OnabotulinumtoxinA injection towards the SPG for treating symptoms of refractory chronic rhinosinusitis with nasal polyposis: a pilot study

BACKGROUND AND OBJECTIVE

The main objective of this prospective, open, uncontrolled pilot study was to investigate the safety of administering onabotulinumtoxinA (BTA) towards the sphenopalatine ganglion (SPG) in 10 patients with refractory chronic rhinosinusitis with nasal polyposis (CRSwNP) using a novel injection tool, the MultiGuide^®.

MATERIAL AND METHODS

A one-month baseline period was followed by bilateral injections of 25 U BTA in the SPG and a follow-up of 12 weeks. The primary outcome was adverse events (AE), and the main efficacy outcome was a 50% reduction in visual analogue scale (VAS) symptoms for nasal obstruction and rhinorrhea in months 2 and 3 post-treatment compared to baseline.

RESULTS

We registered 13 AEs, none of which were serious, however, one patient experienced diplopia which moderately affected his daily activities. The symptoms slowly improved and resolved 4 weeks after injection. Five patients were treatment responders with at least 50% median reduction in the nasal obstruction, and four were treatment responders concerning rhinorrhea.

CONCLUSIONS

Injection of BTA toward the SPG using the MultiGuide^® in patients with CRSwNP appears to be safe but with a potential for moderately disabling side effects. The study indicates a beneficial effect on nasal obstruction.

A novel landmark for endonasal surgery of the pterygopalatine fossa and inferior orbital fissure: The orbito-pterygo-sphenoidal ligament

The pterygopalatine fossa contains a dense and complex array of neurovascular structures vulnerable to accidental surgical injury. This study aims to describe a novel landmark, the orbito-pterygo-sphenoidal ligament (OPSL), and implications of this structure for surgery in the pterygopalatine fossa and the inferior orbital fissure. Six cadaveric specimens (12 sides) were dissected using an endonasal approach to expose the periosteal layers associated with the pterygopalatine fossa and orbit. The thickened triangular-shaped ligament at their confluence was termed the OPSL. Dimensions of its lateral, inferior, and medial borders were measured, and their anatomical relationships defined. The pterygopalatine ganglion and the maxillary nerve lie immediately inferior and deep into the OPSL. The superior aspect of the posterior nasoseptal artery and nerve are covered by the medial OPSL. The lateral and inferior borders of the OPSL are contiguous with the periorbita and the periosteum of the pterygopalatine fossa, respectively. Along the medial border of the ligament, the openings of the palatovaginal fissure, vidian canal, and foramen rotundum were sequentially identified in a medial to lateral trajectory. The length of the lateral, inferior, and medial borders of the triangular OPSL were 13.25 ± 0.62, 14.25 ± 0.45, and 12.08 ± 0.90 mm, respectively. The OPSL is a thick, triangular-shaped fascial confluence, which may serve as a landmark for procedures within the pterygopalatine fossa and the inferior orbital fissure.

A prospective case series of sphenopalatine ganglion pulsed radiofrequency therapy for refractory chronic cluster headache

BACKGROUND AND PURPOSE

The management options for chronic cluster headache (CCH) are limited and a significant proportion of patients become refractory to pharmacological treatments. Pulsed radiofrequency (PRF) of the sphenopalatine ganglion (SPG) may present an efficacious, minimally invasive treatment modality for patients with refractory CCH. We describe the clinical outcomes of 14 patients with refractory CCH treated with PRF of the SPG.

METHODS

Patients with medically refractory CCH who underwent percutaneous SPG-PRF treatment between January 2016 and April 2019 were included in this report. Patients obtaining at least 30% reduction in weekly cluster attacks for at least 3 months were defined as responders. Treatment-related side effects were collected.

