Efficacy of sphenopalatine ganglion blockade in 66 patients suffering from cluster headache: a 12- to 70-month follow-up evaluation

Open label experience of repeated OnabotulinumtoxinA injections towards the sphenopalatine ganglion in patients with chronic cluster headache and chronic migraine

BACKGROUND

A novel technique for injection of OnabotulinumtoxinA (BTA) towards the sphenopalatine ganglion (SPG) has shown promise in refractory chronic migraine (CM) and chronic cluster headache (CCH). Open label safety and efficacy data are presented here.

METHODS

Patients with refractory CM or CCH who had received at least one injection and completed headache diaries were included. Efficacy was defined as ≥50% reduction in moderate-to-severe headache days for CM, or ≥50% reduction in attack frequency for CCH, at weeks five to eight.

RESULTS

Over 261 injections, there were 123 adverse events (AE), of which one was serious. Most (93%) AEs were mild and all were transient. The 50% response to one injection was 81% for CM and 69% for CCH. The response gradually reduced over subsequent months for CM but stayed between 55% and 67% for CCH. Repeated injections were beneficial.

CONCLUSIONS

Injections resulted in improvement for both groups and was maintained with repeated injections. Repeat injection after three months may be beneficial in CM. Adverse events were not uncommon, but universally transient, presumably as a result of the mechanism of action of BTA. Repeated BTA injection towards the SPG could be an effective treatment for refractory CM and CCH. Larger, randomised, placebo-controlled trials are required.

Cluster headache: state of the art in treatment

Cluster headache (CH) is the most common and devastating autonomic headache with multiple and recent advances in treatment. However, it usually goes unrecognized and is found to have a delayed and inappropriate treatment. This paper aims to review the current therapeutic options for patients with CH. We conducted a narrative literature review on the treatments available for this condition using the American Academy of Neurology (AAN) classification of therapeutic evidence. We found effective and safe pharmacological and non-pharmacological therapies with heterogeneity of clinical trial designs for patients with CH, and they are divided into three phases, namely, transitional, acute, and preventive interventions. Prednisone (A) is the most studied treatment in the transitional phase; acute attacks are treated using triptans (A), oxygen (A), and non-invasive transcutaneous vagal nerve stimulation (A). Verapamil (A) and monoclonal antibodies (possible A) are considered the first options in preventive treatments, followed by multiple pharmacological and non-pharmacological options in prophylactic treatments. In conclusion, numerous effective and safe treatments are available in treating patients with episodic, chronic, and pharmacoresistant CH according to the clinical profile of each patient.

Cluster Headache: A Review and Update in Treatment

PURPOSE OF REVIEW

The treatment of cluster headache has evolved to include a handheld neuromodulation device and a monoclonal antibody in addition to more traditional agents.

RECENT FINDINGS

Galcanezumab is an approved treatment for episodic cluster headache. The non-invasive vagal nerve stimulator has been shown to be effective as a treatment for episodic cluster headache. Dedicated pituitary imaging may not be necessary with a normal MRI of the brain. Cluster headache is the most common trigeminal-autonomic cephalalgia, characterized by unilateral, frequent, debilitating attacks associated with ipsilateral autonomic symptoms. Attacks have a circadian and, often, seasonal pattern with periods of remission that can last months to years in episodic patients. Though a rare disease, an increasing number of studies have revealed novel targets for treatment. Treatment in cluster headache should focus on early intervention to reduce frequency of attacks and the length of the cycle, which improves outcomes and disability. Acute therapy is used to treat attacks, while bridging and preventive therapies are combined to reduce cycle length. Case 1: A 43-year-old man presents with the chief complaint of severe headaches. Upon general examination, he seems uncomfortable, agitated, and exhausted. He states that he hasn't "slept in over a week because of debilitating headaches." His headaches start around the same time every night: when he lays down to go to sleep. The pain is described as sharp, like a "hot poker" to his left eye. His partner has noticed that his eye droops and turns red when the pain starts. The attacks come on abruptly and prevent him from sleeping. The severe pain lasts 30 to 45 min, but he has mild-to-moderate pain that lingers for the rest of the night. He has seen his primary care physician, an allergist, and an ear, nose, and throat (ENT) specialist before coming to see a neurologist. Similar headaches occurred last year during the month of October as well. On further questioning, he reports that these headache attacks have been occurring almost yearly for the past 7 years. Each year, these headaches come on as the weather is changing and occur on a nightly basis for about 3 to 4 weeks.

Peripheral neuropathic pain

Neuropathic pain (NP) can have either central nervous system causes or ones from the peripheral nervous system. This article will focus on the epidemiology, classifications, pathology, non-invasive treatments and invasive treatments as a general review of NP involving the peripheral nervous system. NP has characteristic symptomatology such as burning and electrical sensations. It occurs in up to 10% of the general population. Its frequency can be attributed to its occurrence in neck and back pain, diabetes and patients receiving chemotherapy. There are a wide range of pharmacologic options to control this type of pain and when such measures fail, numerous interventional methods can be employed such as nerve blocks and implanted stimulators. NP has a cost to the patient and society in terms of emotional consequences, quality of life, lost wages and the cost of assistance from the medical system and thus deserves serious consideration for prevention, treatment and control.

Interventional Radiofrequency Treatment for the Sympathetic Nervous System: A Review Article

Introduction

Interventional techniques such as radiofrequency (RF) treatment can be used to interrupt pain signals transmitted through the sympathetic nervous system (SNS). RF treatments including the pulsed (PRF) and continuous (CRF) modalities show enhanced control over lesion size and enhanced ability to confirm accurate positioning compared to other interventional methods. PRF also acts to reduce the area of the lesion. In this article, we characterize the currently available evidence supporting the use and efficacy of RF treatments in sympathetically mediated pain (SMP) conditions.

Study Design

A comprehensive literature review.

