Landmarks for the greater petrosal nerve

The anatomy of the greater petrosal nerve while within the middle cranial fossa is lacking in the English literature and must be well understood by the surgeon who operates in this area. Twenty-two sides from six female and five male cadavers were examined. Measurements were made between the greater petrosal nerve as it coursed through the middle cranial fossa and surrounding structures such as the arcuate eminence and lateral wall of the middle cranial fossa. Mean distances from the arcuate eminence to the hiatus of the greater petrosal nerve into the middle cranial fossa measured 17.5 mm (SD = 2.2). The length of this nerve within the middle fossa was approximately 10 mm (SD = 2). From the lateral wall of the middle fossa to a midpoint of the greater petrosal nerve mean distances measured 39 mm (SD = 2.4). The mean distance from the foramen spinosum to the exit of this nerve inferior to the trigeminal ganglion measured 7 mm (SD = 1.8). These measurements will hopefully aid the surgeon who wishes to expose or avoid the greater petrosal nerve within the middle cranial fossa.     

Carotid endarterectomy: Importance of cranial nerve anatomy

A retrospective study of 100 consecutive cases of carotid endarterectomy was performed. Special attention was given to the incidence, clinical significance, and prevention of cranial nerve injury. The operative mortality was 1%, and there were no perioperative strokes. There was clinical evidence of 22 cranial nerve injuries. Nineteen injuries were temporary, resulting in a 3% incidence of permanent cranial nerve deficit. The clinical anatomy of cranial nerves encountered during carotid endarterectomy is reviewed. Technical suggestions to minimize cranial nerve injury based on a thorough knowledge of this anatomy are provided. The relationship of laryngeal physiology and vagus nerve anatomy indicates that unilateral vocal cord dysfunction may be asymptomatic. Bilateral nerve injury can cause potentially fatal airway obstruction, which may be unrecognized until after the second operation. Preoperative laryngoscopy prior to carotid endarterectomy is suggested in patients with a history of prior cardiac or neck surgery and those scheduled for the second of staged bilateral carotid procedures.     

颞骨原发性恶性肿瘤颅神经侵犯的CT与MR影像学评估

目的 探讨颞骨原发恶性肿瘤颅神经侵犯的CT与MR影像学表现。方法 回顾性分析2010年1月-2018年12月中山大学附属第一医院颞骨原发性恶性肿瘤中合并颅神经侵犯的23例患者的CT、MR影像学资料。其中男15例、女8例,年龄3~80岁;出现颅神经功能障碍17例,包括面神经受累症状者15例,外展神经功能障碍者2例。观察颞骨恶性肿瘤神经侵犯的部位、神经根穿行孔道及神经根的形态、信号及强化等颅神经受侵的CT、MR表现,及其与临床症状、手术病理结果的关系。结果 CT、MRI显示颅神经受侵23例,其中面神经受侵22例,三叉神经受侵5例,展神经、舌咽神经、迷走神经受侵各2例,听神经、副神经、舌下神经受侵各1例。颅神经受侵征象:CT显示面神经管扩大破坏22例,圆孔、卵圆孔骨壁、岩尖三叉神经压迹破坏各2例,颈静脉孔、舌下神经管破坏各1例;MRI显示颅神经增粗、强化8例,神经根干与周围软组织强化影紧贴但未完全包绕3例,神经被肿瘤包绕14例。23例CT、MRI显示的神经受侵患者中出现相应神经症状者17例,占73.9%。同时行CT及MRI检查的16例患者中,CT和MRI影像显示的受累神经分别为19、23根,CT、MRI诊断与临床手术病理一致分别为18、22根,其诊断符合率分别为81.8%(18/22)、95.7%(22/23)。结论 颞骨恶性肿瘤容易出现颅神经侵犯,且以面神经受侵最常见。颅神经受侵CT表现为神经穿行孔道破坏,MRI可直接显示神经增粗、异常强化,神经紧贴软组织影或神经直接被肿瘤包绕。结合CT和MRI的影像评估可以全面精准显示颅神经浸润情况,且MR较CT更为灵敏。     

