The Pterygopalatine Ganglion and its Role in Various Pain Syndromes: From Anatomy to Clinical Practice

Ultrasound guided pulsed radiofrequency neuromodulation of sphenopalatine ganglion treatment for allergic rhinitis in childern: A case report

Allergic rhinitis (AR) is a chronic noninfectious inflammation of the nasal mucosa mediated primarily by allergen-specific immunoglobulin E (IgE) in atopic individuals after exposure to allergens, with the involvement of non-IgE-mediated mechanisms and neuroimmune dysregulation. Conservative treatment of AR is ineffective in children who lack compliance, and traditional surgical procedures are risky, making treatment of this community challenging. The sphenopalatine ganglion (SPG), aka pterygopalatine ganglion, is the largest of the four parasympathetic ganglia located within the head region, existing as a bilateral pair. The fibers that arise from the SPG regulate secretomotor functions and provide sensation from various structures, including the lacrimal glands, the mucous membranes of the oropharynx, nasopharynx, nasal cavity, and upper portion of the oral cavity. Previous studies suggest that SPG plays a much crucial role in the neuro-related pathophysiological mechanisms of AR. Pulsed radiofrequency (PRF) is a commonly used technique in pain management to produce neuromodulatory effects without damaging nerve tissue. Previous research suggests that SPG dysfunction is one of the important pathophysiological mechanisms of trigeminal autonomic cephalalgia, and PRF targeting SPG can effectively exert neuromodulatory effects to improve its symptoms. We thus predicted that the application of PRF for neuromodulation of SPG would be beneficial for symptom remission in AR. We report the first case of AR successfully treated with PRF targeting the SPG, symptoms did ameliorate during the 24-week follow-up period, as manifested by the disappearance of nocturnal open-mouth breathing and its murmur and a significant reduction in the frequency and severity of daily episodes of nasal congestion, tearing, and conjunctival congestion, which diversifies clinical interventions for AR.

Efficacy of therapies for post dural puncture headache

PURPOSE OF REVIEW

Clinical management of postdural puncture headache (PDPH) remains an interdisciplinary challenge with significant impact on both morbidity and quality of life. This review aims to give an overview of the most recent literature on prophylactic and therapeutic measures and to discuss novel findings with regard to currently published consensus practice guideline recommendations.

RECENT FINDINGS

Although current evidence does not support a recommendation of any specific prophylactic measure, new data is available on the use of intrathecal catheters to prevent PDPH and/or to avoid invasive procedures. In case of disabling or refractory symptoms despite conservative treatments, the epidural blood patch (EBP) remains the therapeutic gold standard and its use should not be delayed in the absence of contraindications. However, recent clinical studies and meta-analyses provide additional findings on the therapeutic use of local anesthetics as potential noninvasive alternatives for early symptom control.

SUMMARY

There is continuing research focusing on both prophylactic and therapeutic measures offering promising data on potential alternatives to invasive procedures, although there is currently no treatment option that comes close to the effectiveness of an EBP. A better understanding of PDPH pathophysiology is not only necessary to identify new therapeutic targets, but also to recognize patients who benefit most from current treatments, as this might enhance their therapeutic efficacy.

Comparison of Greater Occipital Nerve Blockade and Sphenopalatine Ganglion Blockade in Patients with Episodic Migraine

Objectives: Compare the effects of greater occipital nerve (GON) and sphenopalatine ganglion (SPG) blocks on headache intensity and duration, number of headache days, and disability in patients with episodic migraine. Methods: In this prospective single-blind randomized study, patients with episodic migraine were randomly divided into two groups: GON and SPG block groups. Patients received blocks once a week for 4 weeks, and once a month for 2 months. The number of headache days, the headache duration, numeric rating scale (NRS) scores, and number of acute medical treatments were assessed before the procedures and 1 month, 2 months, and 3 months after the procedures. Disability was evaluated using the migraine disability assessment (MIDAS) questionnaire at baseline and 3 months after treatment. This study protocol is registered at ClinicalTrials.gov (NCT06243874.). Results: 19 patients in the GON block group and 18 patients in the SPG block group were evaluated. Significant improvements in pain severity, headache duration, number of headache days, and the need for acute medical treatment were observed in the 1st, 2nd, and 3rd months compared to baseline in the two groups (p < 0.001). There were significant improvements in the MIDAS scores in the third month (p < 0.001). The GON block group showed a greater reduction in headache intensity, duration, number of headache days, and MIDAS scores compared to the SPG block group in the 3rd month (p < 0.001). Conclusions: GON block reduces headache duration, intensity, the number of headache days, and the need for acute medical treatment much more than SPG block in patients with episodic migraine.

Ultrasound-guided sphenopalatine ganglion block for effective analgesia during awake fiberoptic nasotracheal intubation: A case report

BACKGROUND

Awake fiberoptic nasotracheal intubation (AFNI) is the preferred airway management strategy for patients with difficult airways. However, this procedure can cause significant physical and psychological distress. This case report explores the application of a sphenopalatine ganglion (SPG) block as an alternative analgesic modality to mitigate the discomfort associated with AFNI.

CASE SUMMARY

A 63-year-old female with a history of right maxillary osteosarcoma underwent craniotomy for a suspected malignant brain lesion. The patient's medical history included prior surgery, chemotherapy, and radiation therapy, resulting in significant jaw impairment and limited neck mobility. Considering the anticipated airway challenges, AFNI was planned. A SPG block was performed under real-time ultrasound guidance, providing effective analgesia during nasotracheal intubation.

CONCLUSION

The SPG block represents a promising analgesic approach in AFNI, offering potential benefits in alleviating pain involving the nasal and nasopharyngeal regions as well as improving patient cooperation.

Ultrasound-Guided Suprazygomatic Sphenopalatine Ganglion Block for Postdural Puncture Headache Resistant to Epidural Blood Patch: A Case Report

Even though epidural blood patch (EBP) is thought to be the definitive treatment for severe cases of postdural puncture headache (PDPH), it may be accompanied by complications like adhesion arachnoiditis, and cauda equina syndrome, especially if the injection is repeated. The sphenopalatine ganglion (SPG) block is a new minimally invasive technique for the treatment of PDPH, with variable results according to the clinical situation and deployed approach. We describe a case of PDPH resistant to EBP in which we successfully managed symptoms using ultrasound-guided suprazygomatic SPG block to deliver local anesthetic directly into pterygopalatine fossa, thus avoiding a second EBP.

Refractory primary and secondary headache disorders that dramatically responded to combined treatment of ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks and non-invasive vagus nerve stimulation: a case series

In 1981, Devoghel achieved an 85.6% success rate in treating patients with treatment-refractory cluster headaches with alcoholization of the pterygopalatine ganglion (PPG) via the percutaneous suprazygomatic approach. Devoghel's study led to the theory that interrupting the parasympathetic pathway by blocking its transduction at the PPG could prevent or treat symptoms related to primary headache disorders (PHDs). Furthermore, non-invasive vagus nerve stimulation (nVNS) has proven to treat PHDs and has been approved by national regulatory bodies to treat, among others, cluster headaches and migraines.In this case series, nine desperate patients who presented with 11 longstanding treatment-refractory primary headache disorders and epidural blood patch-resistant postdural puncture headache (PDPH) received ultrasound-guided percutaneous suprazygomatic pterygopalatine ganglion blocks (PPGB), and seven also received nVNS. The patients were randomly selected and were not part of a research study. They experienced dramatic, immediate, satisfactory, and apparently lasting symptom resolution (at the time of the writing of this report). The report provides the case descriptions, briefly reviews the trigeminovascular and neurogenic inflammatory theories of the pathophysiology, outlines aspects of these PPGB and nVNS interventions, and argues for adopting this treatment regime as a first-line or second-line treatment rather than desperate last-line treatment of PDPH and PHDs.

