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Anatomy of Cerebral Veins and Sinuses

The veins of the brain have no muscular tissue in their thin walls and possess no valves. They emerge from the brain and lie in the subarachnoid space. They pierce the arachnoid mater and the meningeal layer of the dura and drain into the cranial venous sinuses. The cerebral venous system can be divided into a superficial and a deep system. The superficial system comprises sagittal sinuses and cortical veins, which drain superficial surfaces of both cerebral hemispheres. The deep system consists of the lateral sinus, straight sinus and sigmoid sinus along with draining deeper cortical veins. Both of these systems mostly drain into internal jugular veins. Generally, venous blood drains into the nearest venous sinus or, in the case of blood draining from the deepest structures, into deep veins. The superficial cerebral veins are interlinked with anastomotic veins of Trolard and Labbé. Thus, the superolateral surface of the hemisphere drains into the superior sagittal sinus while the posteroinferior aspect drains into the transverse sinus. The veins of the posterior fossa are variable in course, and angiographic diagnosis of their occlusion is difficult. The entire deep venous system is drained by internal cerebral and basal veins, which join to form the great vein of Galen that drains into the straight sinus. Though variation in the superficial cerebral venous system is a rule, anatomic configuration of the deep venous system can be used as anatomic landmarks. Since thrombosis or surgical sacrifice of the cerebral veins may lead to venous infarction with serious complications, angiographic and surgical anatomy of the venous system should be seriously investigated for each individual patient.

Surgical anatomy of the cavernous sinus, superior orbital fissure, and orbital apex via a lateral orbitotomy approach: a cadaveric anatomical study

BackgroundTumors of the middle fossa or cavernous sinus (CS), or intraorbital tumors, can penetrate each other through the superior orbital fissure (SOF) or neighboring tissue. These complicated pathologies are often treated with highly invasive surgical procedures. In this article, we demonstrate surgical anatomic dissections of the CS, SOF, orbital apex (OA), and dura mater extending to the periorbita from the middle fossa, by performing an epidural dissection via a lateral orbitotomy approach, and discuss findings that may provide guidance during surgery in these regions.MethodsLateral orbitotomy was performed on latex-injected cadaver heads by making a 2-cm skin incision lateral to the lateral canthus, drilling the lesser and greater sphenoid wings that form the SOF borders, and removing the bone section between the middle fossa and orbit. Dura mater from the middle fossa to the periorbita was exposed to perform anterior clinoidectomy. Meningeal dura was dissected from the endosteal dura, which forms the lateral wall of the CS, to expose the CS, SOF, and OA for dissections.ResultsChanging the orientation of the microscope from posterior to anterior enabled regional control for dissection from the Gasserian ganglion to the OA. Cranial nerves that pass through the CS, SOF, and OA were dissected and exposed. The annular tendon was opened, revealing the oculomotor nerves and its branches, as well as the abducens and nasociliary nerves, which pass through the oculomotor foramen and course within the OA and orbit.ConclusionsThis approach causes less tissue damage; provides control of the surgical area in spheno-orbital tumors invading the fissure and foramen by changing the orientation of the microscope toward the orbit, OA, SOF, CS, and middle fossa; and expands the indication criteria for lateral orbitotomy surgery. This approach, therefore, represents an alternative surgical method for excising complicated tumors in these regions.

Rare and challenging extra-axial brain lesions: CT and MRI findings with clinico-radiological differential diagnosis and pathological correlation.

There are many kinds of extra-axial brain tumors and tumor-like lesions, and definitive diagnosis is complicated in some cases. In this pictorial essay, we present rare and challenging extra-axial brain lesions including neuroenteric cyst, primary leptomeningeal melanomatosis, isolated dural neurosarcoidosis, intradiploic epidermoid cyst, ruptured dermoid cyst, intraventricular cavernoma, and cavernous hemangioma of the skull with imaging findings and clinico-radiological differential diagnosis, including the pathologic correlation. Familiarity with these entities may improve diagnostic accuracy and patient management.

A case of pituitary apoplexy following posterior lumbar fusion surgery.

Pituitary adenoma is a common primary brain neoplasm. Pituitary apoplexy (PA) is a rare complication of pituitary adenoma and occurs as the result of sudden tumor growth and following different comorbidities. The authors describe the first case of PA following posterior lumbar fusion surgery performed while the patient was prone. In patients with a preexisting pituitary adenoma, thorough clinical and laboratory investigations should be conducted using an interdisciplinary approach before any planned surgery. In unknown cases of pituitary adenoma, PA should be kept in mind for the differential diagnosis in a case with headache, nausea, vomiting, ophthalmoplegia, visual loss, and electrolyte imbalance concurrent with an ongoing disease state.

Multiple hemorrhages in brain after spine surgery supra- and infra-tentorial components together.

Remote cerebellar hemorrhage after cranial and spinal surgeries is a well-documented entity, so far concomitant supra- and infra-tentorial hemorrhage after spine surgery has rarely been reported in the literature. A 57-year-old woman presented with intractable low back pain and severely impaired mobility. One year ago, she underwent lumbar laminectomy and fusion with posterior spinal instrumentation between L2 and S1. She developed adjacent segment disease at the upper level of the instrumented vertebra. She had a revision surgery and underwent posterior laminectomy and fusion with bilateral transpedicular instrumentation between T10 and S1. She had severe headache, somnolence, and left hemiparesia 48 h after the surgery. Her emergent head computed tomography depicted intra-parenchymal hemorrhage in the right parietal lobe accompanying with subarachnoid hemorrhage, bilateral symmetrical cerebellar hemorrhages and pneumocephalus. She was treated nonsurgically and she got better despite some residual deficits. Symptoms including constant headache, nausea, vomiting, impaired consciousness, new onset seizure, and focal neurological deficit after spine surgeries should raise suspicion for intracranial intra-parenchymal hemorrhage.

