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OBJECTIVE The dura mater is made of 2 layers: the endosteal layer (outer layer), which is firmly attached to the bone, and the meningeal layer (inner layer), which directly covers the brain and spinal cord. These 2 dural layers join together in most parts of the skull base and cranial convexity, and separate into the orbital and perisellar compartments or into the spinal epidural space to form the extradural neural axis compartment (EDNAC). The EDNAC contains fat and/or venous blood. The aim of this dissection study was to anatomically verify the concept of the EDNAC by focusing on the dural layers surrounding the jugular foramen area. METHODS The authors injected 10 cadaveric heads (20 jugular foramina) with colored latex and fixed them in formalin. The brainstem and cerebellum of 7 specimens were cautiously removed to allow a superior approach to the jugular foramen. Special attention was paid to the meningeal architecture of the jugular foramen, the petrosal inferior sinus and its venous confluence with the sigmoid sinus, and the glossopharyngeal, vagus, and accessory nerves. The 3 remaining heads were bleached with a 20% hydrogen peroxide solution. This procedure produced softening of the bone without modifying the fixed soft tissues, thus permitting coronal and axial dissections. RESULTS The EDNAC of the jugular foramen was limited by the endosteal and meningeal layers and contained venous blood. These 2 dural layers joined together at the level of the petrous and occipital bones and separated at the inferior petrosal sinus and the sigmoid sinus, and around the lower cranial nerves, to form the EDNAC. Study of the dural sheaths allowed the authors to describe an original compartmentalization of the jugular foramen in 3 parts: 2 neural compartments-glossopharyngeal and vagal-and the interperiosteodural compartment. CONCLUSIONS In this dissection study, the existence of the EDNAC concept in the jugular foramen was demonstrated, leading to the proposal of a novel 3-part compartmentalization, challenging the classical 2-part compartmentalization, of the jugular foramen.

Objective: To identify landmarks and to describe a technique for nerve blockade of the dorsal cranium in dogs., Study Design: Anatomic cadaveric study., Animals: A total of 39 dog cadavers, weighing 18.0 ± 9.7 kg (mean ± standard deviation)., Methods: The study was performed in three parts. In the initial part, cadavers were dissected to determine the location of the frontal, zygomaticotemporal, and major occipital nerves, and to identify prominent landmarks for their blockade. In the second part, one technique was developed to block each of the frontal and zygomaticotemporal nerves, and two techniques, rostral and caudal, were developed to block the major occipital nerve. Injection solution was 0.05% methylene blue in 0.5% bupivacaine. In the third part, cadavers were used to test the techniques developed in the second part with 0.04 mL kg -1 of the same injectate administered at each site (maximal volume 0.5 mL per site). The length of nerve stained was measured, with a length ≥6 mm considered successful. Confidence intervals were calculated using Fisher's exact test., Results: Success rates (95% confidence interval) for the frontal, zygomaticotemporal, and rostral and caudal locations for the major occipital nerve were 94% (80-99%), 91% (76-98%), 74% (58-86%) and 77% (59-89%), respectively. With a combination of both locations, the success rate for the major occipital nerve was 100% (90-100%)., Conclusion and Clinical Relevance: This study describes a simple regional anaesthesia technique using palpable anatomical landmarks that may provide analgesia for dogs undergoing craniotomy., (Copyright © 2018 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.)

Introduction: The structure/function of the cranial nerves is a core topic for dental students. However, due to the perceived complexity of the subject, it is often difficult for students to develop a comprehensive understanding of key concepts using textbooks and models. It is accepted that the acquisition of anatomical knowledge can be facilitated by visualisation of structures. This study aimed to develop and assess a novel cranial nerve animation as a supplemental learning aid for dental students., Materials and Methods: A multidisciplinary team of anatomists, neuroscientists and a computer scientist developed a novel animation depicting the cranial nerves. The animation was viewed by newly enrolled first-year dental students, graduate entry dental students (year 1) and dental hygiene students (year 1). A simple life scenario employing the use of the cranial nerves was developed using a cartoon-type animation with a viewing time of 3.58 minutes. The animation was developed with emphasis on a life scenario. The animation was placed online for 2 weeks with open access or viewed once in a controlled laboratory setting. Questionnaires were designed to assess the participants' attitude towards the animation and their knowledge of the cranial nerves before and after visualisation. This study was performed before the delivery of core lectures on the cranial nerves., Results: Our findings indicate that the use of the animation can act as a supplemental tool to improve student knowledge of the cranial nerves. Indeed, data indicate that a single viewing of the animation, in addition to 2-week access to the animation, can act as a supplemental learning tool to assist student understanding of the structure and function of cranial nerves. The animation significantly enhanced the student's opinion that their cranial nerve knowledge had improved. From a qualitative point of view, the students described the animation as an enjoyable and useful supplement to reading material/lectures and indicated that the animation was a useful tool in understanding the cranial nerves., Conclusion: Overall, these findings indicate that an animation demonstrating the cranial nerves in a simple, everyday functional scenario may act as a learning aid in the study of cranial nerves., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The soft-tissue reconstruction and associated osteology of the North American therizinosaurian Nothronychus mckinleyi is updated. The cranial nerve topology is revised, bringing it more in line with coelurosaurs. The trunk of the trigeminal nerve is very short, with an incompletely intracranial trigeminal ganglion, an ophthalmic branch diverging anteriorly first, with later divergences of the maxillomandibular branches, following typical pathways. The facial nerve has been re-evaluated, resulting in a very typical configuration with an extracranial geniculate ganglion. The single foramen leading to the cochlea probably transmitted the vestibulocochlear nerve, along with some fibers of the facial. This configuration is reduced from the more standard three foramina (vestibular, cochlear, and facial) and may be apomorphic for therizinosaurs. Some alteration is proposed for the dorsiflexive musculature. The insertion point for m. transversospinalis capitis is partially changed to extend onto the parietal, along with a proposed functional difference in the moment arm. The expansion of the basicranial pneumatic system is limited to the paratympanic system, enhancing low frequency sound sensitivity. There is little expansion of the median pharyngeal and subcondylar sinuses. Ossification of the surrounding epithelium may provide some information on the embryology of the theropod skull. It may be associated with a reduced stress field, or the general similarity of the basicranium with anterior cervical vertebrae may reflect activation of a cervical vertebral (Hox) gene regulating ossification of the pneumatic sinuses. This might be a local, selectively neutral, fixed gene in the basicranium reflecting embryological regulation of cervical vertebrae development., Competing Interests: The authors have declared that no competing interests exist.