Intranasal Lidocaine Administration via Mucosal Atomization Device: A Simple and Successful Treatment for Postdural Puncture Headache in Obstetric Patients

(1) Background: Postdural puncture headache (PDPH) remains a serious complication in obstetric patients. While the epidural blood patch represents the current gold standard in therapy, a growing number of alternative measures are thought to be beneficial for clinical management. The purpose of this study was to retrospectively analyze the efficacy of intranasal lidocaine administration to treat PDPH in obstetrics at our university hospital; (2) Methods: A retrospective analysis of the medical records of patients with PDPH has been performed focusing on the techniques of administration, dosing, treatment duration, impact on pain intensity as well as side effects of intranasal lidocaine; (3) Results: During the study period, 5610 obstetric patients received neuraxial anesthesia, of whom 43 (0.77%) developed PDPH. About one third of the patients with PDPH after spinal anesthesia (n = 8), epidural anesthesia (n = 5) or both (n = 2) were treated with intranasal lidocaine. Lidocaine was administered either via gauze compresses (GC, n = 4), a mucosal atomization device (MAD, n = 8) or with a second-line mucosal atomization device due to low gauze compress efficacy (n = 3). All patients treated with lidocaine refused the epidural blood patch. Nebulization of lidocaine resulted in a significant reduction in pain intensity after the first dose (p = 0.008). No relevant side effects developed except sporadic temporal pharyngeal numbness. The utilization of the mucosal atomization device averted the necessity for an epidural blood patch, whether employed as the primary or secondary approach; (4) Conclusions: Our data imply that the mucosal atomization device enhances the efficacy of intranasal lidocaine administration in obstetric patients suffering from PDPH.

Managing and Preventing Migraine in the Emergency Department: A Review

Migraine is a leading cause of disability worldwide, and acute migraine attacks are a common reason for patients to seek care in the emergency department (ED). There have been recent advancements in the care of patients with migraine, specifically emerging evidence for nerve blocks and new pharmacological classes of medications like gepants and ditans. This article serves as a comprehensive review of migraine in the ED, including diagnosis and management of acute complications of migraine (eg, status migrainosus, migrainous infarct, persistent aura without infarction, and aura-triggered seizure) and use of evidence-based migraine-specific treatments in the ED. It highlights the role of migraine preventive medications and provides a framework for emergency physicians to prescribe them to eligible patients. Finally, it evaluates the evidence for nerve blocks in the treatment of migraine and introduces the possible role of gepants and ditans in the care of patients with migraine in the ED.

Trans-nasal sphenopalatine ganglion block for post-dural puncture headache management: a meta-analysis of randomized trials

OBJECTIVE

To evaluate the efficacy and safety of trans-nasal Sphenopalatine Ganglion (SPG) block over other treatments for Post-Dural Puncture Headache (PDPH) management.

METHODS

A systematic literature search was conducted on databases for Randomized Controlled Trials (RCTs) comparing trans-nasal SPG blockade for the management of PDPH over other treatment modalities. All outcomes were pooled using the Mantel-Haenszel method and random effect model. Analyses of all outcomes were performed as a subgroup based on the type of control interventions (conservative, intranasal lignocaine puffs, sham, and Greater Occipital Nerve [GON] block). The quality of evidence was assessed using the GRADE approach.

RESULTS

After screening 1748 relevant articles, 9 RCTs comparing SPG block with other interventions (6 conservative treatments, 1 sham, 1 GON and 1 intranasal lidocaine puff) were included in this meta-analysis. SPG block demonstrated superiority over conservative treatment in pain reduction at 30 min, 1 h, 2 h, 4 h after interventions and treatment failures with "very low" to "moderate" quality of evidence. The SPG block failed to demonstrate superiority over conservative treatment in pain reduction beyond 6 h, need for rescue treatment, and adverse events. SPG block demonstrated superiority over intranasal lignocaine puff in pain reduction at 30 min, 1 h, 6 h, and 24 h after interventions. SPG block did not show superiority or equivalence in all efficacy and safety outcomes as compared to sham and GON block.

CONCLUSION

Very Low to moderate quality evidence suggests the superiority of SPG block over conservative treatment and lignocaine puff for short-term pain relief from PDPH.

PROSPERO REGISTRATION

CRD42021291707.

Neuromodulation for the Sphenopalatine Ganglion-a Narrative Review

PURPOSE OF REVIEW

To provide an integrated overview of the current state of knowledge of neuromodulation for the sphenopalatine ganglion (SPG) by reviewing relevant and significant literature.

RECENT FINDINGS

There are several case reports and clinical trials evaluating neuromodulation for the SPG. We identified two blinded, randomized clinical trials for patients with chronic cluster headache. The randomized trials and additional studies demonstrated the long-term safety, efficacy, and cost-effectiveness of neuromodulation for the SPG. Recent studies in Europe and the USA suggest that SPG neuromodulation is a novel modality with clinical importance for treating acute cluster headaches and reducing the frequency of attacks.

A Case Report of Sphenopalatine Ganglion Block Relieving Chronic Pain Post-Dental Bone Graft Surgery

Chronic orofacial pain, by definition, is a pain that can anatomically extend anywhere between the area just under the orbitomeatal line, anterior to the pinnae, and above the neck. It occurs for 15 days or more per month, lasting four or more hours daily, for at least three months. Chronic orofacial pain, including persistent idiopathic facial pain syndrome, can significantly impact patients' quality of life and pose challenges for effective management. This case report describes a successful transnasal approach in treating a patient with severe oral pain following a bone graft surgery by blocking the sphenopalatine ganglion. The block provided significant pain relief and improved the patient's daily functioning. This minimally invasive treatment option offers an alternative for managing chronic orofacial pain after dental procedures such as bone graft surgery.

Review on the possible pathophysiological mechanisms underlying visual display terminal-associated dry eye disease

BACKGROUND

Visual display terminal (VDT) use is a key risk factor for dry eye disease (DED). Visual display terminal (VDT) use reduces the blink rate and increases the number of incomplete blinks. However, the exact mechanisms causing DED development from VDT use have yet to be clearly described.

PURPOSE

The purpose of the study was to conduct a review on pathophysiological mechanisms promoting VDT-associated DED.

METHODS

A PubMed search of the literature investigating the relationship between dry eye and VDT was performed, and relevance to pathophysiology of DED was evaluated.

FINDINGS

Fifty-five articles met the inclusion criteria. Several pathophysiological mechanisms were examined, and multiple hypotheses were extracted from the articles. Visual display terminal (VDT) use causes DED mainly through impaired blinking patterns. Changes in parasympathetic signalling and increased exposure to blue light, which could disrupt ocular homeostasis, were proposed in some studies but lack sufficient scientific support. Together, these changes may lead to a reduced function of the tear film, lacrimal gland, goblet cells and meibomian glands, all contributing to DED development.

