Sphenopalatine ganglion stimulation for the treatment of cluster headache

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.

Peripheral Nerve Stimulation in Pain Management: A Systematic Review

BACKGROUND

Peripheral nerve stimulation (PNS) has been increasingly used to manage acute and chronic pain. However, the level of clinical evidence to support its use is not clear.

OBJECTIVES

To assess the clinical evidence of PNS in the treatment of acute or chronic pain.

STUDY DESIGN

A systematic review of the efficacy and safety of PNS in managing acute or chronic pain.

METHODS

Data sources were PubMed, Cochrane Library, Scopus, CINAHL Plus, Google Scholar, and reference lists. The literature search was performed up to December 2019. Study selection included randomized trials, observational studies, and case reports of PNS in acute or chronic pain. Data extraction and methodological quality assessment were performed utilizing Cochrane review methodologic quality assessment and Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment (IPM-QRB) and Interventional Pain Management Techniques-Quality Appraisal of Reliability and Risk of Bias Assessment for Nonrandomized Studies (IPM-QRBNR). The evidence was summarized utilizing principles of best evidence synthesis on a scale of 1 to 5. Data syntheses: 227 studies met inclusion criteria and were included in qualitative synthesis.

RESULTS

Evidence synthesis based on randomized controlled trials (RCTs) and observational studies showed Level I and II evidence of PNS in chronic migraine headache; Level II evidence in cluster headache, postamputation pain, chronic pelvic pain, chronic low back and lower extremity pain; and Level IV evidence in peripheral neuropathic pain, and postsurgical pain. Peripheral field stimulation has Level II evidence in chronic low back pain, and Level IV evidence in cranial pain.

LIMITATIONS

Lack of high-quality RCTs. Meta-analysis was not possible due to wide variations in experimental design, research protocol, and heterogeneity of study population.

CONCLUSIONS

The findings of this systematic review suggest that PNS may be effective in managing chronic headaches, postamputation pain, chronic pelvic pain, and chronic low back and lower extremity pain, with variable levels of evidence in favor of this technique.

Neuromodulation in headache and craniofacial neuralgia: guidelines from the Spanish Society of Neurology and the Spanish Society of Neurosurgery

INTRODUCTION

Numerous invasive and non-invasive neuromodulation devices have been developed and applied to patients with headache and neuralgia in recent years. However, no updated review addresses their safety and efficacy, and no healthcare institution has issued specific recommendations on their use for these 2 conditions.

METHODS

Neurologists from the Spanish Society of Neurology's (SEN) Headache Study Group and neurosurgeons specialising in functional neurosurgery, selected by the Spanish Society of Neurosurgery (SENEC), performed a comprehensive review of articles on the MEDLINE database addressing the use of the technique in patients with headache and neuralgia.

RESULTS

We present an updated review and establish the first set of consensus recommendations of the SEN and SENC on the use of neuromodulation to treat headache and neuralgia, analysing the current levels of evidence on its effectiveness for each specific condition.

CONCLUSIONS

Current evidence supports the indication of neuromodulation techniques for patients with refractory headache and neuralgia (especially migraine, cluster headache, and trigeminal neuralgia) selected by neurologists and headache specialists, after pharmacological treatment options are exhausted. Furthermore, we recommend that invasive neuromodulation be debated by multidisciplinary committees, and that the procedure be performed by teams of neurosurgeons specialising in functional neurosurgery, with acceptable rates of morbidity and mortality.

Analysis of the Pterygomaxillary Fissure for Surgical Approach to Sphenopalatine Ganglion by Radiological Examination of Cone Beam Computed Tomography

The pterygopalatine fossa (PPF) is a complex and paired anatomical structure located at the skull base. A clinically and surgically relevant structure located in the pterygopalatine fossa is the sphenopalatine ganglion. Electrical stimulation of the sphenopalatine ganglion is one possible method of treating cluster headache. The pterygomaxillary fissure (PMF) defines the pterygopalatine fossa laterally and determines the surgical approach. As part of preoperative surgical planning, each patient undergoes a preoperative head computed tomography or a cone beam computed tomography. In our study cone beam computed tomography images of 90 male and 110 female PMF were analyzed. Generally, males have a wider fissure than females. Moreover, a significant inter-subject difference could be shown between males and females. The analysis of the right and left PMF according to gender and age does not show any significant intra-subject differences. Following an established protocol for high-resolution CT images the measurements were classified into four fissure types and also analyzed according to gender and age. Fissure type I is significantly more often present in males, whereas the smaller fissure types (II, III, and IV) are significantly more often found in females. Older patients presented statistically significant more often with type I, whereas the younger patients showed more often the narrower types II and IV. Due to the fact that narrow fissures smaller than 2 mm could limit the insertion of neurostimulator implants in the PPF, special attention should be paid to females and younger patients during preoperative planning.