Some authors propose a global approach, including imaging, to describe cranial nerves from a clinical point of view. If we can agree to a certain extent with this proposal, we consider that the use of a medical point of view can neglect histological and embryological features which contribute to a better understanding of nerve function. For example, it is false to consider totally "nerves" I and II as "sensory cranial nerves". They are not true nerves, but derive manly from direct expansions of the central nervous system. They differ fundamentally from cranial nerves, except for the fibers present at the roof of olfactory fossa. The cranial nerve nuclei arise from "Herrick's columns", which originate from alar and basal plates. These columns, which correspond to "functional components" of these nerves are extremely important for the understanding of cranial nerve functions (as "viscero-efferent", "somato-afferent", etc.), which also helps students to memorize these nerves. The usual classification of cranial nerves neglect the terminal nerve, present in adult humans and associated to the vomero-nasal organ. It includes in the cranial nerves a trunk nerve secondary associated with the head, the hypoglossal nerve, and creates a supernumerary cranial nerve (the accessory nerve) by fusion of vagous fibers with cervical roots. Close consideration of the development and the comparative anatomy can lead to a new synthesis useful to understand the cranial nerves from a general biological point of view and can facilitate their study., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Introduction: The cerebellopontine angle (CPA) is a subarachnoid space in the lateral aspect of the posterior fossa. In this study, we propose a complementary analysis of the CPA from the cerebellopontine fissure., Methods: We studied 50 hemi-cerebelli in the laboratory of neuroanatomy and included a description of the CPA anatomy from the cerebellopontine fissure and its relationship with the flocculus and the 5th, 6th, 7th, and 8th cranial nerves (CN) origins., Results: The average distance from the 5th CN to the mid-line (ML) was 19.2 mm, 6th CN to ML was 4.4 mm, 7-8 complex to ML was 15.8 mm, flocculus to ML was 20.5 mm, and flocculus to 5th CN was 11.5 mm, additionally, and the diameter of the flocculus was 9.0 mm. The angle between the vertex in the flocculus and the V CN and the medullary-pontine line was 64.8 degrees., Discussion: The most common access to the CPA is through the retrosigmoid-suboccipital region and this approach can be done with the help of an endoscope. The anatomy of origins of neural structures tends to be preserved in cases of CPA lesions., Conclusion: Knowledge of the average distances between the neural structures in the cerebellar-pontine fissure and the angular relationships between these structures facilitates the use of surgical approaches such as microsurgery and endoscopy.

Classically in the cerebello-pontine angle the facial (CN VII) and vestibular-cochlear (CN VIII) nerves should run parallel with the anterior inferior cerebellar artery, whereas the lower nerves (CN IX-XI) continue with the posterior-inferior-cerebellar artery (PICA). In fact, this is not always true, particularly when dealing with hemispasm surgery where the relationships between CN VII, CN VIII and PICA are often different and closer. Knowledge of anatomical bases in surgical situation will help neurosurgeons to appreciate anatomical nuances, that are important to increase effectiveness and safety of hemifacial spasm surgery., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Objective: Surgical operation within the region of the jugular foramen presents a great challenge. The authors characterized the quantitative impact of surgical window parameters on the exposure of the jugular foramen via a trans-mastoidal approach., Methods: Computed tomography and magnetic resonance imaging data were used to establish a 3-dimensional model of the jugular foramen region. The mastoidale, posterior edge of the mastoid, and the superior edge of the bony external acoustic meatus were selected as points a, b, and c. The anterior edge of the tuberculum jugulare was selected as point d. The midpoints of line segments ab, ac, and bc were selected as points e, f, and g. Triangle abc was divided into triangles aef, beg, cfg, and efg. Surgical corridors of the triangular pyramid were outlined by connecting the above triangles to point d. Anatomic exposure was evaluated by measuring the area and volume of various structures within each route. Statistical comparisons were performed via analysis of variance., Results: The model allowed for adequate visualization of all structures. The areas of triangles beg and efg were greater than those of triangles aef and cfg (P < 0.05). The volumes of triangular pyramids d-beg and d-cfg were greater than those of triangular pyramids d-aef and d-efg (P = 0.000). Statistically significant differences were also observed for volumes of osseous, venous, and cranial nerve structures in all divided routes (P = 0.000)., Conclusion: Our results indicate that 3-dimensional modeling may aid in the quantification of surgical exposure and that division of the craniotomy window may allow for more precise operation.

Background: While the subtemporal approach represents the surgical module milestone designed to reach the petrous apex, a novel ventral route, which is the superior eyelid endoscopic transorbital approach, has been proposed to access the skull base. Accordingly, we aimed to evaluate the feasibility of this route to the petrous apex, providing a qualitative and quantitative analysis of this relatively novel pathway., Methods: Five human cadaveric heads were dissected at the Laboratory of Surgical NeuroAnatomy of the University of Barcelona. After proper dissection planning, anterior petrosectomy via the endoscopic transorbital route was performed. Specific quantitative analysis, as well as dedicated three-dimensional reconstruction, was done., Results: Using the endoscopic transorbital approach, it was possible to reach the petrous apex with an average volume bone removal of 1.33 ± 0.21 cm 3 . Three main intradural spaces were exposed: cerebellopontine angle, middle tentorial incisura, and ventral brainstem. The first one was bounded by the origin of the trigeminal nerve medially and the facial and vestibulocochlear nerves laterally, the second extended from the origin of the oculomotor nerve to the entrance of the trochlear nerve into the tentorium free edge while the ventral brainstem area was hardly accessible through the straight, ventral endoscopic transorbital trajectory., Conclusion: This is the first qualitative and quantitative anatomic study concerning details of the lateral aspect of the incisura and ventrolateral posterior fossa reached via the transorbital window. This manuscript is intended as a feasibility anatomic study, and further clinical contributions are mandatory to confirm the effectiveness of this approach, defining its possible role in the neurosurgical armamentarium.

High-resolution isotropic 3-dimensional (D) MR imaging with and without contrast is now routinely used for imaging evaluation of cranial nerve anatomy and pathologic conditions. The anatomic details of the extraforaminal segments are well-visualized on these techniques. A wide range of pathologic entities may cause enhancement or displacement of the nerve, which is now visible to an extent not available on standard 2D imaging. This article highlights the anatomy of extraforaminal segments of the cranial nerves and uses select cases to illustrate the utility and power of these sequences, with a focus on constructive interference in steady-state., (Copyright © 2017 Elsevier Inc. All rights reserved.)

This study aimed to provide topographic information of the greater occipital (GON) and third occipital (3ON) nerves, with the three-dimensional locations of their emerging points on the back muscles (60 sides, 30 cadavers) and their spatial relationship with muscle layers, using a 3D digitizer (Microscribe G2X, Immersion Corp, San Jose CA, USA). With reference to the external occipital protuberance (EOP), GON pierced the trapezius at a point 22.6 ± 7.4 mm lateral and 16.3 ± 5.9 mm inferior and the semispinalis capitis (SSC) at a point 13.1 ± 6.0 mm lateral and 27.7 ± 9.9 mm inferior. With the same reference, 3ON pierced, the trapezius at a point 12.9 ± 9.3 mm lateral and 44.2 ± 21.4 mm inferior, the splenius capitis at a point 10.0 ± 5.3 mm lateral and 59.2 ± 19.8 mm inferior, and SSC at a point 11.5 ± 9.9 mm lateral and 61.4 ± 15.3 mm inferior. Additionally, GON arose, winding up the obliquus capitis inferior, with the winding point located 52.3 ± 11.7 mm inferior to EOP and 30.2 ± 8.9 mm lateral to the midsagittal line. Knowing the course of GON and 3ON, from their emergence between vertebrae to the subcutaneous layer, is necessary for reliable nerve detection and precise analgesic injections. Moreover, stereotactic measurement using the 3D digitizer seems useful and accurate for neurovascular structure study.

