Adult polyglucosan body disease: an acute presentation leading to unmasking of this rare disorder.

INTRODUCTION: Adult polyglucosan body disease (APBD) is an autosomal recessive leukodystrophy caused by abnormal intracellular accumulation of glycogen byproducts. This disorder is linked to a deficiency in glycogen branching enzyme-1 (GBE-1). Neurologic manifestations include upper and lower motor neuron signs, dementia, and peripheral neuropathy. APBD is typically a progressive disease. In this report, we discuss a novel case of APBD in a patient who had a sudden onset of spastic quadriparesis preceded by gradual difficulty with gait. Genetic and postmortem analysis confirmed the diagnosis of APBD. CASE REPORT: A 65-year-old man was evaluated for a new-onset of spastic quadriparesis, right-gaze preference, and left-sided beat nystagmus. Magnetic resonance imaging (MRI) of the brain revealed areas of white matter hyperintensities most prominent in the brainstem and periventricular regions. MRI of the cervical spine showed marked cord atrophy. Laboratory workup and cerebrospinal fluid analysis were unremarkable. Genetic testing supported the diagnosis of APBD due to GBE-1 deficiency. Postmortem analysis showed multiple white matter abnormalities suggestive of a leukodystrophy syndrome, and histopathologic testing revealed abnormal accumulation of polyglucosan bodies in samples from the patient's central nervous system supporting the diagnosis of APBD. CONCLUSION: APBD is a rare disorder that can affect the nervous system. The diagnosis can be confirmed with a combination of genetic testing and pathologic analysis of affected brain tissue.

Classifications of Odontoid Process Fractures: A Systematic Review and Proposal of a New Simplified Classification System Based on Embryology.

Odontoid fractures are the most common cervical spine fractures in the elderly. Although many classification systems have been developed for them, the ambiguity in various definitions can potentially lead to misunderstandings. This paper aims to review the terminologies and current classification systems of odontoid fractures and propose a new, simplified anatomical classification. Given the descriptive variability of odontoid fractures in current classifications, we systematically reviewed the literature using PRISMA guidelines querying the National Library of Medicine PubMed database. The initial literature search yielded 175 publications. A total of seven reports met the inclusion criteria and were ultimately included for a full review. The classification systems previously used to categorize fractures of the odontoid process often need to be more transparent, imprecise, and incongruous. To simplify them, a new embryologically accurate system is proposed. A new embryological and anatomically-based system, combining the former systems' specific attributes, allows a more straightforward and adaptable classification of odontoid fractures.

Stiff-person syndrome: an atypical presentation and a review of the literature.

Introduction: Stiff-person syndrome (SPS) is a rare autoimmune neurological disorder associated with muscle rigidity and spasms. A number of antibodies have been associated with disorder, including anti-glutamic acid decarboxylase and anti-amphiphysin.Case report; In this report, we present a rare case of a 79-year-old woman who presented with bilateral lower extremity weakness who was ultimately diagnosed with stiff-limb syndrome, a rare variant of SPS. Extensive laboratory and CSF studies were unrevealing. Electromyography showed significant peroneal motor neuropathy and complex repetitive discharges in the left tibialis anterior muscle. Antibodies to glutamic acid decarboxylase were significantly elevated at 124 units/mL. She was subsequently started on oral diazepam with significant improvement in her symptoms.Conclusion: The presentation of SPS can vary based on epidemiologic factors, clinical symptoms, and associated disorders. These forms can have overlapping features which may make the categorization of patients into one of these forms challenging.

Venous Drainage of Lumbar Vertebral Bodies: Anatomic Study with Application to Kyphoplasty, Vertebroplasty, and Pedicle Screw Complications.

BACKGROUND: Bone cement augmentation with polymethylmethacrylate is a reliable method for stabilizing osteoporotic compression fractures and improving fixation of pedicle screws. However, cement extrusion into the vertebral venous system can result in pulmonary cement embolism. The goal of this anatomic study was to identify the relationship between the internal/external vertebral plexus and neighboring abdominal caval system. METHODS: Thirty-two lumbar vertebral levels were used in this study. Anterior abdominal dissection was performed to access the lumbar vertebral bodies through the peritoneal cavity, and a 16-gauge needle was placed into the center of each lumbar vertebral body at its anterior aspect. Fluoroscopy was used to confirm if the needle was correctly placed. Next, latex and/or continuous air injections were performed into each lumbar vertebral level (L1-L5). Observations confirmed if the latex or air traveled into the inferior vena cava. In addition, the spinal canal was opened to see if any latex was found to enter inside the vertebral canal in cadavers injected with the latex. RESULTS: Latex or air was found to flow into the inferior vena cava at all the lumbar vertebral levels. The latex/air was not observed in the spinal canal in any specimen. CONCLUSIONS: An exact knowledge of the lumbar vertebral venous anatomy is essential when procedures that could affect the vertebral venous system are involved. Its complexity and anatomic variability necessitate such an understanding to better prevent/understand possible complications associated with polymethylmethacrylate extrusion.

