Anatomy The soft tissue structures of the orbit are contained within a bony cavity and include the globe, extraocular muscles, optic nerve–sheath complex, lacrimal apparatus, and various vascular and nerve structures ( Figs. 20-1 to 20-4 ). Bony Anatomy The…
Introduction The white matter of the central nervous system (CNS) is made up of myelinated neuronal axons. Myelin is a dielectric material composed in large part of lipids; it allows for rapid propagation of nerve impulses and is critical for…
Anatomy and Embryology Meninges The meninges, which form the coverings of the brain and spinal cord, develop from the meninx primitiva. The neural tube is surrounded by this dense cellular layer shortly after the neural tube closes. As early as…
Introduction The first reported in vivo localized proton ( 1 H) magnetic resonance spectroscopy (H1-MRS) studies of the human brain were first reported over 20 years ago. Since these early studies, in vivo H1-MRS brain studies have been shown to…
Introduction Magnetic resonance imaging (MRI) is very adept at displaying structural anatomy of the brain in great detail. However, the correlation between anatomy and function is not always clear or apparent, and this becomes particularly difficult in situations where the…
It is often clinically difficult to differentiate among the various neurodegenerative disorders such as dementias, hydrocephalus, and movement disorders, and even between pathologic and normal aging. In recent years, more specific and sensitive neuroimaging criteria have evolved to more accurately…
Introduction More than 10,000 spinal cord injuries are diagnosed each year in the United States, with over half involving the cervical spinal cord. Multidetector computed tomography (CT) is recommended by the American College of Radiology as the first-line screening exam…
Introduction Nearly 2 million cases of traumatic brain injury (TBI) occur each year. Worldwide, trauma is the leading cause of death and disability in those younger than 45 years, with nearly half of fatalities resulting from TBI. In younger patients,…
Cerebral Aneurysms Incidence and Natural History The incidence of a cerebral aneurysm in the general population is 0.5% to 5%. Women more commonly harbor a cerebral aneurysm than men, and aneurysm development increases with advancing age. Some families demonstrate a…
Introduction Stroke is the second leading cause of death worldwide. Globally an estimated 16.9 million cases of new stroke occurred in 2010, resulting in 5.9 million stroke deaths. In the United States, a stroke occurs every 40 seconds, with a…