Objective: Studying the three-dimensional (3D) anatomy of the cavernous sinus is essential for treating lesions in this region with skull base surgeries. Cadaver dissection is a conventional method that has insurmountable flaws with regard to understanding spatial anatomy. The authors' research aimed to build an image model of the cavernous sinus region in a virtual reality system to precisely, individually and objectively elucidate the complete and local stereo-anatomy., Methods: Computed tomography and magnetic resonance imaging scans were performed on 5 adult cadaver heads. Latex mixed with contrast agent was injected into the arterial system and then into the venous system. Computed tomography scans were performed again following the 2 injections. Magnetic resonance imaging scans were performed again after the cranial nerves were exposed. Image data were input into a virtual reality system to establish a model of the cavernous sinus. Observation results of the image models were compared with those of the cadaver heads., Results: Visualization of the cavernous sinus region models built using the virtual reality system was good for all the cadavers. High resolutions were achieved for the images of different tissues. The observed results were consistent with those of the cadaver head. The spatial architecture and modality of the cavernous sinus were clearly displayed in the 3D model by rotating the model and conveniently changing its transparency., Conclusion: A 3D virtual reality model of the cavernous sinus region is helpful for globally and objectively understanding anatomy. The observation procedure was accurate, convenient, noninvasive, and time and specimen saving.

Steady-state free precession (SSFP) magnetic resonance imaging (MRI) can demonstrate details down to the cranial nerve (CN) level. High-resolution three-dimensional (3D) visualization can now quickly be performed at the workstation. However, we are still limited by visualization on flat screens. The emerging technologies in rapid prototyping or 3D printing overcome this limitation. It comprises a variety of automated manufacturing techniques, which use virtual 3D data sets to fabricate solid forms in a layer-by-layer technique. The complex neuroanatomy of the CNs may be better understood and depicted by the use of highly customizable advanced 3D printed models. In this technical note, after manually perfecting the segmentation of each CN and brain stem on each SSFP-MRI image, initial 3D reconstruction was performed. The bony skull base was also reconstructed from computed tomography (CT) data. Autodesk 3D Studio Max, available through freeware student/educator license, was used to three-dimensionally trace the 3D reconstructed CNs in order to create smooth graphically designed CNs and to assure proper fitting of the CNs into their respective neural foramina and fissures. This model was then 3D printed with polyamide through a commercial online service. Two different methods are discussed for the key segmentation and 3D reconstruction steps, by either using professional commercial software, i.e., Materialise Mimics, or utilizing a combination of the widely available software Adobe Photoshop, as well as a freeware software, OsiriX Lite.

Chronic dry eye (keratitis sicca) is a significant problem that in certain populations can result in corneal desiccation and the potential for blindness. Therefore, novel treatments for such disorders might decrease patient morbidity. The present study aimed to investigate a potential treatment for chronic dry eye via a cadaveric feasibility study. On 10 cadaveric sides, the parotid gland branch of the auriculotemporal nerve (ATN) was identified and anastomosed to an anterior superficial temporal branch (STb) of this same nerve. The STb was then transposed anteriorly and sutured to the lacrimal gland. The parotid branch of the ATN was easily identified on all sides. The STb of the ATN was easily identified and mobilized on all sides. This latter nerve had adequate length to be moved to the ipsilateral lacrimal gland on all sides. Rerouting parotid gland secretomotor fibers to the superficial branch of the ATN and then moving this branch to the lacrimal gland is a feasible surgical maneuver based on our cadaveric study. Clinical studies are now necessary to show utility of this procedure in patients with chronic dry eye. Clin. Anat. 30:839-843, 2017. © 2017Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Background: Bochdalek's flower basket (Bfb) is the distal part of the horizontal segment of the fourth ventricle's choroid plexus protruding through the lateral aperture (foramen of Luschka). The microsurgical anatomy of the cerebellopontine angle, fourth ventricle and its inner choroid plexus is well described in the literature, but only one radiological study has investigated the Bfb so far. The goal of the present study was to give an extensive morphometric analysis of the Bfb for the first time and discuss the surgically relevant anatomical aspects., Method: Forty-two formalin-fixed human brains (84 cerebellopontine angles) were involved in this study. Photomicrographs with scale bars were taken in every step of dissection to perform further measurements with Fiji software. The lengths and widths of the Bfb, rhomboid lip and lateral aperture of the fourth ventricle as well as the related neurovascular and arachnoid structures were measured. The areas of two sides were compared with paired t-tests using R software. Significance level was set at p < 0.05., Results: Protruding choroid plexus was present in 77 cases (91.66%). In 6 cases (7.14%), the Bfb was totally covered by the rhomboid lip, and in one case (1.19%), it was absent. The mean width of the Bfb was 6.618 mm (2-14 mm), the mean height 5.658 mm (1.5-14 mm) and mean area 25.80 mm 2 (3.07-109.83 mm 2 ). There was no statistically significant difference between the two sides (p = 0.1744). The Bfb was in contact with 20 AICAs (23.80%), 6 PICAs (7.14%) and 39 vestibulocochlear nerves (46.42%). Arachnoid trabecules, connecting the lower cranial nerves to the Bfb or rhomboid lip, were found in 57 cases (67.85%)., Conclusions: The Bfb is an important landmark during various surgical procedures. Detailed morphology, dimensions and relations to the surrounding neurovascular structures are described in this study. These data are essential for surgeons operating in this region.

For more than 230 years, anatomical illustrations have faithfully reproduced the German medical student Thomas Soemmerring's cranial nerve (CN) arrangement. Virtually all contemporary atlases show the abducens, facial, and vestibulocochlear nerves (CNs VI-VIII) all emerging from the pontomedullary groove, as originally depicted by Soemmerring in 1778. Direct observation at microsurgery of the cerebellopontine angle reveals that CN VII emerges caudal to the CN VIII root from the lower lateral pons rather than the pontomedullary groove. Additionally, the CN VI root lies in the pontomedullary groove caudal to both CN VII and VIII in the vast majority of cases. In this high-resolution 3D MRI study, the exit location of CN VI was caudal to the CN VII/VIII complex in 93% of the cases. Clearly, Soemmerring's rostrocaudal numbering system of CN VI-VII-VIII (abducens-facial-vestibulocochlear CNs) should instead be VIII-VII-VI (vestibulocochlear-facial-abducens CNs). While the inaccuracy of the CN numbering system is of note, what is remarkable is that generations of authors have almost universally chosen to perpetuate this ancient error. No doubt some did this through faithful copying of their predecessors. Others, it could be speculated, chose to depict the CN relationships incorrectly rather than run contrary to long-established dogma. This study is not advocating that a universally recognized numbering scheme be revised, as this would certainly create confusion. The authors do advocate that future depictions of the anatomical arrangements of the brainstem roots of CNs VI, VII, and VIII ought to reflect actual anatomy, rather than be contorted to conform with the classical CN numbering system.

Objectives/hypothesis: To investigate the extent of carotid artery exposure attained, including the identification of the external carotid branches and lower cranial nerves in five sequential external approaches to the parapharyngeal space, and to provide an anatomical algorithm., Study Design: Anatomical study., Methods: Six latex-injected adult cadaver heads were dissected in five consecutive approaches: transcervical approach with submandibular gland removal, posterior extension of the transcervical approach, transcervical approach with parotidectomy, parotidectomy with lateral mandibulotomy, and parotidectomy with mandibulectomy. The degree of carotid artery exposure attained, external carotid branches, and lower cranial nerves visualized was documented., Results: The transcervical approach exposed 1.5 cm (Standard Deviation (SD) 0.5) of internal carotid artery (ICA) and 1.25 cm (SD 0.25) of external carotid artery (ECA). The superior thyroid and facial arteries and cranial nerve XII and XI were identified. The posterior extension exposed 2.9 cm (SD 0.7) of ICA and 2.7 cm (SD 1.0) of ECA. Occipital and ascending pharyngeal arteries were visualized. The transparotid approach exposed 4.0 cm (SD 1.1) of ICA and 3.98 cm (SD 1.8) of ECA. Lateral mandibulotomy exposed the internal maxillary artery, cranial nerve X, the sympathetic trunk, and 4.6 cm (SD 2.4) of ICA. Mandibulectomy allowed for complete ECA exposure, cranial nerve IX, lingual nerve, and 6.9 cm (SD 1.3) of ICA., Conclusion: Approaches for the parapharyngeal space must be based on anatomic and biological patient factors. This study provides a guide for the skull base surgeon for an extended approach based on the desired anatomic exposure., Level of Evidence: N/A. Laryngoscope, 127:585-591, 2017., (© 2017 The American Laryngological, Rhinological and Otological Society, Inc.)

