Analgesic efficacy and safety of medical therapy alone vs combined medical therapy and extraoral glossopharyngeal nerve block in glossopharyngeal neuralgia

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.

Clinical and physiopathological aspects of the glossopharyngeal neuralgia

Introduction Glossopharyngeal neuralgia is a rare syndrome characterized by paroxysms of unilateral and severe stabbing pain occurring in the nerve’s distribution. Although other neuralgias are well described in the medical literature, glossopharyngeal neuralgia and its physiopathology are not. The vascular compression at the nerve root entry zone is the primary explanation for the disease. The first-line treatment is pharmacological, including carbamazepine, oxcarbazepine, and gabapentin. Surgical treatment is offered to medication-refractory patients, and microvascular decompression surgery has the best outcomes. Objective To investigate the pathophysiological and clinical aspects of the different presentations of glossopharyngeal neuralgia. Method: A systematic review of the literature including case reports and clinical trials, was done. Results A search of the literature yielded 31 papers that regarded glossopharyngeal neuralgia or its variants. Eight of these reports regarded vagoglossopharyngeal neuralgia. Seven regarded the glossopharyngeal neuralgia followed by or caused by another disease. Conclusion Glossopharyngeal neuralgia is a rare disease and requires further studies on its mechanism and clinical assessment; the physician needs to know how to distinguish it from its variants and underlying causes.

Thermographic follow-up of postherpetic neuralgia (PHN) subsequent to Ramsay Hunt syndrome with multicranial nerve (V, VII, VIII and IX) involvement: a case report

Background

Ramsay Hunt syndrome (RHS) is caused by a reactivation of varicella-zoster virus (VZV) infection, and it is characterized by the symptoms of facial paralysis, otalgia, auricular rash, and/or an oral lesion. Elderly patients or immunocompromised patients, deep pain at the initial visit and no prompt treatment are significant predictors of postherpetic neuralgia (PHN). When PHN occurs, especially involved cranial polyneuropathy, multiple modalities should be administered for patients with the intractable PHN. The use of thermography in the follow-up of PHN secondary to RHS with multicranial nerve involvement has not yet been described yet in the literature.

Case presentation

The patient was a 78-year-old man with the chief complaint of a 3-month history of PHN secondary to RHS with polycranial nerve (V, VII, VIII, and IX) involvement. Multimodality therapy with oral gabapentin, pulsed radiofrequency (PRF) application to the Gasserian ganglion for pain in the trigeminal nerve region, linear-polarized near-infrared light irradiation for pain in the facial nerve region, and 2% lidocaine spray for pain in the glossopharyngeal nerve region was used to the treat patient, and follow-up evaluations included thermography. This comprehensive treatment obviously improved the quality of life, resulting in considerable pain relief, as indicated by a decrease in the numerical rating scale (NRS) score from 9 to 3 and a decrease in thermal imaging temperature from higher to average temperature on the ipsilateral side compared with the contralateral side. Lidocaine spray on the tonsillar branches of the glossopharyngeal nerve resulted in an improvement in odynophagia, and the NRS score decreased from 9 to 0 for glossopharyngeal neuralgia after three applications.

Conclusion

Although the use of thermography in the follow-up of RHS with multiple cranial nerve (V, VII, VIII, and IX) involvement is very rare, in this patient, thermal imaging showed the efficacy of combination therapy (oral gabapentin, 2% lidocaine sprayed, PRF application and linear-polarized near-infrared light irradiation) and that is a good option for treatment.

Comparison of extraoral and intraoral routes of glossopharyngeal nerve block for pain relief in patient with carcinoma tongue: A prospective randomized study

Background and Objective

Glossopharyngeal nerve block (GNB) technique has been used as alternative of treatment of cancer and noncancer pain of the oral cavity. The objective of the study is to compare the two approaches (extraoral and intraoral) of GNB in patients of carcinoma of the tongue in terms of efficacy, duration, and complications.