Ⅵ～Ⅷ对脑神经生物塑化薄片断层解剖与MRI对照研究

目的 :对展神经、面神经、前庭蜗神经进行塑化切片与MRI对照研究 ,获得正常影像和断层解剖资料。方法 :采用生物塑化技术制作脑神经横断位 8例、矢状位和冠状位各 1例薄层切片 ,同时采用FLASH -3D序列完成头颅标本及 3 0例正常人脑干MR扫描 ,以MPR技术完整显示展神经、面神经、前庭蜗神经脑池段全程。结果 :塑化薄片断层、标本和活体MR扫描 ,脑神经行程、解剖形态均有良好的对应关系 ,Dorello管和展神经海绵窦段在塑化切片上显示良好 ,MRI仅能部分显示。结论 :生物塑化薄层切片能够对脑神经及相关结构进行准确显示 ,是脑神经影像学研究的重要对比方法     

Optic nerve choristoma

Choristomas are rare lesions that typically involve peripheral nerves and are marked by the presence of histologically normal tissue for an organ or body part other than the site at which it is located. Reports of choristoma involving cranial nerves are extraordinarily rare. We report a case of an optic nerve choristoma arising in a 24-year-old woman. The lesion was marked by a disordered admixture of smooth muscle tissue and optic nerve tissue. The literature on optic nerve choristoma is reviewed.     

Morphological characteristics of the cranial root of the accessory nerve

There has been the controversy surrounding the cranial root (CR) of the accessory nerve. This study was performed to clarify the morphological characteristics of the CR in the cranial cavity. Fifty sides of 25 adult cadaver heads were used. The accessory nerve was easily distinguished from the vagus nerve by the dura mater in the jugular foramen in 80% of 50 specimens. The trunk of the accessory nerve from the spinal cord penetrated the dura mater at various distances before entering the jugular foramen. In 20% of the specimens there was no dural boundary. In these cases, the uppermost cranial rootlet of the accessory nerve could be identified by removing the dura mater around the jugular foramen where it joined to the trunk of the accessory nerve at the superior vagal ganglion. The cranial rootlet was formed by union of two to four short filaments emerging from the medulla oblongata (66%) and emerged single, without filament (34%), and usually joined the trunk of the accessory nerve directly before the jugular foramen. The mean number of rootlets of the CR was 4.9 (range 2–9) above the cervicomedullary junction. The CR of the accessory nerve was composed of two to nine rootlets, which were formed by the union of two to four short filaments and joined the spinal root of the accessory nerve. The CR is morphologically distinct from the vagus nerve, confirming its existence. Clin. Anat. 27:1167–1173, 2014. © 2014 Wiley Periodicals, Inc.     

Mapping sensory nerve communications between peripheral nerve territories

The human cutaneous sensory map has been a work in progress over the past century, depicting sensory territories supplied by both the spinal and cranial nerves. Two critical discoveries, which shaped our understanding of cutaneous innervation, were sensory dermatome overlap between contiguous spinal levels and axial lines across areas where no sensory overlap exists. These concepts define current dermatome maps. We wondered whether the overlap between contiguous sensory territories was even tighter: if neural communications were present in the peripheral nerve territories consistently connecting contiguous spinal levels? A literature search using peer‐reviewed articles and established anatomy texts was performed aimed at identifying the presence of communications between sensory nerves in peripheral nerve territories and their relationship to areas of adjacent and non‐adjacent spinal or cranial nerves and axial lines (lines of discontinuity) in the upper and lower limbs, trunk and perineum, and head and neck regions. Our findings demonstrate the consistent presence of sensory nerve communications between peripheral nerve territories derived from spinal nerves within areas of axial lines in the upper and lower limbs, trunk and perineum, and head and neck. We did not find examples of communications crossing axial lines in the limbs or lines of discontinuity in the face, but did find examples crossing axial lines in the trunk and perineum. Sensory nerve communications are common. They unify concepts of cutaneous innervation territories and their boundaries, and refine our understanding of the sensory map of the human skin. Clin. Anat. 27:681–690, 2014. © 2013 Wiley Periodicals, Inc.     

