The spectrum of venous anomalies associated with atretic parietal cephaloceles: A literature review

A topographical analysis of encephalocele locations: generation of a standardised atlas and cluster analysis

OBJECTIVE

Encephaloceles are considered to result from defects in the developing skull through which meninges, and potentially brain tissue, herniate. The pathological mechanism underlying this process is incompletely understood. We aimed to describe the location of encephaloceles through the generation of a group atlas to determine whether they occur at random sites or clusters within distinct anatomical regions.

METHODS

Patients diagnosed with cranial encephaloceles or meningoceles were identified from a prospectively maintained database between 1984 and 2021. Images were transformed to atlas space using non-linear registration. The bone defect, encephalocele and herniated brain contents were manually segmented allowing for a 3-dimensional heat map of encephalocele locations to be generated. The centroids of the bone defects were clustered utilising a K-mean clustering machine learning algorithm in which the elbow method was used to identify the optimal number of clusters.

RESULTS

Of the 124 patients identified, 55 had volumetric imaging in the form of MRI (48/55) or CT (7/55) that could be used for atlas generation. Median encephalocele volume was 14,704 (IQR 3655-86,746) mm3 and the median surface area of the skull defect was 679 (IQR 374-765) mm2. Brain herniation into the encephalocele was found in 45% (25/55) with a median volume of 7433 (IQR 3123-14,237) mm3. Application of the elbow method revealed 3 discrete clusters: (1) anterior skull base (22%; 12/55), (2) parieto-occipital junction (45%; 25/55) and (3) peri-torcular (33%; 18/55). Cluster analysis revealed no correlation between the location of the encephalocele with gender (χ2 (2, n = 91) = 3.86, p = 0.15). Compared to expected population frequencies, encephaloceles were relatively more common in Black, Asian and Other compared to White ethnicities. A falcine sinus was identified in 51% (28/55) of cases. Falcine sinuses were more common (χ2 (2, n = 55) = 6.09, p = 0.05) whilst brain herniation was less common (χ2 (2, n = 55) = .16.24, p < 0.0003) in the parieto-occipital location.

CONCLUSION

This analysis revealed three predominant clusters for the location of encephaloceles, with the parieto-occipital junction being the most common. The stereotypic location of encephaloceles into anatomically distinct clusters and the coexistence of distinct venous malformations at certain sites suggests that their location is not random and raises the possibility of distinct pathogenic mechanisms unique to each of these regions.

Atretic cephaloceles with different imaging phenotypes - Case series with review of literature

Atretic cephaloceles (ACs) are congenital skull defects with herniation of rudimentary intracranial structures through the defect and associated with persistent falcine sinus or embryonic positioning of straight sinus. We describe five cases of ACs, out of which only one had embryonic straight sinus. Three cases had other intracranial malformations such as hypoplasia of corpus callosum, dysplastic tectum in one child and parieto-occipital polymicrogyria with falcotentorial dehiscence in the other, and frontal horn deformity and cortical dysplasia in the third. The prognosis of AC depends on the coexistent intracranial abnormalities and this highlights the role of magnetic resonance imaging in diagnosing the other associated anomalies for prediction of prognosis and planning of necessary surgical management.

Imaging the Cerebral Veins in Pediatric Patients: Beyond Dural Venous Sinus Thrombosis

The range of intracranial venous anomalies in children differs from that in adults. As a commonly encountered highly morbid disease, sinovenous thrombosis has been discussed extensively in the literature, and the associated imaging considerations are similar in pediatric and adult patients. The authors shift the focus to less frequently discussed cerebral venous diseases in pediatric patients. First, the practical embryology pertinent to malformations, syndromes, and variants such as vein of Galen aneurysmal malformation, Sturge-Weber syndrome, and developmental venous anomalies are discussed. Second, anatomic considerations that are applicable to neuroimaging in pediatric patients with cerebral venous anomalies are reviewed. In the discussion of anatomy, special attention is given to the medullary venous system that serves the cerebral white matter, superficial cortical veins (tributaries of the dural venous sinuses), and bridging veins, which carry blood from the superficial cortical veins through the potential subdural space into the dural venous sinuses. Third, the selection of imaging modalities (US, CT and CT venography, and MRI) is addressed, and various MR venographic pulse sequences (time-of-flight, phase-contrast, and contrast-enhanced sequences) are compared. Finally, a broad variety of congenital and acquired superficial and deep venous diseases in children are reviewed, with emphasis on less frequently discussed entities involving the medullary (eg, deep medullary venous engorgement and thrombosis, periventricular hemorrhagic venous infarction due to germinal matrix hemorrhage), cortical (eg, cortical venous thrombosis), and bridging (eg, acute and chronic manifestations of injury in abusive head trauma) veins, as well as the deep veins and dural venous sinuses (eg, varix). © RSNA, 2023 Quiz questions for this article are available through the Online Learning Center. Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Academic productivity of Iraqi medical students in the field of neurosurgery: A literature review

Background

The interest in clinical research is growing worldwide, and the involvement of medical students in academic and clinical research is increasing. Medical students in Iraq have started to focus on academic activities. However, this trend is in its infancy due to limited resources and the war burden. Their interest in the field of Neurosurgery has been evolving recently. This is the first paper that aims to assess the status of the academic productivity of Iraqi medical students within the neurosurgical field.

Methods

We searched the PubMed Medline database and Google scholar between January 2020 and December 2022 with a different combination of keywords. Additional results were obtained by individually searching for all the medical universities in Iraq that participated in the neurosurgical literature.

Results

Between January 2020 and December 2022, 60 neurosurgical publications included Iraqi medical students. 47 Iraqi medical students from 9 universities (the University of Baghdad 28 students, followed by 6 students from the University of Al-Nahrain, and others) were involved in these 60 neurosurgery publications. The topics of these publications are "vascular neurosurgery" (n = 36) followed by "neurotrauma" (n = 11).

Conclusion

Academic productivity of Iraqi medical students in the field of Neurosurgery has surged in the last 3 years. In the past 3 years, 47 Iraqi medical students from nine different Iraqi universities contributed to sixty international neurosurgical publications. However, there are challenges that are required to be tackled to establish a research-friendly environment despite wars and restrained resources.