Materials and Methods

This was a prospective comparative randomized study over a period of 1 year. Fifty patients of either sex of ASA physical status and 2, between 21 and 70 years of age, suffering from carcinoma of the tongue, were selected. The patients were randomly divided into two groups. Group I received 4 mL of 0.5% bupivacaine combined with 40 mg, of triamcinolonacetonide by extraoral approach of GNB, and Group II received the same amount of drug by intraoral approach of GNB. Hemodynamic parameters, degree of pain relief using visual analog scale (VAS), number of attempts, effect on quality of life (QOL), and complication were noted during the performance of GNB.

Results

Demographic profile in both groups was comparable. Rate of complication and number of attempts to complete intervention were higher in Group I, which was found to be statistically significant. However, mean VAS scores in Group I were significantly higher as compared to those in Group II during most of the study period starting from the 1^st follow-up at 30 min to the 2^nd month postintervention (P < 0.05). No statistically significant difference in mean QOL scores of two groups was observed for the entire study period except at 1 week when mean scores in Group I were higher as compared to those in Group II (P = 0.011).

Conclusion

The intraoral approach of GNB was better with respect to pain control and improvement in QOL whereas the rate of complication and number of attempts was lower in extraoral approach of GNB.

Eagle’s Syndrome Managed Successfully by Pulsed Radiofrequency Treatment

Eagle’s syndrome is a rare cause of craniofacial pain caused by impingement of adjacent neurovascular elements by an elongated styloid process or by a calcified stylohyoid ligament. There is a wide spectrum of clinical presentations, which encompasses craniofacial pain, oropharyngeal pain, otalgia, headache, and vertigo. Typically, the glossopharyngeal nerve gets entrapped, giving rise to characteristic orofacial pain. The diagnosis of Eagle’s syndrome is confirmed radiologically, and the management includes pharmacotherapy and surgical removal of the styloid process. Moreover, minimally invasive interventions in the form of glossopharyngeal nerve block and radiofrequency treatment can also be effective in providing pain relief. We report a case of an elderly male who presented with features of glossopharyngeal neuralgia secondary to an elongated styloid process and was managed successfully with pulsed radiofrequency treatment of the glossopharyngeal nerve.

B12 as a Treatment for Peripheral Neuropathic Pain: A Systematic Review

Neuropathic pain describes a range of unpleasant sensations caused by a lesion or disease of the somatosensory nervous system. The sensations caused by neuropathic pain are debilitating and improved treatment regimens are sought in order to improve the quality of life of patients. One proposed treatment for neuropathic pain is vitamin B12, which is thought to alleviate pain by a number of mechanisms including promoting myelination, increasing nerve regeneration and decreasing ectopic nerve firing. In this paper, the evidence for B12 as a drug treatment for neuropathic pain is reviewed. Twenty four published articles were eligible for inclusion in this systematic review in which a range of treatment regimens were evaluated including both B12 monotherapy and B12 in combination with other vitamins or conventional treatments, such as gabapentinoids. Overall, this systematic review demonstrates that there is currently some evidence for the therapeutic effect of B12 in the treatment of post-herpetic neuralgia (level II evidence) and the treatment of painful peripheral neuropathy (level III evidence).

Randomized Controlled Trial Comparing Landmark and Ultrasound-Guided Glossopharyngeal Nerve in Eagle Syndrome

INTRODUCTION

The glossopharyngeal nerve lies posterior to the internal carotid artery at the submandibular region. The primary objective of this study was to compare ultrasound-guided glossopharyngeal nerve block (UGPNB) and landmark glossopharyngeal nerve block (GPNB).

MATERIALS & METHODS

Inclusion criteria were patients with unilateral Eagle syndrome and ear pain. Group UGPNB (N = 25) received three UGPNBs at weekly intervals with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone. Group GPNB (N = 26) received landmark GPNB. Pain intensity was evaluated with the numerical rating scale (NRS) before every block, 30 minutes after every block, and at one, three, and five weeks after the third block. Quality of life, assessed using the Brief Pain Inventory (BPI), and satisfaction scores were noted.

