Typical brachial plexus: the legacy of a forgotten anatomist, Abram T. Kerr (1873-1938).

The brachial plexus, a complex network of nerves responsible for innervating the upper limb, exhibits remarkable anatomical variations. This editorial explores the composite drawing of a "typical" brachial plexus portrayed by Abram T. Kerr in 1918. This composite drawing of the typical brachial plexus stands as a critical contribution to the field of anatomy and surgery, and encapsulates the most prevalent patterns of formation, branching, and origins within the brachial plexus, offering a statistical map of its common variants. Kerr portrays the typical brachial plexus as a foundational resource for anatomists and medical professionals seeking to navigate the intricate landscape of this neural structure. It serves as a hypothetical model, reflecting the common arrangement of trunks, cords, and branches, shedding light on the typical composition of the plexus observed in most individuals. Beyond being a visual representation, the 'typical' brachial plexus provides a bridge between theoretical knowledge and practical applications, aiding in the identification of variations and deviations in surgical contexts. This composite drawing enhances our comprehension of the intricate and ever-evolving anatomy of the brachial plexus, reinforcing its role as a fundamental reference point for anatomical studies and clinical practice.

Lorenz Fries on the defense of Avicenna, the prince of physicians: Addressed to the medics of Germany (1530).

During the 14th century CE, a pivotal shift took place in the world of medicine as its epicenter transitioned from the Middle East to Europe. The emergence of the European Renaissance sparked skepticism regarding the significance of Avicenna's contributions to the advancement of medicine. This paper explores how the rise of secularization and the Renaissance in Europe marked significant cultural transformations, fostering the spread of literacy. These societal shifts influenced the trajectory of medical thought, and Avicenna's "Canon of Medicine" received both praise and condemnation amidst the evolving intellectual landscape. In this context, Lorenz Fries composed his "Defense of Avicenna," a testament to his profound admiration for Avicenna's legacy. This paper presents an English translation of Fries' 1530 work, and introduces Fries and Avicenna's "Canon," contextualizing Fries' defense within the broader rejection of Arab-language medical texts in the 16th century. It also explores Avicenna's influence on European medicine and anatomy during the Renaissance and highlights the enduring relevance of his contributions to the annals of science. Fries' defense underscores Avicenna's methodological acumen and emphasizes the importance of a robust theoretical foundation in medical practice. Avicenna's integration of Aristotelianism with Platonism highlighted the necessity of a rigorous method informed by theory in medical analysis. Fries' defense remains relevant today, particularly in advocating for systematic medical analysis against subjective approaches. Avicenna's medical philosophy seems nested within a larger, hopeful attempt to resolve the tensions between science or naturalism and religion or spiritualism. The rejection of Avicenna reflects broader conflicts between Aristotelian and Neoplatonic traditions, suggesting a complex interplay of secularization and theological influences in shaping medical thought during the Renaissance.

Covid-19 and kidney injury: Pathophysiology and molecular mechanisms.

The novel coronavirus (SARS-CoV-2) has turned into a life-threatening pandemic disease (Covid-19). About 5% of patients with Covid-19 have severe symptoms including septic shock, acute respiratory distress syndrome, and the failure of several organs, while most of them have mild symptoms. Frequently, the kidneys are involved through direct or indirect mechanisms. Kidney involvement mainly manifests itself as proteinuria and acute kidney injury (AKI). The SARS-CoV-2-induced kidney damage is expected to be multifactorial; directly it can infect the kidney podocytes and proximal tubular cells and based on an angiotensin-converting enzyme 2 (ACE2) pathway it can lead to acute tubular necrosis, protein leakage in Bowman's capsule, collapsing glomerulopathy and mitochondrial impairment. The SARS-CoV-2-driven dysregulation of the immune responses including cytokine storm, macrophage activation syndrome, and lymphopenia can be other causes of the AKI. Organ interactions, endothelial dysfunction, hypercoagulability, rhabdomyolysis, and sepsis are other potential mechanisms of AKI. Moreover, lower oxygen delivery to kidney may cause an ischaemic injury. Understanding the fundamental molecular pathways and pathophysiology of kidney injury and AKI in Covid-19 is necessary to develop management strategies and design effective therapies.

The Role of Cytokines in Nephrotic Syndrome.