Effect of a small-group, active learning, tutorial-based, in-course enrichment program on student performance in medical physiology.

Physiology is one of the major foundational sciences for the medical curriculum. This discipline has proven challenging for students to master due to ineffective content acquisition and retention. Preliminary data obtained from a survey completed by "low-performance" students (those maintaining a grade average below the passing mark of 70%) at Morehouse School of Medicine reported that students lacked the ability to adequately recognize and extract important physiological concepts to successfully navigate multiple-choice assessments. It was hypothesized that a specially designed, small-group, active learning, physiology in-course enrichment program would minimize course assessment failure rates by enhancing the ability of low-performance students to effectively identify important course content, successfully perform on multiple-choice assessments, and, thereby, improve overall course performance. Using self-report surveys, study skills and test-taking deficiencies limiting successful comprehension of course material and examination performance were identified. Mini-quiz assessments and assignments in formulating multiple-choice examination questions were given to help students recognize and solidify core concepts and improve test-taking ability. Lastly, self-report surveys evaluated the effectiveness of the enrichment program on overall course performance. Results showed a marked improvement in student confidence levels with regards to approaching multiple-choice assessments, and a significant improvement in grades achieved in the physiology component of the first-year curriculum, as 100% of participants achieved a final passing grade average of ≥70%. It was concluded that students became more proficient in identifying, understanding, and applying core physiological concepts and more successful in mastering multiple-choice questions.

The Accessory Nerve: A Comprehensive Review of its Anatomy, Development, Variations, Landmarks and Clinical Considerations.

INTRODUCTION: The eleventh cranial nerve, the accessory nerve, has a complex and unique anatomy and has been the subject of much debate. Herein, we review the morphology, embryology, surgical anatomy, and clinical manifestations of the accessory nerve. Included in this review, we mention variant anatomy, molecular development, histology, and imaging of the accessory nerve. CONCLUSIONS: The accessory nerve continues to be a topic of much discussion regarding its exact function and in particular to its cranial roots. Recently, various surgical procedures have been devised that repurpose the accessory nerve (e.g., lengthening procedures, contralateral neurotization procedures). Currently, we continue to learn and have much to learn about this lower cranial nerve. Anat Rec, 302:620-629, 2019. © 2018 Wiley Periodicals, Inc.

Arcuate Foramen: Anatomy, Embryology, Nomenclature, Pathology, and Surgical Considerations.

BACKGROUND: The arcuate foramen is an anatomic variant that is thought to arise from ossification of the posterior atlanto-occipital membrane. Owing to potential entrapment of the vertebral artery segment that traverses the foramen, vertebrobasilar ischemia may occur, and the person may experience vertigo, headache, or neck pain. METHODS: We reviewed the literature regarding anatomy (both human and comparative), embryology, nomenclature, pathology, and surgery of the arcuate foramen. RESULTS: Surgically, the presence of an arcuate foramen is important when placing screws into lateral masses of the atlas. In these cases, the screws can damage the V3 segment of the vertebral artery and/or the suboccipital nerve. CONCLUSIONS: It is important to review the current literature on the arcuate foramen to further understand its morphology and clinical relevance.

Embryology and pathophysiology of the Chiari I and II malformations: A comprehensive review.

Although the Chiari malformations are well-studied and described developmental anomalies, there remains some incongruity in regards to their underlying etiologies. A number of theories have been proposed with the purpose of accounting for the embryology and pathogenesis of the Chiari I and II malformations and their associated complications and clinical syndromes. The present review aims to review the pertinent literature for all of the main theories that have been proposed, and outline their validity and relevance to our contemporary understanding of these anomalies. Clin. Anat. 31:202-215, 2018. © 2017 Wiley Periodicals, Inc.

Gerbode defect: A comprehensive review of its history, anatomy, embryology, pathophysiology, diagnosis, and treatment.