RESULTS

NRS scores before the second and third blocks and a week after were significantly lower in group UGPNB and comparable at weeks 3 and 5. NRS scores 30 minutes after every block were significantly decreased from the preblock values but were comparable between groups. In 68% of patients, a curvilinear probe delineated the internal carotid artery (ICA). Out-of-plane needle trajectory was required in 64% of patients. BPI and satisfaction scores were significantly better in the UGPNB group in the "block" weeks.

CONCLUSIONS

UGPNB with 1.5 mL of 0.5% ropivacaine and 20 mg of methylprednisolone injected posterior to the ICA in the submandibular region provides better pain relief for at least a week compared with an extraoral landmark technique when three weekly consecutive blocks are given. In most patients, a curvilinear probe and out-of-plane needle trajectory are most suitable for ultrasound block.

Ultrasound-guided glossopharyngeal nerve block via the styloid process for glossopharyngeal neuralgia: a retrospective study

Objective

To examine the effectiveness and safety of ultrasound-guided glossopharyngeal nerve block via the styloid process for primary glossopharyngeal neuralgia.

Methods

This retrospective study included all patients receiving glossopharyngeal nerve block via the styloid process under ultrasound guidance for primary glossopharyngeal neuralgia between January 2015 and May 2018 at our hospital. The primary outcome of the study was pain relief as assessed using the visual analog scale (VAS). Treatment was considered effective if the VAS score decreased by more than 2 points.

Results

Twelve patients were included in the analysis. The baseline VAS scores ranged from 5 to 9. All patients received previous pharmacotherapy. Other previous treatments included pulsed mode radiofrequency (n=4), microvascular decompression (n=2), and glossopharyngeal nerve block (not under ultrasound guidance; n=2). The patients completed a total of 48 injections for glossopharyngeal nerve block. At discharge from the hospital, and at 6, 12, and 18 months thereafter, 10/12, 10/12, 7/12, and 4/12 patients achieved pain relief and the effective rate was 83.3% at discharge, 83.3% at 6 months, 58.3% at 1 year, and 33.3% at 18 months, respectively.

Conclusion

Ultrasound-guided glossopharyngeal nerve block via the styloid process is a safe, radiation-free, repeatable, convenient, and effective treatment. It can provide a treatment option for patients with glossopharyngeal neuralgia.

Effect of Mannitol plus Vitamins B in the management of patients with piriformis syndrome

BACKGROUND

Piriformis syndrome (PS) is an entrapment of the sciatic nerve by the piriformis muscle, or myofascial pain from the piriformis muscle.

OBJECTIVE

The aim of this study was to investigate the effectiveness of Mannitol plus Vitamins B regime in the management of PS.

METHODS

Twenty two patients were included in this study and received 250 ml of mannitol 20% intravenous infusion for 5 days + Vitamins B (vitamin B1 10 mg + vitamin B2 10 mg + vitamin B12 50 μg PO) for 6 weeks. Clinical outcomes were assessed systematically by clinical tests (tenderness, FAIR test, Beatty's, Freiberg's and Pace's maneuver), Numeric Rating Scale (NRS), Likert Analogue Scale (LAS), and MR examination.

RESULTS

The clinical evaluations showed a significant reduction (p< 0.05) of tenderness, FAIR test, Beatty's maneuver, Freiberg's maneuver and Pace's maneuver when compared with baseline evaluation during the 3rd and 6th month follow-ups. A statistically significant improvement of pain was measured by NRS at resting (p< 0.001), at night (p< 0.001) and during activities (p< 0.001) and LAS with prolonged sitting (p< 0.001), standing (p< 0.001) and lying (p< 0.001). Concomitantly, swelling of SN revealed a significant reduction (p= 0.003) from 86.4% to 18.2%.

CONCLUSIONS

Mannitol plus Vitamins B is effective in the management of piriformis syndrome and it could be an alternative regime in treating PS.