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.

Sphenopalatine Ganglion Block for the Treatment of Acute Migraine Headache

Transnasal sphenopalatine ganglion block is emerging as is an attractive and effective treatment modality for acute migraine headaches, cluster headache, trigeminal neuralgia, and several other conditions. We assessed the efficacy and safety of this treatment using the Sphenocath® device. 55 patients with acute migraine headaches underwent this procedure, receiving 2 ml of 2% lidocaine in each nostril. Pain numeric rating scale (baseline, 15 minutes, 2 hours, and 24 hours) and patient global impression of change (2 hours and 24 hours after treatment) were recorded. The majority of patients became headache-free at 15 minutes, 2 hours, and 24 hours after procedure (70.9%, 78.2%, and 70.4%, resp.). The rate of headache relief (50% or more reduction in headache intensity) was 27.3% at 15 minutes, 20% at 2 hours, and 22.2% at 24 hours. The mean pain numeric rating scale decreased significantly at 15 minutes, 2 hours, and 24 hours, respectively. Most patients rated the results as very good or good. The procedure was well-tolerated with few adverse events. This treatment is emerging as an effective and safe option for management of acute migraine attacks.

Radiological anatomy assessment of the fissura pterygomaxillaris for a surgical approach to ganglion pterygopalatinum

The ganglion pterygopalatinum has become a therapeutic target to treat various pain syndromes in recent years. It is located in the fossa pterygopalatina, and the fissura pterygomaxillaris is the main access to surgically approach this structure. Recently, the neuromodulation of the ganglion pterygopalatinum by microstimulator implantation has become the first therapeutic line in refractory cluster headache treatment. This invasive technique is performed transorally through the fissura pterygomaxillaris, and is limited by the size of the implantation device, which requires an opening of at least 2 mm. Therefore, extensive knowledge about the anatomy of the fissura pterygomaxillaris prior to surgery is necessary to predict the success of both the approach and intervention. Likewise, establishing a morphological typology of the different fissura pterygomaxillaris variations would be a valuable predictive tool in the clinical practice. In this work, an anatomical analysis was performed of the morphological characteristics of the 242 fissurae pterygomaxillares, which corresponded to 121 adult patients, 58 males and 63 females, aged between 18 and 87 years. For each subject, right and left fissures were studied with radiological computed tomography images. Aperture fissura pterygomaxillaris measurements were taken in an upper (Measure A), middle (Measure B) and lower craneo-caudal third (Measure C). Intra-subject differences were studied between the measurements taken of each patient's right and left fissures, and the inter-subject measures in which fissures were compared according to patients' age and gender. The obtained results showed no significant differences between each patient's right and left fissures in any three measurements taken. Intra-subject differences were not significant for gender or age. No statistically significant differences were found for the inter-subject measures between the measures of fissures according to patients' age. However, our data revealed that males' fissurae pterygomaxillares were significantly larger than those of females in all three measures. Having analysed fissures, a typological classification was made according to the morphological patterns found. A 2-mm limiting measure was considered, and Measures A, B and C of each fissure were classified depending on whether they had a value above or equal to 2 mm, or below 2 mm. With this classification criterion, four fissurae pterygomaxillares types were obtained. Type I and II fissure values (with a higher prevalence) were equal to or were greater than 2 mm in all three measures, or in two measures. Type III fissure values were only greater than or equal to 2 mm in Measure A, whereas all the Type IV fissure values were below 2 mm. Future studies are necessary to correlate the fissure types successfully proposed in the surgical ganglion pterygopalatinum approach.

Facial nerve stimulation as a future treatment for ischemic stroke

Stimulation of the autonomic parasympathetic fibers of the facial nerve system (hereafter simply “facial nerve”) rapidly dilates the cerebral arteries and increases cerebral blood flow whether that stimulation is delivered at the facial nerve trunk or at distal points such as the sphenopalatine ganglion. Facial nerve stimulation thus could be used as an emergency treatment of conditions of brain ischemia such as ischemic stroke. A rich history of scientific research has examined this property of the facial nerve, and various means of activating the facial nerve can be employed including noninvasive means. Herein, we review the anatomical and physiological research behind facial nerve stimulation and the facial nerve stimulation devices that are in development for the treatment of ischemic stroke.

