Cervical anterior spinal artery infarction associated with anomalous vertebral artery: a case report.

We report a unique case of cervical anterior spinal artery (ASA) infarction in a 49-year-old male with hypercholesterolemia and sleep apnea. The patient experienced sudden cervical pain, quadriparesis, areflexia, and urinary incontinence after swallowing a large food bolus. Imaging revealed an infarction at the C3-C5 levels and an anomalous right vertebral artery (VA) originating from the thoracic aorta, tightly enclosed between the aorta and a vertebral column with an anterior osteophyte. This aberrant VA was the primary vascular supply to the ASA, with no contribution from the left VA or supreme intercostal arteries. We propose that transient injury to the right VA, induced by compression between the aortic arch, the food bolus, and the osteophyte, led to temporary hypoperfusion of the ASA, causing a watershed ischemic injury in the mid cervical cord's anterior gray matter. The article also provides an in-depth discussion of the developmental and clinical characteristics associated with this rare vascular anomaly.

Spinal fistulas documented by contrast enhanced computed tomography during myelopathy workup: a lost opportunity.

PURPOSE: Low-flow spinal arteriovenous fistulas (SAVFs) with intradural venous drainage typically manifest with a progressive venous hypertensive myelopathy (VHM) in older patients. VHM is difficult to identify. MRI is often nonspecific, and many cases are initially misdiagnosed, most often as transverse myelitis. The workup of myelopathic patients frequently includes thoracic and/or abdominal contrast-enhanced CT (CECT) that are generally not reviewed by neuroradiologists. The purpose of this work was to investigate how often abnormal enhancing intracanalar structures corresponding to the draining veins of a low-flow SAVF were documented by CECT. MATERIALS AND METHODS: We evaluated 92 consecutive patients with low-flow SAVFs and VHM treated at our institution between 2009 and 2018. The study group included 22 of these patients with at least one thoracoabdominal CECT available for review. The control group consisted of 20 consecutive myelopathy patients with negative angiography and at least one thoracoabdominal CECT. Intracanalar enhancing structures were classified either as (i) conspicuous or (ii) equivocal or absent. RESULTS: One CECT in the study group was technically inadequate. Conspicuous intracanalar enhancing structures were observed in 20 of the remaining 21 patients with SAVFs (95.2%) and in 2 of 20 control patients (10%). None of the enhancing intracanalar structures was mentioned in official study reports. CONCLUSIONS: The presence of enhancing vascular structures within the spinal canal on thoracoabdominal CECT obtained during the workup of myelopathies appears to represent a powerful but currently underappreciated tool for the detection of low-flow SAVFs.

A detailed musculoskeletal study of a fetus with anencephaly and spina bifida (craniorachischisis), and comparison with other cases of human congenital malformations.

Few descriptions of the musculoskeletal system of humans with anencephaly or spina bifida exist in the literature. Even less is published about individuals in which both phenomena occur together, i.e. about craniorachischisis. Here we provide a detailed report on the musculoskeletal structures of a fetus with craniorachischisis, as well as comparisons with the few descriptions for anencephaly and with musculoskeletal anomalies found in other congenital malformations. We focused in particular on the comparison with trisomies 13, 18, and 21 because neural tube defects have been associated with such chromosomal defects. Our results showed that many of the defects found in the fetus with craniorachischisis are similar not only to anomalies previously described in the available works on musculoskeletal phenotypes seen in fetuses with anencephaly and spina bifida, but also to a wide range of other different conditions/syndromes including trisomies 13, 18 and 21, and cyclopia. The fact that similar anomalies are seen commonly not only in a wide range of different syndromes, but also as variants of the normal human population and as the 'normal' phenotype of other animals, supports Pere Alberch's unfortunately named idea of a 'logic of monsters'. That is, it supports the idea that development is so constrained that both in 'normal' and abnormal development one sees certain outcomes being produced again and again because ontogenetic constraints only allow a few possible outcomes, thus also leading to cases where the anatomical defects of some organisms are similar to the 'normal' phenotype of other organisms. In fact, this applies not only to specific anomalies but also to general patterns, such as the fact that in pathological conditions affecting different regions of the body, one consistently sees more defects on the upper limbs than on the lower limbs. Such general patterns are, again, seen in the fetus examined for this study, which had 29 muscle anomalies on the right upper limb and 22 muscle anomalies on the left upper limb, vs. seven muscle anomalies on the right lower limb and two on the left lower limb. It is therefore hoped that this work, which is part of our effort to describe and compile information on human musculoskeletal defects found in a wide range of conditions, will contribute not only to a better understanding of craniorachischisis in particular and of human congenital malformations in general, but also to broader discussions on the fields of comparative anatomy, and developmental and evolutionary biology.