Gradual aggravation of idiopathic glossopharyngeal neuralgia due to chronic tonsillitis: A case report

RATIONALE

Glossopharyngeal neuralgia (GPN) is a rare type of neuralgia. Depending on the cause, it is classified as idiopathic GPN and secondary GPN. Secondary GPN can also be caused by a mass effect or inflammation of the tonsils, the innervation area of glossopharyngeal nerve.

PATIENT CONCERNS

The patient was diagnosed idiopathic GPN 8 years ago. The patient had intermittent pain, but the pain was well controlled. From 5 months ago, the pain gradually worsened, the patient complained severe pain which impaired chewing and swallowing function.

DIAGNOSES

Idiopathic GPN, secondary GPN, chronic tonsillitis INTERVENTIONS:: Percutaneous glossopharyngeal nerve block, glossopharyngeal neurolysis, and pulsed radiofrequency neuromodulation of glossopharyngeal nerve were performed. After the diagnosis of tonsillitis, antibiotic therapy was performed OUTCOMES:: Two weeks after the antibiotic treatment, the pain decreased simultaneously with the patient's tonsillitis recovery.

LESSONS

In a Patient who had already been diagnosed with idiopathic GPN, both pain control and its cause should be considered when the pain is aggravated.

Management of Recurrent Glossopharyngeal Neuralgia Following Microvascular Decompression Surgery

BACKGROUND

Glossopharyngeal neuralgia (GPN) is a rare condition, commonly misdiagnosed as trigeminal neuralgia. Microvascular decompression (MVD) is considered the first line of treatment in medically refractive idiopathic GPN, and the recurrence rate is reported to be 7.1%. We present our first case report on the surgical management of a patient with recurrent GPN and analyze the possible causes for recurrence after MVD.

CASE DESCRIPTION

A 73-year-old gentleman was referred to us with a diagnosis of recurrent left GPN. He was diagnosed 6 years ago with left mandibular branch trigeminal neuralgia for the complaint of left-side tongue pain. He received left mandibular nerve block twice earlier and Gamma Knife radiotherapy 2 years ago without relief. A year ago he was diagnosed with GPN by a neurosurgeon, and MVD was performed. The posterior inferior cerebellar artery and vertebral artery were the offending vessels and were interposed with Teflon. After a temporary pain relief, the patient had a recurrence. Redo-MVD with transposition of the vertebral artery and further interposition of posterior inferior cerebellar artery did not help. After referral to us, we operated on the patient again and found 2 small arteries at the root entry zone (REZ). Interposition with Teflon and splitting of the rootlets relieved the pain.

CONCLUSIONS

MVD is considered the first line of treatment in drug-resistant idiopathic GPN. Thorough exploration of REZ for small arteries and veins is mandatory to prevent recurrence. Vascular compression can occur at the cisternal portion or at the REZ. In recurrent cases, splitting of the glossopharyngeal nerve rootlets adds to the good outcome.

A Rare Case of Glossopharyngeal Neuralgia due to Neurovascular Conflict

In the context of painful cranial neuropathies, a very rare cause is represented by the irritation of the glossopharyngeal nerve due to various aetiologic factors. Here, we present a case of neuralgia of the ninth right cranial nerve due to a compression of its nerve root upon the kinking of the homolateral vertebral artery, resulting in a disabling clinical overview for the patient. Our objective was to focus the reader's attention on the clinical manifestation, which alone could lead to an immediate diagnosis. The imaging and laboratory studies proved to be fundamental in diagnosing the causes, yet the knowledge of the symptoms and the signs of this rare clinical entity can prevent misdiagnosis, mismanagement and consequent economic expenditure as occurred in the case described here.