Methods

A PubMed and Cochrane Library database search was performed for human studies applying RF treatment at sympathetic sites (sphenopalatine ganglion, stellate ganglion, cervical, thoracic, or lumbar sympathetic ganglia, celiac plexus, splanchnic nerves, superior hypogastric plexus, and ganglion impar) between January 1970 to May 2020. Data were extracted, summarized into tables, and qualitatively analyzed.

Results

PRF and CRF both show promise in relieving SMP conditions, such as complex regional pain syndrome (CRPS), pain in the perineal region, headache and facial pain, and oncologic and non-oncologic abdominal pain, in addition to other types of pain, with minimal complications. Furthermore, in most comparative studies, outcomes using RF treatments exceeded other interventional techniques, such as anesthetic block and chemical neurolysis.

Conclusions

RF treatments can be effective in carefully selected patients who are refractory to conservative management. However, further randomized controlled studies are needed prior to implementing it into common practice.

The Efficacy of Sphenopalatine Ganglion Block and Radiofrequency Denervation in the Treatment of Cluster Headache: A Case Series

Background

Cluster headache is a variant of primary neurovascular headaches. some patients with cluster headache are not responsive to medical treatment and may benefit from interventional modalities, including sphenopalatine ganglion block and denervation.

Objectives

Our purpose was to evaluate the efficacy of sphenopalatine ganglion block/denervation in the treatment of cluster headache.

Methods

In this study, we performed the sphenopalatine ganglion block for patients with cluster headaches, intractable to medical therapy, who were referred to our pain clinic between 2014 and 2018. We registered the following information for all patients: demographic data, pain relief, and pain intensity. First, we conducted a prognostic C-arm-guided sphenopalatine ganglion block. If there was at least 50% pain relief within the first 5 h, then we denervated the ganglion by radiofrequency ablation. The main outcome of the study (dependent variable) was pain relief. We followed the patients for 6 months.

Results

Among 23 enrolled patients, 19 consented to interventional treatment. Fifteen out of 19 patients (79%) had an acceptable response to the prognostic block. Ultimately, 11 patients underwent ganglion denervation, and 4 patients did not consent for ganglion ablation. Pain relief at intervals of 48 h, and 1, 3, and 6 months after ganglion denervation was 77, 59, 50, and 31 percent, respectively.

Conclusions

Sphenopalatine ganglion conventional radiofrequency denervation can effectively decrease the pain intensity of the patients with cluster headache for at least several months.

Low-temperature plasma radiofrequency ablation for the management of refractory cluster headache

Introduction

Although the sphenopalatine ganglion (SPG) has been considered a site of therapeutic potential for cluster headache (CH), the optimal technique of SPG is still to be determined. Low-temperature plasma radiofrequency ablation (LTPRA) has been proposed as an alternative treatment for several neuropathic pain diseases.

Aim

To evaluate the effect of LTPRA of SPG in treating chronic and episodic CH.

Material and methods

The patients with CH, who achieved temporary pain relief following SPG block, treated using LTPRA between January 2015 and October 2017 were reviewed. Seventy-six patients were included: 50 patients suffered from episodic CH and the remaining 26 patients from chronic CH. The primary outcomes were clinical improvement rate, defined as the percentage of partial and complete pain relief results at 1 day, 12 months, and 24 months of follow-up after the operation.

Results

Clinical improvement rates were 92.3%, 92.3% and 73.1% in chronic CH and 73.1%, 84% and 68% in episodic CH at each follow-up time point, respectively. 3 chronic CH patients and 7 episodic CH patients showed no pain relief after the operation. Drooping eyelids were found in 2 cases, one recovered at the 3-month follow-up but another one did not in the 24-month follow-up. No serious complications occurred intraoperatively or postoperatively.

Conclusions

LTPRA can be considered an effective and alternative surgical modality in treating patients with chronic and episodic CH, based on SPG block.

Device review: Pulsante™ sphenopalatine ganglion microstimulator

Cluster headache (CH) is a primary headache disorder. The use of neuromodulation in treatment of CH is well documented. The sphenopalatine ganglion (SPG) has long been a target for management of CH. Intervention at the level of the SPG can interrupt the trigemino-autonomic reflex, which mediates CH pain. The Pulsante system is the only device on the market created for SPG stimulation. The Pulsante device consists of the device body, a lead with six stimulating electrodes placed in the pterygopalatine fossa, and a fixation plate to allow anchoring of the device to the maxilla. Stimulation is administered via a patient-controlled handheld remote control held over the cheek. SPG stimulation is an important treatment option for CH patients.

Efficacy and safety of surgical treatment of cluster headache

BACKGROUND AND OBJECTIVES

Cluster headache (CR) is the most severe human headache and is chronic in 10%-20% of patients, and 10% can become refractory to all effective drugs. In this scenario, surgical procedures are indicated: radiofrequencies of the sphenopalatine ganglion ipsilateral to pain (RF-SPG), bilateral stimulation of the occipital nerves (NOM-S) and deep brain stimulation (DBS) of the ipsilateral posterior hypothalamus. The efficacy and safety of each of these procedures has been specifically analyzed, but the progress of a series of patients following this surgical route in order of aggressiveness has not been described.

PATIENTS

Patients with chronic and refractory CR according to the criteria of the European Headache Federation. The patients underwent RF-SPG, NOM-S sequentially if the previous procedure had been ineffective, and DBS if the previous procedure had been ineffective.

RESULTS

We prospectively included 44 patients between November 2003 and June 2018 with an average age of 38.3 years; 70% were men. The mean follow-up was 87.4 months. Nineteen patients responded to 74 procedures of RF-SPG (33.3%). Of the remaining 25 patients, a NOM-S device was implanted in 22, showing an efficacy of 50%. Finally, 9 patients underwent ECP of the ipsilateral lower-posterior hypothalamus with an efficacy of 88.8%. No serious complications were found following any of these 3 procedures.