Spontaneous resolution of low-flow spinal arteriovenous fistulas.

PURPOSE: Spinal vascular anomalies with arteriovenous blood shunting include spinal arteriovenous malformations (SAVMs) and spinal arteriovenous fistulas (SAVFs), which are distinguished by the presence or absence of an interposed nidus. SAVFs can be further characterized based on their location (perimedullary, dural, or extradural) and flow pattern (high-flow versus low-flow shunts). The spontaneous resolution of a spinal vascular malformation, i.e., the complete disappearance-in the absence of therapeutic measures-of a lesion previously identified by angiography, seems to represent an exceptional phenomenon. METHODS: This study retrospectively analyzed seven patients with spontaneously resolving spinal vascular malformations observed by the senior author between January 2008 and April 2017. RESULTS: A total of 143 spinal vascular malformations were angiographically evaluated during the considered time period, including nine spontaneously resolving SAVFs in six patients, seven spinal epidural fistulas, and two spinal dural arteriovenous fistula. CONCLUSION: The "spontaneous" resolution of spinal vascular malformations appears to selectively involve SAVFs. While vessel wall alterations previously documented on the venous side of SAVFs may play an important role in the regression of these lesions, angiography seems to represent a significant contributing factor, probably through the prothrombotic properties of nonionic contrast agents.

Anterior disco-osteo-arterial conflict as a cause of intersegmental arterial flow impairment and spinal cord ischemia.

INTRODUCTION: This article describes anterior disco-osteo-arterial conflict as an insofar unsuspected mechanism of arterial flow impairment potentially leading to spinal cord ischemia and infarction. METHODS: The anterior disco-osteo-arterial conflict described in this report is illustrated with angiographic observations of patients presenting with spinal cord ischemia documented by MRI, and radiculomedullary flow impairment diagnosed by spinal digital subtraction angiography and spinal CTA. RESULTS: Proximal intersegmental artery flow impairment was found in association with anterior disc bulging and anterior osteophytic formation, alone or in combination. Patients either presented with an initial acute medullary syndrome or with a long-standing history of spinal claudication with acute secondary pejoration. CONCLUSION: Spinal ischemia can be the result of intersegmental and radiculomedullary flow impairment caused by an anterior disco-osteo-arterial conflict.

'That's just the Ovary!' and other cases of mistaken identity on CT of the female pelvis.

CT is often the first imaging test in female patients with lower abdominal and pelvic pain because of the wide availability of CT and differential diagnoses that span both gynecologic and gastrointestinal disease. Pathology within the female pelvis may be difficult to diagnose on CT owing to suboptimal delineation of anatomy in comparison to MRI and ultrasound. These challenges are confounded by overlapping imaging features of a wide range of gynecologic entities and can lead to diagnostic dilemmas. High value CT interpretation will direct the clinician to the best next diagnostic step as ultrasound and MRI provide superior soft tissue delineation. Other imaging modalities, laboratory investigations, or tissue sampling may be necessary to definitively characterize indeterminate lesions. In this review, we illustrate various cases of mistaken identity on CT of the female pelvis involving the ovaries, uterus, and peritoneal cavity while highlighting clinical pearls that may aid the radiologist in arriving at the correct diagnosis and avoiding potential pitfalls.

Insights into Presbycusis From the First Temporal Bone Laboratory Within the United States.