Background: Exposure of the common trunk of the facial nerve has traditionally been approached based on principles of parotidectomy, which is associated with high rates of facial nerve palsy and landmarks that may be unreliable. On the basis of experience gained with vascularized composite allotransplantation of the face, the authors propose a retroauricular approach that may be more time-effective and safe., Methods: In the proposed retroauricular facial nerve approach, an incision is made posterior to the ear in the retroauricular sulcus, and dissection proceeds anteriorly to the mastoid fascia to the base of the conchal bowl. The anteroinferior edge of the external auditory canal is followed as a reference structure to locate the facial nerve trunk (FNT), coursing between the stylomastoid foramen (posteromedially) and entering the parotid gland (anteriorly). Twelve unilateral FNT dissections were performed in 6 fresh human cadaver heads. Six dissections were performed for illustration and proof of concept using full facial transplant, conventional, and limited retroauricular exposures; 6 additional dissections were performed by trainees to assess reliability and replicability of technique., Results: The FNT was successfully identified in all 12 dissections. Trainees tended toward being more time efficient in exploring the anatomy when using the limited retroauricular technique than with the conventional approach, 7.8 ± 0.78 minutes versus 13.0 ± 3.3 minutes (P = 0.089). No intraoperative injury to any critical structure was noted with either technique., Conclusion: A retroauricular approach to the FNT based on liberating anterior tissues from the auditory canal provides expedient and aesthetic exposure of the FNT.

Three systems, two sensory and one protective, are present in the skin of the living Australian lungfish, Neoceratodus forsteri, and in fossil lungfish, and the arrangement and innervation of the sense organs is peculiar to lungfish. Peripheral branches of nerves that innervate the sense organs are slender and unprotected, and form before any skeletal structures appear. When the olfactory capsule develops, it traps some of the anterior branches of cranial nerve V, which emerged from the chondrocranium from the lateral sphenotic foramen. Cranial nerve I innervates the olfactory organ enclosed within the olfactory capsule and cranial nerve II innervates the eye. Cranial nerve V innervates the sense organs of the snout and upper lip, and, in conjunction with nerve IX and X, the sense organs of the posterior and lateral head. Cranial nerve VII is primarily a motor nerve, and a single branch innervates sense organs in the mandible. There are no connections between nerves V and VII, although both emerge from the brain close to each other. The third associated system consists of lymphatic vessels covered by an extracellular matrix of collagen, mineralised as tubules in fossils. Innervation of the sensory organs is separate from the lymphatic system and from the tubule system of fossil lungfish., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Introduction: The anatomy of the accessory nerve has been well described but continued new clinical and anatomical findings exemplify our lack of a full understanding of the course of this nerve. Therefore, this study aimed to expand on our knowledge of the course of the 11th cranial nerve via anatomical dissections., Methods: Fifty-six cadavers (112 sides) underwent dissection of the accessory nerve from its cranial and spinal origins to its emergence into the posterior cervical triangle. Immunohistochemistry was performed when appropriate., Results: Our findings included two cases (1.8%) where the nerve was duplicated, one intracranially and one extracranially. One accessory nerve (0.9%) was found to enter its own dural compartment within the jugular foramen. The majority of sides (80%) were found to have a cranial root of the accessory nerve. Thirty-one sides (28%) had connections to cervical dorsal roots medially and three sides (2.7%) laterally. Medial connections were most common with the C1 nerve. Medial components of these dorsal root connections were all sensory in nature. However, lateral components were motor on two sides (1.8%). Nerves traveled anterior to the internal jugular vein on 88% of sides. One (0.9%) left side nerve joined an interneural anastomosis between the dorsal rootlets. Macroganglia were found on the spinal part of the intracranial nerve on 13% of sides. The lesser occipital nerve arose directly from the accessory nerve on two sides (1.8%) and communicated with the accessory nerve on 5.4% of sides. One side (0.9%) was found to communicate with the facial nerve with both nerves innervating the sternocleidomastoid muscle., Conclusions: Additional anatomical knowledge of the variants of the accessory nerve may benefit patient care when this nerve is pathologically involved.

Background: Tumors of the middle fossa or cavernous sinus (CS), or intraorbital tumors, can penetrate each other through the superior orbital fissure (SOF) or neighboring tissue. These complicated pathologies are often treated with highly invasive surgical procedures. In this article, we demonstrate surgical anatomic dissections of the CS, SOF, orbital apex (OA), and dura mater extending to the periorbita from the middle fossa, by performing an epidural dissection via a lateral orbitotomy approach, and discuss findings that may provide guidance during surgery in these regions., Methods: Lateral orbitotomy was performed on latex-injected cadaver heads by making a 2-cm skin incision lateral to the lateral canthus, drilling the lesser and greater sphenoid wings that form the SOF borders, and removing the bone section between the middle fossa and orbit. Dura mater from the middle fossa to the periorbita was exposed to perform anterior clinoidectomy. Meningeal dura was dissected from the endosteal dura, which forms the lateral wall of the CS, to expose the CS, SOF, and OA for dissections., Results: Changing the orientation of the microscope from posterior to anterior enabled regional control for dissection from the Gasserian ganglion to the OA. Cranial nerves that pass through the CS, SOF, and OA were dissected and exposed. The annular tendon was opened, revealing the oculomotor nerves and its branches, as well as the abducens and nasociliary nerves, which pass through the oculomotor foramen and course within the OA and orbit., Conclusions: This approach causes less tissue damage; provides control of the surgical area in spheno-orbital tumors invading the fissure and foramen by changing the orientation of the microscope toward the orbit, OA, SOF, CS, and middle fossa; and expands the indication criteria for lateral orbitotomy surgery. This approach, therefore, represents an alternative surgical method for excising complicated tumors in these regions.

The sphenopalatine ganglion is an extracranial neural structure within the pterygopalatine fossa. Modulation of this region via implantation of a neuromodulatory device presents a novel therapy for the treatment of facial and head pain. Yet sex, race, and genetic factors contribute to morphological variations between individuals. This study defines the standards and variations of the bony landmarks surrounding the pterygopalatine fossa. One hundred dry skulls were analyzed from the Hamann-Todd osteological collection. Ten anatomical dimensions were measured on each side of the face for each specimen (vidian foramen, zygomatic buttress, zygomatic maxillary suture, pyriform rim, infraorbital rim, pterygoid maxillary suture, greater palatine foramen, auditory canal, and pterygoid fossa). A statistical analysis was performed for both sides of the face based on sex and race. When stratified by sex, 7 of the 10 measurements revealed a statistically significant difference bilaterally. When stratified by race, 5 of the 10 measurements demonstrated a statistically significant difference bilaterally. Both male and African American skulls showed greater hemifacial values bilaterally when compared with their respective counterparts. The only statistically significant measurement on both the left and right sides of all skulls was the length from the vidian foramen to the infraorbital rim. Defining the anatomical mean distance between skull landmarks and highlighting differences between sex and race not only provides further insight into relative skull anatomy, but also sets the stage for device innovation.