CONCLUSIONS

The sequential application of these three surgical procedures succeeded in reversing the serious situation of chronic CR refractory to an episodic CR in 93% of patients with acceptable surgical morbidity.

Chronic Headache: a Review of Interventional Treatment Strategies in Headache Management

PURPOSE OF THE REVIEW

To provide an overview of current interventional pain management techniques for primary headaches with a focus on peripheral nerve stimulation and nerve blocks.

RECENT FINDINGS

Despite a plethora of treatment modalities, some forms of headaches remain intractable to conservative therapies. Interventional pain modalities have found a niche in treating headaches. Individuals resistant to common regimens, intolerant to pharmaceutical agents, or those with co-morbid factors that cause interactions with their therapies are some instances where interventions could be considered in the therapeutic algorithm. In this review, we will discuss these techniques including peripheral nerve stimulation, third occipital nerve block (TON), lesser occipital nerve block (LON), greater occipital nerve block (GON), sphenopalatine block (SPG), radiofrequency ablation (RFA), and cervical epidural steroid injections (CESI). Physicians have used several interventional techniques to treat primary headaches. While many can be treated pharmacologically, those who continue to suffer from refractory or severe headaches may see tremendous benefit from a range of more invasive treatments which focus on directly inhibiting the painful nerves. While there is a plethora of evidence suggesting these methods are effective and possibly durable interventions, there is still a need for large, prospective, randomized trials to clearly demonstrate their efficacy.

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.

Prediction of the sphenopalatine ganglion localization in computerized tomography images

Background:

The sphenopalatine ganglion (SPG) is a target for several headache syndromes. Most of the groups targeting the SPG do not localize it directly, and this might account for some therapeutic failures. As the SPG cannot be seen on computerized tomography (CT) scans, magnetic resonance image (MRI) must be used to visualize the ganglion. It would be advantageous to be able to predict the location of the SPG on CT scans for those using fluoroscopy or CT-guided injections and for those in whom MRI is not accessible or contraindicated.

Methods:

We localized the SPG in 21 Caucasian patients (21 right and 17 left ganglia; total 38) in 3 tesla MR images subsequently fused with CT scans. We measured the distance from the SPG to two bony landmarks identified on CT scans. We then applied the average distances to find an estimated position of the SPG. The first landmark was the center of the anterior opening of the vidian canal (VC). The second landmark was a point on the sphenoidal bone, defined in an axial plane at the level of the center of the VC (S-point). The predicted position of the SPG measured from the VC and the sphenoidal bone were referred to as, respectively, vcSPG and sSPG. Finally, the distances between the SPG, as seen on MRI, and predicted vcSPG/sSPG were calculated.

Results:

The average distance between SPG as seen on the MRI images and the estimated position based on CT images were 1.82 mm (SD 0.83, range 0.22–3.57 mm) for vcSPG and 2.09 mm (SD 0.99, range 0.71–4.79 mm) for sSPG.

Conclusions:

The localization of the SPG can be predicted on CT images using bony landmarks. Localization of the SPG may be important in achieving successful therapeutic outcomes for treatments that are directed toward the SPG.

Effect of Sphenopalatine Ganglion Block With Bupivacaine on Postoperative Pain in Patients Undergoing Endoscopic Sinus Surgery

Background

Postoperative pain is one of the most complications in endoscopic sinus surgery. We aimed to evaluate the effect of the sphenopalatine ganglion block (SPGB) with bupivacaine on postoperative pain in patients undergoing endoscopic sinus surgery.Methods and Materials: In this clinical trial, 40 patients who indicated functional endoscopic sinus surgery were selected and then divided into 2 parallel groups as intervention and control. The intervention group was received 1.5 mL of bupivacaine 0.5% (injected to sphenopalatine ganglion) and while control was injected 1.5 mL of normal saline at the same injection site. Also, the visual analogue scale (VAS) was recorded immediately after anesthesia, along with 6, 12, 24, 48 h, 7 days, and 21 days after the operation for all patients.

Results

Immediately after anesthesia, as well as 6, 12, and 24 h after the operation, VAS in the intervention group was significantly lower than in the control group (P < .05, for all). However, there were no significant differences between the 2 groups regarding VAS 48 h as well as 7 and 21 days after surgery (P > .05, for both). Also, the rescue analgesia in the intervention group was significantly lower than in the control group (P = .01).

Conclusion

SPGB with bupivacaine 0.5% (1.5 mL) was a simple, effective, safe, and noninvasive method for the management of postoperative pain in the patients undergoing endoscopic sinus surgery.

Long-Term Outcome of Patients With Intractable Chronic Cluster Headache Treated With Injection of Onabotulinum Toxin A Toward the Sphenopalatine Ganglion - An Observational Study

Objectives

To investigate long‐term outcomes in per‐protocol chronic cluster headache patients (n = 7), 18 and 24 months after participation in “Pilot study of sphenopalatine injection of onabotulinumtoxinA for the treatment of intractable chronic cluster headache.”

Methods

Data were collected prospectively through headache diaries, HIT‐6, and open questionnaire forms at 18 and 24 months after the first treatment. Patients had access to repeated injections when needed.

Results

An overall significant reduction in cluster headache attack frequency per month (57.3 ± 35.6 at baseline vs 12.4 ± 15.2 at month 18 and 24.6 ± 19.2 at month 24) was found. In addition, there was a reduction in attacks with severe and unbearably intensity (50.0 ± 38.3 at baseline vs 10.1 ± 14.7 at month 18 and 16.6 ± 13.7 at month 24) and an increase in attack free days (4.2 ± 5.9 at baseline vs 19.1 ± 9.4 at month 18 and 12.9 ± 8.8 at month 24).

Conclusions

Our findings suggest sustained headache relief after repeated onabotulinumtoxinA injections toward the sphenopalatine ganglion in intractable chronic cluster headache. A placebo‐controlled trial with long‐term follow‐up is warranted.