RESULTS

A total of 14 patients were included in this report (nine males). At a median follow-up of 6.5 (range 6-13) months post-procedure, eight patients (57.1%) were defined as responders to the treatment. Six patients were non-responders and reported either a reduction in frequency and severity of attacks for <3 months (2/6), no improvement (2/6) or temporary worsening of symptoms (1/6). The majority of patients (63.6%, n = 7/11) treated with >45 V were responders compared with responders treated with 45 V (33.3%, n = 1/3). Five patients (35.7%) experienced post-procedural side effects.

CONCLUSION

This case series suggests that PRF targeting the SPG might offer a safe, minimally invasive and effective treatment for medically refractory CCH. Given the small number of cases and the short follow-up, larger and more robust studies will be needed to confirm our findings.

Locating and Preserving the Sphenopalatine Ganglion in Endoscopic Endonasal Pterygopalatine Fossa Surgery: An Anatomical Study

Background

The pterygopalatine fossa (PPF) contains numerous important neurovascular structures; notably, the sphenopalatine ganglion (SPG), the maxillary branch of the trigeminal nerve (V2), and the internal maxillary artery. With the advent of extended endoscopic endonasal surgery, the surgical anatomy of the PPF warrants increased investigation. Intraoperative dissection and preservation of the SPG is essential to prevent postoperative xeropthalmia and facial hypoesthesia.

Objective

This study aims to (1) describe a novel dissection technique for identifying the SPG and (2) define the SPG location relative to the sphenopalatine foramen (SPF), which is a consistently identifiable landmark.

Methods

Eight cadaveric PPFs were dissected in step-wise fashion. An endoscopic medial maxillectomy was performed, the SPF was identified, and the posterior maxillary wall was resected. The maxillary branch of the trigeminal nerve (V2) was identified anterolaterally in its infraorbital canal and traced medially to identify the pterygopalatine nerve to the SPG. The lateral distance and superior/inferior distance from the SPG to the fixed SPF was measured.

Results

The surgical technique described allowed for reliable identification of the SPG. The SPG was located on average 4.5 ± 1.1 mm lateral and 1 ± 1.4 mm inferior to the SPF.

Conclusion

Identification and preservation of the SPG is necessary to prevent complications in endoscopic endonasal PPF surgery. The SPG can be reliably located near the SPF by following the pterygopalatine nerve branch of V2.

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

Background

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

Objective

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

Methods

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

Results

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

Conclusions

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

Pilot study of sphenopalatine injection of onabotulinumtoxinA for the treatment of intractable chronic migraine

Objective The main objective of this pilot study was to investigate the safety of administering onabotulinumtoxinA towards the sphenopalatine ganglion in 10 patients with intractable chronic migraine with an open, uncontrolled design. We also collected efficacy data to provide an indication as to whether future placebo-controlled studies should be performed. Method In a prospective, open-label, uncontrolled study after one-month baseline, we performed bilateral injections of 25 IU onabotulinumtoxinA (total dose 50 IU) toward the sphenopalatine ganglion in a single outpatient session in 10 patients with intractable migraine with a follow-up of 12 weeks. The primary outcome was adverse events and the main efficacy outcome was frequency of moderate and severe headache days in month 2 post-treatment compared to baseline. Results All 10 patients experienced a total of 25 adverse events. The majority of these were different types of local discomfort in the face and jaw, and none were classified as serious. In an intention-to-treat analysis of the main efficacy outcome, a statistically significant reduction of moderate and severe headache days in baseline versus month 2 was observed (16.3 ± 6.2 days baseline versus 7.6 ± 7.6 days month 2, p = 0.009). Eight out of 10 patients experienced an at least 50% reduction of moderate and severe headache days compared to baseline. Conclusion The result warrants randomised, placebo-controlled studies to establish both safety and efficacy of this potential novel treatment of chronic migraine.

Pilot study of sphenopalatine injection of onabotulinumtoxinA for the treatment of intractable chronic cluster headache

OBJECTIVE

The main object of this pilot study was to investigate the safety of administering onabotulinumtoxinA (BTA) towards the sphenopalatine ganglion (SPG) in intractable chronic cluster headache. Efficacy data were also collected to provide indication on whether future placebo-controlled studies should be performed.