A Very Quickly Prepared, Colored Silicone Material for Injecting into Cerebral Vasculature for Anatomical Dissection: A Novel and Suitable Material for both Fresh and Non-Fresh Cadavers.

AIM Cadaveric studies have a great impact on neuroanatomy learning. Cadaver preparation may take a lot of effort, especially at the phase of intravascular color filling. The authors describe their silicone dye technique and a novel mixture which is self-curing, quick to prepare and easy to inject. MATERIAL AND METHODS The first one of these processes is undoubtedly embalming and decapitation of the cadaver. If possible, the most appropriate time that should be preferred is immediately after the donors death. Preparation for cadaveric dissection of the brain requires some fundamental steps that can be summarized into: a) Embalming and decapitation, b) Exposing, cannulization and irrigation of main vascular structures, c) Preparing colored silicone, d) Injection of colored silicone and staining the vascular tree, e) Sample maintenance RESULTS Our method of preparation of silicone dye and injection enables neurosurgeons and anatomists to fill cerebral and dural vascular structures, and even diploic veins nicely in both fresh and aged cadaveric heads. Moreover, the main vascular structures and their branches in the lateral and third ventricles are painted remarkably beautifully. CONCLUSION We tried to provide our experience about the preparation of head cadavers for anatomical dissection using a novel mixture of colored silicone that is very easy to prepare and inject with very satisfactory results.

Isolated metastasis of breast cancer to the pituitary gland

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Ossified-calcified intradural and extradural thoracic spinal meningioma with neural foraminal extension

A 26-year-old woman presented with progressive back pain and paraparesis. Thoracic spine magnetic resonance imaging revealed an intradural-extradural D9–D11 mass that extended to the enlarged left neural foramens. The tumor showed heterogeneous low signal on the T2and T1-weighted images, and intense enhancement on postcontrast images. The compressed spinal cord revealed T2-hyperintensity caused by myelopathy (Figs. 1–3). The plain computed tomography scan demonstrated a heavily ossified-calcified tumor (Fig. 4). Total tumor resection was performed, and the pathologic diagnosis was meningothelial meningioma WHO grade 1 with psammoma bodies. Ossified-calcified intradural and extradural thoracic spinal meningioma is extremely rare [1–3], and together with foraminal extension is yet to be reported. Awareness of the imaging findings of this rare presentation is essential to overcoming diagnostic and therapeutic difficulties.

Isolated third ventricle glioblastoma

AbstractIntroduction Glioblastoma is the most common and the most malignant type of gliomas. Cerebral hemispheres are usual locations for gliomas. Isolated third ventricular presentation is very rare for glioblastomas. A new case of isolated third ventricular glioblastoma has been presented in this report.Case descriptionA 36-year-old woman was admitted to outpatient clinic with headache, blurred vision and confusion. A head CT scan and MRI had showed third ventricular mass lesion with obstructive hydrocephalus. Previous to her admission to our clinic, a ventriculo-peritoneal shunt had been inserted and her hydrocephalus had been relieved to some extent in acute settings. In our clinic, stereotactic biopsy was performed and a second ventriculoperitoneal shunt was inserted from the opposite site. Histopathological diagnosis was glioblastoma. Radiotherapy and chemotherapy were started immediately after the surgery. Patient’s hydrocephalus has resolved and she was well at post-operative 6th month.Discussion and evaluationIn differential diagnosis list of the tumors presenting in the third ventricle, there are plenty of tumors such as colloid cyst, meningioma, germinoma, craniopharyngioma, lymphoma, choroid plexus papilloma, subependymal giant cell astrocytoma, chiasmatic and hypothalamic benign astrocytoma. Ring enhancement of this region pathology is a peculiar sign for glioblastoma, yet not pathognomonic. Tumor histology is crucial to yield the final diagnosis.ConclusionManagement of obstructive hydrocephalus, making histopathological diagnosis, starting adjuvant radiotherapy and chemotherapy in isolated third ventricular glioblastomas is a safe and effective approach when we consider malignant nature and intractable progress of glioblastomas.

Familial occurrence of brain arteriovenous malformation: a novel ACVRL1 mutation detected by whole exome sequencing

OBJECTIVE Brain arteriovenous malformations (AVMs) can occur in patients with hereditary hemorrhagic telangiectasia (HHT). However, brain AVM without HHT has also been reported. Using whole exome sequencing, the authors performed comprehensive genomic characterization of a 6-person Turkish family with 3 cases of brain AVM without HHT. METHODS Three siblings with brain AVM, one of whom also had spinal AVM, were evaluated. The parents and the fourth sibling had no AVM on cranial MRI. The authors performed a whole exome capture and Illumina sequencing on blood samples from 2 siblings with AVM. RESULTS An ACVRL1 heterozygous mutation (p.Lys332Glu) was identified in 2 patients via whole exome sequencing. Variant segregation was confirmed using direct Sanger sequencing. CONCLUSIONS Study results suggested that whole exome sequencing analysis is particularly useful in cases of locus heterogeneity and uncertain diagnostic classification schemes in patients with hereditary brain AVM.