The pterygopalatine ganglion and its role in various pain syndromes: from anatomy to clinical practice

Abstract The postsynaptic fibers of the pterygopalatine or sphenopalatine ganglion (PPG or SPG) supply the lacrimal and nasal glands. The PPG appears to play an important role in various pain syndromes including headaches, trigeminal and sphenopalatine neuralgia, atypical facial pain, muscle pain, vasomotor rhinitis, eye disorders, and herpes infection. Clinical trials have shown that these pain disorders can be managed effectively with sphenopalatine ganglion blockade (SPGB). In addition, regional anesthesia of the distribution area of the SPG sensory fibers for nasal and dental surgery can be provided by SPGB via a transnasal, transoral, or lateral infratemporal approach. To arouse the interest of the modern‐day clinicians in the use of the SPGB, the advantages, disadvantages, and modifications of the available methods for blockade are discussed.?     

Sphenopalatine Ganglion Pulsed Radiofrequency Treatment in 30 Patients Suffering from Chronic Face and Head Pain

Abstract:   This study evaluated the efficacy of sphenopalatine ganglion pulsed radiofrequency (SPG-PRF) treatment in patients suffering from chronic head and face pain. Thirty patients were observed from 4 to 52 months after PRF treatment. The primary efficacy measures were the reduction in oral medication use, including opioids, time-to-next-treatment modality for presenting symptoms, duration of pain relief, and the presence of residual symptoms. Secondary objectives included the evaluation of adverse effects and complications. All data were derived from patient charts, phone conversations, and clinical follow-up visits. Fourteen percent of respondents reported no pain relief, 21% had complete pain relief, and 65% of the patients reported mild to moderate pain relief from SPG-PRF treatment. Sixty-five percent of the respondents reported mild to moderate reduction in oral opioids. None of the patients developed significant infection, bleeding, hematoma formation, dysesthesia, or numbness of palate, maxilla, or posterior pharynx. A large-scale study of SPG-PRF for the treatment of face and head pain has not been previously reported. Our results suggest that a prospective, randomized, controlled trial study to confirm efficacy and safety of this novel treatment for chronic head and face pain is justified.     

Neurolysis of the Trigeminal and Sphenopalatine Ganglions

Abstract: Facial pain of trigeminal and sphenopalatine ganglion origin is the bain of existence for thousands of people. Treatment protocols typically begin with oral medication, usually anticonvulsants, and may progress to percutaneous and open surgical procedures. Several new medications show promise as alternatives to carbamazepine, which has been the standard first-line treatment (trigeminal neuralgia), while electromagnetic pulsed radiofrequency and gamma knife surgery are new options when the surgical route is warranted.
This article will examine the anatomy of the trigeminal and sphenopalatine ganglions. Indications for neurolysis and neurolytic options will be discussed. Efficacy of the various neurolytic techniques will be thoroughly reviewed.     

Intranasal lidocaine for migraine: a randomized trial and open-label follow-up

OBJECTIVE: To study the efficacy of intranasal lidocaine for the treatment of migraine when administered by subjects in a nonclinic setting. DESIGN: A 1-month, randomized, controlled, double-blind trial, followed by a 6-month open-label follow-up. SETTING: Ambulatory subjects treating themselves outside of a medical setting. SUBJECTS: One hundred thirty-one adult subjects with migraine, diagnosed according to International Headache Society criteria, were enrolled in the study: 113 treated at least one headache in the controlled trial, and 74 treated at least one headache in the open-label phase. All subjects were members of the Kaiser Permanente Southern California Medical Care Program and were recruited at two urban medical centers. INTERVENTION: Intranasal lidocaine 4% or saline placebo 0.5 mL was dropped into the nostril on the side of the headache, or bilaterally for bilateral headache, according to study protocol. MAIN OUTCOME MEASURES: Trial: percent of headaches relieved to mild or none at 15 minutes and relapse of headache within 24 hours. Open-label: percent of headaches relieved to mild or none at 15 and 30 minutes and relapse within 24 hours. RESULTS: In the controlled trial, headache was relieved within 15 minutes in 34 (35.8%) of 95 subjects treated with 4% intranasal lidocaine compared with 8 (7.4%) of 108 subjects receiving placebo (P < .001). Headaches relapsed in 7 (20.6%) of 34 subjects treated with 4% intranasal lidocaine compared to 0 of 8 placebo subjects (P = .312). In the open-label follow-up, headaches were relieved in 129 (41.2%) of 313 episodes within 15 minutes and in 141 (57.6%) of 245 episodes after 30 minutes. Headaches relapsed in 28 (19.9%) of 140. The response did not diminish over time: 32 (62.8%) of 51 first headaches were relieved at 30 minutes and 10 (71.4%) of 14 seventh headaches were relieved. Relapse occurred in 28 (20%) [corrected] of 129 headaches at a mean time (+/- SD) of 7.4 (+/- 6.6) hours. CONCLUSION: Intranasal lidocaine 4% provides rapid relief of migraine symptoms. For those subjects who do respond, the effect does not diminish over 6-month follow-up.     