METHOD

In a prospective, open-label, uncontrolled study, we performed a single injection of 25 IU (n = 5) or 50 IU BTA (n = 5) towards the SPG in 10 patients with intractable chronic cluster headache with a follow-up of 24 weeks. The primary outcome was adverse events (AEs) and the main efficacy outcome was attack frequency in weeks 3 and 4 post-treatment.

RESULTS

A total of 11 AEs were registered. There was one severe adverse event (SAE): posterior epistaxis. The number of cluster headache attacks (main efficacy outcome) was statistically significantly reduced in the intention-to-treat analysis from 18 ± 12 per week in baseline to 11 ± 14 (p = 0.038) in weeks 3 and 4, and five out of 10 patients had at least 50% reduction of attack frequency compared to baseline. The cluster attack frequency was significantly reduced for five out of six months post-treatment.

CONCLUSION

Randomised, placebo-controlled studies are warranted to establish the potential of this possible novel treatment of cluster headache.

Distribution of cocaine- and amphetamine-regulated transcript (CART), neuropeptide Y (NPY) and galanin (GAL) in the pterygopalatine ganglion of the domestic duck (Anas platyrhynchos f. domestica)

INTRODUCTION

Cocaine- and amphetamine-regulated transcript (CART), neuropeptide Y (NPY) and galanin (GAL) act as neurotransmitters and neuromodulators in both the central and peripheral nervous systems. Their presence has been found in different taxonomic groups, in particular in mammals. However, only few investigators have studied these neuropeptides in the class Aves (birds). The aim of the present study was to describe the distribution of CART, NPY and GAL in the pterygopalatine ganglion (PPG) of the domestic duck (Anas platyrhynchos f. domestica).

MATERIAL AND METHODS

The experiment was conducted on 16 one-year-old domestic ducks of the Pekin breed of both sexes (8 males and 8 females). Frozen sections of the PPG were subjected to immunofluorescence staining using primary mouse monoclonal antibodies directed against CART and GAL and rabbit polyclonal antibody directed against NPY. Secondary antibodies were conjugated with Cy3 and FITC fluorochromes.

RESULTS

CART, NPY, and GAL were present in the PPG of the domestic duck. The highest immunoreactivity (IR) in the ganglionic cells was found for CART in the majority (83-85%) of neurons of both superior (SPPG) and inferior (IPPG) PPG. CART-IR was also found in small aggregations of neurons on the medial surface of the Harderian gland, and on the course of the palatine branch of the facial nerve. CART-IR was also observed in the nerve fibers of these neurons' aggregations; however, it was low in comparison to the immunoreactivity of the perikarya. Immunoreactivity of NPY was found in ganglionic neurons, but above all in numerous fibers of the SPPG and IPPG and within aggregations on the surface of the Harderian gland. NPY-IR cells were distributed irregularly over the cross-sections of the tested aggregations, and constituted from 36% to 43% of the SPPG and from 37% to 40% of the IPPG of all cross-sectioned neurons. GAL-immunoreactive perikarya, distributed irregularly across the sections, were observed in the SPPG, where they constituted 61-65%, and in the IPPG, where they made up 50-57% of all neurons. All immunoreactive neurons were characterized by immunopositive neuroplasm and immunonegative cell nuclei.

CONCLUSIONS

The presence of CART, NPY, and GAL in the PPG of the domestic duck suggests that these peptides may contribute to the secretory innervation of the glands of the mucosa of the palate and nasal cavity, the Harderian gland, and the lacrimal gland.