CONCLUSION

Visual display terminal (VDT) use appears to induce DED through both direct and indirect routes. Decreased blink rates and increased incomplete blinks increase the exposed ocular evaporative area and inhibit lipid distribution from meibomian glands. Although not adequately investigated, changes in parasympathetic signalling may impair lacrimal gland and goblet cell function, promoting tear film instability. More studies are needed to better target and improve the treatment and prevention of VDT-associated DED.

Effect of neuropathic pain on sphenopalatine ganglion block responses in persistent idiopathic facial pain

OBJECTIVES

Management of persistent idiopathic facial pain (PIFP) can be challenging. Sphenopalatine ganglion (SPG) has been the target for the interventional treatment of many facial pain syndromes. However, possible factors that may affect SPG block success are unknown. It was aimed to investigate the effect of neuropathic pain on SPG block outcomes in PIFP, which includes a heterogeneous patient group.

METHODS

All of the patients underwent fluoroscopy-guided SPG block with an injection of 40 mg of 2% lidocaine and 8 mg of dexamethasone. The patients were assigned to 2 groups according to existence of neuropathic pain determined with the DN4 questionnaire score: 19 patients with neuropathic pain (Group 1) and 15 patients without neuropathic pain (Group 2). Preprocedural and postprocedural Visual Analog Scale (VAS) scores were compared between the 2 groups.

RESULTS

The mean age of the patients was 47.65 ± 6.50 years. The average pain duration was 52.95 ± 34.81 weeks. A significantly greater decrease was detected in the VAS scores at 1 week (p = 0.036) and 1 month (p < 0.001) in Group 1 when compared to Group 2. Moreover, the proportion of patients with >50% improvement in the VAS scores at 1 week (p = 0.012) and 1 month (P = 0.017) was significantly lower in Group 1 than in Group 2.

DISCUSSION

SPG block appears as a safe, effective, and rapid method to treat PIFP, especially in cases with neuropathic pain. Neuropathic pain may be a predictor for pain relief in interventional procedures targeting SPG in the treatment of PIFP.

Ultrasound-Guided Suprazygomatic Nerve Blocks to the Pterygopalatine Fossa: A Safe Procedure

OBJECTIVES

Large-scale procedural safety data on pterygopalatine fossa nerve blocks (PPFBs) performed via a suprazygomatic, ultrasound-guided approach are lacking, leading to hesitancy surrounding this technique. The aim of this study was to characterize the safety of PPFB.

METHODS

This retrospective chart review examined the records of adults who received an ultrasound-guided PPFB between January 1, 2016, and August 30, 2020, at the University of Florida. Indications included surgical procedures and nonsurgical pain. Clinical data describing PPFB were extracted from medical records. Descriptive statistics were calculated for all variables, and quantitative variables were analyzed with the paired t test to detect differences between before and after the procedure.

RESULTS

A total of 833 distinct PPFBs were performed on 411 subjects (59% female, mean age 48.5 years). Minor oozing from the injection site was the only reported side effect, in a single subject. Although systolic blood pressure, heart rate, and oxygen saturation were significantly different before and after the procedure (132.3 vs 136.4 mm Hg, P < 0.0001; 78.2 vs 80.8, P = 0.0003; and 97.8% vs 96.3%, P < 0.0001; respectively), mean arterial pressure and diastolic blood pressure were not significantly different (96.2 vs 97.1 mm Hg, P = 0.1545, and 78.2 vs 77.4 mm Hg, P = 0.1314, respectively). Similar results were found within subgroups, including subgroups by sex, race, and indication for PPFB.

DISCUSSION

We have not identified clinically significant adverse effects from PPFB performed with an ultrasound-guided suprazygomatic approach in a large cohort in the hospital setting. PPFBs are a safe and well-tolerated pain management strategy; however, prospective multicenter studies are needed.

Identification of cranial nerve ganglia using sectioned images and three-dimensional models of a cadaver

Background

Cranial nerve ganglia, which are prone to viral infections and tumors, are located deep in the head, so their detailed anatomy is difficult to understand using conventional cadaver dissection. For locating the small ganglia in medical images, their sectional anatomy should be learned by medical students and doctors. The purpose of this study is to elucidate cranial ganglia anatomy using sectioned images and three-dimensional (3D) models of a cadaver.

Methods

One thousand two hundred and forty-six sectioned images of a male cadaver were examined to identify the cranial nerve ganglia. Using the real color sectioned images, real color volume model having a voxel size of 0.4 × 0.4 × 0.4 mm was produced.

Results

The sectioned images and 3D models can be downloaded for free from a webpage, anatomy.dongguk.ac.kr/ganglia. On the images and model, all the cranial nerve ganglia and their whole course were identified. In case of the facial nerve, the geniculate, pterygopalatine, and submandibular ganglia were clearly identified. In case of the glossopharyngeal nerve, the superior, inferior, and otic ganglia were found. Thanks to the high resolution and real color of the sectioned images and volume models, detailed observation of the ganglia was possible. Since the volume models can be cut both in orthogonal planes and oblique planes, advanced sectional anatomy of the ganglia can be explained concretely.

Conclusions

The sectioned images and 3D models will be helpful resources for understanding cranial nerve ganglia anatomy, for performing related surgical procedures.

Transnasal sphenopalatine ganglion block for pain relief during panretinal photocoagulation laser for diabetic retinopathy: a pre and post interventional study

This study was performed to utilize transnasal Sphenopalatine Ganglion (SPG) block for pain reliving during panretinal photocoagulation (PRP) in diabetic patients with diabetic retinopathy. This pre and post interventional study was performed on 20 patients with proliferative diabetic retinopathy. The first PRP treatment session of all the patients is performed with no transnasal SPG block, but before holding the second session, all the patients underwent transnasal SPG block and pain levels during and after PRP were compared to each other. Before the transnasal SPG block, each nostril of all the cases was inspected for finding any obstruction in each PRP session. Transnasal SPG block was also performed in with 2% lidocaine. The mean age of the included cases was 52.84 ± 8.62 years old (from 36 to 72 years old). All the cases underwent two PRP lasers treatment sessions with the same characteristic (spot size, power and duration) for each patient. In the first and second PRP treatment sessions, the mean NRS scores were obtained immediately after the PRP laser (8.4 vs. 4.2), 15 min (8.2 vs. 4.2), 1 h (8.0 vs. 4.1), and 24 h (5.4 vs. 3.6) after the PRP respectively. The mean NRS scores significantly reduced during the second PRP treatment session compared to the first session (p < 0.001). Transnasal SPG block is a safe and effective strategy used for relieving pain caused by the PRP laser treatment in patients with diabetic retinopathy.

