procedures, including microvascular decompression (MVD) (n = 2) and balloon compression (n = 1). The radiosurgical target was the glossopharyngeal meatus. The median maximum dose was 80 Gy. RESULTS The median follow-up was 45 months after SRS (range 6-120 months). Twelve patients (55%) had < 4 years of follow-up. Thirteen patients (59%) had initial complete pain relief at a median of 12 days after SRS (range 1-60 days). Three patients (14%) had partial pain relief at a median of 70 days after SRS (range 60-90 days). Six patients (27%) had no pain relief. Among 16 patients with initial pain relief, 5 maintained complete pain relief without medication (Barrow Neurological Institute [BNI] pain intensity score Grade I), 1 maintained occasional pain relief without medication (BNI Grade II), 3 maintained complete pain relief with medication (BNI Grade IIIb), and 7 patients had pain recurrence at a median of 20 months after SRS (range 6-120 months). The rates of maintenance of adequate pain relief (BNI Grades I-IIIb) were 63% at 1 year, 49% at 2 years, 38% at 3 years, 38% at 5 years, and 28% at 7 years. When 7 patients without pain recurrence within 4 years of follow-up were excluded, the rates of maintenance of adequate pain relief were 38% at 5 years and 28% at 7 years. Ten patients required additional procedures (MVD, n = 4; repeat SRS, n = 5; glossopharyngeal nerve block, n = 1). Four of 5 patients who underwent repeat SRS maintained pain relief (BNI Grade I, n = 3; and BNI Grade IIIb, n = 1). No adverse effects of radiation were observed after a single SRS. Two patients developed hyperesthesia in the palatoglossal arch 5 and 8 months after repeat SRS, respectively. CONCLUSIONS Stereotactic radiosurgery for intractable, medically refractory glossopharyngeal neuralgia provided lasting pain reduction in 55% of patients after 1 or 2 SRS procedures. Patients who had a poor response or pain recurrence may require additional procedures such as repeat SRS, MVD, nerve blocks, or nerve section. No patient developed changes in vocal cord function or swallowing disorders after SRS in this study.

Neuropathic Orofacial Pain

Neuropathic pain of the orofacial region can cause much distress in individuals presenting with this condition. It may be easily mistaken for dental pain, and hence many individuals may undergo unnecessary dental work. Knowledge of the types of neuropathic orofacial pain may assist in timely diagnosis and improvement of a patient's quality of life.

Glossopharyngeal neuralgia treated by Gamma Knife radiosurgery: safety and efficacy through long-term follow-up

OBJECTIVE

Glossopharyngeal neuralgia (GPN) is a rare and disabling condition. Just as for trigeminal neuralgia, Gamma Knife radiosurgery (GKRS) is increasingly proposed as a therapeutic option for GPN. The purpose of this study was to assess long-term safety and efficacy of GKRS for this indication.

METHODS

From 2007 to 2015, 9 patients (4 male and 5 female) underwent a total of 10 GKRS procedures. All of the patients presented with GPN that was refractory to all medical treatment, and all had a long history of pain. One patient had previously undergone surgical microvascular decompression. In 5 cases, a neurovascular conflict had been identified on MRI. For the GKRS procedure, the glossopharyngeal nerve was localized on MRI and CT under stereotactic conditions. The target was located at the glossopharyngeal meatus of the jugular foramen. The dose administered to the nerve was 80 Gy in 3 procedures and 90 Gy in the others. Follow-up was planned for 3, 6, and 12 months after the procedure and annually thereafter.

RESULTS

Eight patients experienced an improvement in their pain. The median length of time from GKRS to symptom improvement in this group was 7 weeks (range 2–12 months). At the first follow-up, 6 patients were pain-free (pain intensity scores of I–III, based on an adaptation of the Barrow Neurological Institute scoring system for trigeminal neuralgia), including 4 patients who were also medication-free (I). One patient had partial improvement (IV) and 2 patients had no change. The mean duration of follow-up was 46 months (range 10–90 months). At the last follow-up 6 patients remained pain-free (pain scores of I–III), including 4 patients who were pain free with no medication (I). No side effect was observed.

CONCLUSIONS

Because of its safety and efficacy, GKRS appears to be a useful tool for treatment of GPN, including first-line treatment.