The purpose of this paper is to survey the literature on Gerbode defect and provide an overview of its history, anatomy, development, pathophysiology, diagnosis, and treatment options. The available literature on this topic, including case reports, was thoroughly reviewed. Gerbode defect is defined as abnormal shunting between the left ventricle and right atrium resulting from either a congenital defect or prior cardiac insults. The pathophysiology underlying the development of Gerbode defect is a disease process that injures the atrioventricular septum and leads to the abnormal shunting of blood. Although the most prevalent cause of Gerbode defect has historically been congenital, an increasing trend towards acquired cases has recently been reported owing to improved diagnostic capabilities and a greater number of invasive cardiac procedures. In conclusion, Gerbode defect is an increasingly recognized condition that warrants further study.

Anterior Fontanelle Wormian Bone/ Fontanellar Bone: A Review of this Rare Anomaly with Case Illustration.

Wormian bones are a relatively rare skeletal anomaly that present as accessory bone(s) within the sutures of the cranium and even more rarely within the fontanelles. It is believed that they arise from the formation of abnormal cranial ossification centers. Although not extensively reported in the literature, this anomaly is thought to be associated with other anatomical anomalies such as osteogenesis imperfecta, rickets, and other bone dysplasias. When located within the fontanelles, the most likely site of occurrence is the posterior fontanelle. This case report describes a rare incidence of wormian bone within the anterior fontanelle of an infant who had concurrent craniosynostosis. More research and reporting of this anomaly is necessary to verify any correlated syndromes, and determine the underlying etiology.

A comprehensive review of the foramina of Luschka: history, anatomy, embryology, and surgery.

PURPOSE: The purpose of this review is to comprehensively review the foramina of Luschka in regard to their discovery, embryology, anatomy, and surgical relevance. METHODS: This subject review of the foramina of Luschka was composed after conducting a thorough review of the available literature on this topic using PubMed and other primary sources. RESULTS: The foramina of Luschka are paired apertures located in the lateral recesses of the fourth ventricle, within the posterior cranial fossa. The foramina of Luschka are of importance clinically as their blockage can disrupt the flow of cerebrospinal fluid leading to the development of hydrocephalus. These apertures were first described by the German anatomist Hubert von Luschka in the nineteenth century. These foramina are thought to emerge at around the 26th week of development. The apertures project into the cerebellopontine angle at the lateral border of the pontomedullary sulcus. CONCLUSION: The foramina of Luschka may be surgically manipulated for the excision of tumors involving the fourth ventricle and surrounding structures and accessed for cochlear nucleus stimulation.

"Political co-authorships" in medical science journals.

The issue of co-author relationships on medical sciences journal publications has become more pronounced as advances in technology have enabled collaboration across countries and institutions to occur much more efficiently. These relationships often have underlying political motivations and outcomes, including career advancement, attempting to increase prestige of a project, and maintaining research grants. Some authors may be listed as senior or honorary authors despite offering little or no contribution to the original research project. This may be done in an effort to enhance the gravitas of a research project, and attain publication in a highly regarded medical journal. The current review covers the topic of political co-authorship and germane literature and lists strategies to combat this phenomenon. Such co-authorship practices corrupt the integrity of the research process as they attempt to bypass the safeguard that medical journals and institutions have put in place to prevent fraud and falsification. A number of strategies have been proposed to combat the practice of co-authorship, but it may ultimately be an unavoidable feature of contemporary medical research publishing that is difficult to police. Clin. Anat. 30:831-834, 2017. © 2017Wiley Periodicals, Inc.

Beware of the predatory science journal: A potential threat to the integrity of medical research.

The issue of predatory journals has become increasingly more prevalent over the past decade, as the open-access model of publishing has gained prominence. Although the open-access model is well intentioned to increase accessibility of biomedical research, it is vulnerable to exploitation by those looking to corrupt medical academia and circumvent ethics and research standards. Predatory journals will achieve publication by either soliciting unsuspecting researchers who have legitimate research but fall victim to these predators or researchers looking to quickly publish their research without a thorough review process. Some features of predatory journals are a quick non-peer-review process, falsely listing or exaggerating the credibility of editorial board members, and either lack of or falsification of institutional affiliations and database listings. These predatory journals are a serious threat to the integrity of medical research, as they will infect the available literature with unsubstantiated articles, and allow low-quality research. A number of steps can be taken to prevent the spread and increase awareness of predatory publishers, and these must be done to maintain the integrity of medical academia. Clin. Anat. 30:767-773, 2017. © 2017Wiley Periodicals, Inc.

The vertebral nerve: A comprehensive review of its form and function.