Comparison of Temperature and Pain Changes between the Drip and Topical Methods of Administering the Transnasal Sphenopalatine Ganglion Block

The objective of this study was to compare facial temperatures and the visual analogue scale (VAS) between the drip method and the topical method of transnasal sphenopalatine ganglion block (SPGB). The transnasal SPGB is administered to patients with facial or head and neck pain. In the transnasal approach, the drip and topical methods are frequently used. We compared facial temperatures and VAS after transnasal SPGB. Medical records of 74 patients who visited the pain clinic and underwent transnasal SPGB were retrospectively reviewed. A total of 156 transnasal SPGB were performed. The patients were divided into the drip-method and topical-method groups. Facial temperatures were measured in six areas of the right and left forehead, maxilla, and mandible before and 30 min after completion of the transnasal SPGB. Temperatures were compared before and 30 min after SPGB in each group and between the two groups. VAS scores were compared at the same times of SPGB in each group and between the two groups. In the drip-method group, there were significant increases at four areas of the face in temperature changes at 30 min after SPGB. In the topical-method group, there was no significant difference in the temperature changes at 30 min after SPGB. There were statistically significant differences in the facial temperature changes between the two groups in the right forehead (p = 0.001), left forehead (p = 0.015), and right maxillary area (p = 0.046). In herpes zoster, there were statistically significant differences in the VAS scores between before and 30 min after SPGB in both groups (p < 0.001, p = 0.008) and between two groups (p < 0.001). In migraine, there were statistically significant differences in VAS scores between before and 30 min after SPGB in both groups (p < 0.001, p = 0.004) and between two groups (p = 0.014). Transnasal SPGB using two methods showed different temperature changes and VAS scores.

Sphenopalatine ganglion block for ipsilateral shoulder pain following open pancreaticoduodenectomy

A 59-year-old woman underwent an open pancreaticoduodenectomy. Thoracic patient controlled-epidural anaesthesia provided excellent incisional pain relief; however, the patient experienced intractable left shoulder pain (10/10 on the Numerical Rating Scale). To our knowledge, there is no effective established treatment for patients experiencing shoulder pain after an open pancreaticoduodenectomy. The patient’s shoulder pain did not respond to medical management with acetaminophen, ketorolac, lidocaine transdermal patch, oxycodone and hydromorphone. Then, on postoperative day 2, the acute pain service was consulted. Considering that the sphenopalatine ganglion block has been previously reported to be helpful in a number of painful conditions, including shoulder tip pain after thoracic surgery, we offered this treatment to the patient. After just one topical sphenopalatine ganglion block, using a cotton-tipped applicator, the patient’s shoulder pain entirely resolved and did not return. This is the first report of a successful treatment of intractable ipsilateral shoulder pain following an open pancreaticoduodenectomy with transnasal sphenopalatine ganglion block.

A randomized control study to assess the efficacy of the sphenopalatine ganglion block in patients with post dural puncture headache

Background:

Post dural puncture headache (PDPH) delays discharge from hospital. We studied the efficacy of sphenopalatine ganglion (SPG) block, a novel technique in management of PDPH using 0.25% Ropivacaine.

Methodology:

Forty patients presenting with PDPH after urological procedures under spinal anaesthesia were randomized into two groups: Group C and Group S. Group C received conservative treatment with bed rest, adequate hydration and caffeine 200 mg 6^th hourly. Group S patients received SPG block (packing bilateral nostril for 10 minutes with 0.25% Ropivacaine). Inj Paracetamol 1 g IV was given as primary analgesic. Intravenous Diclofenac 75 mg was administered as rescue analgesic. Patients were monitored for 72 hours. Total analgesic requirement, time to attain adequate pain relief, headache pain score, patient satisfactory score were compared between the two groups. We compared the PDPH severity score for headache using 5-point scale method and patient satisfaction score using Likert-type scale.

Results:

Demographic data, onset of PDPH, needle size, intervention time were statistically insignificant. Total paracetamol consumption was significantly reduced in SPG group. Headache pain score was significantly low in Group S up to 54 hours. Patient satisfaction score was statistically better in Group S. Mean block onset time was 12 minutes. One patient in Group C required Epidural blood patch.

Conclusion:

SPG block is an effective alternative in managing patients with PDPH. The need for epidural blood patch is greatly reduced using SPG block. Procedural safety, immediate and sustained pain relief make it an evolving treatment modality for PDPH.

Sphenopalatine Ganglion Block for Postdural Puncture Headaches in a Thrombocytopenic Adolescent Young Adult: A Case Report

The epidural blood patch is the gold-standard therapy to treat postdural puncture headaches from dural puncture when conservative therapies fail. However, an epidural blood patch is contraindicated in patients with coagulopathy and thrombocytopenia (platelet count of 60,000/µL) due to concerns of an epidural hematoma. We present a case of an adolescent with acute lymphocytic leukemia, thrombocytopenia, and persistent postdural puncture headaches. The patient was successfully treated with a sphenopalatine ganglion nerve block at the bedside without any side effects and complications.

Endoscopic Anatomy of the Zygomatic Nerve: Implications for the Endoscopic Transmaxillary Approach

Background Understanding the anatomic features of the zygomatic nerve is critical for performing the endoscopic transmaxillary approach properly. Injury to the zygomatic nerve can result in facial numbness and corneal problems.

Objective To evaluate the surgical anatomy of the zygomatic nerve and its segments from an endoscopic endonasal perspective for clinical implications of performing the endoscopic transmaxillary approach.

Methods The origin, course, length, and segments of the zygomatic nerve were studied in four specimens from an endonasal perspective.

Results The zygomatic nerve arises 4.1 ± 1.7 mm from the foramen rotundum of the maxillary nerve in the superolateral pterygopalatine fossa (PPF). According to its anatomic region in endonasal endoscopic surgery, we divided the zygomatic nerve into two segments: the PPF segment, from origin to the point of entry under Muller's muscle, which runs superolaterally to the inferior orbital fissure (IOF) (length, 4.6 ± 1.3 mm), and the IOF segment, starting at the entry point in Muller's muscle and terminating at the exit point in the IOF, which travels between Muller's muscle and the great wing of the sphenoid bone (length, 19.6 ± 3.6 mm). In the transmaxillary approach, the zygomatic nerve is a critical landmark in the superolateral PPF.

Conclusion The zygomatic nerve travels in the PPF and the IOF; better visualization and preservation of this nerve during endonasal endoscopic surgery are crucial for successful outcomes.

Interventional Treatments for Cancer Pain

Interventional pain management is a subspecialty of medicine devoted to the use of invasive techniques such as joint injections, nerve blocks/or neurolysis, neuromodulation, and epidural and selective nerve blocks to provide diagnosis and treatment of pain syndromes unresponsive to conventional medical management.

Transnasal Sphenopalatine Ganglion Block for Management of Postdural Puncture Headache in Non-Obstetric Patients

BACKGROUND

This study investigated the efficacy and safety of transnasal sphenopalatine ganglion block (SPGB) for treatment of postural puncture headache (PDPH) in non-obstetric patients.

METHODS

This retrospective study was conducted at the Ankara Research and Educational Hospital, in Turkey, and included 26 non-obstetric patients (age, ≥18 years) who were diagnosed with PDPH and unresponsive to conservative therapy or unable to continue it because of side effects. Transnasal SPGB was performed in each nostril. Pain severity was assessed with the Visual Analogue Scale (VAS) at 15 min, 30 min, 24 h, and 48 h after the procedure, while patients were seated. The patients were monitored for 48 h for adverse effects (AEs). Patient treatment satisfaction was assessed at 48 h after the procedure by using the Patient Global Impression of Change (PGIC) scale.