The Johns Hopkins Otologic Research Laboratory was founded in 1924 as the first human temporal bone laboratory within the United States. To better understand the contributions of the Johns Hopkins Otologic Research Laboratory to our understanding of presbycusis, we consulted with a medical librarian and archivist to search the Alan Mason Chesney Medical Archives, PubMed, JSTOR, and Johns Hopkins Bulletin for published and unpublished works from the lab. Between 1924 and 1938, Samuel J. Crowe, the Chairman of Otolaryngology, and anatomist Stacy R. Guild amassed a collection of ∼1,800 temporal bones. This collection allowed for an unprecedented period of discovery related to otologic disease. They combined hearing thresholds measured by the recently invented audiometer with new techniques for temporal bone decalcification, sectioning, and staining, and a method for the graphic reconstruction of the cochlea. Crowe and Guild used this unique opportunity to correlate otopathology with hearing and to make the first detailed descriptions of the otopathology of presbycusis. In 1931 and 1934, they observed spiral ganglion neuron and outer hair cell loss in the basal turn of the cochlea in individuals with high-frequency hearing loss. These were the first studies to reveal that stria vascularis degeneration and middle ear pathology were not the most common causes for high-frequency hearing loss. Aside from revealing the primary driving factors of presbycusis, this work provided insight into the tonotopic organization of the cochlea. After initially being recruited to help raise money for the laboratory, medical illustrator Max Brödel used the vertical histologic cross-sections of the cochlea to produce illustrations of the ear. The decision to produce histologic sections in the plane of the superior semicircular canal likely influenced Brödel's illustrations that share a similar orientation and would later become widely circulated. Significant contributions from the Otologic Research Laboratory were also made by Mary Hardy, D.Sc., a woman who has previously received little recognition for her work. The sectioning of temporal bones was stopped in 1938 due to World War II, but much of Crowe's and Guild's work continued into the 1940s until a rift between the two resulted in the temporary closure of the laboratory in 1949. Nearly 100 years after its founding, discoveries from the Johns Hopkins Otologic Research Laboratory remain relevant and emphasize the importance of continued human temporal bone research to improve our understanding and treatment of otologic disease.

Normal cerebral arterial development and variations.

The cerebral vascular architecture is both unique and heterogeneous in its structure, organization, and function. For many years, it was believed that brain vasculature was dominated by nonanastomosing terminal or "end-arteries." This was primarily based upon the observation of discrete distribution of brain infarcts after embolic occlusion of particular vessels. It was not until the detailed anatomy work of Pfeiffer in 1928 that the new concept of an almost-uninterrupted vascular network of brain vasculature was proposed. Since then, the cerebral vascular anatomy and embryology has been studied in great detail. Its full description is beyond the scope of this article, and our aim is to provide a brief overview of the development of cranial arterial anatomy, with special emphasis on commonly encountered anatomical variations that may have clinical implications. The failure to recognize these can lead to misdiagnosis as well as otherwise-preventable iatrogenic injuries and complications. We describe the proposed underlying embryologic processes, pathology and clinical implications of these variations, including aberrant internal carotid arteries, carotid agenesis and hypoplasia, azygous anterior cerebral arteries, arterial fenestrations, and persistent embryonic vessels.

Cerebral venous development in relation to developmental venous anomalies and Vein of Galen aneurysmal malformations.

Cerebrovascular venous development and intracranial vascular malformations are extensive topics for which volumes of text may be devoted. However, a basic knowledge of the embryology of cerebral venous system and venous architecture is essential for understanding of cerebral vascular malformations. The aim of this work is to provide the reader with a brief overview of the development of the cranial venous anatomy. We will highlight the superficial and deep venous systems with special attention to developmental venous anomalies and vein of Galen aneurysmal malformations.

Neurovascular anatomy: Spine.