The literature is littered with variable and scant reports of the vertebral nerve. The present paper reviews the literature regarding this nervous structure of the neck and attempts to clarify a number of issues surrounding its form, function, and implications of surgical manipulation. The nerve may arise from the stellate ganglion or the ansa subclavia, amongst a number of other structures. Additionally, the terminal insertion of the vertebral nerve varies in the reported literature, with authors observing various terminations. Animal models of the vertebral nerve have limited value, as variations between species and with species have been observed. This review also indicates that contradictory evidence exists regarding the clinical implications of vertebral nerve damage. Although irritation may result in ocular disturbance, hearing loss, headaches, and dizziness, a high degree of incongruity exists around whether or not any clinical findings will actually be observed. Based on our review of the available literature and recent cadaveric research, it appears it may be more logical to classify the vertebral nerve as a variable ramus communicans that connects the stellate or inferior cervical ganglia to the lower cervical spinal nerves and not a structure that ascends entirely with the vertebral artery to enter the cranium.

The Dens: A Review of its Diverse Nomenclature and a Recommended Simplified Terminology.

Pathology of the dens, such as fractures, demands precise terminology so that communication between physicians are succinct, diagnoses are accurate, and treatment strategies exact. This review aims to summarize the various terms used to describe the parts of the dens and recommend the ideal terminology. Using standard search engines, English language publications were searched for the many terms used to describe parts of the dens. A multitude of terms was identified with many demonstrating overlaps. Terms identified included apex, tip, apicodental, subdental, dentocentral and odontocentral junctions, peg, waist, base, neck, shaft, shoulder, and stem. Exact terminology is necessary when diagnosing or treating patients with pathology of or near the dens. The authors suggest simplified terminology for describing the parts of the dens that can be used in the future in order to be unequivocal and to avoid confusion when classifying and communicating fractures through its parts.

Detethering of the C2 Nerve Root and Avoidance of Transection and Injury During C1 Screw Placement: A Cadaveric Feasibility Study.

INTRODUCTION: Regional neurovascular structures must be avoided during invasive spine hardware placement. During C1 lateral mass screw placement, the C2 nerve root is put in harm's way. Therefore the current anatomic study was performed to identify techniques that might avoid such neural injury. MATERIALS AND METHODS: On 10 cadaveric sides, dissection was carried down to the craniocervical junction. The C2 nerve root was identified, and its distal branches were traced out into the surrounding posterior cervical musculature. Once dissected, the nerve was displaced inferiorly away from the lateral mass of C1. RESULTS: On all sides, the C2 nerve root could be easily detethered from surrounding tissues. On all sides, this allowed lateral mass screw placement without compression of the nerve. CONCLUSION: On the basis of our cadaveric study, the C2 nerve root can be detethered enough at the level of the posterior lateral mass of C1 to avoid its injury during screw placement into this area.

Hemivertebrae: a comprehensive review of embryology, imaging, classification, and management.

PURPOSE: The purpose of this paper was to comprehensively review hemivertebrae in regard to their classification, embryology, etiology, diagnosis, clinical manifestations, and management of this developmental anomaly. METHODS: This subject review of hemivertebrae was composed after conducting a thorough review of the available literature on this topic using PubMed and other standard search engines. RESULTS: Hemivertebrae are incomplete vertebral column segments that can result in congenital scoliosis and be associated with a range of other structural anomalies. Presentations may differ and based on location and classification, treatments may vary. CONCLUSION: Hemivertebrae are structural anomalies of the vertebral column that can potentially disrupt the spine's normal curvature. Their clinical impact depends on factors such as degree of segmentation and concurrence with other structural anomalies. It is hoped that this review will provide the clinician who treats patients with hemivertebrae a resource in better understanding this finding and its subsequent pathological effects.

Bergmann's ossicle (ossiculum terminale persistens): a brief review and differentiation from other findings of the odontoid process.

PURPOSE: The purpose of this paper was to review the literature on Bergmann's ossicle and provide an overview on its development, etiology, and clinical presentation while also differentiating it from similar structural anomalies. METHODS: A thorough review of the literature available on Bergmann's ossicle was performed. RESULTS: Bergmann's ossicle, also referred to as ossiculum terminale persistens, was defined as a developmental anomaly of the odontoid process in which an ossification center that gives rise to the tip of the dens fails to fuse properly with the body of the axis. CONCLUSION: Bergmann's ossicle is most often a benign condition, although it rarely may present with clinical symptoms such as neck pain and neurological signs. It may be associated with Down's syndrome and contribute to atlantoaxial instability.