Histologic confirmation of neuronal cell bodies along the spinal accessory nerve.

INTRODUCTION: Most sources conclude that the spinal accessory nerve (SAN) is a purely motor nerve. There are some reports that suggest a sensory component, although the exact nature of such sensory fibers has yet to be elucidated. With such discrepancies in the literature and with well-established pain syndromes of unknown etiology following SAN injury, the authors performed the present study to better clarify this anatomy. MATERIALS AND METHODS: The entire accessory nerve was harvested from 10 adult cadavers. Samples were then submitted for immunohistochemical analyses. RESULTS: Occasional microganglia cells were identified along the SAN in all specimens. These ganglia were most numerous along the intracranial segment of the SAN, but none was found along the cranial rootlets of the accessory nerve. CONCLUSIONS: Neuronal cell bodies were identified along the course of the SAN in human cadavers. Although the function is not certain, such cells have been found in other animals to be nocioceptive in nature. Pending further study, these cells may be found to be involved in enigmatic pain syndromes thought to arise in the sternocleidomastoid and trapezius muscles.

The development of a core syllabus for the teaching of head and neck anatomy to medical students.

The study of human anatomy has traditionally served as a fundamental component in the basic science education of medical students, yet there exists a remarkable lack of firm guidance on essential features that must be included in a gross anatomy course, which would constitute a "Core Syllabus" of absolutely mandatory structures and related clinical pathologies. While universal agreement on the details of a core syllabus is elusive, there is a general consensus that a core syllabus aims to identify the minimum level of knowledge expected of recently qualified medical graduates in order to carry out clinical procedures safely and effectively, while avoiding overloading students with unnecessary facts that have less immediate application to their future careers as clinicians. This paper aims to identify consensus standards of essential features of Head and Neck anatomy via a Delphi Panel consisting of anatomists and clinicians who evaluated syllabus content structures (greater than 1,000) as "essential", "important", "acceptable", or "not required." The goal is to provide guidance for program/course directors who intend to provide the optimal balance between establishing a comprehensive list of clinically relevant essential structures and an overwhelming litany, which would otherwise overburden trainees in their initial years of medical school with superficial rote learning, which potentially dilutes the key and enduring fundamental lessons that prepare students for training in any medical field.

Amyand's hernia: a review.

Abstract Amyand's hernia is defined as when the appendix is trapped within an inguinal hernia. While the incidence of this type of hernia is rare, the appendix may become incarcerated within Amyand's hernia and lead to further complications such as strangulation and perforation. Incarceration of the appendix most commonly occurs within inguinal and femoral hernias, but may arise to a lesser extent in incisional and umbilical hernias. Incarcerated appendix has been reported in a variety of ventral abdominal and inguinal locations, yet its indistinct clinical presentation represents a diagnostic challenge. This paper reviews the literature on incarceration of the appendix within inguinal hernias and discusses current approaches to diagnosis and treatment of Amyand's hernia and complications that may arise from incarceration of the appendix within the hernia.

Thoracic outlet syndrome: a neurological and vascular disorder.

Thoracic outlet syndrome (TOS) is a condition arising from compression of the subclavian vessels and/or brachial plexus as the structures travel from the thoracic outlet to the axilla. Despite the significant pathology associated with TOS, there remains some general disagreement among experts on the specific anatomy, etiology, and pathophysiology of the condition, presumably because of the wide variation in symptoms that manifest in presenting patients, and because of lack of a definitive gold standard for diagnosis. Symptoms associated with TOS have traditionally been divided into vascular and neurogenic categories, a distinction based on the underlying structure(s) implicated. Of the two, neurogenic TOS (nTOS) is more common, and typically presents as compression of the brachial plexus; primarily, but not exclusively, involving its lower trunk. Vascular TOS (vTOS) usually involves compression of the vessel, most commonly the subclavian artery or vein, or is secondary to thrombus formation in the venous vasculature. Any anatomical anomaly in the thoracic outlet has the potential to predispose a patient to TOS. Common anomalies include variations in the insertion of the anterior scalene muscle (ASM) or scalenus minimus muscle, the presence of a cervical rib or of fibrous and muscular bands, variations in insertion of pectoralis minor, and the presence of neurovascular structures, which follow an atypical course. A common diagnostic technique for vTOS is duplex imaging, which has generally replaced more invasive angiographic techniques. In cases of suspected nTOS, electrophysiological nerve studies and ASM blocks provide guidance when screening for patients likely to benefit from surgical decompression of TOS. Surgeons generally agree that the transaxillary approach allows the greatest field of view for first rib excision to relieve compressed vessels. Alternatively, a supraclavicular approach is favored for scalenotomies when the ASM impinges on surrounding structures. A combined supraclavicular and infraclavicular approach is preferred when a larger field of view is required. The future of TOS management must emphasize the improvement of available diagnostic and treatment techniques, and the development of a consensus gold standard for diagnosis. Helical computed tomography offers a three-dimensional view of the thoracic outlet, and may be valuable in the detection of anatomical variations, which may predispose patients to TOS. This review summarizes the history of TOS, the pertinent clinical and anatomical presentations of TOS, and the commonly used diagnostic and treatment techniques for the condition.

Tectal plate gliomas: a review.

INTRODUCTION: Tectal plate gliomas are generally benign neoplastic lesions arising in the brainstem which can, with local extension, obstruct the aqueduct of Sylvius and lead to hydrocephalus. ANATOMY: Diagnosis is based on initial suspicion fostered by the presentation of an obstructive hydrocephalus followed by physical exam which may potentially reveal indications of pyramidal tract dysfunction or cranial nerve palsies. DISCUSSION: MRI studies reveal a characteristic well-circumscribed, isodense or hypodense mass on T1-weighted images, with hyperdensity on T2 imaging. Yet current radiological methods insufficiently distinguish tectal plate gliomas from brainstem tumors or gliomas in the neighboring structures, and a definitive diagnosis requires biopsy and histopathological analysis. Management is planned according to the degree of associated signs and symptoms, and may range from diligent observation and periodic screening for advancing tumor development, to cerebrospinal fluid shunting in an effort to resolve obstructive hydrocephalus, to radio- and chemotherapy. A wide range of minimally invasive approaches using endoscopy is available for the neurosurgeon, including endoscopic third ventriculostomy and endoscopic aqueductoplasty.

The clinical anatomy of the coronary arteries.

There are a manifold number of variations and anomalies of the origin and course of coronary arteries described in the literature. The incidence of such variations in the general population is reported to range between 0.3 and 1.6 %. Although uncommon, they may be benign or produce symptoms ranging from mild dyspnea to sudden cardiac death, and have been associated with an increased risk of accelerated atherosclerosis and perfusion defects. Thus, in order to effectively utilize the increasing number of therapeutic options available for treating coronary artery diseases, an appreciation of the likely normal and variable arrangements of the coronary arteries is essential. This review will describe the normal anatomy of the coronary arteries as well as the common variations with potential clinical effects.

Scalp dermoids: a review of their anatomy, diagnosis, and treatment.

BACKGROUND: Scalp dermoid cysts are subcutaneous sacs lined with a stratified squamous epithelium containing developmentally mature ectodermal tissues, including skin, hair follicles, sweat glands, and sebaceous glands. METHODS: Because they consist of developmentally mature tissues, scalp dermoid cysts are generally benign. Typically, cysts are limited to an extracranial location, and management generally involves simple surgical resection. DISCUSSION: Because of the potential for intracranial and/or intradural extension associated with some scalp dermoids, however, a comprehensive clinical evaluation incorporating MRI and CT imaging is included in the diagnostic process.