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Frontiers in Physiology 2023Computational fluid dynamics (CFD) assess biological systems based on specific boundary conditions. We propose modeling more advanced hemodynamic metrics, such as core...
Understanding development of jugular bulb stenosis in vein of galen malformations: identifying metrics of complex flow dynamics in the cerebral venous vasculature of infants.
Computational fluid dynamics (CFD) assess biological systems based on specific boundary conditions. We propose modeling more advanced hemodynamic metrics, such as core line length (CL) and critical points which characterize complexity of flow in the context of cerebral vasculature, and specifically cerebral veins during the physiologically evolving early neonatal state of vein of Galen malformations (VOGM). CFD has not been applied to the study of arteriovenous shunting in Vein of Galen Malformations but could help illustrate the pathophysiology of this malformation. Three neonatal patients with VOGM at Boston Children's Hospital met inclusion criteria for this study. Structural MRI data was segmented to generate a mesh of the VOGM and venous outflow. Boundary condition flow velocity was derived from PC-MR sequences with arterial and venous dual velocity encoding. The mesh and boundary conditions were applied to model the cerebral venous flow. We computed flow variables including mean wall shear stress (WSSmean), mean OSI, CL, and the mean number of critical points (nCrPointsmean) for each patient specific model. A critical point is defined as the location where the shear stress vector field is zero (stationary point) and can be used to describe complexity of flow. The division of flow into the left and right venous outflow was comparable between PC-MR and CFD modeling. A high complexity recirculating flow pattern observed on PC-MR was also identified on CFD modeling. Regions of similar WSSmean and OSImean (<1.3 fold) in the left and right venous outflow channels of a single patient have several-fold magnitude difference in higher order hemodynamic metrics (> 3.3 fold CL, > 1.7 fold nCrPointsmean). Specifically, the side which developed JBS in each model had greater nCrPointsmean compared to the jugular bulb with no stenosis (VOGM1: 4.49 vs. 2.53, VOGM2: 1.94 vs. 0, VOGM3: 1 vs. 0). Biologically, these regions had subsequently divergent development, with increased complexity of flow associating with venous stenosis. Advanced metrics of flow complexity identified in computational models may reflect observed flow phenomena not fully characterized by primary or secondary hemodynamic parameters. These advanced metrics may indicate physiological states that impact development of jugular bulb stenosis in VOGM.
PubMed: 37275225
DOI: 10.3389/fphys.2023.1113034 -
Journal of Cerebral Blood Flow and... Oct 2023Brain fluid dynamics remains poorly understood with central issues unresolved. In this study, we first review the literature regarding points of controversy, then pilot...
Brain fluid dynamics remains poorly understood with central issues unresolved. In this study, we first review the literature regarding points of controversy, then pilot study if conventional MRI techniques can assess brain fluid outflow pathways and explore potential associations with small vessel disease (SVD). We assessed 19 subjects participating in the Mild Stroke Study 3 who had FLAIR imaging before and 20-30 minutes after intravenous Gadolinium (Gd)-based contrast. Signal intensity (SI) change was assessed semi-quantitatively by placing regions of interest, and qualitatively by a visual scoring system, along dorsal and basal fluid outflow routes. Following i.v. Gd, SI increased substantially along the anterior, middle, and posterior superior sagittal sinus (SSS) (82%, 104%, and 119%, respectively), at basal areas (cribriform plate, 67%; jugular foramina, 72%), and in narrow channels surrounding superficial cortical veins separated from surrounding cerebrospinal fluid (CSF) (96%) (all p < 0.001). The SI increase was associated with higher intraparenchymal perivascular spaces (PVS) scores (Std. Beta 0.71, p = 0.01). Our findings suggests that interstitial fluid drainage is visible on conventional MRI and drains from brain parenchyma via cortical perivenous spaces to dural meningeal lymphatics along the SSS remaining separate from the CSF. An association with parenchymal PVS requires further research, now feasible in humans.
Topics: Humans; Pilot Projects; Brain; Magnetic Resonance Imaging; Stroke
PubMed: 37254892
DOI: 10.1177/0271678X231179555 -
Pediatric Neurosurgery 2023Extraskeletal myxoid chondrosarcoma of the jugular foramen is a rare clinical entity, especially in the pediatric population. Thus, it can be confused with other... (Review)
Review
INTRODUCTION
Extraskeletal myxoid chondrosarcoma of the jugular foramen is a rare clinical entity, especially in the pediatric population. Thus, it can be confused with other pathologies.
CASE PRESENTATION
We report an extremely rare case of a 14-year-old female patient with jugular foramen myxoid chondrosarcoma that was completely removed through microsurgical resection.
CONCLUSION
The primary purpose of the treatment is gross total resection of the chondrosarcomas. However, adjuvant methods such as radiotherapy should additionally be applied in patients who have high-grade diseases or cannot undergo gross total resection because of anatomic localization.