Trigeminal Neuralgia in Pregnancy: A Management Challenge

Pregnancy is known to aggravate pre-existing chronic painful conditions. Trigeminal neuralgia (TN), albeit a disease of the elderly, may afflict pregnant females, which can further complicate its management. Teratogenic effects of the commonly used drugs on the developing fetus limit pharmacological treatment. Moreover, safety of commonly performed interventional therapies is marred by their inherent fetomaternal effects and more importantly the risk for radiation effects on the fetus due to the use of fluoroscopy. This rare coexistence of TN in pregnancy has not been reported before. Here we present a case of TN in a young woman, whose pain was aggravated when she became pregnant, and she was treated successfully by conventional radiofrequency ablation of the Gasserian ganglion.

Long-term outcomes of percutaneous radiofrequency thermocoagulation for glossopharyngeal neuralgia: A retrospective observational study

The aim of this study was to investigate the long-term results of computed tomography (CT)-guided percutaneous radiofrequency thermocoagulation (PRT) for glossopharyngeal neuralgia (GPN).A retrospective review of medical records for patients with GPN who were treated with CT-guided PRT between 2003 and 2014 was performed to investigate baseline characteristics and immediate outcomes during the hospitalization. Long-term pain relief outcomes and complications were obtained via telephone survey. Duration of pain-free was assessed by Kaplan-Meier analysis.Eighty patients with GPN were treated with CT-guided PRT, and 71 patients could be contacted for the follow-up. The mean length of follow-up after PRT was 56.2 ± 43.3 months. Pain relief occurred in 63 patients (78.8%) immediate after the PRT procedure. The percentage of patients who remained in an "excellent" or "good" pain relief condition was 73.2%, 63.0%, 53.2%, and 43.0% at 1, 3, 5, and 10 years. Postprocedure complication included dysesthesias, dysphagia, and diminished gag reflex. No mortality was observed during or after PRT procedures.This study indicates that CT-guided PRT is a safe and effective method for patients with GPN and should be considered as an alternative treatment for these patients.

Angular Relationship Between the Foramen Ovale and the Trigeminal Impression: Percutaneous Cannulation Trajectories for Trigeminal Neuralgia

The debilitating pain of trigeminal neuralgia often necessitates neurosurgical intervention via percutaneous transovale cannulation. While most percutaneous treatments of trigeminal neuralgia are successful, severe adverse events resulting from failure to properly cannulate the foramen ovale (FO) have been reported. With regard to specific targeting of particular trigeminal divisions (ie, V1, V2, V3, and combinations thereof), operative techniques have been described; however, these descriptions have not included specific angulation data. This anatomic study analyzed the angular relationship between the centroid and anteromedial- and posterolateral-most aspects of the FO and the boundaries of the trigeminal impression. The study is the first to detail the angular relationship between the FO boundaries and the boundaries of the trigeminal impression in dry human skulls relative to the coronal plane. The information may be used to prevent miscannulation and also target specific branches of the trigeminal nerve for optimal operative results.

Efficacy of primary microvascular decompression versus subsequent microvascular decompression for trigeminal neuralgia

OBJECTIVE Trigeminal neuralgia (TN) is characterized by intermittent, paroxysmal, and lancinating pain along the distribution of the trigeminal nerve. Microvascular decompression (MVD) directly addresses compression of the trigeminal nerve. The purpose of this study was to determine whether patients undergoing MVD as their first surgical intervention experience greater pain control than patients who undergo subsequent MVD. METHODS A retrospective review of patient records from 1998 to 2015 identified a total of 942 patients with TN and 500 patients who underwent MVD. After excluding several cases, 306 patients underwent MVD as their first surgical intervention and 175 patients underwent subsequent MVD. Demographics and clinicopathological data and outcomes were obtained for analysis. RESULTS In patients who underwent subsequent MVD, surgical intervention was performed at an older age (55.22 vs 49.98 years old, p < 0.0001) and the duration of symptoms was greater (7.22 vs 4.45 years, p < 0.0001) than for patients in whom MVD was their first surgical intervention. Patients who underwent initial MVD had improved pain relief and no improvement in pain rates compared with those who had subsequent MVD (95.8% and 4.2% vs 90.3% and 9.7%, respectively, p = 0.0041). Patients who underwent initial MVD had significantly lower rates of facial numbness in the pre- and postoperative periods compared with patients who underwent subsequent MVD (p < 0.0001). The number of complications in both groups was similar (p = 0.4572). CONCLUSIONS The results demonstrate that patients who underwent other procedures prior to MVD had less pain relief and a higher incidence of facial numbness despite rates of complications similar to patients who underwent MVD as their first surgical intervention.