Trigeminal Neuralgia, Glossopharyngeal Neuralgia, and Myofascial Pain Dysfunction Syndrome: An Update

Neuropathic pain is a common phenomenon that affects millions of people worldwide. Maxillofacial structures consist of various tissues that receive frequent stimulation during food digestion. The unique functions (masticatory process and facial expression) of the maxillofacial structure require the exquisite organization of both the peripheral and central nervous systems. Neuralgia is painful paroxysmal disorder of the head-neck region characterized by some commonly shared features such as the unilateral pain, transience and recurrence of attacks, and superficial and shock-like pain at a trigger point. These types of pain can be experienced after nerve injury or as a part of diseases that affect peripheral and central nerve function, or they can be psychological. Since the trigeminal and glossopharyngeal nerves innervate the oral structure, trigeminal and glossopharyngeal neuralgia are the most common syndromes following myofascial pain dysfunction syndrome. Nevertheless, misdiagnoses are common. The aim of this review is to discuss the currently available diagnostic procedures and treatment options for trigeminal neuralgia, glossopharyngeal neuralgia, and myofascial pain dysfunction syndrome.

Estrogen affects neuropathic pain through upregulating N-methyl-D-aspartate acid receptor 1 expression in the dorsal root ganglion of rats

Estrogen affects the generation and transmission of neuropathic pain, but the specific regulatory mechanism is still unclear. Activation of the N-methyl-D-aspartate acid receptor 1 (NMDAR1) plays an important role in the production and maintenance of hyperalgesia and allodynia. The present study was conducted to determine whether a relationship exists between estrogen and NMDAR1 in peripheral nerve pain. A chronic sciatic nerve constriction injury model of chronic neuropathic pain was established in rats. These rats were then subcutaneously injected with 17β-estradiol, the NMDAR1 antagonist D(-)-2-amino-5-phosphonopentanoic acid (AP-5), or both once daily for 15 days. Compared with injured drug naïve rats, rats with chronic sciatic nerve injury that were administered estradiol showed a lower paw withdrawal mechanical threshold and a shorter paw withdrawal thermal latency, indicating increased sensitivity to mechanical and thermal pain. Estrogen administration was also associated with increased expression of NMDAR1 immunoreactivity (as assessed by immunohistochemistry) and protein (as determined by western blot assay) in spinal dorsal root ganglia. This 17β-estradiol-induced increase in NMDAR1 expression was blocked by co-administration with AP-5, whereas AP-5 alone did not affect NMDAR1 expression. These results suggest that 17β-estradiol administration significantly reduced mechanical and thermal pain thresholds in rats with chronic constriction of the sciatic nerve, and that the mechanism for this increased sensitivity may be related to the upregulation of NMDAR1 expression in dorsal root ganglia.

A description of the anatomy of the glossopharyngeal nerve as encountered in transoral surgery

OBJECTIVES/HYPOTHESIS

To illustrate detailed anatomy of the extracranial portion of the glossopharyngeal nerve in the parapharyngeal space as encountered during transoral surgery.

STUDY DESIGN

Prospective cadaveric dissection. All dissections were performed transorally and confirmed with transcervical dissection.

METHODS

Eight color-injected cadaveric heads (16 sides) were dissected to demonstrate the course and anatomy of the glossopharyngeal nerve. Conventional external dissections were performed to verify our anatomic measurements. Anatomical measurements of the glossopharyngeal nerve, including segments, branches in each segment, relationship with stylopharyngeus muscle, internal carotid artery, and pharyngeal branch of Vagus were recorded and analyzed.

RESULTS

The glossopharyngeal nerve was separated into three segments according to the relationship with the stylopharyngeus muscle. Total lengths of the glossopharyngeal nerve are 32.6 ± 3.1 (left side) and 30.6 ± 3.7 (right side) mm, respectively. The average number of branches in the upper, middle, and lower segments is 3 (range 1-3), 4 (range 2-4), and 3 (range 1-3), respectively. The total number of branches is 8 (range 6-9). The average diameter of the main trunk of the glossopharyngeal nerve is 1.2 ± 0.3 mm, and the average diameter of the lingual branch of the glossopharyngeal nerve is approximately 0.6 ± 0.2 mm. In 75% of cases, pharyngeal branch of Vagus crosses the glossopharyngeal nerve, whereas in 25% of cases it parallels the course of the glossopharyngeal nerve to form the pharyngeal nerve plexus to innervate the pharyngeal wall.