Background: The brainstem comprises a large variety of fiber tracts and nerve nuclei and is unarguably one of the most crucial parts of the brain. Reliable noninvasive visualization of its anatomy may help relate normal and pathological anatomic variations to neurologic/psychiatric disorders. In this study, we explored the potential of direction-encoded track-density imaging (TDI) for depicting the intricate anatomy of the brainstem., Methods: A total of 18 healthy volunteers (10 females, 8 males; median age, 34.5 years; interquartile range, 31-44.5 years) were examined on a 3-T MRI system. Diffusion tensor imaging data were processed using MRtrix to generate TDI images. These images were then compared with anatomic atlases to identify nerve nuclei and fiber tracts. The ability of TDI to delineate anatomic structures in the mesencephalon, pons, and medulla oblongata was evaluated using a 6-point Likert scale (5, excellent; 4, good; 3, moderate; 2, poor; 1, no adequate differentiation; 0, evaluation not possible)., Results: All generated TDI images were evaluable without limitations. In the mesencephalon, delineation of the substantia nigra, crus cerebri, and red nucleus was rated as excellent, that of the medial lemniscus was rated as good, and that of the inferior colliculus was rated as poor. Delineation of all anatomic structures in the pons was rated as excellent. In the medulla oblongata, delineation of the pyramid was rated as excellent and that of the medial lemniscus as moderate, whereas delineation of the inferior olive was not possible., Conclusions: TDI images provide optimal delineation of nerve nuclei and fibers in the upper brainstem, but have more difficulty identifying more caudal structures., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Morphometric measurements of cranial nerves in posterior cranial fossa of fetus cadavers were carried out in an attempt to identify any asymmetry in their openings into the cranium. Twenty-two fetus cadavers (8 females, 14 males) with gestational age ranging between 22 and 38 weeks (mean 30 weeks) were included in this study. The calvaria were removed, the brains were lifted, and the cranial nerves were identified. The distance of each cranial nerve opening to midline and the distances between different cranial nerve openings were measured on the left and right side and compared. The mean clivus length and width were 21.2 ± 4.4 and 13.2 ± 1.5 mm, respectively. The distance of the twelfth cranial nerve opening from midline was shorter on the right side when compared with the left side (6.6 ± 1.1 versus 7.1 ± 0.8 mm, p = 0.038). Openings of other cranial nerves did not show such asymmetry with regard to their distance from midline, and the distances between different cranial nerves were similar on the left and right side. Cranial nerves at petroclival region seem to show minimal asymmetry in fetuses.

While our knowledge about the senses of pinnipeds has increased over the last decades almost nothing is known about the organization of the neuroanatomical pathways. In a first approach to this field of research, we assessed the total number of myelinated axons of three cranial nerves (CNs) in the harbor (Phoca vitulina, Pv) and hooded seal (Cystophora cristata, Cc). Axons were counted in semithin sections of the nerves embedded in Epon and stained with toluidine blue. In both species, the highest axon number was found within the optic nerve (Pv 187,000 ± 8,000 axons, Cc 481,600 ± 1,300 axons). Generally, considering absolute axon numbers, far more axons were counted within the optic and trigmenial nerve (Pv 136,700 ± 2,500 axons, Cc 179,300 ± 6,900 axons) in hooded in comparison to harbor seals. The axon counts of the vestibulocochlear nerve are nearly identical for both species (Pv 87,100 ± 8,100 axons, Cc 86,600 ± 2,700 axons). However, when comparing cell density, the cell density is almost equal for all nerves for both species except for the optic nerve in which cell density was particularly higher than in the other nerves and higher in hooded in comparison to harbor seals. We here present the first comparative analysis of three CNs in two phocid seals. While the CNs of these closely related species share some general characteristics, pronounced differences in axon numbers/densities are apparent. These differences seem to reflect differences in e.g. size, habitat, and/or functional significance of the innervated sensory systems., (© 2015 Wiley Periodicals, Inc.)

In veterinary medicine, the cognitive skills necessary to interpret neurological disorders from text-based case descriptions may not translate into the diagnostic capabilities required for clinical neurological patients. As live animals exhibiting certain specific neurological disorders are infrequent during a student's exposure to clinics, students may graduate without the experience necessary to make an accurate diagnosis in the field. To address this, we have developed a computerized simulated dog head that can exhibit cranial nerve dysfunctions and respond to specific testing procedures in a clinically accurate manner. To evaluate whether this type of model could add value to traditional student assessments, we created a multiple-choice quiz system with three types of questions: standard text-based cases, videos of an expert performing an examination of the simulated dog, and an interactive version requiring the student to perform an appropriate examination of the simulated dog to uncover the lesion localization. In an experiment conducted with 97 freshman veterinary students who had recently been taught cranial nerve anatomy and function, we found that examination performance decreased with the need for interactivity compared to memorization of fact, while satisfaction increased. Students were less likely to identify the correct disorder when they had to conduct the examination of the virtual dog themselves, revealing an inadequacy in traditional neuroanatomical teaching. However, students overwhelmingly supported the use of interactive question for assessment. Interestingly, performance on text-based questions did not correlate significantly with interactive or video questions. The results have implications for veterinary teaching and assessment within the classroom and in clinical environments.

Riojasuchus tenuisceps Bonaparte 1967 is currently known from four specimens, including two complete skulls, collected in the late 1960s from the upper levels of the Los Colorados Formation (Late Triassic), La Rioja, Argentina. Computed tomography (CT) scans of the skulls of the holotype and a referred specimen of Riojasuchus tenuisceps and the repreparation of the latter allows recognition of new features for a detailed analysis of its cranial anatomy and its comparison with a wide variety of other archosauriform taxa. The diagnosis of Riojasuchus tenuisceps is emended and two autapomorphies are identified on the skull: (1) a deep antorbital fossa with its anterior and ventral edges almost coinciding with the same edges of the maxilla itself and (2) a suborbital fenestra equal in size to the palatine-pterygoid fenestra. Also, the first digital 3D reconstruction of the encephalon of Riojasuchus tenuisceps was carried out to study its neuroanatomy, showing a shape and cranial nerve disposition consistent to that of other pseudosuchians.

Face and neck: airway and sensorial capacities. For the assessment and the management of face and neck trauma knowledge of the neuro-anatomy and physiology of the ear, nose, throat (ENT) and head and neck (HN) region and structures is essential, as this area is particularly vulnerable to injury. Indeed, the complex anatomy and physiology in this specific area supports important basic functions. In addition, this review elaborates on upper airway and sensorial capacities. Upper airway dimensions are influenced by bony and soft tissues. Age is of fundamental importance in the upper airway assessment, as significant differences in size and proportions apply in children and adults. The cranial nerves (CN) supply motor, sensory ad special sensory fibres to the upper airway. Injury of the CN is a frequent complication of trauma.