RESULTS

Headache at 15 min post-procedure was relieved rapidly. At 24 h post-procedure, nearly half of patients (42.3%) had no pain, and all patients (100%) had a VAS score of <3. Nasal discomfort, throat numbness, and nausea were AEs reported after SPGB; however, these AEs were completely relieved at 24 h after the procedure. According to the PGIC scale scores at 48 h post-procedure, 73.1% of patients evaluated themselves as "much improved" and 26.9% evaluated themselves as "very much improved".

CONCLUSION

When PDPH does not respond to conservative treatment, it may be treated effectively with transnasal SPGB, which is a noninvasive, safe, well-tolerated, and straightforward method with a low complication rate.

Transnasal Sphenopalatine Ganglion Block for the Preventive Treatment of Chronic Daily Headache in Adolescents

Chronic headaches are a major source of morbidity in the pediatric population, affecting physical function, school attendance, social capacity, mood, and sleep. In adults, repetitive sphenopalatine ganglion (SPG) blockade has been studied as a preventive treatment for chronic migraines. This case series aims to evaluate the SPG block for the preventive treatment of chronic daily headache (CDH) in adolescents. We prospectively evaluated 17 adolescents (14 females, 14 ± 1 year) with CDH not responding to cognitive behavioral therapy (CBT), physiotherapy, and standard medications. Each patient received 10 SPG blocks (two blocks/week) using the Tx360® device. At the end of treatment, 10 patients (59%) reported a Patient's Global Impression of Change (PGIC) score ≥ 67%, and 3 months after the end of treatment, nine patients (53%) sustained a PGIC ≥ 67%. There was also a statistically significant reduction in the depression subscale of the Revised Children's Anxiety and Depression Scale (RCADS) at the end of treatment and 3 months post-treatment compared with baseline. The procedure was well tolerated with no adverse effects. In our study, the use of repeat SPG blockade was associated with sustained benefits on the PGIC and the depression subscale of the RCADS when used as preventive headache treatment in adolescents with refractory CDH.

Endoscopic Sphenopalatine Ganglion Block Efficacy in the Management of Periorbital Edema and Ecchymosis After Septorhinoplasty

AIM

This study aims to evaluate the efficacy of sphenopalatine ganglion block (SPGB) on postoperative edema and ecchymosis for the patients undergoing septorhinoplasty (SRP).

METHODS

In the study, a total number of 55 participant patients (40% male and 60% female, aged between 18 and 42 years) undergoing hump resection and osteotomies were allocated into 2 groups. The SPGB (+) group consisted of 27 patients who underwent SPGB, while the SPGB (-) group consisted of 28 patients who underwent SRP without SPGB. On the first, third, and seventh postoperative days (POD1, POD3, POD7), the score marks of periorbital edema and ecchymosis of the patients were evaluated. Additionally, postoperative upper eyelid edema and upper eyelid ecchymosis as well as lower eyelid edema, and lower eyelid ecchymosis on POD1, POD3, POD7 were evaluated. A comparison with regard to intraoperative bleeding, surgical field, and operation time between the 2 groups was also conducted.

RESULTS

Upper eyelid edema, upper eyelid ecchymosis, lower eyelid edema, lower eyelid ecchymosis on POD 1, 3, 7 were found to be significantly lower in SPGB (+) group in comparison to SPGB (-) group (P < 0.001). Intraoperative blood loss and surgical field were found to be significantly lower in SPGB group (+) than in SPGB (-) group (P < 0.00). The operation time was not found statistically significant between the 2 groups (P = 0.212).

CONCLUSION

Sphenopalatine ganglion block is a safe and effective way of reducing postoperative edema and ecchymosis after SRP. Besides, it provides a better surgical field and reduced bleeding intraoperatively.

Pterygopalatine Fossa Blockade as Novel, Narcotic-Sparing Treatment for Headache in Patients with Spontaneous Subarachnoid Hemorrhage

BACKGROUND

Severe headache is a hallmark clinical feature of spontaneous subarachnoid hemorrhage (SAH), affecting nearly 90% of patients during index hospitalization, regardless of the SAH severity or presence of a culprit aneurysm. Up to 1 in 4 survivors of SAH experience chronic headaches, which may be severe and last for years. Data guiding the optimal management of post-SAH headache are lacking. Opioids, often in escalating doses, remain the guideline-recommended mainstay of acute therapy, but pain relief remains suboptimal.

METHODS

This study is a case series of adult patients who received bilateral pterygopalatine fossa (PPF) blockade for the management of refractory headaches after spontaneous SAH (aneurysmal and non-aneurysmal) at a single tertiary care center. We examined pain scores and analgesic requirements before and after block placement.

RESULTS

Seven patients (median age 54 years, 3 men, four aneurysmal and three non-aneurysmal) received a PPF-block between post-bleed day 6-11 during index hospitalization in the neurointensive care unit. The worst pain recorded in the 24-h period before the block was significantly higher than in the period 4 h after the block (9.1 vs. 3.1; p = 0.0156), and in the period 8 h after the block (9.1 vs. 2.8; p = 0.0313). The only complication was minor oozing from the needle insertion sites, which subsided completely with gauze pressure within 1 min.

CONCLUSIONS

PPF blockade might constitute a promising opioid-sparing therapeutic strategy for the management of post-SAH headache that merits further prospective controlled randomized studies.

The efficacy of sphenopalatine ganglion block for pain management after endoscopic sinus surgery: a meta-analysis of randomized controlled studies

INTRODUCTION

The efficacy of sphenopalatine ganglion (SPG) block for pain control after endoscopic sinus surgery remains controversial. We conduct a systematic review and meta-analysis to explore the influence of SPG block on pain intensity after endoscopic sinus surgery.

METHODS

We search PubMed, EMbase, Web of science, EBSCO, and Cochrane library databases through June 2019 for randomized controlled trials (RCTs) assessing the efficacy of SPG block for pain management after endoscopic sinus surgery. This meta-analysis is performed using the random-effect model.

RESULTS

Six RCTs are included in the meta-analysis. Overall, compared with control group for endoscopic sinus surgery, SPG block is associated with the decrease in pain scores at 6 h (Std. MD =  - 0.71; 95% CI =  - 1.08 to - 0.34; P = 0.0002) and 24 h (Std. MD =  - 0.51; 95% CI =  - 0.87 to - 0.14; P = 0.006), the number of rescue analgesics (RR = 0.26; 95% CI = 0.16 to 0.42; P < 0.00001) and incidence of nausea and vomiting (RR = 0.52; 95% CI = 0.30-0.89; P = 0.02), but demonstrate no obvious impact on pain scores at 2 h (Std. MD =  - 0.99; 95% CI =  - 2.80-0.83; P = 0.29) or headache (RR = 1.30; 95% CI = 0.38-4.46; P = 0.67).

CONCLUSIONS

SPG block can provide additional benefits for pain management after endoscopic sinus surgery.

Surgical Treatment for the Cluster Headache: Clinical Experience

BACKGROUND

Cluster headache (CH) refers to the most painful primary headache that sometimes leads to poor quality of life and associated disability. So far, no treatment has been found to cure CHs. In this study, we introduce a novel and effective surgery for CH.

METHODS

We studied 6 patients with CH diagnosed according to the criteria of the Headache Classification Committee of the IHS, third edition, who were eligible for surgical treatment on the basis of strong requirements. All of them underwent temporal craniectomy and transection of the greater superficial petrosal nerve and deep petrosal nerve pathway to the sphenopalatine ganglion.