CONCLUSION

Understanding the precise and detailed anatomy of the glossopharyngeal nerve in the parapharyngeal space is important in transoral surgery for indications such as transoral robotic surgery or transoral laser microsurgery tumor resection, lingual tonsillectomy, glossopharyngeal neuralgia, glossopharyngeal nerve block, and internal carotid artery dissection.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 126:2010-2015, 2016.

Psychological Treatments and Psychotherapies in the Neurorehabilitation of Pain: Evidences and Recommendations from the Italian Consensus Conference on Pain in Neurorehabilitation

BACKGROUND

It is increasingly recognized that treating pain is crucial for effective care within neurological rehabilitation in the setting of the neurological rehabilitation. The Italian Consensus Conference on Pain in Neurorehabilitation was constituted with the purpose identifying best practices for us in this context. Along with drug therapies and physical interventions, psychological treatments have been proven to be some of the most valuable tools that can be used within a multidisciplinary approach for fostering a reduction in pain intensity. However, there is a need to elucidate what forms of psychotherapy could be effectively matched with the specific pathologies that are typically addressed by neurorehabilitation teams.

OBJECTIVES

To extensively assess the available evidence which supports the use of psychological therapies for pain reduction in neurological diseases.

METHODS

A systematic review of the studies evaluating the effect of psychotherapies on pain intensity in neurological disorders was performed through an electronic search using PUBMED, EMBASE, and the Cochrane Database of Systematic Reviews. Based on the level of evidence of the included studies, recommendations were outlined separately for the different conditions.

RESULTS

The literature search yielded 2352 results and the final database included 400 articles. The overall strength of the recommendations was medium/low. The different forms of psychological interventions, including Cognitive-Behavioral Therapy, cognitive or behavioral techniques, Mindfulness, hypnosis, Acceptance and Commitment Therapy (ACT), Brief Interpersonal Therapy, virtual reality interventions, various forms of biofeedback and mirror therapy were found to be effective for pain reduction in pathologies such as musculoskeletal pain, fibromyalgia, Complex Regional Pain Syndrome, Central Post-Stroke pain, Phantom Limb Pain, pain secondary to Spinal Cord Injury, multiple sclerosis and other debilitating syndromes, diabetic neuropathy, Medically Unexplained Symptoms, migraine and headache.

CONCLUSIONS

Psychological interventions and psychotherapies are safe and effective treatments that can be used within an integrated approach for patients undergoing neurological rehabilitation for pain. The different interventions can be specifically selected depending on the disease being treated. A table of evidence and recommendations from the Italian Consensus Conference on Pain in Neurorehabilitation is also provided in the final part of the paper.

Local Administration of Methylcobalamin and Lidocaine for Acute Ophthalmic Herpetic Neuralgia: A Single-Center Randomized Controlled Trial

OBJECTIVES

To determine the therapeutic efficacy of combined methylcobalamin and lidocaine for acute ophthalmic herpetic neuralgia (AOHN).

METHODS

Based on the onset, patients with AOHN (n = 98) were randomly allocated into groups A (≤ 3 days) and B (4 to 7 days) and then subdivided into control (A0, B0; received intramuscular methylcobalamin in addition to local lidocaine injection) and treatment (A1, B1; received local injection of the methylcobalamin and lidocaine combination for 14 days) groups. Treatment efficacy was assessed based on rash healing time, alteration of pain intensity, and interference with quality of life. Multilevel modeling and survival analysis were performed.

RESULTS

The time (hours) to start and full opening of the affected eye and the time (hours) to start and full crusting were significantly reduced in both treatment groups (P < 0.05 vs. controls). The mean pain scores in A1 (2.6 ± 0.7) and B1 (1.2 ± 0.8) decreased significantly compared with those in A0 (7.0 ± 1.7) and B0 (5.6 ± 1.9), and the difference between the two therapeutic strategies significantly increased over time. The median minimum intervention time was 6 days in B1 and 11 days in A1. The incidence of postherpetic neuralgia (PHN) was 2.04% at 3 months.