Recent studies have highlighted the mechanism of vascular and axonal guidance to ensure proper morphogenesis and organogenesis. We aimed to perform global mapping of developing neurovascular networks during craniofacial development of embryonic mice. To this end, we developed histology-based three-dimensional (3D) reconstructions using paraffin-embedded serial sections obtained from mouse embryos. All serial sections were dual-immunolabeled with Pecam1 and Pgp9.5/Gap43 cocktail antibodies. All immunolabeled serial sections were digitized with virtual microscopy to acquire high spatial resolution images. The 3D reconstructs warranted superior positional accuracy to trace the long-range connectivity of blood vessels and individual cranial nerve axons. It was feasible to depict simultaneously the details of angiogenic sprouting and axon terminal arborization and to assess quantitatively the locoregional proximity between blood vessels and cranial nerve axons. Notably, 3D views of the craniofacial region revealed the following: Branchial arch arteries and blood capillary plexi were formed without accompanying nerves at embryonic day (E) 9.5. Cranial nerve axons began to grow into the branchial arches, developing a labyrinth of small blood vessels at E10.5. Vascular remodeling occurred, and axon terminals of the maxillary, mandibular, chorda tympani, and hypoglossal nerve axons had arborized around the lateral lingual swellings at E11.5. The diverged patterning of trigeminal nerves and the arterial branches from the carotid artery became congruent at E11.5. The overall results support the advantage of dual-immunolabeling and 3D reconstruction technology to document the architecture and wiring of the developing neurovascular networks in mouse embryos., (© 2015 Wiley Periodicals, Inc.)

Cranial nerve (CN) knowledge is essential for students in health professions. Gestures and body movements (e.g., mime) have been shown to improve cognition and satisfaction with anatomy teaching. The aim of this pilot study was to compare the effectiveness of didactic lecturing with that of miming lecturing for student learning of the CNs. The research design involved exposure of the same group of students to didactic followed by miming lecturing of CNs. The effectiveness of each lecturing strategy was measured via pre- and post-testing. Student perceptions of these strategies were measured by a survey. As an example of miming, gestures for CN VII included funny faces for muscles of facial expression, kangaroo vocalization for taste, spitting action for saliva production, and crying for lacrimal gland production. Accounting for extra duration of the miming lecture, it was shown that pre- to post-test improvement was higher for the miming presentation than for the didactic (0.47 ± 0.03 marks/minute versus 0.33 ± 0.03, n = 39, P < 0.005). Students perceived that the miming lecture was more interactive, engaging, effective, and motivating to attend (mean on five-point Likert scale: 4.62, 4.64, 4.56, 4.31, respectively) than the didactic lecture. In the final examination, performance was better (P < 0.001, n = 39) on the CN than on the non-CN questions-particularly for students scoring ≤60%. While mediating factors need elucidation (e.g., learning due to repetition of content), this study's findings support the theory that gestures and body movements help learners to acquire anatomical knowledge., (© 2015 The Authors. Published by Wiley Periodicals, Inc. on behalf of the American Association of Anatomists.)

The posterior deep temporal nerve (PDTN) groove accommodates the posterior deep temporal nerve and is infrequently described. This area is important for some clinical procedures including mandibular nerve blockade. This study assesses the prevalence and morphological variations of the PDTN groove in a single population, investigating its relationship with basicranial angle to assess predictive value for the existence of this feature. The infratemporal regions of 101 contemporary Sinhalese Sri Lankan skulls were examined bilaterally and ordinally scored for PDTN groove morphology (six point scale); 11 random skulls were radiographed and basicranial angles measured. Descriptive statistics and significance testing (P < 0.05) were used for analysis, including symmetry (Wilcoxon matched-pairs signed rank test), sex differences (Mann and Whitney U test), and between basicranial angle and PDTN morphology (Pearson's product-moment correlation coefficient). Ninety skulls (44 males) were included for analysis (180 sides). PDTN groove morphology on individual sides ranged from non-existent (20.6%) to partial (5.6%) and complete canals (1.1%); 93.3% of skulls had a PDTN groove or canal. Skulls exhibited bilateral symmetry (P = 0.12) and males had significantly deeper PDTN grooves or canals (P = 0.018). Basicranial flexion correlated strongly with PDTN groove or canal prevalence (P = 0.0028). Sri Lankan skulls have a high prevalence of PDTN grooves and also canals, a feature not previously described. Prevalence was related significantly to sex but not symmetry, and PDTN grooves and canals correlated significantly with basicranial angle. Knowledge of this morphology is important for some clinical procedures, anthropological assessment, and as a location for PDTN entrapment.

The detailed morphology and topography of the cranial cervical ganglion (CCG) with its surrounding structures were studied in 10 sides of five heads of adult one-humped camel to determine its general arrangement as well as its differences and similarities to other animals. The following detailed descriptions were obtained: (1) the bilateral CCG was constantly present caudal to cranial base at the rostroventral border of the occipital condyle over the caudolateral part of nasopharynx; (2) the CCG was always in close relations medially with the longus capitis muscle, rostrolaterally with the internal carotid artery, and caudally with the vagus nerve; and (3) the branches of the CCG were the internal carotid and external carotid nerves, jugular nerve, cervical interganglionic branch, laryngopharyngeal branch, carotid sinus branch and communicating branches to the vagus, and first spinal nerves. In conclusion, there was no variation regarding topography of dromedary CCG among the specimens, in spite of typical variations in number, and mainly in origin of nerve branches ramifying from the CCG. In comparative anatomy aspect, the close constant relations, and presence of major nerves (internal/external carotid and jugular nerves) of dromedary CCG exhibited a typical reported animal's pattern. However, the shape, structures lateral to the CCG, the origin and course pattern of external carotid and jugular nerves, the number of the major nerves branches, the communicating branches of the CCG to the spinal and cranial nerves, and the separation of most rostral parts of vagosympathetic trunk of dromedary were different from those of most reported animals., (© 2015 Wiley Periodicals, Inc.)

Aim: The major aim of the present anatomical study was to demonstrate the anatomical structures that can be visualized using the supraorbital keyhole approach, both endoscopically and microscopically, from an eyebrow incision to intracranial structures. Furthermore, it defines an optimal craniotomy for surgery., Methods: Fine dissection was performed on each side of 5 formalin-fixed adult cadavers according to the surgical procedures of the supraorbital keyhole approach, and each step was documented both endoscopically and microscopically. Furthermore, the distance between the superior temporal line and the supraorbital notch/foramen was measured from the 10 total sides of the 5 cadavers and from the 118 sides of the 59 autopsies., Results: Tumors and aneurysms of the anterior cranial fossa can be visualized during the supraorbital keyhole approach. The average distance between the superior temporal line and the supraorbital notch/foramen was measured. The distance obtained from the autopsies on the 25 females was 31.56 ± 4.03  mm on the right side and 31.04 ± 5.40  mm on the left side. The average distance obtained from the autopsies on the 34 males was 34.00 ± 4.59  mm on the right side and 33.59 ± 5.41  mm on the left side. There was no statistically significant difference between right and left in the female and male autopsies or between sexes., Conclusions: This anatomical study showed that structures in the anterior and middle cranial fossa can be reached via the supraorbital keyhole craniotomy approach with minimal brain retraction and adequate exposure and with minimal craniotomy size.