RESULTS

All 6 patients had the surgery for CH and follow-up per 3 months. We significantly cured their pain and autonomic dysfunction. In the follow-up process none of the patients had reoccurring alacrimia. All of them had reduction of secretion of nasal, oral mucosa, and parotid and were satisfied with the surgery.

CONCLUSIONS

All 6 patients with CH received surgery by transection greater superficial petrosal nerve and deep petrosal nerve pathway to the sphenopalatine ganglion and were completely cured, and adverse events and serious complications did not occur.

Retrospective Study on Ganglionic and Nerve Block Series as Therapeutic Option for Chronic Pain Patients with Refractory Neuropathic Pain

Objective

Current recommendations controversially discuss local infiltration techniques as specific treatment for refractory pain syndromes. Evidence of effectiveness remains inconclusive and local infiltration series are discussed as a therapeutic option in patients not responding to standard therapy. The aim of this study was to investigate the effectiveness of infiltration series with techniques such as sphenopalatine ganglion (SPG) block and ganglionic local opioid analgesia (GLOA) for the treatment of neuropathic pain in the head and neck area in a selected patient group.

Methods

In a retrospective clinical study, 4960 cases presenting to our university hospital outpatient pain clinic between 2009 and 2016 were screened. Altogether, 83 patients with neuropathic pain syndromes receiving local infiltration series were included. Numeric rating scale (NRS) scores before, during, and after infiltration series, comorbidity, and psychological assessment were evaluated.

Results

Maximum NRS before infiltration series was median 9 (IQR 8–10). During infiltration series, maximum NRS was reduced by mean 3.2 points (SD 3.3, p < 0.001) equaling a pain reduction of 41.0% (SD 40.4%). With infiltration series, mean pain reduction of at least 30% or 50% NRS was achieved in 54.2% or 44.6% of cases, respectively. In six percent of patients, increased pain intensity was noted. Initial improvement after the first infiltration was strongly associated with overall improvement throughout the series.

Conclusion

This study suggests a beneficial effect of local infiltration series as a treatment option for refractory neuropathic pain syndromes in the context of a multimodal approach. This effect is both significant and clinically relevant and therefore highlights the need for further randomized controlled trials.

Images in anesthesiology: three safe, simple, and inexpensive methods to administer the sphenopalatine ganglion block

The sphenopalatine ganglion (SPG) block is a simple and valuable technique that was discovered over a century ago, but, unfortunately, very few anesthesiology providers are familiar with this block. After some of our recent publications, physicians from different countries have reached out to us requesting more specifics on how we perform our version of the block. In this report, we provide a brief history of the block and demonstrate our three effective, simple, readily available, and inexpensive methodologies with images. We are proud to share that our three SPG block techniques have so far effectively relieved patients of chronic migraines, acute migraines, tension headaches, moderate-to-severe back pain, and post-dural puncture headaches.

Neurobehavioral Disorders: The Corticolimbic System in Health and Disease

The corticolimbic system (prefrontal cortices, amygdala, and hippocampus) integrates emotion with cognition and produces a behavioral output that is flexible based on the environmental circumstances. It also modulates pain, being implicated in pathophysiology of maladaptive pain. Because of the anatomic and function overlap between corticolimbic circuitry for pain and emotion, the pathophysiology for maladaptive pain conditions is extremely complex. Addressing environmental needs and underlying triggers is more important than pharmacotherapy when dealing with feline orofacial pain syndrome or feline hyperesthesia syndrome. By contrast, autoimmune limbic encephalitis requires prompt diagnosis and management with immunosuppression and seizure control.

Sphenopalatine Ganglion Block: Treatment of Migraine and Trigeminal Neuralgia Associated With Multiple Sclerosis

Head and facial pain are a burden to many people both directly and indirectly. This is manifested not only as a personal burden but also as a financial one in the form of sick leaves from work and loss of workplace productivity. These costs stem from emergency department visits, hospitalizations, preventative treatments, and medical management. Medical management of migraine headaches and other causes of facial pain often proves insufficient, and sphenopalatine ganglion block (SPGB) provides an innovative, adjunctive outpatient treatment option with excellent results in alleviating symptoms. We present a case of a young female suffering from headache and orofacial pain secondary to multiple sclerosis (MS) and trigeminal neuralgia (TN) refractory to traditional medical management, who underwent SPGB with immediate relief of her symptoms. Due to its effectiveness, the role of the SPGB in the treatment of various other conditions causing headache and orofacial pain, such as MS or even TN, continues to expand providing relief and restoring functionality.

The Effect of Sphenopalatine Ganglion Block on the Postoperative Pain in Patients Undergoing Septorhinoplasty

OBJECTIVES

This study aimed to evaluate the effect of preoperative sphenopalatine ganglion block (SPBG) on the postoperative pain (POP) in patients undergoing septorhinoplasty (SRP).

METHODS

A retrospective cohort study was performed. A total of 42 patients that had received septorhinoplasty included in the study. The patients that had received SPBG before the surgery included in the Block group (n:20) and the patients that had not received SPBG before the surgery included in the Control group (n:22). POP was questioned with a numeric rating scale (NRS) at the 30th minute (t1), 1st hour (t2), 4th hour (t3), 12th hour (t4), and 24th hour (t5) and noted. The intraoperative details and the dose of the postoperative rescue analgesics were also noted.

RESULTS

The average dose of Paracetamol that was used in the postoperative first 24 hours was 500 mg in the Block group and 1363 mg in the Control group, and the difference was statistically significant (P = .001). The average dose of Tramadol was 0 mg in the Block group and 45 mg in the Control group, and the difference was statistically significant (P = .001). There was a statistically significant difference among the groups with respect to NRS in the first 24 hours postoperatively (P < .05). The number of the patients requiring rescue analgesics was lower in the Block group than the Control group. The difference was statistically significant at the t1, t2, and t5 time intervals (P > .05).

CONCLUSIONS

Preoperative SPGB is an effective option to reduce POP and the need for rescue analgesics for patients undergoing SRP.

CLINICAL TRIAL NUMBER

NCT04020393.

Effect of pterygopalatine blockade on perioperative stress and inflammatory outcomes following paediatric cataract surgery

BACKGROUND

General anesthesia is required to perform pediatric cataract surgery. To reduce severity of surgical intervention and postoperative complications, regional techniques have been concomitantly used. The traditional regional ophthalmic techniques are retrobulbar, peribulbar and sub-Tenon blocks, which present some technical difficulties and associated complication risks. The pterygopalatine blockade has been exempt of many of these concerns as it is performed out of the orbit. The purpose of this study was to compare the analgesic and anti-inflammatory effects of the pterygopalatine blockade with retrobulbar block in children undergoing elective congenital cataract surgery.

METHODS

After approval of ethics committee and informed consents, patients were enrolled to the study to have either ultrasound-guided pterygopalatine block (group P) or retrobulbar block (group R), with 2 mL lidocaine 2% and 1 mL ropivacaine 0.5%. Hemodynamic monitoring was recorded throughout the perioperative period. Cortisol level and oxidation-reduction status were assessed before and after surgery. Pain and inflammatory response (Tyndall effect, corneal syndrome and edema) were assessed on the first postoperative day.