Vasomotor rhinitis and sphenopalatineganglion block

The effectiveness of the sphenopalatine ganglion (SPG) block for the relief of symptoms inchronic vasomotor rhinitis was assessed in 30 patients of both genders. The number of blocks required for complete relief was three (range from two to four) at weekly intervals in 66.7% of volunteers. There was no recurrence of symptoms during a follow-up period of 12–20 months in 29 patients, and one patient was symptom free for 8 months. The technique is simple and can be performed as an outpatient procedure without side effects.     

Organizational Evolution: A Hospice Case Study

An analysis of the maturation process of a large, multiple site hospice using Greiner’s organizational development model is presented. Past and present growth phases and crises are described. The value of such an analysis lies in its insights into organizational growth and the resultant lessons for other, similar agencies. The ability to assess an organization’s stage of development means that crises and needs can be anticipated and appropriate resolutions can be planned. Generalizations can be made to multiple site or regionally organized hospice development elsewhere.     

Intranasal lidocaine to prevent headache following migraine aura

OBJECTIVE: To report the consistent effect of intranasal lidocaine 4% on preventing headache following aura in one individual. BACKGROUND: A treatment that could prevent the headache which follows an aura would be an important advance in the treatment of migraine. No migraine abortive treatment has been shown to have such an effect. METHODS: A 15-year-old adolescent boy with a history of recurrent headache since aged 2, fulfilling the criteria for migraine with aura, was seen in consultation. Intranasal lidocaine 4% was used during the aura phase to prevent the headaches. RESULTS: Before using intranasal lidocaine, the patient invariably experienced a migraine following a typical visual aura. The episodes occurred approximately weekly, with a stable pattern for several years. When given during the aura, intranasal lidocaine prevented the headache following the aura, and remained successful on all but two occasions over 1 1/2 years of use (approximately 75 episodes). There was no effect on the duration of the aura itself. CONCLUSIONS: Intranasal lidocaine consistently prevented the development of headache symptoms following aura in this individual. Such an effect suggests a role for the sphenopalatine ganglion in the development of migraine pain.     

Acute Treatment of Intractable Migraine With Sphenopalatine Ganglion Electrical Stimulation

Background.— We report preliminary results of a novel acute treatment for intractable migraine. The sphenopalatine ganglion (SPG) has sensorimotor and autonomic components and is involved in migraine pathophysiology.
Methods.— In 11 patients with medically refractory migraine, the sphenopalatine fossa was accessed with a 20-gauge needle using the standard infrazygomatic transcoronoid approach under fluoroscopy. Patients underwent temporary unilateral electric stimulation of the SPG with a Medtronic 3057 test stimulation lead after induction of full-blown migraine. Both sham and active stimulations with different settings were carried out for ≤60 minutes, and then the lead was removed.
Results.— In 11 evaluations, 2 patients were pain-free within 3 minutes of stimulation. Three had pain reduction; 5 had no response; 1 was not stimulated. Five patients had no pain relief. Stimulation settings: mean amplitude of 1.2V, mean pulse rate of 67 Hz, mean pulse width of 462 µs. Lack of headache relief appeared linked to suboptimal lead placement, poor physiologic sensory response to localization stimulation, and diagnosis of medication overuse headache.
Conclusion.— This study suggests a possible role for SPG stimulation in the treatment of refractory migraine headaches.     