For accurate interpretation of magnetic resonance (MR) images of the equine brain, knowledge of the normal cross-sectional anatomy of the brain and associated structures (such as the cranial nerves) is essential. The purpose of this prospective cadaver study was to describe and compare MRI and computed tomography (CT) anatomy of cranial nerves' origins and associated skull foramina in a sample of five horses. All horses were presented for euthanasia for reasons unrelated to the head. Heads were collected posteuthanasia and T2-weighted MR images were obtained in the transverse, sagittal, and dorsal planes. Thin-slice MR sequences were also acquired using transverse 3D-CISS sequences that allowed mutliplanar reformatting. Transverse thin-slice CT images were acquired and multiplanar reformatting was used to create comparative images. Magnetic resonance imaging consistently allowed visualization of cranial nerves II, V, VII, VIII, and XII in all horses. The cranial nerves III, IV, and VI were identifiable as a group despite difficulties in identification of individual nerves. The group of cranial nerves IX, X, and XI were identified in 4/5 horses although the region where they exited the skull was identified in all cases. The course of nerves II and V could be followed on several slices and the main divisions of cranial nerve V could be distinguished in all cases. In conclusion, CT allowed clear visualization of the skull foramina and occasionally the nerves themselves, facilitating identification of the nerves for comparison with MRI images., (© 2015 American College of Veterinary Radiology.)

Introduction: Posterior nasal neurectomy is an effective way of treating recalcitrant rhinitis. The aim of this study is to describe the anatomic relationship between the posterior inferior nasal nerve (PINN) and the structures that might be important for posterior nasal neurectomy., Materials and Methods: An anatomic study was conducted in a university hospital dissection laboratory with 15 formalin-fixed, sagittally cut adult cadaver heads. The distance between PINN and (1) nasal sill, (2) maxillary sinus ostium, (3) posterior fontanel, (4) torus tubarius, and (5) crista ethmoidalis was measured and the location of PINN with respect to the sphenopalatine artery was assessed to define the exact location of PINN., Results: The mean distance between PINN and nasal sill (56.4 mm), maxillary sinus ostium (27 mm), posterior fontanel (12.5 mm), torus tubarius (13 mm), and crista ethmoidalis (8 mm) was determined. PINN was found consistently posterior to the sphenopalatine artery where the inferior turbinate attaches to the lateral nasal wall., Conclusion: Instead of finding PINN around the sphenopalatine foramen, PINN can be located more easily posterior to the sphenopalatine artery where the inferior turbinate attaches to the lateral nasal wall without cauterizing the sphenopalatine artery.

Our objective was to construct a 3D, interactive, and reference atlas of the extracranial vasculature spatially correlated with the intracranial blood vessels, cranial nerves, skull, glands, and head muscles.The atlas has been constructed from multiple 3T and 7T magnetic resonance angiogram (MRA) brain scans, and 3T phase contrast and inflow MRA neck scans of the same specimen in the following steps: vessel extraction from the scans, building 3D tubular models of the vessels, spatial registration of the extra- and intracranial vessels, vessel editing, vessel naming and color-coding, vessel simplification, and atlas validation.This new atlas contains 48 names of the extracranial vessels (25 arterial and 23 venous) and it has been integrated with the existing brain atlas.The atlas is valuable for medical students and residents to easily get familiarized with the extracranial vasculature with a few clicks; is useful for educators to prepare teaching materials; and potentially can serve as a reference in the diagnosis of vascular disease and treatment, including craniomaxillofacial surgeries and radiologic interventions of the face and neck., (© The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)

Aim: To describe the origin, the course, and relationships of the labyrinthine artery (LA)., Material and Methods: Thanks to a colored silicone mix preparation, ten cranial bases were examined using x3 to x40 magnification under surgical microscope., Results: The LA often arose from the meatal loop of the anterior inferior cerebellar artery (AICA) (90%), or basilar artery (10%). The loop was extra-meatal of the internal auditory meatus (IAM) in 30%, at the opening of the internal auditory meatus in 20%, or intra-meatal in 35%. The AICA coursed in closed relationship to the VII and VIII cranial nerves. It coursed between VII and VIII cranial nerve roots in 85%, or passed over the ventral side of both VII and VIII cranial nerve. The average diameter of the LA was 0.2 +/- 0.05 mm. LA was single trunk in 60%, and bi-arterial in 40%., Conclusion: The implication of these anatomic findings for cerebello-pontine angle tumors surgery and neurovascular pathology such as infarction, aneurysm of the LA or the AICA are reviewed and discussed.

Background: The posterolateral sulcus (PLS) is an important surgical landmark, especially for DREZ (dorsal root entry zone) operations., Methods: The present study aimed to show the variations of the PLS using human spinal cord histological sections and report the variability in the number of dorsal rootlets of the spinal nerves in each the spinal cord segment. Further, measure the height and width of the dorsal horn on histological sections for cervical, thoracic, and lumbar levels., Results: The results of the present study showed various patterns of PLS 1.clearly present PLS, 2. short PLS, 3. absent PLS or 4. irregular PLS. Height and width measurements of the dorsal horn showed that the average width was greatest at lower cervical (0.48 ± 0.04 mm) and least at lower thoracic levels (0.41 ± 0.04 mm), whereas the average height was greatest at upper cervical (3.0 ± 0.06 mm) and smallest at lower lumbar levels (1.8 ± 0.08 mm). The average number of rootlets varied considerably, at cervical level it was 7.6 ± 1.4 mm, at thoracic 6.6 ± 0.8 mm and at lumbar 6.1 ± 0.4 mm., Conclusions: The detailed anatomy of the variations of the PLS and the average number of rootlets at each spinal level can increase the success of regional surgery. Further, fine measurements on histological sections can give detailed knowledge on the size necessary for lesioning in DREZ operations.

Purpose: Perineural invasion (PNI) is a frequent pathological finding in head and neck cancers. When adjuvant radiation to cranial nerves at risk in head and neck cancers with PNI is considered, there is a need for consensus on which nerves are at risk and how to contour these nerves. This contouring guide attempts to address this need., Methods and Materials: Representative patient diagnostic computed tomographic (CT) scans with contrast of the neck were used to create example contours. The cranial nerves V2, V3, VII, and XII, and sample primary tumor sites were initially delineated using the Varian Eclipse planning system by 5 radiation oncologists. All of the images were then reviewed with a diagnostic radiologist to establish consensus for delineating the cranial nerves., Results: We provided detailed contouring and planning guidelines on a CT atlas, with figures to help illustrate internerve connections, based on clinical experience, literature-based patterns of failure, and established anatomic connections between cranial nerves. Tumor bed, cranial nerve, and elective target volumes are depicted., Conclusions: These planning guidelines and atlas provide anatomic, clinical, and technical recommendations for guiding radiation oncologists in the planning and delivery of intensity modulated radiation therapy for head and neck cancer with PNI.