Idiopathic nephrotic syndrome (INS) is an important primary glomerular disease characterized by severe proteinuria. Evidence supports a role for T cell dysfunction in the pathogenesis of INS. Glucocorticoids are the primary therapy for INS; however, steroid-resistant NS (SRNS) patients are at a higher risk of drug-induced side effects and harbor poor prognosis. Although the exact mechanism of the resistance is unknown, the imbalances of T helper subtype 1 (Th1), Th2, and regulatory T cells (Tregs) and their cytokines may be involved in the pathogenesis of glucocorticoid responsiveness. Up to now, no confirmed biomarkers have been able to predict SRNS; however, a panel of cytokines may predict responsiveness and identify SRNS patients. Thus, the introduction of distinctive cytokines as novel biomarkers of SRNS enables both preventions of drug-related toxicity and earlier switch to more effective therapies. This review highlights the impacts of T cell population imbalances and their downstream cytokines on response to glucocorticoid responsiveness state in INS.

Loss of consciousness at onset of aneurysmal subarachnoid hemorrhage in good-grade patients.

Loss of consciousness (LOC) at presentation with aneurysmal subarachnoid hemorrhage (aSAH) has been associated with early brain injury and poor functional outcome. The impact of LOC on the clinical course after aSAH deserves further exploration. A retrospective analysis of 149 aSAH patients who were prospectively enrolled in the Cerebral Aneurysm Renin Angiotensin Study (CARAS) between 2012 and 2015 was performed. The impact of LOC was analyzed with emphasis on patients presenting in excellent or good neurological condition (Hunt and Hess 1 and 2). A total of 50/149 aSAH patients (33.6%) experienced LOC at presentation. Loss of consciousness was associated with severity of neurological condition upon admission (Hunt and Hess, World Federation of Neurosurgical Societies (WFNS), Glasgow Coma Scale (GCS) grade), hemorrhage burden on initial head CT (Fisher CT grade), acute hydrocephalus, cardiac instability, and nosocomial infection. Of Hunt and Hess grade 1 and 2 patients, 21/84 (25.0%) suffered LOC at presentation. Cardiac instability and nosocomial infection were significantly more frequent in these patients. In multivariable analysis, LOC was the predominant predictor of cardiac instability and nosocomial infection. Loss of consciousness at presentation with aSAH is associated with an increased rate of complications, even in good-grade patients. The presence of LOC may identify good-grade patients at risk for complications such as cardiac instability and nosocomial infection.

The History of Discovery of Adult Neurogenesis.

The scientific community's understanding of neuronal plasticity has evolved considerably over recent decades, thanks largely to Josef Altman. Altman's findings laid the groundwork for an entire subfield of neuroscience research dedicated to exploring the potential of the adult brain to create new neurons, which until then had been considered impossible. From the formative years of this field until the 1990s, when adult neurogenesis was finally accepted as a legitimate topic of study, Altman's work was followed by a series of pivotal discoveries by a handful of other dedicated neuroscientists such as Shirley Bayer, Michael Kaplan, and Fernando Nottebohm. In any sphere of activity, some wish to maintain the status quo when change occurs; science is no different. For many years, influential figures in neuroscience dismissed and marginalized the concept of adult neurogenesis, sometimes going so far as to censor the studies and launch personal attacks against their proponents. Nevertheless, despite obstacles to their research, these scientists persisted and built upon one another's work. During the 1970s, Kaplan confirmed neurogenesis in the adult mammalian neocortex and also performed some of the first neurogenesis studies on primates. During the 1980s, Nottebohm drew on his fascination with the songs of canaries and finches to show that neurogenesis happens on a grand scale in the avian brain as well, regardless of age. Today, more than half a century after Altman's discovery, the adult neurogenesis field is growing rapidly and new research is realizing its potential to revolutionize treatment for neurodegenerative disorders and brain injuries. Clin. Anat. 32:41-55, 2019. © 2019 Wiley Periodicals, Inc.

Double dermal sinus tracts of the cervical and thoracic regions: a case in a 3-year-old child and review of the literature.

INTRODUCTION: Dermal sinus tracts are rare congenital abnormalities characterized by an epithelium-lined tract that extends from the subcutaneous tissue to the underlying thecal sac or neural tube. These developmental anomalies can present asymptomatically with a cutaneous dimple or with devastating complications including recurrent episodes of meningitis, or neurological complications including paralysis. Dermal sinus tracts generally occur as single lesions, and the presentation of midline double dermal sinus tracts of the cervical and thoracic regions has not been previously described. METHODS: Here, we present the case of a 3-year-old girl suffering from recurrent episodes of myelitis, paraparesis, and intramedullary intradural masses, who was diagnosed with double dermal sinus tracts of the cervical and thoracic regions. We also present a summary of all previous reported cases of multiple dermal sinus tracts. RESULTS: Our patient was successfully treated surgically and is now 2 years status post her last procedure with a significant improvement in her neurologic function and normal muscle strength and tone for her age, and there was no recurrence of her symptoms. CONCLUSIONS: Early treatment with prophylactic surgery should be performed when possible, but removal of these lesions once symptoms have arisen can also lead to success, as in the case presented here. Complete excision and intradural exploration is required to excise the complete tract.