Topics: Female; Humans; Child; Adolescent; Jugular Foramina; Chondrosarcoma; Neoplasms, Connective and Soft Tissue
PubMed: 37231851
DOI: 10.1159/000530990 -
Cureus Apr 2023This ChatGPT-driven case report describes a unique presentation of neurosarcoidosis. The patient, a 58-year-old female, initially presented with hoarseness and was found...
This ChatGPT-driven case report describes a unique presentation of neurosarcoidosis. The patient, a 58-year-old female, initially presented with hoarseness and was found to have bilateral jugular foramen tumors and thoracic lymphadenopathy. Imaging revealed significant enlargement and thickening of the vagus nerve and a separate mass of the cervical sympathetic trunk. The patient was referred for an ultrasound-guided biopsy of the abnormal neck masses to establish a pathologic diagnosis. The patient subsequently underwent neck dissection for exposure of the vagus nerve and isolation of the great vessels in preparation for a transmastoid approach to the skull base. The presence of multifocal tumors prompted the need for a biopsy, which ultimately revealed sarcoid granulomas in the nervous system. The patient was diagnosed with neurosarcoidosis. This case highlights the potential for sarcoidosis to affect the nervous system, with multiple cranial nerve involvement, seizures, and cognitive impairment. It also emphasizes the need for a combination of clinical, radiological, and pathological findings for an accurate diagnosis of neurosarcoidosis. Additionally, this case highlights the utility of natural language processing (NLP), as the entire case report was written using ChatGPT. This report serves as a comparison of the quality of case reports generated by humans versus NLP algorithms. The original case report can be found in the references.
PubMed: 37181995
DOI: 10.7759/cureus.37368 -
BioMedicine 2023Differentiating jugular foramen from hypoglossal canal in computed tomography (CT) scan is vital for correct diagnosis of posterior fossa pathologies; however, it has...
BACKGROUND
Differentiating jugular foramen from hypoglossal canal in computed tomography (CT) scan is vital for correct diagnosis of posterior fossa pathologies; however, it has been shown that the ability for differentiating these skull base elements is limited. The purpose of this study was to produce a simple algorithm for differentiating the jugular foramen from the hypoglossal canal in axial CT scan on two levels (top level where bony carotid canal is evident and lower level where bony carotid canal is not evident).
METHODS
Data derived from axial CT scan of 250 patients (500 sides) were used for producing algorithm. At top level petro-occipital fissure utilized for recognizing occipital condyle in which hypoglossal canal is located; and, at lower level the distance between the posterior border of the anatomic element (jugular foramen or hypoglossal canal) and the tangent to the anterior bony part is used for producing algorithm.
RESULTS
The mean age of patients was 38.1 ± 19 years. The petro-occipital fissure can be used in all patients for differentiating hypoglossal canal. At lower level the distance between the anterior tangent and the posterior border of the element was significantly lower for hypoglossal canal (P value < 0.001). The distance more than 3.5 mm with sensitivity 83.8% and specificity 97.1% differentiate jugular foramen from hypoglossal canal.
CONCLUSION
Simple algorithms based on quantitative morphologic features of the jugular foramen and hypoglossal canal can be used with high sensitivity and specificity to distinguish these elements.
PubMed: 37168727
DOI: 10.37796/2211-8039.1393 -
World Neurosurgery: X Apr 2023The distinctive bilateral carotid sheaths (CS) reside in the neck region and form part of the deep cervical fasciae. Aspects of the CS anatomy are controversial, most... (Review)
Review
OBJECTIVES
The distinctive bilateral carotid sheaths (CS) reside in the neck region and form part of the deep cervical fasciae. Aspects of the CS anatomy are controversial, most notably its specific attachment sites and fascial makeup, which are key determinants for the spread of tumours and infections and surgical planning. This review aimed to organise the pertinent aspects relating to CS anatomy and pathology, explore their clinical relevance and highlight areas of disagreement in the literature.
METHODS
A narrative review identified key papers relating to CS anatomy, histology, embryology, pathology and clinical and surgical significance using PubMed and Google Scholar. This was supported by a systematic review focused on the fascia forming the CS which was conducted using PubMed, Web of Science and Core Collection which yielded 22 papers.
RESULTS
and Discussion: The CS surrounds the internal carotid artery, internal jugular vein, cranial nerves IX - XII, lymph nodes and nervous plexuses as they course from the jugular foramen superiorly down along into the mediastinum inferiorly. There are contradicting descriptions regarding the CS attachments at the extracranial skull base and within the mediastinum. Author descriptions of the CS fasciae are complex, varied and incongruent. Pathologies affecting the CS include malignancies of the nerves, vascular lesions and utilisation of the CS space as a corridor for the spread of deep neck infections.
CONCLUSION
This paper collates and presents pertinent anatomical and clinical aspects regarding the CS. A proper knowledge of the CS anatomy and structural relationships will optimise surgical approaches and orientation when operating within the region.