小儿脑神经发育监测的临床分析研究

目的通过对小儿脑神经发育系统监测的研究,了解早期发现高危异常儿并早期干预或康复治疗,对保障小儿脑神经生正常生长发育以及防止残障的重要作用。方法本院出生后的婴儿从28天开始建档,采用NBNA和儿心量表进行0-3岁系统脑神经发育监测,高危儿专案管理,对干预康复治疗小儿做好记录,本研究选取2007-2009年监测档案随机抽样做对照研究。结果小儿脑神经发育监测水平对照,正常组小儿与高危儿组脑神经发育水平有显著性差异,高危儿组落后人数较多。脑神经发育水平干预治疗组与未干预治疗组有显著性差异,未干预治疗组脑神经发育水平落后人数较干预治疗组明显多。结论开展小儿脑神经发育系统监测是一级预防,并且对发现高危儿脑损伤和发育偏离的早期诊断,早期干预治疗有重要意义,是减少小儿残障发生的关键措施。     

Anatomy of the cranial nerve foramina in the Risso's dolphin (Grampus griseus).

In the present study, we examined the cranial nerve foramina of Risso's dolphin (Grampus griseus). There were two distinguishable characters in the cranial nerve foramina compared with terrestrial mammals. One was that the foramen infraorbitale was composed of several holes, but not a single hole. They should therefore be termed foramina infraorbitales. The infraorbital nerves ran through these foramina, went into the 'melon' and then branched in a complicated fashion. The facial nerve innervated the muscles surrounding the melon. A well-developed infraorbital and facial nerve complex may control the melon. Another was the presence of a porus acusticus internus and independent tympano-periotic bone. The separate ear bone forced the vestibulocochlear and facial nerves to exit from the cranial cavity through the porus acusticus internus. The independent ear bone structure may shut off the noise from the cranial bone to the periotic bone with a true receptor of hearing. It may be an adaptation for an acute sense of hearing. Compared with other dolphins, the cranial foramina of Risso's dolphin are definitely separate. The structure of the foramina is similar to that of pilot whales, but not to dolphins, so that Grampus may be closely allied to pilot whales.     

The role of immunophilin ligands in nerve regeneration

Tacrolimus (FK506) is a widely used immunosuppressant in organ transplantation. However, it also has neurotrophic activity that occurs independently of its immunosuppressive effects. Other neurotrophic immunophilin ligands that do not exhibit immunosuppression have subsequently been developed and studied in various models of nerve injury. This article reviews the literature on the use of tacrolimus and other immunophilin ligands in peripheral nerve, cranial nerve and spinal cord injuries. The most convincing evidence of enhanced nerve regeneration is seen with systemic administration of tacrolimus in peripheral nerve injury, although clinical use is limited due to its immunosuppressive side effects. Local tacrolimus delivery to the site of nerve repair in peripheral and cranial nerve injury is less effective but requires further investigation. Tacrolimus can enhance outcomes in nerve allograft reconstruction and accelerates reinnervation of complex functional allograft transplants. Other non-immunosuppressive immunophilins ligands such as V-10367 and FK1706 demonstrate enhanced neuroregeneration in the peripheral nervous system and CNS. Mixed results are found in the application of immunophilin ligands to treat spinal cord injury. Immunophilin ligands have great potential in the treatment of nerve injury, but further preclinical studies are necessary to permit translation into clinical trials.     

Peripheral facial nerve communications and their clinical implications

The facial nerve (CN VII) nerve follows a torturous and complex path from its emergence at the pontomedullary junction to its various destinations. It exhibits a highly variable and complicated branching pattern and forms communications with several other cranial nerves. The facial nerve forms most of these neural intercommunications with branches of all three divisions of the trigeminal nerve (CN V), including branches of the auriculotemporal, buccal, mental, lingual, infraorbital, zygomatic, and ophthalmic nerves. Furthermore, CN VII also communicates with branches of the vestibulocochlear nerve (CN VIII), glossopharyngeal nerve (CN IX), and vagus nerve (CN X) as well as with branches of the cervical plexus such as the great auricular, greater, and lesser occipital, and transverse cervical nerves. This review intends to explore the many communications between the facial nerve and other nerves along its course from the brainstem to its peripheral branches on the human face. Such connections may have importance during clinical examination and surgical procedures of the facial nerve. Knowledge of the anatomy of these neural connections may be particularly important in facial reconstructive surgery, neck dissection, and various nerve transfer procedures as well as for understanding the pathophysiology of various cranial, skull base, and neck disorders.     