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.

Embryology of the craniocervical junction and posterior cranial fossa, part II: Embryogenesis of the hindbrain.

Although pathology of the hindbrain and its derivatives can have life altering effects on a patient, a comprehensive review on its embryology is difficult to find in the peer-reviewed medical literature. Therefore, this review article, using standard search engines, seemed timely. The embryology of the hindbrain is complex and relies on a unique timing of various neurovascular and bony elements. Derailment of these developmental processes can lead to a wide range of malformations such as the Chiari malformations. Therefore, a good working knowledge of this embryology as outlined in this review of the hindbrain is important for those treating patients with involvement of this region of the central nervous system. Clin. Anat. 31:488-500, 2018. © 2018 Wiley Periodicals, Inc.

Embryology of the craniocervical junction and posterior cranial fossa, part I: Development of the upper vertebrae and skull.

Although the embryology of the posterior cranial fossa can have life altering effects on a patient, a comprehensive review on this topic is difficult to find in the peer-reviewed medical literature. Therefore, this review article, using standard search engines, seemed timely. The embryology of the posterior cranial fossa is complex and relies on a unique timing of various neurovascular and bony elements. Derailment of these developmental processes can lead to a wide range of malformations such as the Chiari malformations. Therefore, a good working knowledge of this embryology as outlined in this review of its bony architecture is important for those treating patients with involvement of this region of the cranium. Clin. Anat. 31:466-487, 2018. © 2018 Wiley Periodicals, Inc.

The role of endothelial nitric oxide synthase -786 T/C polymorphism in cardiac instability following aneurysmal subarachnoid hemorrhage.

INTRODUCTION: Cardiac abnormalities are observed frequently after aneurysmal subarachnoid hemorrhage (aSAH). A subset of aSAH patients develops neurogenic cardiomyopathy, likely induced by catecholamine excess. Genetic polymorphisms of the endothelial nitric oxide synthase (eNOS) gene have been linked to decreased nitric oxide (NO) levels, coronary artery spasm, and myocardial infarction. The role of the eNOS single nucleotide polymorphism (SNP) -786 T/C in cardiac instability following aSAH has not been previously investigated. METHODS: From 2012 to 2015, aSAH patients were prospectively enrolled in the Cerebral Aneurysm Renin Angiotensin System (CARAS) study at two academic institutions. Blood samples were used to assess the eNOS SNP -786 T/C rs2070744 through 5'exonuclease (Taqman) genotyping assays. Associations between this polymorphism and cardiac instability following aSAH were analyzed. RESULTS: Multivariable analysis demonstrated a dominant effect of the C allele of eNOS SNP -786 T/C on cardiac instability in patients with aSAH. A lower Glasgow Coma Scale score and a history of ischemic vascular disease were also associated with cardiac instability. Furthermore, cardiac instability independently predicted poor functional outcome upon discharge from the hospital. CONCLUSIONS: The C allele of the eNOS SNP -786 T/C was independently associated with an increased risk for cardiac instability following aSAH. Cardiac instability itself was a risk factor for an unfavorable functional outcome upon discharge from the hospital.

The Chiari 3.5 malformation: a review of the only reported case.

INTRODUCTION: In 1894, Giuseppe Muscatello described what we believe to be the only case of an occipitocervical encephalocele with a communication to the stomach. This case and its history and context compared to the Chiari 3 malformation as described 3 years earlier by Hans Chiari are presented. CONCLUSIONS: Based on the uniqueness of this case, we propose the term Chiari 3.5 malformation be used to describe its anatomical derailment.

The Roman Empire legacy of Galen (129-200 AD).

INTRODUCTION: Galen of Pergamum was the physician of Roman Emperors and contributed to our early understanding of medicine and anatomy. Herein, we present a short biography of Galen and review his multiple contributions to medicine and anatomy. CONCLUSIONS: Although it has been almost 2,000 years since Galen walked the streets of the Roman Empire, his legacy continues via multiple eponyms that bare his name.

Humphrey Ridley (1653-1708): forgotten neuroanatomist and neurophysiologist.