The arterial supply of the spinal cord is provided by the spinal branch of the cervical, thoracic, and lumbar intersegmental arteries. While supply is initially provided at each embryonic segment, only a few prominent anterior radiculomedullary arteries remain at the adult stage, including the arteries of the cervical and lumbosacral enlargements as well as a constant upper thoracic contributor. The spinal cord is surrounded by the vasocorona, an arterial network that includes several longitudinal anastomotic chains, notably the anterior and posterior spinal arteries, which respectively supply the central and peripheral components of the intrinsic vascularization. The intrinsic venous circulation is also divided into central and peripheral components. The perimedullary venous system includes several longitudinal anastomotic chains interconnected by the coronary plexus. The radiculomedullary veins loosely follow the spinal nerve roots on their way to the epidural plexus. Their point of passage through the thecal sac forms an important valve-like structure, the antireflux mechanism.

Report of a spinal extradural arteriovenous fistula with double radiculomedullary venous drainage: therapeutic implications and role of intraoperative spinal angiography.

Low-flow spinal extradural arteriovenous fistulas (SEAVFs) are frequently misdiagnosed as spinal dural arteriovenous fistulas (SDAVFs), and their true prevalence is unknown. The principal feature distinguishing low-flow SEAVFs from SDAVFs is the location of the shunt, which involves a pouch of epidural plexus in SEAVFs and a radiculomedullary vein (RMV) in SDAVFs. A venous hypertensive myelopathy comparable to the one observed with SDAVFs develops when the arterialized venous pouch of an SEAVF is connected to an RMV. Depending on the size of the epidural pouch, a low-flow SEAVF may uncommonly drain into multiple RMVs. The authors present an observation of a low-flow SEAVF whose double radiculomedullary drainage was revealed only after intraoperative digital subtraction angiography, and they discuss the surgical implications of this anatomical configuration.

Endovascular management of vein of Galen aneurysmal malformations. Influence of the normal venous drainage on the choice of a treatment strategy.

INTRODUCTION: Vein of Galen arteriovenous malformations (VGAM) are rare intracranial vascular lesions mostly involving young children. Endovascular therapy is the current standard of care. Albeit interventional techniques have greatly reduced the once dismal vital and functional prognoses previously associated with these lesions, the treatment of VGAMs remains a complex therapeutic challenge. DISCUSSIONS: This article reviews the available endovascular options for VGAM therapy, emphasizing three points that we have identified as critical in our practice for the establishment of a treatment strategy: (1) the importance of the deep cerebral venous anatomy, in particular the existence of normal drainage through the Galenic system in spite of the VGAM; (2) the concept of treatment staging, for arterial as well as for venous interventions; and (3) the definition of a therapeutic goal that can be attained at a reasonable cost in terms of complication risks and functional outcome.

Biodistribution of Glial Progenitors in a Three Dimensional-Printed Model of the Piglet Cerebral Ventricular System.

White matter damage persists in hypoxic-ischemic newborns even when treated with hypothermia. We have previously shown that intraventricular delivery of human glial progenitors (GPs) at the neonatal stage is capable of replacing abnormal host glia and rescuing the lifespan of dysmyelinated mice. However, such transplantation in the human brain poses significant challenges as related to high-volume ventricles and long cell migration distances. These challenges can only be studied in large animal model systems. In this study, we developed a three dimensional (3D)-printed model of the ventricular system sized to a newborn pig to investigate the parameters that can maximize a global biodistribution of injected GPs within the ventricular system, while minimizing outflow to the subarachnoid space. Bioluminescent imaging and magnetic resonance imaging were used to image the biodistribution of luciferase-transduced GPs in simple fluid containers and a custom-designed, 3D-printed model of the piglet ventricular system. Seven independent variables were investigated. The results demonstrated that a low volume (0.1 mL) of cell suspension is essential to keep cells within the ventricular system. If higher volumes (1 mL) are needed, a very slow infusion speed (0.01 mL/min) is necessary. Real-time magnetic resonance imaging demonstrated that superparamagnetic iron oxide (SPIO) labeling significantly alters the rheological properties of the GP suspension, such that, even at high speeds and high volumes, the outflow to the subarachnoid space is reduced. Several other factors, including GP species (human vs. mouse), type of catheter tip (end hole vs. side hole), catheter length (0.3 vs. 7.62 m), and cell concentration, had less effect on the overall distribution of GPs. We conclude that the use of a 3D-printed phantom model represents a robust, reproducible, and cost-saving alternative to in vivo large animal studies for determining optimal injection parameters.