High-Resolution MRI Findings following Trigeminal Rhizotomy

BACKGROUND AND PURPOSE

Patients with trigeminal neuralgia often undergo trigeminal rhizotomy via radiofrequency thermocoagulation or glycerol injection for treatment of symptoms. To date, radiologic changes in patients with trigeminal neuralgia post-rhizotomy have not been described, to our knowledge. The aim of this study was to evaluate patients after trigeminal rhizotomy to characterize post-rhizotomy changes on 3D high-resolution MR imaging.

MATERIALS AND METHODS

A retrospective review of trigeminal neuralgia protocol studies was performed in 26 patients after rhizotomy compared with 54 treatment-naïve subjects with trigeminal neuralgia. Examinations were reviewed independently by 2 neuroradiologists blinded to the side of symptoms and treatment history. The symmetry of Meckel's cave on constructive interference in steady-state and the presence of contrast enhancement within the trigeminal nerves on volumetric interpolated breath-hold examination images were assessed subjectively. The signal intensity of Meckel's cave was measured on coronal noncontrast constructive interference in steady-state imaging on each side.

RESULTS

Post-rhizotomy changes included subjective clumping of nerve roots and/or decreased constructive interference in steady-state signal intensity within Meckel's cave, which was identified in 17/26 (65%) patients after rhizotomy and 3/54 (6%) treatment-naïve patients (P < .001). Constructive interference in steady-state signal intensity within Meckel's cave was, on average, 13% lower on the side of the rhizotomy in patients posttreatment compared with a 1% difference in controls (P < .001). Small regions of temporal encephalomalacia were noted in 8/26 (31%) patients after rhizotomy and 0/54 (0%) treatment-naïve patients (P < .001).

CONCLUSIONS

Post-trigeminal rhizotomy findings frequently include nerve clumping and decreased constructive interference in steady-state signal intensity in Meckel's cave. Small areas of temporal lobe encephalomalacia are encountered less frequently.

Microvascular decompression for glossopharyngeal neuralgia through a microasterional approach: A case series

Background:

Glossopharyngeal neuralgia (GPN) is an uncommon craniofacial pain syndrome. It is characterized by a sudden onset lancinating pain usually localized in the sensory distribution of the IX cranial nerve associated with excessive vagal outflow, which leads to bradycardia, hypotension, syncope, or cardiac arrest. This study aims to review our surgical experience performing microvascular decompression (MVD) in patients with GPN.

Methods:

Over the last 20 years, 14 consecutive cases were diagnosed with GPN. MVD using a microasterional approach was performed in all patients. Demographic data, clinical presentation, surgical findings, clinical outcome, complications, and long-term follow-up were reviewed.

Results:

The median age of onset was 58.7 years. The mean time from onset of symptoms to treatment was 8.8 years. Glossopharyngeal and vagus nerve compression was from the posterior inferior cerebellar artery in eleven cases (78.5%), vertebral artery in two cases (14.2%), and choroid plexus in one case (7.1%). Postoperative mean follow-up was 26 months (3–180 months). Pain analysis demonstrated long-term pain improvement of 114 ± 27.1 months and pain remission in 13 patients (92.9%) (P = 0.0001) two complications were documented, one patient had a cerebrospinal fluid leak, and another had bacterial meningitis. There was no surgical mortality.

Conclusions:

GPN is a rare entity, and secondary causes should be discarded. MVD through a retractorless microasterional approach is a safe and effective technique. Our series demonstrated an excellent clinical outcome with pain remission in 92.9%.

Orofacial Pain: Pharmacologic Paradigms for Therapeutic Intervention

Pain is a universal experience with profound effects on the physiology, psychology, and sociology of the population. Orofacial pain (OFP) conditions are especially prevalent and can be severely debilitating to a patient's health-related quality of life. Evidence-based clinical trials suggest that pharmacologic therapy may significantly improve patient outcomes either alone or when used as part of a comprehensive treatment plan for OFP. The aim of this article is to provide therapeutic options from a pharmacologic perspective to treat a broad spectrum of OFP. Clinical-based systemic and topical applied pharmaceutical approaches are presented to treat the most common OFP syndromes.

Classification of neurovascular compression in glossopharyngeal neuralgia: Three-dimensional visualization of the glossopharyngeal nerve

BACKGROUND

We introduce a method of noninvasive topographical analysis of the neurovascular relationships of the glossopharyngeal nerve (CN IX) by three-dimensional (3D) visualization. Patients with glossopharyngeal neuralgia (GN) resulting from neurovascular compression (NVC) were studied.

METHODS

15 patients with GN were prospectively examined with 3D visualization using high-resolution magnetic resonance imaging with constructive interference in steady state (MR-CISS). The datasets were segmented and visualized with the real, individual neurovascular relationships by direct volume rendering. Segmentation and 3D visualization of the CN IX and corresponding blood vessels were performed. The 3D visualizations were interactively compared with the intraoperative setup during microvascular decompression (MVD) in order to verify the results by the observed surgical-anatomical findings.