Humphrey Ridley is a little known character in the history of anatomy and physiology. Born in 1653, Ridley was a physician and anatomist who followed the research done by Willis, Vieussens, and Galen. Outside of a cursory knowledge of his birth and death, readers have only two remnants of his contributions to science: The Anatomy of the Brain, containing its Mechanism and Physiology and Observationes Quaedam Medico-Practicae et Physiologicae de Asthmate et Hydrophobia. The former text was the first book in the English language written on the human brain. Ridley's studies using cadavers executed by hanging provided him with a novel view of the venous drainage and lymphatic system not seen as accurately by those before him. Since the study of the brain was still largely in its infancy, he was not without his errors of deduction as to the purpose of parts of the brain and its pathologies. With his dissections, however, Ridley was able to build on the collective knowledge of neuroanatomy and provided new insight into brain structure and function. The current paper reviews what is known of Ridley's life and contributions to neuroanatomy and neurophysiology.

Venous drainage of the spine and spinal cord: a comprehensive review of its history, embryology, anatomy, physiology, and pathology.

Venous drainage of the spine and spinal cord is accomplished through a complex network of venous structures compartmentalized to intrinsic, extrinsic, and extradural systems. As the literature on this topic is scarce, the following review was performed to summarize the available literature into a single coherent format. The medical literature on the spinal venous system was reviewed using online sources as well as historical documents that were not available online in regard to history, embryology, anatomy, and physiology with a particular emphasis on the pathology affecting this system. The spinal venous system is complex and variable. Proper understanding of all aspects is critical for the management of the pathology that results from its failure.

Spinal diffusion tensor imaging: a comprehensive review with emphasis on spinal cord anatomy and clinical applications.

Magnetic resonance imaging technology allows for in vivo visualization of fiber tracts of the central nervous system using diffusion-weighted imaging sequences and data processing referred to as "diffusion tensor imaging" and "diffusion tensor tractography." While protocols for high-fidelity diffusion tensor imaging of the brain are well established, the spinal cord has proven a more difficult target for diffusion tensor methods. Here, we review the current literature on spinal diffusion tensor imaging and tractography with special emphasis on neuroanatomical correlations and clinical applications.

The Mozzafari Hospital of Shiraz, Persia.

INTRODUCTION: This article discusses three significant hospitals that were constructed in medieval Persia, specifically in the city of Shiraz, which is located in central present-day Iran. The first of these three hospitals is the Azodi Hospital, which was constructed during the Buyid dynasty. The second hospital was constructed during the Salghurid dynasty and is referred to as the Mozzafari Hospital by a primary source written by Qutb al-Din Shirazi, a physician who worked there. The third hospital is also referred to as the Mozzafari Hospital and was constructed during the Mozzafarid dynasty. Recent efforts have yielded archaeological evidence that marks the location in present-day Shiraz of this third hospital or an area south of its location. The evidence consists of the gravesite for Seyed Sharaf al-Din Jorjani, a prominent theologian who was employed by Shah Shoja of the Mozzafarid dynasty in the fourteenth century CE. at the compound containing the third hospital. CONCLUSION: The gravesite for Sharaf al-Din Jorjani in present-day Shiraz marks the site of the remains of the Mozzafari Hospital built during the reign of Shah Shoja of the Mozzafarid dynasty or an area south of Shah Shoja's Mozzafari Hospital.

Relation between exhaled nitric oxide and left ventricular performance in chronic hemodialysis patients.

INTRODUCTION: End-stage renal disease is the most debilitating condition for patients with renal diseases. Cardiovascular disease is the leading cause of death in these patients. It has been shown that nitric oxide (NO) increases in renal failure and hemodialysis patients and could be correlated with cardiovascular diseases in this population. OBJECTIVES: To investigate the relation between exhaled nitric oxide (eNO) and left ventricular performance in chronic hemodialysis patients. METHODS: In this prospective study, eNO was measured in 20 chronic hemodialysis patients (13 males and 7 females with the mean age of 45.20 ± 14.99 years). Left ventricular findings were studied by conventional and Doppler echocardiography. eNO correlation with the echocardiographic parameters was evaluated. RESULTS: The median eNO was 11.65 ppb (range: 1.9-29.9 ppb). eNO was positively correlated with left ventricular ejection fraction (ρ = 0.561, p = 0.01) and negatively correlated with left ventricular end systolic volume (ρ = -0.451, p = 0.046), isovolumic relaxation time (ρ = -0.448, p = 0.047) and myocardial performance index (ρ = -0.587, p = 0.007). CONCLUSION: There is a positive correlation between eNO and left ventricular performance in chronic hemodialysis patients. Therefore, eNO may play an important role in pathophysiology of cardiac involvement in these patients.