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Head and Neck
Published in Bobby Krishnachetty, Abdul Syed, Harriet Scott, Applied Anatomy for the FRCA, 2020
Bobby Krishnachetty, Abdul Syed, Harriet Scott
The optic nerve receives its inputs at the optic disc of the retina. It leaves the retina at its site of origin (optic disc) and follows an intraconal course (approximately 2.5 cm), exiting the orbit at the optic foramen superomedially to the ophthalmic artery to enter the middle cranial fossa. It passes medially to the internal carotid artery before reaching the optic chiasm, located above the sella turcica. The intracranial component of the nerve is 1.25 cm long. There is some decussation of fibres at the chiasm after which the nerve travels on its respective side to synapse in the lateral geniculate body within the thalamus. Fibres pass from here to the occipital cortex.
The endocrine system
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
The pituitary gland lies in the middle cranial fossa in a small central depression in the sphenoid bone called the sella turcica. Immediately inferior to the sella turcica is the sphenoid sinus and superiorly lies the optic chiasm. The cavernous sinuses containing several cranial nerves (III, IV, branches of V and VI) and the internal carotid arteries lie laterally. The sella turcica is covered by a thin layer of dura. A central defect in the dura allows passage of the pituitary stalk which connects part of the pituitary gland to the hypothalamus.
Summation of Basic Endocrine Data
Published in George H. Gass, Harold M. Kaplan, Handbook of Endocrinology, 2020
The pituitary gland is at the base of the brain, in a depression called the sella turcica. It is connected to the hypothalamus above by a hypophyseal stalk. The gland is divided into an anterior lobe (adenohypophysis) and a posterior lobe (neurohypophysis), and between them a small structure called the pars intermedia. The posterior lobe hormones are manufactured first in the hypothalamus and then transported through a neurosecretory pathway to the posterior lobe where they are stored.
CSF rhinorrhoea after endonasal intervention to the anterior skull base (CRANIAL): proposal for a prospective multicentre observational cohort study
Published in British Journal of Neurosurgery, 2021
Danyal Z. Khan, Soham Bandyopadhyay, Vikesh Patel, Benjamin E. Schroeder, Ivan Cabrilo, David Choi, Simon A. Cudlip, Neil Donnelly, Neil L. Dorward, Daniel M. Fountain, Joan Grieve, Jane Halliday, Angelos G. Kolias, Richard J. Mannion, Alice O’Donnell, Nick Phillips, Rory J. Piper, Bhavna Ramachandran, Thomas Santarius, Parag Sayal, Rishi Sharma, Georgios Solomou, James R. Tysome, Hani J. Marcus, Andrew F Alalade, Shahzada Ahmed, Sinan Al-Barazi, Rafid Al-Mahfoudh, Anuj Bahl, David Bennett, Raj Bhalla, Pragnesh Bhatt, Graham Dow, Anastasios Giamouriadis, Catherine Gilkes, Kanna Gnanalingham, Brendan Hanna, Caroline Hayhurst, Jonathan Hempenstall, Kismet Hossain-Ibrahim, Mark Hughes, Mohsen Javadpour, Alistair Jenkins, Mahmoud Kamel, Mohammad Habibullah Khan, Peter Lacy, Eleni Maratos, Andrew Martin, Nijaguna Mathad, Nigel Mendoza, Showkat Mirza, Sam Muquit, Ramesh Nair, Claire Nicholson, Alex Paluzzi, Dimitris Paraskevopoulos, Omar Pathmanaban, Jonathan Pollock, Bhaskar Ram, Iain Robertson, Peter Ross, Simon Shaw, Alireza Shoakazemi, Saurabh Sinha, Simon Stapleton, Patrick Statham, Benjamin Stew, Nick Thomas, Georgios Tsermoulas, Philip Weir, Adam Williams
The endonasal transsphenoidal approach (TSA) has emerged as the preferred approach in order to resect pituitary adenoma and related sellar pathologies owing to its superior effectiveness and safety profile when compared to transcranial approaches.1,2 This approach is defined by its purpose of accessing the sella turcica through the sphenoid bone. Whilst traditionally performed microscopically, recent technological advances have allowed the TSA to be performed with success endoscopically.1,3 Furthermore, building on these endoscopic techniques, the development of the expanded endonasal approach (EEA) has further improved access to the anterior skull base.4 This approach refers to accessing an area beyond the sella alone, bounded by the frontal sinus, cribriform plate, medial orbital wall, cavernous sinus, posterior clinoid processes, and clivus.5 The EEA is used for the surgical management of many pathologies including large pituitary adenomas, craniopharyngiomas, meningiomas, Rathke’s pouch cysts, clival chordomas and chondrosarcomas.5
Extramedullary hematopoiesis masquerading as a cranial (clivus) tumor
Published in Baylor University Medical Center Proceedings, 2020
John R. Krause, Laura Baugh, Shannon Kelley, Antonio Onofrio, George Snipes
A 57-year-old woman with known hypertension, neurofibromatosis, and polycythemia vera presented with progressive bilateral vision loss. Magnetic resonance imaging revealed a transpatial mass thought to originate from the sella turcica (Figure 1a). The mass measured approximately 5 cm with regional osseous remodeling, and given its presumed origin from the clivus the differential diagnosis favored a clival chondroma, with pituitary macroadenoma, giant cell tumor, plasmacytoma, and lymphoma being additional considerations. A biopsy showed a collection of hematopoietic elements containing erythroid, myeloid, and megakaryocytic cells (Figure 1b). Blasts were not increased with a CD34 immunostain, ruling out a granulocytic sarcoma. The tissue was considered to represent a collection of extramedullary hematopoietic tissue. Given the patient’s history of polycythemia vera, a subsequent bone marrow biopsy was performed, which documented a marrow consistent with polycythemia vera that had evolved to the fibrotic stage (Figures 1c, 1d). The patient was treated with a course of low-dose radiotherapy with resolution of the mass and her visual symptoms.
Amenorrhoea and reversible infertility due to obstructive hydrocephalus: literature review and case report*
Published in British Journal of Neurosurgery, 2018
Kimberly Hamilton, Bermans Iskandar
Literature dating back to the early 1900’s attempts to explain the pathophysiological relationship between endocrine abnormalities and hydrocephalus. In the early days, endocrine dysfunction was suspected in hydrocephalic patients with enlargement of the sella turcica on x-rays of the skull, concurrent obesity and occasionally under-developed genitalia.2 In 1951, Guillaume reported two cases of hydrocephalus and amenorrhoea, in which treatment of the hydrocephalus with lamina terminalis fenestration led to normalization of the hormonal dysfunction.13 This was followed by 29 other reported cases of amenorrhoea in conjunction with hydrocephalus, 23 of which resolved following surgical treatment of hydrocephalus. Three patients underwent the Torkildsen shunt procedure; however all three died of their primary CNS pathology before further assessment of post-operative hormonal status.12 All cases identified in the literature are summarized in Table 1.