With continuous refinement of neurosurgical techniques and higher resolution in neuroimaging, the management of pontine lesions is constantly improving. Among pontine structures with vital functions that are at risk of being damaged by surgical manipulation, cranial nerves (CN) and cranial nerve nuclei (CNN) such as CN V, VI, and VII are critical. Pre-operative localization of the intrapontine course of CN and CNN should be beneficial for surgical outcomes. Our objective was to accurately localize CN and CNN in patients with intra-axial lesions in the pons using diffusion tensor imaging (DTI) and estimate its input in surgical planning for avoiding unintended loss of their function during surgery. DTI of the pons obtained pre-operatively on a 3Tesla MR scanner was analyzed prospectively for the accurate localization of CN and CNN V, VI and VII in seven patients with intra-axial lesions in the pons. Anatomical sections in the pons were used to estimate abnormalities on color-coded fractional anisotropy maps. Imaging abnormalities were correlated with CN symptoms before and after surgery. The course of CN and the area of CNN were identified using DTI pre- and post-operatively. Clinical associations between post-operative improvements and the corresponding CN area of the pons were demonstrated. Our results suggest that pre- and post-operative DTI allows identification of key anatomical structures in the pons and enables estimation of their involvement by pathology. It may predict clinical outcome and help us to better understand the involvement of the intrinsic anatomy by pathological processes., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Visualization of the complex courses of the cranial nerves by students in the health-related professions is challenging through either diagrams in books or plastic models in the gross laboratory. Furthermore, dissection of the cranial nerves in the gross laboratory is an extremely meticulous task. Teaching and learning the cranial nerve pathways is difficult using two-dimensional (2D) illustrations alone. Three-dimensional (3D) models aid the teacher in describing intricate and complex anatomical structures and help students visualize them. The study of the cranial nerves can be supplemented with 3D, which permits the students to fully visualize their distribution within the craniofacial complex. This article describes the construction and usage of a virtual anatomy platform in Second Life™, which contains 3D models of the cranial nerves III, V, VII, and IX. The Cranial Nerve Skywalk features select cranial nerves and the associated autonomic pathways in an immersive online environment. This teaching supplement was introduced to groups of pre-healthcare professional students in gross anatomy courses at both institutions and student feedback is included., (© 2014 American Association of Anatomists.)

Objective: To provide anantomical basis for the endoscope-assisted partial superficial parotidectomy via retroauricular hairline approach (EASPRHA) and assess its feasibility and safety., Method: The surgical anatomy of retroauricular hairline region and parotid gland region were observed in 15 fresh human cadavers (30 halves). The EASPRHA was performed on 5 human cadavers (10 halves). After the procedure, the related vascular and neural structures were evaluated., Result: The retroauricular hairline region extends between superficial musculoaponeurotic system and superficial cervical fascia. On the superficial surface of the upper sternocleidomastoid lie the lesser occipital nerve, the great auricular nerve and the external jugular vein. The bifurcation of great auricular nerve is(22.85 ± 2.01) mm from the bottom of earlobe. The parotid gland region extends between parotidomassteric fascia and parotid gland parenchyma. The facial nerve emerging from the stylomastoid foramen runs across the superficial surface of base of styloid process, passes through the interspace between cartilage of external acoustic meatus and posterior belly of digastric muscle, and enters the parotid gland. The bifurcation of facial nerve trunk is (19.10 ± 3.10)mm from the mastoidale and (39.49 ± 5.78) mm from the mandibular angle. Above the posterior belly of digastric muscle, the posterior auricular artery arises from the posterior wall of the external carotid artery with its main stem running over the superficial surface of facial nerve trunk. In all endoscope-assisted operations, the partial superficial parotidectomy was successful without the need for an additional incision. No major neurovascular damage wasobserved., Conclusion: A thorough knowledge of the surgical anatomy of retroauricular hairline region and parotid gland region is an essential requirement in performing the safe and feasible EASPRHA.

Background: One of the authors' encounter with one of Sigmund Freud's original works about the anatomy of the human brain stem and his interest in the scientist, anatomist, philosopher, writer and revolutionary Georg Büchner led to re-examination and review of the original writings of two major 19th century protagonists of brain anatomy research. The aim of the authors is to highlight the achievements of both Freud and Büchner in the field of comparative brain morphology., Methods: The medical and philosophical publications of Georg Büchner were reviewed with reference to the historical-critical edition of his complete works and writings (the so-called Marburg edition). Evaluation of the neuroanatomical achievements of Sigmund Freud was based on a summary of his publications and also partially on his autobiographical writings., Results: After careful review of their publications both Freud and Büchner should be acknowledged as brain scientists focusing particularly on comparative morphology. Both chose fish as the subject of their macroscopic (Büchner) and microscopic (Freud) neuroanatomical studies, and both cut across their own language and cultural space by continuing their work in France. In interpreting their findings both were influenced by their respective contemporary methodological schools of thought. Büchner became a soul scientist/psychologist by turning to the writing of literary texts, heralding the end of his idealistic and metaphysical interpretation of life. Likewise, Freud increasingly devoted himself to the destiny of man and his "conditio humana," eventually turning away from anatomical brain research., Conclusion: Review of the biographies and medical-scientific, as well as philosophical publications, of Georg Büchner and Sigmund Freud reveal striking parallels between the two researchers in addition to common insights that have generally been ignored or only marginally addressed in the past. Both should be appreciated and remembered as forerunners of today's neuroscientific community.

The vertebrate hindbrain develops as a series of well-defined neuroepithelial segments or rhombomeres. While rhombomeres are visible in all vertebrate embryos, generally there is not any visible segmental anatomy in the brains of adults. Teleost fish are exceptional in retaining a rhombomeric pattern of reticulospinal neurons through embryonic, larval, and adult periods. We use this feature to map more precisely the segmental imprint in the reticular and motor basal hindbrain of adult goldfish. Analysis of serial sections cut in three planes and computer reconstructions of retrogradely labeled reticulospinal neurons yielded a segmental framework compatible with previous reports and more amenable to correlation with surrounding neuronal features. Cranial nerve motoneurons and octavolateral efferent neurons were aligned to the reticulospinal scaffold by mapping neurons immunopositive for choline acetyltransferase or retrogradely labeled from cranial nerve roots. The mapping corresponded well with the known ontogeny of these neurons and helps confirm the segmental territories defined by reticulospinal anatomy. Because both the reticulospinal and the motoneuronal segmental patterns persist in the hindbrain of adult goldfish, we hypothesize that a permanent "hindbrain framework" may be a general property that is retained in adult vertebrates. The establishment of a relationship between individual segments and neuronal phenotypes provides a convenient method for future studies that combine form, physiology, and function in adult vertebrates., (Copyright © 2014 Wiley Periodicals, Inc.)

Introduction: The purpose of this paper is to assess the value of 7 Tesla (7 T) MRI for the depiction of brain stem and cranial nerve (CN) anatomy., Methods: Six volunteers were examined at 7 T using high-resolution SWI, MPRAGE, MP2RAGE, 3D SPACE T2, T2, and PD images to establish scanning parameters targeted at optimizing spatial resolution. Direct comparisons between 3 and 7 T were performed in two additional subjects using the finalized sequences (3 T: T2, PD, MPRAGE, SWAN; 7 T: 3D T2, MPRAGE, SWI, MP2RAGE). Artifacts and the depiction of structures were evaluated by two neuroradiologists using a standardized score sheet., Results: Sequences could be established for high-resolution 7 T imaging even in caudal cranial areas. High in-plane resolution T2, PD, and SWI images provided depiction of inner brain stem structures such as pons fibers, raphe, reticular formation, nerve roots, and periaqueductal gray. MPRAGE and MP2RAGE provided clear depiction of the CNs. 3D T2 images improved depiction of inner brain structure in comparison to T2 images at 3 T. Although the 7-T SWI sequence provided improved contrast to some inner structures, extended areas were influenced by artifacts due to image disturbances from susceptibility differences., Conclusions: Seven-tesla imaging of basal brain areas is feasible and might have significant impact on detection and diagnosis in patients with specific diseases, e.g., trigeminal pain related to affection of the nerve root. Some inner brain stem structures can be depicted at 3 T, but certain sequences at 7 T, in particular 3D SPACE T2, are superior in producing anatomical in vivo images of deep brain stem structures.