Treatment of Cluster Headache

Cluster headache (CH) is a debilitating primary headache disorder. Although uncommon, affecting only 0.1% of population, it is one of the most painful conditions known to humankind. Three strategies are employed for effective treatment of CH, namely, abortive therapy, transitional therapy, and preventive therapy. Being an uncommon condition, there is a paucity of large-scale controlled trials and evidence of various therapies are based on smaller studies. This review primarily focuses on therapies with highest quality of evidence and also on the emerging therapies for CH.

Managing cluster headache with sphenopalatine ganglion stimulation: a review

Cluster headache (CH) is a primary headache and considered as one of the worst pains known to man. The sphenopalatine ganglion (SPG) plays a pivotal role in cranial autonomic symptoms associated with pain. Lesioning procedures involving the SPG and experimental acute SPG stimulation have shown some degree of efficacy with regard to CH. A neuromodulation device, chronically implanted in the pterygopalatine fossa, has been specifically designed for acute on-demand SPG stimulation. In a pilot placebo-controlled study in 28 patients suffering from refractory chronic CH, alleviation of pain was achieved in 67.1% of full stimulation-treated attacks compared to 7% of sham stimulation-treated attacks (p<0.0001). Long-term results (24 months; 33 patients) confirmed the efficacy of SPG stimulation as an abortive treatment for CH attacks. Moreover, 35% of the patients observed a >50% reduction in attack frequency, suggesting that repeated use of SPG stimulation might act as a CH-preventive treatment. Globally, 61% of the patients were acute responders, frequency responders, or both, and 39% did not respond to SPG stimulation. The safety of SPG microstimulator implantation procedure was evaluated in a cohort of 99 patients; facial sensory disturbances were observed in 67% of the patients (46% of them being transient), transient allodynia in 3%, and infection in 5%. SPG stimulation appears as a promising innovative, efficient, and safe therapeutic solution for patients suffering from severe CH. It has shown its efficacy in aborting CH attacks compared to placebo stimulation, suggesting that it is particularly adapted for CH patients who are not sufficiently improved by abortive treatments such as sumatriptan and oxygen. However, further studies comparing SPG stimulation with standard abortive and/or preventive CH treatments will be necessary to define more precisely its place within the management of severe chronic and/or episodic CH.

Sphenopalatine ganglion: block, radiofrequency ablation and neurostimulation - a systematic review

Background

Sphenopalatine ganglion is the largest collection of neurons in the calvarium outside of the brain. Over the past century, it has been a target for interventional treatment of head and facial pain due to its ease of access. Block, radiofrequency ablation, and neurostimulation have all been applied to treat a myriad of painful syndromes. Despite the routine use of these interventions, the literature supporting their use has not been systematically summarized. This systematic review aims to collect and summarize the level of evidence supporting the use of sphenopalatine ganglion block, radiofrequency ablation and neurostimulation.

Methods

Medline, Google Scholar, and the Cochrane Central Register of Controlled Trials (CENTRAL) databases were reviewed for studies on sphenopalatine ganglion block, radiofrequency ablation and neurostimulation. Studies included in this review were compiled and analyzed for their treated medical conditions, study design, outcomes and procedural details. Studies were graded using Oxford Center for Evidence-Based Medicine for level of evidence. Based on the level of evidence, grades of recommendations are provided for each intervention and its associated medical conditions.

Results

Eighty-three publications were included in this review, of which 60 were studies on sphenopalatine ganglion block, 15 were on radiofrequency ablation, and 8 were on neurostimulation. Of all the studies, 23 have evidence level above case series. Of the 23 studies, 19 were on sphenopalatine ganglion block, 1 study on radiofrequency ablation, and 3 studies on neurostimulation. The rest of the available literature was case reports and case series. The strongest evidence lies in using sphenopalatine ganglion block, radiofrequency ablation and neurostimulation for cluster headache. Sphenopalatine ganglion block also has evidence in treating trigeminal neuralgia, migraines, reducing the needs of analgesics after endoscopic sinus surgery and reducing pain associated with nasal packing removal after nasal operations.

Conclusions

Overall, sphenopalatine ganglion is a promising target for treating cluster headache using blocks, radiofrequency ablation and neurostimulation. Sphenopalatine ganglion block also has some evidence supporting its use in a few other conditions. However, most of the controlled studies were small and without replications. Further controlled studies are warranted to replicate and expand on these previous findings.

Electronic supplementary material

The online version of this article (10.1186/s10194-017-0826-y) contains supplementary material, which is available to authorized users.

Sphenopalatine Ganglion (SPG): Stimulation Mechanism, Safety, and Efficacy

OBJECTIVE

To describe the history of and available data on sphenopalatine ganglion (SPG) neuromodulation in the treatment of headache up to the present.

BACKGROUND

The SPG has been a therapeutic target to treat primary headache disorders for over 100 years. Multiple destructive lesions have also been tried with variable rate and duration of success. Neurostimulation of the SPG for cluster headache was first described in 2007.

METHODS

This is not a systematic review. The authors review the anatomy and pathophysiology of the SPG and cluster headache and the important clinical trials, relating a history of how SPG neuromodulation reached the current state of approval in the European Union (EU) and pivotal registration study for cluster headache in the US.

RESULTS

The EU approved SPG stimulation for cluster headache with a CE Mark in February of 2012. Since then, several EU countries have elected to reimburse implantation for cluster headache, and over 300 patients have been implanted worldwide.

CONCLUSIONS

Success rates for implanted SPG neuromodulation in the experimental phase of the European randomized controlled trial, in the open label extension trial, and in the registry of patients implanted outside of the trial remain at about two-thirds of patients implanted being responders, defined as being able to terminate at least 50% of attacks or having at least a 50% decrease in attack frequency or both. A US pivotal registration study is underway to confirm these results and obtain FDA approval for this treatment for cluster headache patients. Further studies in migraine are also underway.