RESULTS

Comparative analysis demonstrated a decrease in cortisol of 123.24% (p˂0.05) and an increase in the redox coefficient of 37.7% (p˂0.05) in group P. Pain intensity was significantly higher in group R until the 16th postoperative hour. The corneal syndrome in patients in group P and group R was noted by 7.6% and in 32.1%, respectively (p˂0.05).

CONCLUSION

The use of the pterygopalatine blockade as a component of anesthesia in pediatric cataract surgery allows reduction of the severity of surgical stress during surgical intervention, providing intraoperative hemodynamic stability and prolonged analgesia.

Pilot Study of Injection of OnabotulinumtoxinA Toward the Sphenopalatine Ganglion for the Treatment of Classical Trigeminal Neuralgia

Background

The sphenopalatine ganglion (SPG) has previously been targeted in trigeminal neuralgia (TN), but its role in this condition has not been established.

Objective

To investigate the safety of injecting onabotulinumtoxinA (BTA) toward the SPG using the MultiGuide^® in 10 patients with refractory classical TN, and collect preliminary efficacy data.

Methods

Twenty‐five international units (IU) of BTA were injected toward the SPG in a prospective, open‐label study in 10 patients with refractory classical TN. All patients were recruited and treated on an out‐patient basis at St. Olav's University Hospital in Trondheim (Norway). Primary outcome: adverse events (AEs). Primary efficacy outcome: number of TN attacks at weeks 5‐8 after injection compared to baseline. A treatment responder was predefined as at least 50% reduction in the median number of attacks per day between baseline and weeks 5‐8. Other efficacy outcomes were intensity of attacks (numeric rating scale, 0 to 10) and functional level (1 to 4; 1 best and 4 worst) at weeks 5‐8 after injection compared to baseline. Percentage of the day with concomitant persistent pain was registered at baseline and at weeks 1‐4, 6, 8, and 12 after injection. Patient global impression of change (PGIC) was ascertained at month 3.

Results

For the primary endpoint, we analyzed data for all 10 patients. For efficacy outcomes we analyzed data for 9 patients (1 patient violated protocol). We registered 13 AEs, none of which were serious. The median number of TN attacks during the 4‐week baseline and weeks 5‐8 after injection was 5.5 (range: 1.0‐51.5) and 5 (range: 0‐225.0), respectively (P = .401). Four patients were treatment responders. The median intensity of attacks at baseline and weeks 5‐8 after injection was 6 (range: 3.0‐8.5) and 3 (range: 0.0‐9.0) respectively (P = .024). The median functional level at baseline was 2 (range: 1.0‐3.3) and at month 2, 1 (range 1.0‐4.0; P = .750). Median percentage of the day with concomitant persistent pain was 75% (minimum 37.5%, maximum 100%) at baseline and 18.75% (minimum 0%, maximum 100%) at week 8 (P = .023).

Conclusions

Injection of BTA toward the SPG using the MultiGuide^® in patients with TN appears to be safe and well tolerated. This study was negative for the main efficacy endpoint (reduction in the number of attacks from baseline to weeks 5‐8). Further studies examining the role of the SPG in TN are necessary.

Regional techniques for head and neck surgical procedures

Regional anesthesia has evolved as an important tool for anesthesiologists and surgeons managing patients for surgery of the head and neck region. In recent years, ultrasound use has increased significantly, and newer nerve blocks have been established for surgeries of the head and regions. In this review, anatomy, indications, efficacy, and potential side effects of regional anesthesia for the head and neck region are presented. Evolving practice strongly suggests that regional nerve blocks for the head and neck region are safe and effective. Future studies and education will likely evolve practice to make these regional techniques standards for future surgeries of the head and neck region.

Expression Analysis of Serotonin Receptors, Serotonin Transporter and l-Amino Acid Decarboxylase in the Mouse Sphenopalatine Ganglion by RT-PCR, Northern Blot Analysis and In Situ Hybridization

The sphenopalatine ganglion (SPG) is a gathering of the cell bodies of parasympathetic fibers that dominate the nasal gland, lacrimal gland and cerebral blood vessels. The SPG controls nasal secretions, tears, and the dilation of cerebral blood vessels. However, it is unclear how serotonin regulates SPG functions. In this study, we investigated the expression of genes involved in the serotonergic system in the mouse SPG. We examined the mRNA expression levels of 5-HT_1A, 5-HT_1B, 5-HT_1D, 5-HT_1F, 5-HT_2A, 5-HT_2B, 5-HT_2C, 5-HT_3A, 5-HT_3B, 5-HT₄, 5-HT_5A, 5-HT_5B, 5-HT₆ and 5-HT₇ receptors, as well as serotonin transporter, tryptophan hydroxylases 1 and 2, and L-amino acid decarboxylase (AADC) by RT-PCR. It revealed that the 5-HT_3A and 5-HT_3B ionotropic receptors and AADC were likely to be highly expressed in the SPG, as measured by RT-PCR. We next performed in situ hybridization on the SPG to examine the expression of these three genes at the cellular level after validating the specificity of each cRNA probe by northern blotting. The 5-HT_3A receptor, 5-HT_3B receptor, and AADC were expressed in 96.5% ± 1.0%, 29.7% ± 10.7%, and 57.4% ± 2.9% of neuronal cell bodies in the SPG, respectively, indicating that the 5-HT_3A receptor was virtually expressed in all SPG neurons. Our results on the expression of these critical serotonin system genes in the parasympathetic SPG provide insight into the pathogenetics of rhinitis, conjunctivitis and headache. Furthermore, our findings suggest that targeting the 5-HT_3A receptor might have therapeutic potential in the treatment of these ailments.

Vidian Neurectomy for Management of Chronic Cluster Headache

BACKGROUND

Management of chronic cluster headache (CCH) remains a challenging endeavor, and the optimal surgical approach for medically refractory CCH remains controversial.

OBJECTIVE

To conduct a preliminary evaluation of the efficacy and safety of vidian neurectomy (VN) in patients with medically refractory CCH.

METHODS

Between March 2013 and December 2015, 9 CCH patients, all of whom had failed to respond to conservative therapy, underwent VN with a precise nerve cut and maximal preservation of the sphenopalatine ganglion. Data included demographic variables, cluster headache onset and duration, mean attack frequency, mean attack intensity, and pain disability index measures pre- and through 12-mo postsurgery.

RESULTS

Seven of the 9 cases (77.8%) showed immediate improvement. Improvement was delayed by 1 mo in 1 patient, after which the surgical effects of pain relief were maintained throughout the follow-up period. One patient (11.1%) did not improve after surgery. One year after VN, patients' mean attack frequency, mean attack intensity, and pain disability index decreased by 54.5%, 52.9%, and 56.4%, respectively. No patient experienced treatment-related side effects or complications.

CONCLUSION

VN is an effective treatment method for CCH patients. Precise Vidian nerve identification and maximal preservation of the sphenopalatine ganglion may achieve good surgical outcomes and dramatically improve quality of life among patients, without significant adverse events.