CONCLUSIONS

Methylcobalamin combined with lidocaine mediated detumescence and improved cutaneous healing of the affected area, as well as a significant and sustained analgesic effect on AOHN. The incidence of PHN was also significantly decreased. Local methylcobalamin intervention within 4 to 7 days of onset may be an effective therapeutic option for AOHN.

Inhibition of Hyperpolarization-Activated Cation Current in Medium-Sized DRG Neurons Contributed to the Antiallodynic Effect of Methylcobalamin in the Rat of a Chronic Compression of the DRG

Recently several lines of evidence demonstrated that methylcobalamin (MeCbl) might have potential analgesic effect in experimental and clinical studies. However, it was reported that MeCbl had no effect on treating lumbar spinal stenosis induced pain. Thus, the effects of short-term and long-term administration of MeCbl were examined in the chronic compression of dorsal root ganglion (CCD) model. We found that mechanical allodynia was significantly inhibited by a continuous application of high dose and a single treatment of a super high dose of MeCbl. Little is known about mechanisms underlying the analgesia of MeCbl. We examined the effect of MeCbl on the spontaneous activity (SA), the excitability, and hyperpolarization-activated nonselective cation ion current in compressed medium-sized dorsal root ganglion (DRG) neurons using extracellular single fiber recording in vivo and whole-cell patch clamp in vitro. We found that MeCbl significantly inhibited the SA of A-type sensory neurons in a dose-dependent manner and inhibited the excitability of medium-sized DRG neurons. In addition, MeCbl also decreased I_h current density in injured medium-sized DRG neurons. Our results proved that MeCbl might exert an analgesic effect through the inhibition I_h current and then might inhibit the hyperexcitability of primary sensory neurons under neuropathic pain state.

Neuralgia of the glossopharyngeal nerve in a patient with posttonsillectomy scarring: recovery after local infiltration of procaine-case report and pathophysiologic discussion

We describe a patient with a three-year history of severe progressive left-sided glossopharyngeal neuralgia (GPN) that failed to adequately respond to various drug therapies. The application of lidocaine spray to the posterior pharyngeal wall provided no more than short-term relief. Apart from a large hypertrophic tonsillectomy scar on the left side all clinical and radiologic findings were normal. In terms of therapeutic local anaesthesia, the hypertrophic tonsillectomy scar tissue was completely infiltrated with the local anaesthetic (LA) procaine 1%. The patient has been almost completely pain-free ever since, and the lidocaine spray is no longer needed. Six weeks after the first treatment a repeat infiltration of the tonsillectomy scar led to the complete resolution of all symptoms. The patient has become totally symptom-free without the need to take any medication now for two and a half years. This is the first report of a successful therapeutic infiltration of a tonsillectomy scar using an LA in a patient with GPN that has been refractory to medical treatment for several years. A possible explanation may be that the positive feedback loop maintaining neurogenic inflammation is disrupted and “sympathetically maintained pain” resolved by LA infiltration.

Perineural steroids for trauma and compression-related peripheral neuropathic pain: a systematic review and meta-analysis

PURPOSE

Perineural steroids are often used to treat chronic peripheral neuropathic pain (NP) secondary to trauma or compression. Nevertheless, when compared with local anesthetics (LA) or conventional medical management (CMM), their efficacy and safety in patients with trauma or compression-related neuropathic pain syndromes is unclear. The purpose of this systematic review and meta-analysis was to determine the efficacy and safety of perineural steroids in compression or trauma-related NP after one to three months of injection.