Sphenopalatine ganglion radiofrequency ablation for the management of chronic cluster headache

Objectives.— Chronic cluster headache patients are often resistant to pharmacological management. Percutaneous radiofrequency ablation (RFA) of the sphenopalatine ganglion (SPG) was shown before to improve episodic cluster headache but not chronic cluster headache. We were interested to examine the effect of such intervention in patients with intractable chronic cluster headache who failed pharmacological management.
Methods.— Fifteen patients with chronic cluster headache, who experienced temporary pain relief following SPG block, underwent percutaneous RFA via the infrazygomatic approach under fluoroscopic guidance. Collected data include demographic variables, onset and duration of the headache, mean attack intensity (MAI), mean attack frequency (MAF), and pain disability index (PDI) before and up to 18 months after procedure.
Results.— At 1-, 3-, 6-, 12-, 18-month follow-up, the MAI was 2.6, 3.2, 3.2, 3.4, 4.2, respectively ( P  < .0001, P  < .0001, P  < .0001, P  < .0005, P  < .003, respectively). The PDI improved from 55 (baseline) to 17.2 and 25.6 at 6 and 12 months respectively ( P  < .001). The MAF improved from 17 attacks/week to 5.4, 6.4, 7.8, 8.6, 8.3 at 1-, 3-, 6-, 12-, 18-month follow-up visits ( P  < .0001, P  < .0001, P  < .0001, P  < .002, P  < .004, respectively).
Conclusion.— Our data showed that percutaneous RFA of the SPG is an effective modality of treatment for patients with intractable chronic cluster headaches. Precise needle placement with the use of real-time fluoroscopy and electrical stimulation prior to attempting radiofrequency lesioning may reduce the incidence of adverse events.     

Electrical Stimulation of Sphenopalatine Ganglion for Acute Treatment of Cluster Headaches

(Headache 2010;50:1164‐1174) Introduction.— Cluster headaches (CH) are primary headaches marked by repeated short‐lasting attacks of severe, unilateral head pain and associated autonomic symptoms. Despite aggressive management with medications, oxygen therapy, nerve blocks, as well as various lesioning and neurostimulation therapies, a number of patients are incapacitated and suffering. The sphenopalatine ganglion (SPG) has been implicated in the pathophysiology of CH and has been a target for blocks, lesioning, and other surgical approaches. For this reason, it was selected as a target for an acute neurostimulation study. Methods.— Six patients with refractory chronic CH were treated with short‐term (up to 1 hour) electrical stimulation of the SPG during an acute CH. Headaches were spontaneously present at the time of stimulation or were triggered with agents known to trigger clusters headache in each patient. A standard percutaneous infrazygomatic approach was used to place a needle at the ipsilateral SPG in the pterygopalatine fossa under fluoroscopic guidance. Electrical stimulation was performed using a temporary stimulating electrode. Stimulation was performed at various settings during maximal headache intensity. Results.— Five patients had CH during the initial evaluation. Three returned 3 months later for a second evaluation. There were 18 acute and distinct CH attacks with clinically maximal visual analog scale (VAS) intensity of 8 (out of 10) and above. SPG stimulation resulted in complete resolution of the headache in 11 attacks, partial resolution (>50% VAS reduction) in 3, and minimal to no relief in 4 attacks. Associated autonomic features of CH were resolved in each responder. Pain relief was noted within several minutes of stimulation. Conclusion.— Sphenopalatine ganglion stimulation can be effective in relieving acute severe CH pain and associated autonomic features. Chronic long‐term outcome studies are needed to determine the utility of SPG stimulation for management and prevention of CH.     