Anatomic variations in the course of the hypoglossal nerve: A case report

To achieve a successful surgical anatomy a detailed knowledge of regional anatomy and anatomical variations is an important fundamental. The extra cranial hypoglossal nerve has a well described course as it traverses the neck, and is frequently identified during neck dissection. This serves a guide to the surgeon of such atypical variations in anatomy to avoid injury to important structures during dissection. We are presenting a case report which demonstrates the extra cranial variation of Hypoglossal nerve.     

Autoradiographic demonstration of VIIIth nerve projections in Rana pipiens

The anterograde transport of radioactive amino acid was used to demonstrate the primary projections of the VIIIth cranial nerve in 5 leopard frogs. Projections were found to be limited to one contiguous termination field ipsilateral to the injected nerve. The most rostral projections were in the marginal cerebellar granular layer; the most caudal projections were slightly posterior to the entry of nerve X. These projections covered the dorsal, ventral, and caudal nuclei of nerve VIII that have been described by others. No projections were found outside this area.     

Microsurgical anatomy of the facial nerve trunk

Dissection and manipulation of the facial nerve (FN) trunk between its exit from the cranial base through the stylomastoid foramen (SMF) and its bifurcation is a critical step in various otologic, plastic and neurosurgical procedures. This study demonstrates the anatomical relationships and variability of the FN trunk with emphasis on some important morphometric data, particularly with relevance to hypoglossal-facial nerve anastomosis (HFA). Bilateral microsurgical dissection was performed on twenty-three human cadavers fixed with formalin. The whole trunk of the FN was exposed, its diameter at the SMF and its length were measured, its branches were observed and the site of its bifurcation was determined. Anastomotic connections with other nerves and blood supply of the trunk were studied. The FN invariably emerged from the cranial base through the SMF. Its diameter upon its emergence from the foramen was 2.66 +/- 0.55 mm. Two branches consistently originated from the trunk: the posterior auricular nerve and the nerve to the digastric muscle. Less consistent were the communicating branch with the glossopharyngeal nerve and the nerve to the stylohyoid muscle. The bifurcation of the FN occurred before its penetration into the parotid gland in 15% of cases and within the gland in 85%. The length of the FN trunk was 16.44 +/- 3.2 mm. Anastomoses between the FN and other nerves were observed in one-third of the dissections. The blood supply to the FN trunk was provided by the stylomastoid artery that was identified in 91% of cases. Understanding the microsurgical anatomy of the FN trunk is essential for performing any surgical procedure in the relevant region. Surgical implications of this study are presented with emphasis on HFA surgery.     

Metastatic hepatocellular carcinoma presenting as facial nerve palsy and facial pain

Facial nerve palsy due to temporal bone metastasis of hepatocellular carcinoma (HCC) has rarely been reported. We experienced a rare case of temporal bone metastasis of HCC that initially presented as facial nerve palsy and was diagnosed by surgical biopsy. This patient also discovered for the first time that he had chronic hepatitis B and C infections due to this facial nerve palsy. Radiation therapy greatly relieved the facial pain and facial nerve palsy. This report suggests that hepatologists should consider metastatic HCC as a rare but possible cause of new-onset cranial neuropathy in patients with chronic viral hepatitis.     