Developing the Storyline for an Advance Care Planning Video for Surgery Patients: Patient-Centered Outcomes Research Engagement from Stakeholder Summit to State Fair.

BACKGROUND: Patient-centered outcomes research (PCOR) methods and social learning theory (SLT) require intensive interaction between researchers and stakeholders. Advance care planning (ACP) is valuable before major surgery, but a systematic review found no extant perioperative ACP tools. Consequently, PCOR methods and SLT can inform the development of an ACP educational video for patients and families preparing for major surgery. OBJECTIVE: The objective is to develop and test acceptability of an ACP video storyline. DESIGN: The design is a stakeholder-guided development of the ACP video storyline. Design-thinking methods explored and prioritized stakeholder perspectives. Patients and family members evaluated storyboards containing the proposed storyline. SETTING/SUBJECTS: The study was conducted at hospital outpatient surgical clinics, in-person stakeholder summit, and the 2014 Maryland State Fair. MEASUREMENTS: Measurements are done through stakeholder engagement and deidentified survey. RESULTS: Stakeholders evaluated and prioritized evidence from an environmental scan. A surgeon, family member, and palliative care physician team iteratively developed a script featuring 12 core themes and worked with a medical graphic designer to translate the script into storyboards. For 10 days, 359 attendees of the 2014 Maryland State Fair evaluated the storyboards and 87% noted that they would be "very comfortable" or "comfortable" seeing the storyboard before major surgery, 89% considered the storyboards "very helpful" or "helpful," and 89% would "definitely recommend" or "recommend" this story to others preparing for major surgery. CONCLUSIONS: Through an iterative process utilizing diverse PCOR engagement methods and informed by SLT, storyboards were developed for an ACP video. Field testing revealed the storyline to be highly meaningful for surgery patients and family members.

The Role of the Primitive Lateral Basilovertebral Anastomosis of Padget in Variations of the Vertebrobasilar Arterial System.

PURPOSE: The primitive lateral basilovertebral anastomosis (PLBA) is an embryonic longitudinal anastomotic channel that transiently interconnects the developing branches of the vertebrobasilar system. This study reviews the anatomy of the PLBA and describes several variants associated with its partial persistence. METHODS: Four types of vertebrobasilar anomalies linked to the PLBA are illustrated by 13 angiographic observations. RESULTS: The angiographic appearances of (i) typical and atypical persistent trigeminal artery variants, (ii) common trunks of origin for one, two, or three cerebellar arteries, (iii) aberrant origins of the cerebellar arteries, and (iv) vertebrobasilar duplications are described. The PLBA is the cranial continuation of the ascending ramus of the dorsal radicular branch of the proatlantal artery (i.e., the radicular artery of C1) and represents the cranial equivalent of the posterior-lateral spinal artery. CONCLUSION: Several previously ill-defined or misunderstood variations of the vertebrobasilar system can be explained by partial persistence of the PLBA. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:2025-2038, 2017. © 2017 Wiley Periodicals, Inc.

Ventral and Dorsal Persistent Primitive Ophthalmic Arteries.

BACKGROUND: Before the development of the adult ophthalmic artery (OA), the primitive maxillary artery (MA), the primitive dorsal OA, and the primitive ventral OA contribute to the vascularization of early ocular structures, whereas the primitive olfactory artery (OlfA) forms in the vicinity of the optic vesicle. These vessels are involved in several OA origin variants. OBJECTIVE: To clarify the developmental history of the OA, emphasizing in particular the criteria used to define persistent primitive OAs. METHODS: Eight rare variants relevant to the discussion of aberrant OA origins are presented. RESULTS: Five abnormal anatomic configurations are described including (1) OAs branching from the cavernous internal carotid artery (ICA) involving a persistent primitive MA, (2) OAs originating from the distal supraclinoid ICA involving persistent primitive ventral or dorsal OAs, (3) an OA originating from the anterior cerebral artery (ACA) involving a persistent primitive OlfA, (4) a persistent primitive OlfA, and (5) infraoptic ACAs involving the persistent primitive MA, OlfA, and OA. CONCLUSION: Discrepancies regarding the identification of persistent primitive OAs appear to result from a misinterpretation of the literature. Notably, an OA arising from the cavernous segment of the ICA derives from a primitive MA, whereas an OA arising from the ACA represents the partial persistence of a primitive OlfA; neither corresponds to a persistent primitive OA. Two new observations of this latter variant, which is exceptional, are presented.