SOURCE

We reviewed randomized controlled trials from MEDLINE(®), EMBASE™, Cochrane central register of controlled trials, Cochrane database of systematic reviews, and Google Scholar (first 200 hits) up to April 2014 that compared perineural injections of steroids with LA or CMM in adult patients with trauma or compression-related chronic peripheral NP. A meta-analysis was performed on the data on pain scores measured at one to three months after the interventions. Quality of evidence was classified using the GRADE system. Two authors independently reviewed all identified titles and abstracts for eligibility.

PRINCIPAL FINDINGS

Five trials comprising 353 patients (177 in the steroid group and 176 in the comparator groups) were included. At one to three months after the interventions, patients who received perineural steroids reported lower pain scores than those who received LA or CMM (mean difference: -1.31 points on a 0-10 numerical rating scale for pain; 95% confidence interval: -2.50 to -0.13; quality of evidence: low; I(2) = 89%). None of the studies reported any significant adverse effects.

CONCLUSIONS

Perineural steroids may provide analgesic efficacy for one to three months in patients with chronic peripheral NP of traumatic or compressive origin; however, the strength of this recommendation is weak. Well-designed large randomized studies are required.

Nerve block for the treatment of headaches and cranial neuralgias - a practical approach

BACKGROUND

Several studies have presented evidence that blocking peripheral nerves is effective for the treatment of some headaches and cranial neuralgias, resulting in reduction of the frequency, intensity, and duration of pain.

OBJECTIVES

In this article we describe the role of nerve block in the treatment of headaches and cranial neuralgias, and the experience of a tertiary headache center regarding this issue. We also report the anatomical landmarks, techniques, materials used, contraindications, and side effects of peripheral nerve block, as well as the mechanisms of action of lidocaine and dexamethasone.

CONCLUSIONS

The nerve block can be used in primary (migraine, cluster headache, and nummular headache) and secondary headaches (cervicogenic headache and headache attributed to craniotomy), as well in cranial neuralgias (trigeminal neuropathies, glossopharyngeal and occipital neuralgias). In some of them this procedure is necessary for both diagnosis and treatment, while in others it is an adjuvant treatment. The block of the greater occipital nerve with an anesthetic and corticosteroid compound has proved to be effective in the treatment of cluster headache. Regarding the treatment of other headaches and cranial neuralgias, controlled studies are still necessary to clarify the real role of peripheral nerve block.

Update on neuropathic pain treatment: ion channel blockers and gabapentinoids

Neuropathic pain is a debilitating chronic pain condition, which remains difficult to treat. The current mainstays of treatment include physical therapy, interventional procedures and medications. Among medications, ion channel blockers and gabapentinoids are the 2 classes of drugs commonly used to treat neuropathic pain. It has been suggested that these medications may be useful to treat a variety of neuropathic pain conditions. This article provides several updates on the utility of both ion channel blockers and gabapentinoids for the treatment of neuropathic pain.

Methylcobalamin: a potential vitamin of pain killer

Methylcobalamin (MeCbl), the activated form of vitamin B12, has been used to treat some nutritional diseases and other diseases in clinic, such as Alzheimer's disease and rheumatoid arthritis. As an auxiliary agent, it exerts neuronal protection by promoting regeneration of injured nerves and antagonizing glutamate-induced neurotoxicity. Recently several lines of evidence demonstrated that MeCbl may have potential analgesic effects in experimental and clinical studies. For example, MeCbl alleviated pain behaviors in diabetic neuropathy, low back pain and neuralgia. MeCbl improved nerve conduction, promoted the regeneration of injured nerves, and inhibited ectopic spontaneous discharges of injured primary sensory neurons. This review aims to summarize the analgesic effect and mechanisms of MeCbl at the present.

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.

An uncommonly common: Glossopharyngeal neuralgia

Glossopharyngeal neuralgia is a relatively rare condition characterized by severe, paroxysmal episodes of pain localized to the external ear canal, the base of the tongue, the tonsil or the area beneath the angle of the jaw. This pain is many a times confused with Trigeminal Neuralgia and mistreated. There are various diagnostic and management dilemmas which are herein addressed in this review.