RESULTS

15 patients (female/male: 5/10) were examined. All of them underwent MVD (100%). Microvascular details were documented. The posterior inferior cerebellar artery (PICA) was the most common causative vessel in 12 of 15 patients (80%), the vertebral artery (VA) alone in one case (6.7%), and the combination of compression by the VA and PICA in 3 patients (13.3%). We identified three distinct types of NVC within the root entry zone of CN IX.

CONCLUSION

3D visualization by direct volume rendering of MR-CISS data offers the opportunity of noninvasive exploration and anatomical categorization of the CN IX. It proves to be advantageous in supporting to establish the diagnosis and microneurosurgical interventions by representing original, individual patient data in a 3D fashion. It provides an excellent global individual view over the entire neurovascular relationships of the brainstem and corresponding nerves in each case.

Three common neuralgias

The pain experienced by patients with trigeminal, occipital, or postherpetic neuralgia is often severe, chronic, and difficult to treat. In this article, Drs Ashkenazi and Levin outline the pathologic mechanisms of pain in these common neuralgias and discuss individually tailored pharmacologic and surgical approaches to their treatment.

The efficacy and safety of combined pulsed and conventional radiofrequency treatment of refractory cases of idiopathic trigeminal neuralgia: a retrospective study

PURPOSE

We conducted a retrospective study to evaluate the efficacy and duration of pain relief for idiopathic trigeminal neuralgia (TN) patients after continuous radiofrequency (CRF) combined with pulsed radiofrequency (PRF) treatment of the Gasserian ganglion (GG).

METHODS

Twenty-one patients were treated with pulsed RF for 6 min repeated after rotating the needle tip by 180°, at a pulse width of 10 ms and at 45 °C. This was followed by conventional RF at 60 °C for 60 s, repeated after needle rotation by 180°, then finally at 65 °C for 60 s also repeated after needle rotation by 180°. Patients were assessed for pain intensity and consumption of analgesics at baseline and 7 days, 1 month, 6 months, and 12 months after the procedure. The patients' global impression of change (PGIC) scale was also assessed 7 days, 1 month, 6 months, and 12 months after the procedure. The incidence of facial dysthesia was evaluated 7 days after the procedure.

RESULTS

Excellent pain relief was achieved for 15 of 21 patients (71.4 %) after 1 week, 1 month, and 6 months. and for 14 of 21 patients (66.7 %) after 12 months. Consumption of analgesics was significantly reduced for more than 6 months, and for fifteen patients the PGIC scale result was very much improved 12 months after the procedure compared with baseline. Eighteen of the 21 patients (85.7 %) experienced facial dysthesia 1 week after the procedure.

CONCLUSION

Excellent pain relief and reduced consumption of analgesics for more than 6 months were observed in patients who received PRF combined with CRF to the GG for treatment of idiopathic TN.

Glossopharyngeal neuralgia and radiosurgery

OBJECT

Glossopharyngeal neuralgia is difficult to treat. On the basis of results obtained by using Gamma Knife surgery (GKS) to treat trigeminal neuralgia, the authors have used GKS to treat glossopharyngeal neuralgia in a series of patients since 2007. Their objectives with this study were to demonstrate the usefulness and safety of GKS for treating glossopharyngeal neuralgia and to describe a simple treatment method.

METHODS

From 2007 through 2013, the authors treated glossopharyngeal neuralgia in 5 patients (4 women and 1 man), who ranged in age from 36 to 74 years. One patient had previously undergone treatment for trigeminal neuralgia at the Ruber International Hospital, Department of Functional Neurosurgery and Gamma Knife Radiosurgery. For all patients, before GKS, medical management did not control the pain. Three patients had previously undergone surgery (2 microvascular decompression and 1 rhizotomy) without improvement. For the GKS procedure, the nerve was localized by MRI and CT under stereotactic conditions and the target was located at the level of the glossopharyngeal meatus of the jugular foramen. For 1 patient, a maximum dose of 80 Gy was administrated with a 4-mm collimator, and for the others, the maximum dose was 90 Gy. The nerves located near the glossopharyngeal nerve received between 63 and 10 Gy, and the brainstem received less than 10 Gy. The mean follow-up time was 43 months (range 14-83 months).

RESULTS

All patients improved within 3-6 months after undergoing GKS. All 5 are without pain; 3 patients take no medication, but the other 2 patients continue to take medication. No neurological deficits after GKS were observed.