Periconal arterial anastomotic circle and posterior lumbosacral watershed zone of the spinal cord.

BACKGROUND: The existence of spinal cord watershed territories was suggested in the 1950s. Segmental infarcts within the junctional territories of adjacent radiculomedullary contributors and isolated spinal gray matter ischemia constitute two well-recognized types of watershed injury. This report describes the existence of another watershed territory related to the particular configuration of the spinal vasculature in the region of the conus medullaris. METHODS: The anatomical bases underlying the concept of a posterior lumbosacral watershed zone are demonstrated with angiographic images obtained in a 16-year-old child. The clinical importance of this watershed zone is illustrated with MRI and angiographic data of three patients with a conus medullaris infarction. RESULTS: In all three cases of spinal ischemia an intersegmental artery providing a significant radiculomedullary contribution for the lower cord was compromised by a compressive mechanism responsible for decreased spinal cord perfusion (diaphragmatic crus syndrome in two cases, disk herniation in one). The ischemic injury, located at the junction of the anterior and posterior spinal artery territories along the dorsal aspect of the conus medullaris, was consistent with a watershed mechanism. This zone is at risk because of the caudocranial direction of flow within the most caudal segment of the posterior spinal arterial network which, from a functional standpoint, depends on the anterior spinal artery. CONCLUSIONS: The posterior thoracolumbar watershed zone of the spinal cord represents an area at increased risk of ischemic injury, particularly in the context of partial flow impairment related to arterial compression mechanisms.

Duplicated origin of a radiculomedullary artery supplying a perimedullary arteriovenous fistula: angiographic observation and developmental considerations.

The angiographic observation of a radiculomedullary artery variation found in a patient with a spinal cord vascular malformation is presented. A posterior radiculomedullary artery arising from the left L2 intersegmental artery had a duplicated origin. Two radicular trunks were seen aiming towards the neural foramen: a dominant anterior one providing a retrocorporeal artery and the anterior limb of the radicular artery, and a smaller posterior one branching off a prelaminar artery and the posterior limb of the radicular artery. The two limbs then joined to continue as a single posterior radiculomedullary artery, which participated in the vascularization of the vascular malformation. The clinical and developmental aspects of this exceptional variant are discussed.

Endovascular treatment of cranial arteriovenous malformations and dural arteriovenous fistulas.

Pial arteriovenous malformations (AVMs) and dural arteriovenous fistulas (DAVFs) are high-flow vascular lesions with abnormal communications between the arterial and venous system. AVMs are congenital lesions, whereas DAVFs are considered acquired lesions. Both can cause significant morbidity and mortality if they rupture and result in intracranial hemorrhage. The primary goal of treatment is to eliminate the risk of bleeding or at least decrease it. Because the epidemiology, clinical presentation, and classification of AVMs and DAVFs have been covered in previous articles in this issue, the authors only briefly touch on these subjects as they relate to endovascular treatment.

Classification schemes of cranial dural arteriovenous fistulas.

The clinical presentation of dural arteriovenous fistulas (DAVFs), in particular the associated risk of intracranial hemorrhage, shows a strong correlation with their pattern of venous drainage. The two most commonly used and clinically accepted DAVF classifications are the Merland-Cognard classification and the Borden classification, both based on the morphology of the venous drainage. A revised classification that grades DAVFs through a combination of angiographic and clinical features has also been proposed. This article offers a review of these various classification schemes, and discusses their application to treatment decision making.