Neuronavigated percutaneous approach to the sphenopalatine ganglion

The sphenopalatine ganglion (SPG) has been assumed to be involved in the genesis of several types of facial pain, including Sluder's neuralgia, trigeminal neuralgia, persistent idiopathic facial pain, cluster headache, and atypical facial pain. The gold standard treatments for SPG-related pain are percutaneous procedures performed with the aid of fluoroscopy or CT. In this technical note the authors present, for the first time, an SPG approach using the aid of a neuronavigator.

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.

Evaluation of sphenopalatine ganglion blockade via intra oral route for the management of atypical trigeminal neuralgia

Background

The sphenopalatine ganglion (SPG) may be involved in persistent idiopathic facial pain and unilateral headaches. The role of SPG blockade via intra oral route in the management of trigeminal neuralgia (TN) is worthy of study.

Methods

In this retrospective study, patient records included patients with atypical TN (type 2) that persisted in spite of conservative treatment for at least 2 years, and an average pain intensity from the craniofacial region visual analogue scale (VAS) before examination. In group I the patients received carmapazepin 800 mg a day for at least 2 years. In group II 3 ml of local anesthetic agent consisting 2 ml bupivacaine and 1 ml prilocain in addition to 1 ml fentanyl, 0.5 ml betametasone disodium phosphate and 0.5 ml opaque was injected by the intraoral route. In this group, injection procedures were performed under local anesthesia with fluoroscopic guidance. The Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction were used for intergroup analysis. Age and sex differences were evaluated with one-way ANOVA and Fisher’s exact tests, respectively.

Results

Significant differences were found between pre-op and 3rd day VAS values and also pre-op and 1st month VAS values. No significant differences were found between pre-op and 6th month VAS values.

Conclusion

The SPG blockade improves the quality of life of patients and a minimally-invasive procedure to management of TN, when compared to other methods.

The effectiveness of neurolytic block of sphenopalatine ganglion using zygomatic approach for the management of trigeminal neuropathy

This study was performed to present the outcomes of trigeminal neuropathy management with the application of neurolytic block of sphenopalatine ganglion. This type of procedure is used in cases where pain is not well controlled with medical treatment. Twenty patients were treated with sphenopalatine ganglion neurolysis after their response to pharmacological management was not satisfactory. Significant pain relief was experienced by all but one patient and they were able to reduce or stop their pain medication. The time of pain relief was between a few months and 9 years during the study period. Number of procedures implemented varied as some of the patients have been under the care of our Pain Clinic for as long as 18 years, satisfied with this type of management and willing to have the procedure repeated if necessary. It appears that neurolytic block of sphenopalatine ganglion is effective enough and may be an option worth further consideration in battling the pain associated with trigeminal neuropathy.

Computerized tomography-guided sphenopalatine ganglion pulsed radiofrequency treatment in 16 patients with refractory cluster headaches: Twelve- to 30-month follow-up evaluations

BACKGROUND

Sphenopalatine ganglion percutaneous radiofrequency thermocoagulation treatment can improve the symptoms of cluster headaches to some extent. However, as an ablation treatment, radiofrequency thermocoagulation treatment also has side effects.

OBJECTIVE

To preliminarily evaluate the efficacy and safety of a non-ablative computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion in patients with refractory cluster headaches.

METHODS

We included and analysed 16 consecutive cluster headache patients who failed to respond to conservative therapy from the Pain Management Center at the Beijing Tiantan Hospital between April 2012 and September 2013 treated with pulsed radiofrequency treatment of sphenopalatine ganglion.

RESULTS

Eleven of 13 episodic cluster headaches patients and one of three chronic cluster headaches patient were completely relieved of the headache within an average of 6.3 ± 6.0 days following the treatment. Two episodic cluster headache patients and two chronic cluster headache patients showed no pain relief following the treatment. The mean follow-up time was 17.0 ± 5.5 months. All patients enrolled in this study showed no treatment-related side effects or complications.

CONCLUSION

Our data show that patients with refractory episodic cluster headaches were quickly, effectively and safely relieved from the cluster period after computerized tomography-guided pulsed radiofrequency treatment of sphenopalatine ganglion, suggesting that it may be a therapeutic option if conservative treatments fail.

Unsuccessful pulsed radiofrequency of the sphenopalatine ganglion in patients with chronic cluster headache and subsequent successful thermocoagulation

We present the results of pulsed and continuous radiofrequency (CRF) of the sphenopalatine ganglion in a case series of 3 patients with chronic cluster headache (CCH). Three patients were referred to our neurosurgical department because of CCH, which was refractory to pharmacological treatment. They underwent pulsed radiofrequency of the sphenopalatine ganglion (PRF-SPG), and the procedure was performed through an infrazygomatic approach. In the PRF procedures, we applied 2 cycles of PRF at 42°C and 45 V for 120 seconds, with a pulse frequency of 2 Hz and a pulse width of 20 ms. In those procedures where thermocoagulation was carried out, 2 CRF lesions at 80°C for 90 seconds each were performed. Following corticosteroid and local anesthetic (40 mg of methylprednisolone and 1 mL of 1% lidocaine) injection, 2 patients had no pain relief at all, whereas the third one experienced a partial response, which lasted only 1 month and his pain then returned to its baseline level. Thus, this outcome was assessed as a nonsustained partial response. Therefore, all of them underwent a CRF lesioning of the SPG, and after this procedure, they achieved complete pain relief until the end of the follow-up period. Furthermore, the associated autonomic manifestations disappeared. The 3 patients presented in this case series failed to achieve adequate pain relief after PRF-SPG. However, these same patients subsequently underwent a successful CRF of the SPG.