Developmental changes in nerve growth factor (NGF) binding and NGF receptor proteins trkA and p75 in the facial nerve

This study characterizes the temporal-spatial distribution of nerve growth factor (NGF) low (p75) and high-affinity (trkA) receptors in the facial nerve and geniculate ganglion (GG) of developing quail embryos (E-3 to E-14). We used ¹²⁵I-labeled NGF (¹²⁵I-NGF) to study binding dynamics in a temporal series of isolated primordia and an autoradiographic series of staged specimens to characterize the occurrence and distribution of NGF receptors in this cranial nerve and its ganglion. In addition, expression of trkA and p75 protein-like immunoreactivity in the facial nerve and GG was studied by Western blot, in order to distinguish between high- and low-affinity NGF receptors respectively. The quantitative study of binding show that isolated facial primordia ranging from E-3 to E-14 exhibit different levels of specific binding. High initial binding levels were observed on E-3 specimens, then an initial decrease on day 4 (E-4) followed by a steady increase from days E-4 to E-7. Maximum ¹²⁵I-NGF binding was achieved on E-7, followed by a steady decline in binding on days 8 (E-8) and 9 (E-9), reaching near background levels on day 10 (E-10) of development and until the oldest stage assayed (E-14). Most of the cells bearing NGF receptors appeared to be nonneuronal crest-derived cells, but some placode-derived neurons and motor fibers of the VIIth cranial nerve transiently expressed the ability to bind ¹²⁵I-NGF. The temporal pattern of p75 expression matches the pattern of quantitative binding of NGF, while the trkA expression is restricted to a few stages mainly E7 and E9, implying that most of the binding detected is via low-affinity receptors, except for a proportion of high-affinity receptors present at stages of maximum binding. This temporal pattern of NGF binding sites suggests that cells within the VIIth cranial nerve are responsive to and/or dependent upon NGF in vivo, so NGF may play a biological role during normal development of the facial nerve. In view of the developmental events that parallel the occurrence and type of NGF binding sites, we suggest that this role may be to modulate from earlier chemotaxis and cell proliferation to much later events, such as neuronal differentiation and neuron-glia interactions. The significance of these findings in regeneration during adult life remain to be investigated.     

视神经的断层解剖学研究及其临床意义

目的：为视神经的影像检查提供断层解剖学资料。方法：应用50侧成人头颅湿标本制成0.5mm的火棉胶连续切片，用计算机图像分析系统对36侧冠状位标本上的视神经进行测量。结果：视神经分颅内段、管内段、眶内段和球内段四部分。管内段从视神经管颅口到眶口逐渐变细，眶内段中点最细。结论：视神经的测量可在冠状面上进行，眶内段中点可作为测量标准。     

Emergence and distribution of the ilioinguinal nerve in the inguinal region: applications to the ilioinguinal anaesthetic block (about 100 dissections)

The variations in the emergence and distribution of the ilioinguinal nerve are the cause of the failures of the ilioinguinal block and the difficulties at interpreting the ilioinguinal nerve syndrome. In order to identify its variations and set reliable anatomical landmarks for performing the ilioinguinal block, we dissected 100 inguinal regions of 51 adult corpses. The nerve was absent in seven cases and double in one case. The ilioinguinal nerve emerged from the internal oblique muscle, passing at 1 ± 0.8 cm of the inguinal ligament and 3.33 ± 2 cm of the ventral cranial iliac spine. It appeared behind the inguinal ligament and/or the ventral cranial iliac spine in 19 cases and presented a common trunk with the iliohypogastric nerve in 13 cases. In 47 cases, the nerve appeared in the form of a single trunk. Sixteen modes of division and eight types of predominantly anterior scrotal topographic distribution could be noted. These results show the high variability of the emergence and the sensory distribution of the ilioinguinal nerve. They enable us to propose techniques for ilioinguinal block performance using more accurate anatomical landmarks formed by the inguinal ligament and the ventral cranial iliac spine and a better diagnostic approach of ilioinguinal neuropathies.     

The nerve supply of the human auricle

Knowledge of the innervation of the outer ear is crucial for surgery in this region. The aim of this study was to describe the system of the auricular nerve supply. On 14 ears of seven cadavers the complete course of the nerve supply was exposed and categorized. A heterogeneous distribution of two cranial branchial nerves and two somatic cervical nerves was found. At the lateral as well as the medial surface the great auricular nerve prevails. No region with triple innervation was found.