The identification and neurochemical characterization of central neurons that target parasympathetic preganglionic neurons involved in the regulation of choroidal blood flow in the rat eye using pseudorabies virus, immunolabeling and conventional pathway tracing methods

The choroidal blood vessels of the eye provide the main vascular support to the outer retina. These blood vessels are under parasympathetic vasodilatory control via input from the pterygopalatine ganglion (PPG), which in turn receives its preganglionic input from the superior salivatory nucleus (SSN) of the hindbrain. The present study characterized the central neurons projecting to the SSN neurons innervating choroidal PPG neurons, using pathway tracing and immunolabeling. In the initial set of studies, minute injections of the Bartha strain of the retrograde transneuronal tracer pseudorabies virus (PRV) were made into choroid in rats in which the superior cervical ganglia had been excised (to prevent labeling of sympathetic circuitry). Diverse neuronal populations beyond the choroidal part of ipsilateral SSN showed transneuronal labeling, which notably included the parvocellular part of the paraventricular nucleus of the hypothalamus (PVN), the periaqueductal gray, the raphe magnus (RaM), the B3 region of the pons, A5, the nucleus of the solitary tract (NTS), the rostral ventrolateral medulla (RVLM), and the intermediate reticular nucleus of the medulla. The PRV+ neurons were located in the parts of these cell groups that are responsive to systemic blood pressure signals and involved in systemic blood pressure regulation by the sympathetic nervous system. In a second set of studies using PRV labeling, conventional pathway tracing, and immunolabeling, we found that PVN neurons projecting to SSN tended to be oxytocinergic and glutamatergic, RaM neurons projecting to SSN were serotonergic, and NTS neurons projecting to SSN were glutamatergic. Our results suggest that blood pressure and volume signals that drive sympathetic constriction of the systemic vasculature may also drive parasympathetic vasodilation of the choroidal vasculature, and may thereby contribute to choroidal baroregulation during low blood pressure.

The anatomical and functional relationship between allergic conjunctivitis and allergic rhinitis

There are numerous anatomic connections between the allergic conjunctivitis and allergic rhinitis. The most obvious reason is the physical connection via the nasolacrimal apparatus. However, a closer look at innervation, circulatory, lymphatic, and neurogenic systems reveals much more than a physical connection. The eye is richly innervated by parasympathetic nerves that enter the eyes after traveling in conjunction with the parasympathetic input to the nasal cavity. Parasympathetic innervation governing the tear film and nasal secretion can intersect at the pterygopalatine ganglion. Neurogenic inflammation affects both the eye and the nose as evidenced by the presence of the same neurogenic factors. Venous flow is in the SOV area connecting the eye and the nose, once thought to be without valves. In the past, this thinking is the basis for concern about the danger triangle of the face. Recent literature has shown otherwise. Although valves are present, there are still pathways where bidirectional flow exists and a venous connection is made. The most likely area for venous communication is the pterygoid plexus and cavernous sinus. The venous flow and connections also offers a pathway for allergic shiners. Understanding the mutual connections between the nasal mucosa and the ocular surface can also affect treatment strategies.

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.

The origin of extrinsic nitrergic axons supplying the human eye

Nitrergic nerve fibres of intrinsic and extrinsic origin constitute an important component of the autonomic innervation in the human eye. The intrinsic source of nitrergic nerves are the ganglion cells in choroid and ciliary muscle. In order to obtain more information on the origin of extrinsic nitrergic nerves in the human eye, we obtained superior cervical, ciliary, pterygopalatine and trigeminal ganglia from six human donors, and stained them for neuronal nitric oxide synthase (nNOS) and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-D). In the superior cervical ganglia, nNOS/NADPH-D-positive varicose axons were observed whereas perikarya were consistently negative. Fewer than 1% of perikarya in the ciliary ganglia were labelled for nNOS/NADPH-D. The diameter of nNOS/NADPH-D-positive ciliary perikarya was between 8 and 10 microm, which was markedly smaller than the diameter of the vast majority of negative perikarya in the ciliary ganglion. More than 70% of perikarya in the pterygopalatine ganglia were intensely labelled for both nNOS and NADPH-D. In trigeminal ganglia, 18% of perikarya were nNOS/NADPH-D-positive. The average diameter of trigeminal nNOS/NADPH-D perikarya was between 25 and 45 microm. Pterygopalatine and trigeminal ganglia are the most likely sources for extrinsic nerve fibres to the human eye.