Neuromodulation in cluster headache

Medically refractory chronic cluster headache (CH) is a severely disabling headache condition for which several surgical procedures have been proposed as a prophylactic treatment. None of them have been evaluated in controlled conditions, only open studies and case series being available. Destructive procedures (radiofrequency lesioning, radiosurgery, section) and microvascular decompression of the trigeminal nerve or the sphenopalatine ganglion (SPG) have induced short-term improvement which did not maintain on long term in most of the patients. They carried a high risk of complications, including severe sensory loss and neuropathic pain, and consequently should not be proposed in first intention.Deep brain stimulation (DBS), targeting the presumed CH generator in the retro-hypothalamic region or fibers connecting it, decreased the attack frequency >50 in 60 % of the 52 patients reported. Complications were infrequent: gaze disturbances, autonomic disturbances, and intracranial hemorrhage (2).Occipital nerve stimulation (ONS) was efficient (decrease of attack frequency >50 %) in about 70 % of the 60 patients reported, with a low risk of complications (essentially hardware related). Considering their respective risks, ONS should be proposed first and DBS only in case of ONS failure.New on-demand chronically implanted SPG stimulation seemed to be efficient to abort CH attacks in a pilot controlled trial, but its long-term safety needs to be further studied.

[Sphenopalatine ganglion pulsed radiofrequency treatment in patients suffering from chronic face and head pain]

PURPOSE

There are various facial pain syndromes including trigeminal neuralgia, trigeminal neuropathic pain and atypical facial pain syndromes. Effectiveness of the pulsed radiofrequency in managing various pain syndromes has been clearly demonstrated. There are a limited number of studies on the pulsed radiofrequency treatment for sphenopalatine ganglion in patients suffering from face and head pain. The purpose of this study is to evaluate the satisfaction of pulsed radiofrequency treatment at our patients retrospectively.

METHODS

Infrazygomatic approach was used for the pulsed radiofrequency of the sphenopalatine ganglion under fluoroscopic guidance. After the tip of the needle reached the target point, 0.25-0.5ms pulse width was applied for sensory stimulation at frequencies from 50Hz to 1V. Paraesthesias were exposed at the roof of the nose at 0.5-0.7V. To rule out trigeminal contact that led to rhythmic mandibular contraction, motor stimulation at a frequency of 2Hz was applied. Then, four cycles of pulsed radiofrequency lesioning were performed for 120s at a temperature of 42°C.

RESULTS

Pain relief could not be achieved in 23% of the patients (unacceptable), whereas pain was completely relieved in 35% of the patients (excellent) and mild to moderate pain relief could be achieved in 42% of the patients (good) through sphenopalatine ganglion-pulsed radiofrequency treatment.

CONCLUSION

Pulsed radiofrequency of the sphenopalatine ganglion is effective in treating the patients suffering from intractable chronic facial and head pain as shown by our findings. There is a need for prospective, randomized, controlled trials in order to confirm the efficacy and safety of this new treatment modality in chronic head and face pain.

Successful Management of Refractory Headache and Facial Pain due to Cavernous Sinus Meningioma with Sphenopalatine Ganglion Radiofrequency

Headaches and facial pain can be extremely difficult to manage for the patient and the clinician. In the medical literature, it has been suggested that the autonomic reflex plays an important role in the pathophysiology of facial neuralgia. The sphenopalatine ganglion is the largest parasympathetic ganglion outside the cranium. It is an easy accessible target for pain management. The application of radiofrequency nerve ablation was described in the medical literature. In this case report, we describe a 54-year-old female. She was diagnosed with a cavernous sinus meningioma. She underwent surgical resection and gamma knife radiosurgery. She was suffering from an intractable hemifacial pain for many years. Her pain started shortly after surgery and continued throughout many years. Sphenopalatine ganglion block in multiple occasions was able to provide temporary relief. The patient's intractable hemicranial headaches and hemifacial pain responded to the sphenopalatine ganglion radiofrequency nerve ablation. The pain response remained unchanged for 12 months after procedure. This case report increased our current knowledge about the sphenopalatine ganglion role in the headache and facial intractable pain management. The failure of available antalgic medications to adequately control pain in similar patients underscores the need to develop an algorithm for therapies.

Sphenopalatine ganglion pulsed radiofrequency treatment in patients suffering from chronic face and head pain

PURPOSE

There are various facial pain syndromes including trigeminal neuralgia, trigeminal neuropathic pain and atypical facial pain syndromes. Effectiveness of the pulsed radiofrequency in managing various pain syndromes has been clearly demonstrated. There are a limited number of studies on the pulsed radiofrequency treatment for sphenopalatine ganglion in patients suffering from face and head pain. The purpose of this study is to evaluate the satisfaction of pulsed radiofrequency treatment at our patients retrospectively.

METHODS

Infrazygomatic approach was used for the pulsed radiofrequency of the sphenopalatine ganglion under fluoroscopic guidance. After the tip of the needle reached the target point, 0.25-0.5 ms pulse width was applied for sensory stimulation at frequencies from 50 Hz to 1 V. Paraesthesias were exposed at the roof of the nose at 0.5-0.7 V. To rule out trigeminal contact that led to rhythmic mandibular contraction, motor stimulation at a frequency of 2 Hz was applied. Then, four cycles of pulsed radiofrequency lesioning were performed for 120 s at a temperature of 42°C.

RESULTS

Pain relief could not be achieved in 23% of the patients (unacceptable), whereas pain was completely relieved in 35% of the patients (excellent) and mild to moderate pain relief could be achieved in 42% of the patients (good) through sphenopalatine ganglion-pulsed radiofrequency treatment.

CONCLUSION

Pulsed radiofrequency of the sphenopalatine ganglion is effective in treating the patients suffering from intractable chronic facial and head pain as shown by our findings. There is a need for prospective, randomized, controlled trials in order to confirm the efficacy and safety of this new treatment modality in chronic head and face pain.