CONCLUSIONS

GKS is useful and safe for treating glossopharyngeal neuralgia, even for patients who have previously undergone surgery. GKS should be considered as the initial therapy for glossopharyngeal neuralgia.

Orofacial pain syndromes: evaluation and management

Patients will often visit their primary medical practitioner with orofacial pain complaints. Hence, it is important to recognize and have an understanding of these conditions to properly evaluate and potentially manage these disorders. If the practitioner is uncertain or uncomfortable with these conditions, then patient referral to a knowledgeable health care practitioner should be considered for further evaluation and management. In this article, the evaluation and management of various neuropathic, neurovascular, and vascular pains are discussed.

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.

CT-guided percutaneous infrazygomatic radiofrequency neurolysis through foramen rotundum to treat V2 trigeminal neuralgia

OBJECTIVE

Percutaneous radiofrequency thermocoagulation or neurolysis of Gasserian ganglion through foramen ovale (FO) is the classical approach to treat trigeminal neuralgia (TN). However, it has been technically challenging when individual trigeminal sub-branch nerve block is desired through this approach. We have thus developed a novel computed tomograph-guided technique to block the V2 trigeminal nerve through foramen rotundum (FR). With this technique, we have conducted a study of 27 patients with isolated V2 TN. We hypothesize that this new technique will have comparable clinical outcome with the conventional FO approach.

DESIGN

Prospective study.

SETTING

Academic hospitals.

SUBJECTS

Twenty-seven patients with isolated classical V2 TN were enrolled and divided into FO group (N = 12) and FR group (N = 15).

METHODS

Numeric Rating Scale (NRS) scores for facial pain, at pretreatment, immediate postoperative, postoperative 1 day, and 1, 6, and 12 months were recorded. The primary clinical outcome (successful pain relief with 50% or more reduction in NRS) and secondary adverse clinical outcome (hematoma, facial numbness, masticatory weakness, and corneal involvement) were compared and analyzed.

RESULTS

Both groups have good immediate and sustained pain relief. However, when compared with the FO group, the FR group is associated with shorter procedural time (29.2 ± 9.3 vs 45.4 ± 22.13 minutes, P < 0.05), has less nonspecific block in V1 and V3 dermatomes, and has fewer adverse outcomes including masticatory weakness (0/15 vs 5/12) and corneal perforation (0/12 vs 1/15).

CONCLUSIONS

We have developed a novel technique to selectively block the V2 trigeminal nerve at FR. This novel FR approach may be a good alternative to the classical FO approach when an isolated V2 branch block is desired.

Immediate analgesic effect of 8% lidocaine applied to the oral mucosa in patients with trigeminal neuralgia

BACKGROUND

Trigeminal nerve block is widely used for trigeminal neuralgia (TN), though with much painful procedure and potential serious complications. The pain of TN occurs most frequently in the second and the third divisions of the trigeminal nerve, which are distributed in intraoral mucous membrane as well as face skin. Here, we examined the response to intraoral application of 8% lidocaine (LDC) in patients with oral TN pain in a double-blind, placebo (PBO)-controlled crossover study.

METHODS

Twenty-four outpatients with oral TN pain were randomized to receive intraoral application of either 8% LDC or saline PBO to the painful area. Following 7-days period, patients were crossed over to receive the alternative treatment. The pain was assessed with a numerical rating scale (NRS) before and 15 minutes after treatment. Patients used a descriptive scale to grade pain outcome and were asked to note any recurrence and the latency for recurrence after therapy.

RESULTS

Intraoral LDC, but not PBO, significantly decreased the NRS from 5 (4, 8) (median [25, 75 percentiles]) to 1 (0, 4) (P = 0.001). Of the 24 patients, 19 described marked or moderate relief of pain after LDC but only three described the same after PBO application. The effect of LDC and PBO persisted for 2.8 (0.3, 3.0) and 0 (0, 0) hours, respectively.

CONCLUSIONS

Intraoral application of 8% LDC produced prompt analgesia without serious side effects in patients with TN who presented with severe intraoral pain.

Trigeminal and glossopharyngeal neuralgia

Trigeminal neuralgia and glossopharyngeal neuralgia are two causes of paroxysmal craniofacial pain. Either can be debilitating in affected individuals. This article reviews the epidemiology, pathogenesis, diagnosis, and treatment options for these disorders.

Glossopharyngeal neuralgia

In this review, the clinical characteristics, differentiating features from other forms of neuralgia, etiology and treatment options of glossopharyngeal neuralgia will be discussed.