Depicting the pterygopalatine ganglion on 3 Tesla magnetic resonance images

PURPOSE: The pterygopalatine ganglion has yet not been identified on medical images in living humans. The primary aim of this study was to evaluate whether the pterygopalatine ganglion could be identified on 3 T MR imaging. METHODS: This study was performed on medical images of 20 Caucasian subjects on both sides (n = 40 ganglia) with an exploratory design. 3 T MR images were assessed by two physicians for the presence and size of the pterygopalatine ganglion. The distance from the pterygopalatine ganglion to four bony landmarks was registered from fused MR and CT images. In an equivalence analysis, the distances were compared to those obtained in an anatomical cadaveric study serving as historical controls (n = 50). RESULTS: A structure assumed to be the pterygopalatine ganglion was identified on MR images in all patients on both sides by both physicians. The mean size was depth 2.1 ± 0.5 mm, width 4.2 ± 1.1 mm and height 5.1 ± 1.4 mm, which is in accordance with formerly published data. Equivalence of the measurements on MR images and the historical controls was established, suggesting that the structure identified on the MR images is the pterygopalatine ganglion. CONCLUSION: Our findings suggest that the pterygopalatine ganglion can be detected on 3 T MR images. Identification of the pterygopalatine ganglion may be important for image-guided interventions targeting the pterygopalatine ganglion, and has the potential to increase the efficacy, safety and reliability for these treatments

Morphology, topography and cytoarchitectonics of the pterygopalatine ganglion in Egyptian spiny mouse (Acomys cahirinus, Desmarest)

Using the thiocholine method of Koelle and Friedenwald and histological techniques the pterygopalatine ganglion in Egyptian spiny mouse (Acomys cahirinus, Desmarest) was studied. The ganglion was found to be a single irregular cluster of neurocytes, situated on the medial surface of the maxillary nerve. The ganglion is composed of oval, elliptical and sometimes fusiform ganglionic neurones in compact arrangement without a thick connective-tissue capsule

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

Dissection and Exposure of the Whole Course of Deep Nerves in Human Head Specimens after Decalcification

The whole course of the chorda tympani nerve, nerve of pterygoid canal, and facial nerves and their relationships with surrounding structures are complex. After reviewing the literature, it was found that details of the whole course of these deep nerves are rarely reported and specimens displaying these nerves are rarely seen in the dissecting room, anatomical museum, or atlases. Dissections were performed on 16 decalcified human head specimens, exposing the chorda tympani and the nerve connection between the geniculate and pterygopalatine ganglia. Measurements of nerve lengths, branching distances, and ganglia size were taken. The chorda tympani is a very fine nerve (0.44 mm in diameter within the tympanic cavity) and approximately 54 mm in length. The mean length of the facial nerve from opening of internal acoustic meatus to stylomastoid foramen was 52.5 mm. The mean length of the greater petrosal nerve was 26.1 mm and nerve of the pterygoid canal was 15.1 mm

Anatomic variation of cranial parasympathetic ganglia

Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia

Microanatomy of the neural scaffold of the pterygopalatine fossa in humans: trigeminovascular projections and trigeminal-autonomic plexuses

The pterygopalatine fossa (PPF) is an anatomically-hidden deep extracranial space. The neural scaffold of the PPF remains anatomically understudied in humans. Moreover, there are no anatomical data in humans pointing out the extracranial trigeminovascular distributions, in contrast to the trigeminal supratentorial ones. By anatomical microdissections, the neural scaffold of the PPF and the presence of trigeminovascular projections were evaluated. The anterior and superior approaches of the pterygopalatine fossae in nine dissected blocks of human middle skull base and the frontal cuts of two different specimens, led to several results: (1) the neurovascular contents of the PPF, embedded in the pterygopalatine adipose body, have a layered disposition; (2) the posterior neural layer is represented by a pterygopalatine cross, centred by the pterygopalatine ganglion (PPG) that sends off ascending, descending, and medial branches and has a lateral connection with the maxillary nerve - 4 quadrants could have been defined as referring to this cross; (3) at the level of the upper lateral quadrant there are two superposed layers (i) a superficial plexus contributed by the maxillary nerve, the maxillary artery plexus and the PPG and its orbital branches (OBs) and (ii) a deep layer, consisting of the OBs proper of the PPG; (4) within the PPF and on the posterior wall of the maxillary sinus distinctive trigeminovascular projections were evidenced. The anastomoses involving autonomic and trigeminal fibres, located in the PPF passage to the orbital apex, support the complicate and polymorphous neural input to the orbit, while the evidence of a pterygopalatine trigeminovascular scaffold offers a substrate for a better understanding of various facial algias. (Folia Morphol 2010; 69, 2: 84-91

Greater superficial petrosal nerve and its surgical importance: a review

The greater superficial petrosal nerve (GSPN) is an important but often underappreciated branch of the facial nerve. The GSPN is a mixed nerve which contains both sensory and parasympathetic fibers. It serves as the motor root of the pterygopalatine (sphenopalatine) ganglion. GSPN has a long course which passes across the middle skull base between the petrous bone and dura mater and running through the foramen lacerum. It then incorporates to the deep petrosal nerve and crosses along the pterygoid canal to the pterygopalatine ganglion. The postganglionic nerve fibers innervates the lacrimal glands, nasal mucosa and palatal mucosal glands via branches of the zygomatic nerve/zygomaticotemporal branch, sphenopalatine, greater palatine, lesser palatine nerves and pharyngeal nerve. Surgical anatomy of the GSPN nerve is often unfamiliar to many clinicians. As this nerve is usually unrecognized without use of high resolution microscope or endoscope, its anatomical knowledge is essential for surgeons basically otologists and other head and neck surgeon to minimize the risk of injury during surgical intervention. This review article surely increases the precise knowledge of the GSPN including its embryology, surgical anatomy, blood supply, relations with other structures and imaging

Peripheral Nervous System

This study guide is intended for the students of medical higher educational institutions of IV accreditation level who study Human Anatomy in the English language