Introduction to neuropathic pain syndromes

Chronic pain impairs the quality of life for millions of individuals and therefore presents a serious ongoing challenge to clinicians and researchers. Debilitating chronic pain syndromes cost the US economy more than $600 billion per year. This article provides an overview of the epidemiology, clinical presentation, and treatment outcomes for craniofacial, spinal, and peripheral neurologic pain syndromes. Although the authors recognize that the diagnosis and treatment of the chronic forms of neuropathic pain syndromes represent a clinical challenge, there is an urgent need for standardized classification systems, improved epidemiologic data, and reliable treatment outcomes data.

Posterior hypothalamic modulation of ocular-responsive trigeminal subnucleus caudalis neurons is mediated by Orexin-A and Orexin1 receptors

Orexin-A (OxA) is synthesized in posterior and lateral regions of the hypothalamus and contributes to homeostatic regulation of body functions including pain modulation. To determine if orexinergic mechanisms contribute to posterior hypothalamus (PH)-induced modulation of ocular input to subnucleus caudalis/upper cervical (Vc/C1) neurons, the orexin-1 receptor antagonist SB334867 was applied to the dorsal brainstem surface prior to PH disinhibition, by bicuculline methiodide, in male rats under isoflurane anesthesia. Ocular input to Vc/C1 units by bright light or hypertonic saline was markedly reduced by PH disinhibition and reversed completely by local Vc/C1 application of SB334867. OxA applied to the Vc/C1 surface mimicked the effects of PH disinhibition in a dose-dependent manner. OxA-induced inhibition was prevented by co-application of SB334867, but not by the orexin-2 receptor antagonist TCS Ox2 29. PH disinhibition and local OxA application also reduced the high threshold convergent cutaneous receptive field area of ocular units, suggesting widespread effects on somatic input to Vc/C1 ocular units. Vc/C1 application of OxA or SB334867 alone did not affect the background discharge of ocular units and suggested that the PH-OxA influence on ocular unit activity was not tonically active. Vc/C1 application of OxA or SB334867 alone also did not alter mean arterial pressure, whereas PH disinhibition evoked prompt and sustained increases. These results suggest that stimulus-evoked increases in PH outflow acts through OxA and orexin-1 receptors to alter the encoding properties of trigeminal brainstem neurons responsive to input from the ocular surface and deep tissues of the eye.

Sphenopalatine ganglion stimulation for the treatment of cluster headache

Cluster headache is a severe, debilitating disorder with pain that ranks among the most severe known to humans. Patients with cluster headaches have few therapeutic options and further, 10-20% develop drug-resistant attacks. The often brief duration of cluster attacks makes abortive therapy a challenge, and preventive medications are almost always provided to patients, but the side effects of these preventive medications can be significant. The sphenopalatine ganglion (SPG) is believed to play a role in headache pain and cranial autonomic symptoms associated with cluster headache, which is a result of activation of the trigeminal-autonomic reflex. For over 100 years, the SPG has been a clinical target to treat primary headache disorders using pharmacologic and nonpharmacologic methods. Radiofrequency lesioning and nerve-resection therapies, while initially beneficial, are irreversible procedures, and the use of neurostimulation provides one method of interfacing with the neural pathways without causing permanent damage to neural tissue. SPG neurostimulation is both reversible and adjustable, and has recently been tested in both proof-of-concept work and in a randomized, sham-controlled trial for the treatment of cluster headache. A randomized, sham-controlled study of 32 patients was performed to evaluate further the use of SPG stimulation for the acute treatment of chronic cluster headache. Of the 32 patients, 28 completed the randomized experimental period. Overall, 68% of patients experienced an acute response, a frequency response, or both. In this study the majority of adverse events were related to the implantation procedure, which typically resolved or remained mild in nature at 3 months following the implant procedure. This and other studies highlight the promise of using SPG stimulation to treat the pain-associated cluster headache. SPG stimulation could be a safe and effective option for chronic cluster headache.

Alcohol percutaneous neurolysis of the sphenopalatine ganglion in the management of refractory cranio-facial pain

INTRODUCTION

The sphenopalatine ganglion (SPN) has been proven to be involved in various types of facial pain syndromes. Management of these cranio-facial pain syndromes can be challenging, and existing specific treatments are sometimes inefficient and may fail. The purpose of this study is to describe and evaluate alcohol SPN in the management of cranio-facial pain.

METHODS

Forty-two patients suffering from refractory facial pain who underwent 58 consecutive SPN were included in this study between 2000 and 2013. Patients were divided into three groups: group "cluster headache" (CH), group "persistent idiopathic facial pain" (PFIP), and group "Other". Pain was assessed using Visual Analogue Scale scores (measured immediately before and after procedure and at regular intervals following the procedure). Alcohol SPN was considered to be effective when pain relief was equal to or greater than 50 % and lasting for at least 1 month. All procedures were realized ambulatory under CT guidance and consisted of an injection of 1 ml of absolute alcohol.

RESULTS

Overall efficacy rate of alcohol SPN was 67.2 %, with mean pain relief duration of 10.3 months. Procedure was graded either not painful or tolerable by patients in 64.2 %. Analysis showed a higher efficacy rate in the groups CH (76.5 %) and PFIP (85.7 %) compared to the group Other (40 %). No difference was found between groups regarding the recurrence rate.

CONCLUSION

Alcohol SPN under CT guidance appears as a safe and effective treatment of refractory facial pain, especially in cases of cluster headache and persistent idiopathic facial pain.

An unusual challenge in performing sphenopalatine ganglion block with enlarged coronoid process: Jacob's disease

OBJECTIVES

Sphenopalatine ganglion block for the treatment of cluster headache has been well-described for medically refractory cases. Technical challenges in performing this procedure via the mandibular notch can be found in patients with elongation of the coronoid process. Objectives include correlation of physical exam findings and computed tomography (CT) imaging, followed by recommendations for future treatment.