Post-Traumatic External Nasal Pain Syndrome (a Trigeminal Based Pain Disorder)

Little has been written about persistent external nasal pain after injury to the nose in the neurologic or headache literature. In clinical practice, this can be a disabling and treatment refractory condition. The external portion of the nose is highly innervated by branches of the ophthalmic and maxillary divisions of the trigeminal nerve including the nasociliary nerve, external nasal nerve, infratrochlear nerve, anterior ethmoidal nerve, and infraorbital nerve. As these nerves are located on the external portion of the nose just deep enough to the skin they can be easily traumatized with any impact to the nose.
Four patients with what is termed the post-traumatic external nasal pain syndrome are reported in this paper, describing the clinical presentation of the disorder and providing treatment options. Post-traumatic external nasal pain syndrome appears to be a novel form of trigeminal-based pain not previously reported in the neurologic literature.     

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.     

Sphenopalatine ganglion block for treatment of sinus arrest in postherpetic neuralgia

A 64-year-old woman presented with bradycardia from sinus pauses during exacerbations of postherpetic trigeminal distribution neuralgia. She had underlying systemic lupus erythematosus. Sphenopalatine ganglion blockade was employed to treat her pain. The episodes of bradycardia resolved with successful alleviation of pain. This report emphasizes that a sphenopalatine ganglion blockade can be employed in the treatment and prevention of sinus arrest associated with postherpetic trigeminal distribution neuralgia.     

2003 Wolff Award: Possible parasympathetic contributions to peripheral and central sensitization during migraine

BACKGROUND: Neurologic signs of increased parasympathetic outflow to the head often accompany migraine attacks. Because increased parasympathetic outflow to the cranial cavity induces vasodilation of cerebral and meningeal blood vessels, it can enhance plasma protein extravasation and the release of proinflammatory mediators that activate perivascular nociceptors. We recently showed that activation of intracranial perivascular nociceptors induces peripheral and central sensitization along the trigeminovascular pathway and proposed that these sensitizations mediate the intracranial hypersensitivity and the cutaneous allodynia of migraine. METHODS: The present study investigates possible parasympathetic contributions to the generation of peripheral and central sensitization during migraine by applying intranasal lidocaine to reduce cranial parasympathetic outflow through the sphenopalatine ganglion. RESULTS: In the absence of migraine, patients were pain-free, and their skin sensitivity was normal. Their mean baseline pain thresholds were less than 15 degrees C for cold, more than 45 degrees C for heat, and more than 100 g for mechanical pressure. Their mean pain score was 7.5 of 10 (standard deviation, 1.4) during untreated migraine and 3.5 of 10 (standard deviation, 2.4) after the nasal lidocaine-induced sphenopalatine ganglion block (P <.0001). Most patients developed cutaneous allodynia during migraine, and their mean pain thresholds changed to more than 25 degrees C for cold, less than 40 degrees C for heat, and less than 10 g for mechanical pressure. Following the nasal lidocaine administration (sphenopalatine ganglion block), this allodynia remained unchanged in spite of the pain relief. CONCLUSION: These findings suggest that cranial parasympathetic outflow contributes to migraine pain by activating or sensitizing (or both) intracranial nociceptors, and that these events induce parasympathetically independent allodynia by sensitizing the central nociceptive neurons in the spinal trigeminal nucleus.     

The Sphenopalatine Ganglion: Anatomy,Pathophysiology, and Therapeutic Targeting in Headache

The sphenopalatine ganglion (SPG) has attracted the interest of practitioners treating head and face pain for over a century because of its anatomical connections and role in the trigemino‐autonomic reflex. In this review, we discuss the anatomy of the SPG, as well as what is known about its role in the pathophysiology of headache disorders, including cluster headache and migraine. We then address various therapies that target the SPG, including intranasal medication delivery, new SPG blocking catheter devices, neurostimulation, chemical neurolysis, and ablation procedures.     

Cluster Headache: Potential Options for Medically Refractory Patients (When All Else Fails)

The most evidence exists for mixed anesthetic/steroid occipital nerve blocks (which are also useful in non‐refractory patients), deep brain stimulation, sphenopalatine ganglion (SPG) blocks, SPG radiofrequency ablation, and SPG stimulation with the Autonomic Technologies, Inc (ATI) SPG Neurostimulator, the latter approved in the European Union and reimbursed in several countries.