PubMed: 37081926
DOI: 10.1016/j.wnsx.2023.100158 -
Cureus Feb 2023Jugular foramen tumours are uncommon, deeply located, and eloquently situated, making their diagnosis and management challenging. Paragangliomas and other benign tumours...
Jugular foramen tumours are uncommon, deeply located, and eloquently situated, making their diagnosis and management challenging. Paragangliomas and other benign tumours comprise the large majority of lesions in this region, but malignant tumours are occasionally identified. We report a unique case of a solitary plasmacytoma of the jugular foramen resembling a jugulotympanic paraganglioma. A solitary plasmacytoma of the jugular foramen is both rare in location and in disease presentation, as most plasma cell neoplasms are diagnosed as multiple myeloma. Our 75-year-old patient presented with symptoms typical for a jugular foramen tumour. Although there are radiographic features which help differentiate paragangliomas from other benign and malignant tumours, plasmacytomas are highly vascular and can demonstrate a local infiltrative spread which can mimic the radiographic appearance of a paraganglioma. Clinicians should consider plasma cell neoplasms in the differential when faced with an unusual presentation of a jugular foramen lesion. Our patient was treated with definitive radiotherapy to 45 Gy, which was very effective local treatment for the solitary plasmacytoma.
PubMed: 37007391
DOI: 10.7759/cureus.35592 -
Surgical and Radiologic Anatomy : SRA May 2023Anatomical knowledge of the hypoglossal canal is very important in relation to drilling of occipital condyle, jugular tubercle etc. So, this study was conducted to...
PURPOSE
Anatomical knowledge of the hypoglossal canal is very important in relation to drilling of occipital condyle, jugular tubercle etc. So, this study was conducted to identify various morphometric and morphological features of the hypoglossal canal and its distance from adjacent structures relative to stable and reliable anatomic landmarks.
METHODS
The study was performed on 142 hypoglossal canals of 71 adult human dry skulls. The parameters measured were the transverse, vertical diameter, depth of the hypoglossal canal. The distances from the hypoglossal canal to the foramen magnum, occipital condyle and jugular foramen were also noted. In addition, the different locations of the hypoglossal canal orifices in relation to the occipital condyle were assessed. The different shapes and types of the hypoglossal canal were also noted.
RESULTS
There was significant difference (p < 0.05) in measurements taken on the right and left sides in males and females. The intracranial orifice of hypoglossal canal was present in middle 1/3rd in 100% of occipital condyle for both genders. The extracranial orifice of the hypoglossal canal was found to be in the anterior 1/3rd in 99% and 93.7% for male and female, respectively. Simple hypoglossal canal with no traces of partition was found to be more in males and females. The most common shape noted was oval both in males and females (71.8% and 68.7% respectively).
CONCLUSION
The results of the dimensions of the hypoglossal canal and its distance from other bony landmarks will be helpful for neurosurgeons to plan which surgical approaches should be undertaken while doing various surgeries in posterior cranial fossa.
Topics: Adult; Female; Male; Humans; Occipital Bone; Foramen Magnum; Skull; Neurosurgical Procedures; Cranial Fossa, Posterior; Orthopedic Procedures; Skull Base
PubMed: 36930271
DOI: 10.1007/s00276-023-03126-7 -
Journal of Neurological Surgery. Part... Apr 2023Skull base neuroanatomy is classically taught using surgical atlases. Although these texts are critical and rich resources for learning three-dimensional (3D)...
Skull base neuroanatomy is classically taught using surgical atlases. Although these texts are critical and rich resources for learning three-dimensional (3D) relationships between key structures, we believe they could be optimized and complemented with step-by-step anatomical dissections to fully meet the learning needs of trainees. Six sides of three formalin-fixed latex-injected specimens were dissected under microscopic magnification. A far lateral craniotomy was performed by each of three neurosurgery resident/fellow at varying stages of training. The study objective was the completion and photodocumentation of the craniotomy to accompany a stepwise description of the exposure to provide a comprehensive, intelligible, and anatomically oriented resource for trainees at any level. Illustrative case examples were prepared to supplement approach dissections. The far lateral approach provides a wide and versatile corridor for posterior fossa operation, with access spanning the entire cerebellopontine angle (CPA), foramen magnum, and upper cervical region. The study includes the following steps: positioning and skin incision, myocutaneous flap, placement of burr holes and sigmoid trough, fashioning of the craniotomy bone flap, bilateral C1 laminectomy, occipital condyle/jugular tubercle drilling, and dural opening. Although more cumbersome than the retrosigmoid approach, a far lateral craniotomy offers unparalleled access to lesions centered lower or more medially in the CPA, as well as those with significant extension into the clival or foramen magnum regions. Dissection-based neuroanatomic guides to operative approaches provide a unique and rich resource for trainees to comprehend, prepare for, practice, and perform complex cranial operations, such as the far lateral craniotomy.
PubMed: 36895809
DOI: 10.1055/a-1760-2528