METHODS

Case report.

RESULTS

Patient had a history of cluster headache and a 35 mm interincisal opening. Initially, sphenopalatine ganglion block could not be performed via standard mandibular notch approach due to the inability to advance past superficial tissues. Subsequent CT scan revealed a congenitally enlarged coronoid process with a shortened ramus. Usage of a bite block facilitated completion of the sphenopalatine block on subsequent visit.

CONCLUSIONS

Patients with diminished oral interincisal opening and deviation of the jaw to one side are consistent with Jacob's disease. Using a bite block in these patients may be critical to completion of the procedure.

Clinical functional anatomy of the pterygopalatine ganglion, cephalgia and related dysautonomias: A review

The purpose of this article is to explain the anatomy of the pterygopalatine ganglion (PPG), its location in the pterygopalatine fossa (PPF) in the skull, and the relationship it has to the Vidian nerve terminal branches and the fifth cranial nerve. An overview of the neuro-anatomical/clinical correlations, a spectrum of pathologies affecting the seventh cranial nerve and some therapies both medical and surgical are noted. The focus is the pterygopalatine region with discussion of the proximal courses of the seventh and fifth cranial nerves and their pathological processes. The ganglion is used as an example of neuro-anatomical model for explaining cluster headaches (CH). Radiological correlation is included to clarify the location of the PPF and its clinical importance.

Neuromodulation of chronic headaches: position statement from the European Headache Federation

The medical treatment of patients with chronic primary headache syndromes (chronic migraine, chronic tension-type headache, chronic cluster headache, hemicrania continua) is challenging as serious side effects frequently complicate the course of medical treatment and some patients may be even medically intractable. When a definitive lack of responsiveness to conservative treatments is ascertained and medication overuse headache is excluded, neuromodulation options can be considered in selected cases. Here, the various invasive and non-invasive approaches, such as hypothalamic deep brain stimulation, occipital nerve stimulation, stimulation of sphenopalatine ganglion, cervical spinal cord stimulation, vagus nerve stimulation, transcranial direct current stimulation, repetitive transcranial magnetic stimulation, and transcutaneous electrical nerve stimulation are extensively published although proper RCT-based evidence is limited. The European Headache Federation herewith provides a consensus statement on the clinical use of neuromodulation in headache, based on theoretical background, clinical data, and side effect of each method. This international consensus further gives recommendations for future studies on these new approaches. In spite of a growing field of stimulation devices in headaches treatment, further controlled studies to validate, strengthen and disseminate the use of neurostimulation are clearly warranted. Consequently, until these data are available any neurostimulation device should only be used in patients with medically intractable syndromes from tertiary headache centers either as part of a valid study or have shown to be effective in such controlled studies with an acceptable side effect profile.

Neurostimulation in cluster headache: A review of current progress

Purpose of review

Neurostimulation has emerged as a viable treatment for intractable chronic cluster headache. Several therapeutic strategies are being investigated including stimulation of the hypothalamus, occipital nerves and sphenopalatine ganglion. The aim of this review is to provide an overview of the rationale, methods and progress for each of these.

Latest findings

Results from a randomized, controlled trial investigating sphenopalatine ganglion stimulation have just been published. Reportedly the surgery is relatively simple and it is apparently the only therapy that provides relief acutely.

Summary

The rationale behind these therapies is based on growing evidence from clinical, hormonal and neuroimaging studies. The overall results are encouraging, but unfortunately not all patients have benefited. All the mentioned therapies require weeks to months of stimulation for a prophylactic effect to occur, suggesting brain plasticity as a possible mechanism, and only stimulation of the sphenopalatine ganglion has demonstrated an acute, abortive effect. Predictors of effect for all modes of neurostimulation still need to be identified and in the future, the least invasive and most effective strategy must be preferred as first-line therapy for intractable chronic cluster headache.

Neuromodulation for cephalgias

Headaches (cephalgias) are a common reason for patients to seek medical care. There are groups of patients with recurrent headache and craniofacial pain presenting with malignant course of their disease that becomes refractory to pharmacotherapy and other medical management options. Neuromodulation can be a viable treatment modality for at least some of these patients. We review the available evidence related to the use of neuromodulation modalities for the treatment of medically refractory craniofacial pain of different nosology based on the International Classification of Headache Disorders, 2(nd) edition (ICHD-II) classification. This article also reviews the scientific rationale of neuromodulation application in management of cephalgias.

Experimental activation of the sphenopalatine ganglion provokes cluster-like attacks in humans

Background

High frequency (HF) stimulation of the sphenopalatine ganglion (SPG) is an emerging abortive treatment for cluster headache (CH) attacks. HF SPG stimulation is thought to exert its effect by physiologically blocking parasympathetic outflow. We hypothesized that low frequency (LF) SPG stimulation may activate the SPG, causing increased parasympathetic outflow and thereby provoking cluster attacks in CH patients.

Methods

In a double-blind randomized cross-over study, seven CH patients implanted with an SPG neurostimulator were randomly allocated to receive HF or LF stimulation for 3 min on 2 separate days. We recorded headache characteristics and autonomic symptoms during and after stimulation.

Results

Six patients completed the study. Three out of six patients (50%) reported ipsilateral cluster-like attacks during or within 30 min of LF SPG stimulation. These cluster-like attacks were all successfully treated with the therapeutic HF SPG stimulation. One out of six reported a cluster-like attack with 3 min HF SPG stimulation, which was also successfully treated with continued HF therapeutic SPG stimulation.

Discussion

LF SPG stimulation may induce cluster-like attacks with autonomic features, which can subsequently be treated by HF SPG stimulation. Efferent parasympathetic outflow from the SPG may initiate autonomic symptoms and activate trigeminovascular sensory afferents, which may initiate the onset of pain associated with CH.