Sphenopalatine ganglion stimulation in cluster headache and other types of headache

Objectives The cluster headache is the most excruciatingly painful primary headache. In some patients, neither preventive treatment nor acute treatment is effective or treatment is poorly tolerated. The sphenopalatine ganglion (SPG) has an important role in the pathophysiology of cluster headache and, for this reason, SPG stimulation has been used to treat cluster headache. Methods We have reviewed the published literature on the role of the SPG in cluster headache and the use of different treatments targeting the SPG. Results Multiple procedures have been used over the SPG to treat pain and trigemino-autonomic symptoms in patients with refractory cluster headache. After obtaining good results in a small number of patients, a miniaturized stimulator was developed. Stimulation of the SPG with this device proved to be efficacious in acute and preventive treatment in a clinical trial involving patients with chronic refractory cluster headache. Implantation of the device is minimally invasive and the most frequent side-effects are mild, such as paraesthesia and pain over the maxillary area. In patients who have used the SPG device for longer than one year, the therapeutic effect remains effective and the side-effects decrease. Conclusions The reported studies have demonstrated that SPG stimulation is a safe and effective treatment for chronic cluster headache. Long-term studies have shown that the effect remains over time and this treatment could be a good choice in patients with chronic refractory headache. We need more data about its potential use in other forms of headache, such as other trigemino-autonomic headaches or migraine.

Long-term efficacy of a double-blind, placebo-controlled, randomized study for repetitive sphenopalatine blockade with bupivacaine vs. saline with the Tx360 device for treatment of chronic migraine

Background

This study aims to determine if repetitive sphenopalatine ganglion (SPG) blockades with 0.5% bupivacaine delivered with the Tx360^® device results in long‐term improvement in chronic migraine (CM). The SPG is a small concentrated structure of neuronal tissue that resides within the pterygopalatine fossa in close proximity to the sphenopalatine foramen and is innervated by the maxillary division of the trigeminal nerve. In a previous article, these authors reported repetitive SPG blockades with 0.5% bupivacaine delivered by the Tx360^® device, which was an effective and well‐tolerated intervention to incrementally decrease baseline headache intensity of subjects with CM.

Methods

This was a double‐blind, parallel‐arm, placebo‐controlled, randomized pilot study using a novel intervention for acute treatment in CM. A total of 41 subjects were enrolled at two headache specialty clinics in the USA. Eligible subjects were between 18 and 80 years of age and had a history of CM defined by International Classification of Headache Disorders‐II definition. Subjects were allowed a stable dose of migraine preventive medications that was maintained throughout the study. Following a 28‐day baseline period, subjects were randomized by computer‐generated lists 2:1 to receive 0.3 cc of 0.5% bupivacaine or saline, respectively, delivered with the Tx360^® twice a week for 6 weeks. Secondary end‐points reported in this manuscript include post‐treatment measures including number of headache days and quality of life measures.

Results

The final data set included 38 subjects: 26 in the bupivacaine group and 12 in the saline group. Our primary end‐point for the study, difference in numeric pain rating scale scores, was met and reported in a previous article. The supplemental secondary end‐points reported in this manuscript did not reach statistical significance. When looking collectively at these end‐points, trends were noticed and worthy of reporting. Subjects receiving bupivacaine reported a decrease in the number of headache days 1 month post‐treatment (M_diff = −5.71), whereas those receiving saline only saw a slight improvement (M_diff = −1.93). Headache Impact Test 6 scores were decreased in the bupivacaine group at 1 month (M_diff = −5.13) and 6 months (M_diff = −4.78) post‐treatment, but only a modest reduction was seen for those receiving saline at 1 and 6 months, respectively (M_diff = −2.08, M_diff = −1.58). Furthermore, subjects receiving bupivacaine reported a reduction in acute medication usage and improved quality of life measures (average pain in the previous 24 hours, mood, normal work, and general activity) up to 6 months post‐treatment. The changes in these measures for the saline group were minimal.

Conclusions

Data from this exploratory pilot study suggest that there may be long‐term clinical benefits with the use of repetitive SPG blockades with bupivacaine delivered with the simple to use Tx360^® device. These include a sustained reduction of headache days and improvement in several important quality of life assessments. The SPG blockades were not associated with any significant or lasting adverse events. Further research on SPG blockade is warranted.