Changes in facial temperature measured by digital infrared thermal imaging in patients after transnasal sphenopalatine ganglion block: Retrospective observational study

Sphenopalatine ganglion block (SPGB) is a technique developed in the 1990s for the management of head and neck pain patients. Recently, transnasal sphenopalatine ganglion block (TN-SPGB) has been widely used for these patients; however, no objective methods exist for validating the success of TN-SPGB. In this study, we measured the changes in facial temperature before and 30 minutes after TN-SPGB by using digital infrared thermal imaging (DITI) to validate its success.The medical records of patients, who underwent TN-SPGB and facial DITI between January 2016 and December 2017, were reviewed. TN-SPGB and facial DITI were performed 36 times in 32 patients. The changes in facial temperatures measured at the forehead (V1), maxillary area (V2), and mandibular area (V3) by using DITI before and 30 minutes after TN-SPGB were recorded and compared. The temperatures on the ipsilateral and contralateral sides of these areas were also compared. The comparison between pain relief group and pain maintenance group was analyzed.After TN-SPGB, the temperature decreased significantly on both sides of V1 (P = .0208, 0.0181). No significant differences were observed between the ipsilateral and contralateral sides (P > .05). There was no correlation between changes in temperature and changes in pain score in the pain regions after the procedure (P > .05).The temperature decreased significantly in V1 area at 30 minutes after TN-SPGB compared with the temperature before TN-SPGB. Based on these results, we propose using DITI to measure temperature changes as an objective method for verifying the success of TN-SPGB.

Multicentre, prospective, randomised, controlled, blinded-endpoint study to evaluate the efficacy and safety of pterygopalatine ganglion pulsed radiofrequency treatment for cluster headache: study protocol

INTRODUCTION

Single-centre reports on small groups of patients have shown that pterygopalatine ganglion pulsed radiofrequency treatment in patients with refractory cluster headache (CH) can quickly relieve pain without significant side effects. However, a randomised controlled trial is still necessary to evaluate whether pterygopalatine ganglion pulsed radiofrequency (PRF) treatment is a viable treatment option for patients with CH who are not responding to drug treatment.

METHODS AND ANALYSIS

This investigation is a multicentre, prospective, randomised, controlled, blinded-endpoint study. We will enrol 80 patients with CH who are not responding to medication. The enrolled patients will be randomly divided into two groups: the nerve block (NB) group and the PRF group. All patients will undergo CT-guided pterygopalatine ganglion puncture. A mixture containing steroids and local anaesthetics will be slowly injected into the patients in the NB group. The patients in the PRF group will be treated with PRF at 42°C for 360 s. After treatment, the duration of cluster periods; degree of pain during headache attacks; frequency of headache attacks; duration of each headache attack; dose of auxiliary analgesic drugs; duration of remission; degree of patient satisfaction; effectiveness rates at 1 day, 3 days, 1 week, 2 weeks, 1 month, 3 months, 6 months, and 1 year after the procedure; and intraoperative and postoperative adverse events will be compared between the two groups.

ETHICS AND DISSEMINATION

This study was approved by the institutional ethics committee of the Beijing Tiantan Hospital (approval number: KY 2018-027-02). The results of the study will be published in peer-reviewed journals, and the findings will be presented at scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03567590; Pre-results.

Vagal Nerve Stimulation Attenuates Ischemia-Reperfusion Induced Retina Dysfunction in Acute Ocular Hypertension

Purpose: The present study aimed to investigate whether cervical vagal nerve stimulation (VNS) could prevent retinal ganglion cell (RGC) loss and retinal dysfunction after ischemia/reperfusion (I/R) injury.

Methods: First, rats were randomly divided into sham group (n = 4) and VNS group (n = 12). Activation of the nodose ganglia (NOG), nucleus of the solitary tract (NTS), superior salivatory nucleus (SSN), and pterygopalatine ganglion (PPG) neural circuit were evaluated by c-fos expression at 0 h after sham VNS and at 0 h (n = 4), 6 h (n = 4), 72 h (n = 4) after VNS. Secondly, rats were randomly assigned to I/R group (pressure-induced retinal ischemia for 1 h and reperfusion for 1 h in the right eye, n = 16) and I/R+VNS group (right cervical VNS for 2 h during the I/R period, n = 16). The left eye of each rat served as a control. Electroretinogram (ERG), RGC numbers, tumor necrosis factor-α (TNF-α) and vasoactive intestinal polypeptide (VIP) levels in retina were determined. Additionally, the level of VIP in PPG was evaluated.

Results: In the first part of the study, compared with the sham group, the VNS group exhibited significantly increased expression of c-fos in NOG, NTS, SSN, and PPG tissues at 0, 6, and 72 h. In the second part of the study, compared with left eyes, retinal function in right eyes (as assessed by the a-wave, b-wave and the oscillatory potential amplitudes of ERG and RGC data) was significantly decreased by I/R. The decreased retinal function was attenuated by VNS. In addition, I/R induced an increase in inflammation, which was reflected by elevated TNF-α expression in the retina. VNS significantly attenuated the increase in I/R-induced inflammation. Moreover, VIP expression in the retina and PPG, which may contribute to the inhibition of the inflammatory response, was significantly increased after VNS.

Conclusion: VNS could protect against retinal I/R injury by downregulating TNF-α. Upregulation of VIP expression due to activation of the NOG-NTS-SSN-PPG neural circuit may underlie to the protective effects of VNS.

Sphenopalatine Ganglion Block and Radiofrequency Ablation: Technical Notes and Efficacy

Background: Sphenopalatine ganglion (SPG) blockade or lesioning can offer significant pain relief for cluster headaches (CHs) and a variety of other pain syndromes involving the head and face. Methods: We reviewed the literature on the efficacy of SPG block and radiofrequency ablation (RFA) using PubMed and Google Scholar. Results: The infrazygomatic technique can be used to directly access the SPG for injection of local anesthetic or lesioning using RFA. Important technical points to achieve these procedures are described. SPG blockade efficacy is supported by randomized controlled studies but SPG RFA is not. Conclusion: Targeting the SPG is a promising treatment option for refractory CHs. RFA and neuromodulation have the potential to offer long-term significant pain relief, but more randomized studies are needed to demonstrate their efficacy.

Morphological Description and Clinical Implication of Sphenopalatine Foramen for Accurate Transnasal Sphenopalatine Ganglion Block: An Anatomical Study

Objective:

Transnasal sphenopalatine ganglion block is a commonly used approach for treatment of a variety of headache disorders. However, no standard technique has yet been defined for this less invasive approach. In this study, our aim was to investigate morphometric and anatomical features of the sphenopalatine foramen, and to describe a more efficient approach for transnasal sphenopalatine ganglion block.

Method:

The present study was designed retrospectively. Ten cadaver semi- heads and 18 adult dry skulls (28 samples totally) were included in the study. The distances between the sphenopalatine foramen and palatum durum, and also between the sphenopalatine foramen and the spina nasalis anterior, angle of elevation of the sphenopalatine foramen from palatum durum, and the length and width of the sphenopalatine foramen were measured.

Results:

The mean width and length of the foramen were 3.79±0.35 and 6.44±0.94 mm, respectively. The mean distance between the palatum durum and the sphenopalatine foramen was 15.58±1.68 mm. The mean angle of elevation of the sphenopalatine foramen from the palatum durum was 26.10±3.97 degrees. The mean distance between the sphenopalatine foramen and the anterior nasal spine was 52.90±2.98 mm.

Conclusions:

In the transnasal sphenopalatine block, we suggest advancement of nasal applicator through superolateral direction for approximately 5.3 cm, and at an angle of about 26° from the nasal base..