Translabyrinthine Approach
The translabyrinthine approach is a surgical approach to treating serious disorders of the cerebellopontine angle, (CPA), which is the most common location of posterior fossa tumors. especially acoustic neuroma. In this approach, the semicircular canals and vestibule, including the utricle and the saccule of the inner ear are removed, causing complete hearing loss in the operated ear. The procedure is typically performed by a team of surgeons, including a neurotologist (an ear, nose, and throat surgeon specializing in skull base surgery) as well as a neurosurgeon. Background The translabyrinthine approach was developed by William F. House, M.D., who began doing dissections in the laboratory with the aid of magnification and subsequently developed the first middle cranial fossa and then the translabyrinthine approach for the removal of acoustic neuroma. This surgical approach is typically performed by a team of surgeons, including a neurotologist (an ear, nose, and throat sur ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cerebellopontine Angle
The cerebellopontine angle (CPA) () is located between the cerebellum and the pons. The cerebellopontine angle is the site of the cerebellopontine angle cistern. The cerebellopontine angle is also the site of a set of neurological disorders known as the cerebellopontine angle syndrome. Structure The cerebellopontine angle is formed by the cerebellopontine fissure. This fissure is made when the cerebellum folds over to the pons, creating a sharply defined angle between them. The angle formed in turn creates a subarachnoid cistern, the cerebellopontine angle cistern. The pia mater follows the outline of the fissure and the arachnoid mater continues across the divide so that the subarachnoid space is dilated at this area, forming the cerebellopontine angle cistern. The anterior inferior cerebellar artery (AICA) is the principal vessel of the cerebellopontine angle. It also contains two cranial nerves – the vestibulocochlear nerve and the facial nerve; the cerebellar flocculus ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Acoustic Neuroma
A vestibular schwannoma (VS), also called acoustic neuroma, is a benign tumor that develops on the vestibulocochlear nerve that passes from the inner ear to the brain. The tumor originates when Schwann cells that form the insulating myelin sheath on the nerve malfunction. Normally, Schwann cells function beneficially to protect the nerves which transmit balance and sound information to the brain. However, sometimes a mutation in the tumor suppressor gene, NF2, located on chromosome 22, results in abnormal production of the cell protein named ''Merlin'', and Schwann cells multiply to form a tumor. The tumor originates mostly on the vestibular division of the nerve rather than the cochlear division, but hearing as well as balance will be affected as the tumor enlarges. The great majority of these VSs (95%) are unilateral, in one ear only. They are called "sporadic" (i.e., by-chance, non-hereditary). Although non-cancerous, they can do harm or even become life-threatening if they gr ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Semicircular Canals
The semicircular canals are three semicircular interconnected tubes located in the innermost part of each ear, the inner ear. The three canals are the lateral, anterior and posterior semicircular canals. They are the part of the bony labyrinth, a periosteum-lined cavity on the petrous part of the temporal bone filled with perilymph. Each semicircular canal contains its respective semicircular duct, i.e. the lateral, anterior and posterior semicircular ducts, which provide the sensation of angular acceleration and are part of the membranous labyrinth—therefore filled with endolymph. Structure The semicircular canals are a component of the bony labyrinth that are at right angles from each other and contain their respective semicircular duct. At one end of each of the semicircular ducts is a dilated sac called a membranous ampulla, which is more than twice the diameter of the ducts. Each ampulla contains an ampullary crest, the crista ampullaris which consists of a t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Vestibule Of The Ear
The vestibule is the central part of the bony labyrinth in the inner ear, and is situated medial to the eardrum, behind the cochlea, and in front of the three semicircular canals. The name comes from the Latin ', literally an entrance hall. Structure The vestibule is somewhat oval in shape, but flattened transversely; it measures about 5 mm from front to back, the same from top to bottom, and about 3 mm across. In its lateral or tympanic wall is the oval window, closed, in the fresh state, by the base of the stapes and annular ligament. On its medial wall, at the forepart, is a small circular depression, the recessus sphæricus, which is perforated, at its anterior and inferior part, by several minute holes (macula cribrosa media) for the passage of filaments of the acoustic nerve to the saccule; and behind this depression is an oblique ridge, the crista vestibuli, the anterior end of which is named the pyramid of the vestibule. This ridge bifurcates below to e ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Utricle (ear)
The utricle and saccule are the two otolith organs in the vertebrate inner ear. The word utricle comes . The utricle and saccule are part of the balancing system ( membranous labyrinth) in the vestibule of the bony labyrinth (small oval chamber). They use small stones and a viscous fluid to stimulate hair cells to detect motion and orientation. The utricle detects linear accelerations and head-tilts in the horizontal plane. Structure The utricle is larger than the saccule and is of an oblong form, compressed transversely, and occupies the upper and back part of the vestibule, lying in contact with the recessus ellipticus and the part below it. Macula The macula of utricle (macula acustica utriculi) is a small (2 by 3 mm) thickening lying horizontally on the floor of the utricle where the epithelium contains vestibular hair cells that allow a person to perceive changes in latitudinal acceleration as well as the effects of gravity; it receives the utricular filaments of th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Saccule
The saccule (Latin: sacculus) is a bed of sensory cells in the inner ear that detects linear acceleration and head tilting in the vertical plane, and converts these vibrations into electrical impulses to be interpreted by the brain. When the head moves vertically, the sensory cells of the saccule are moved due to a combination of inertia and gravity. In response, the neurons connected to the saccule transmit electrical impulses that represent this movement to the brain. These impulses travel along the vestibular portion of the eighth cranial nerve to the vestibular nuclei in the brainstem. The vestibular system is important for balance, or equilibrium. It includes the saccule, utricle, and the three semicircular canals. The vestibule is the name of the fluid-filled, membranous duct that contains these organs of balance and is in turn encased in the temporal bone of the skull as a part of the inner ear. Structure The saccule, or sacculus, is the smaller of the two vestib ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Inner Ear
The inner ear (internal ear, auris interna) is the innermost part of the vertebrate ear. In vertebrates, the inner ear is mainly responsible for sound detection and balance. In mammals, it consists of the bony labyrinth, a hollow cavity in the temporal bone of the skull with a system of passages comprising two main functional parts: * The cochlea, dedicated to hearing; converting sound pressure patterns from the outer ear into electrochemical impulses which are passed on to the brain via the auditory nerve. * The vestibular system, dedicated to balance (ability), balance. The inner ear is found in all vertebrates, with substantial variations in form and function. The inner ear is innervated by the eighth cranial nerve in all vertebrates. Structure The labyrinth can be divided by layer or by region. Bony and membranous labyrinths The bony labyrinth, or osseous labyrinth, is the network of passages with bony walls lined with periosteum. The three major parts of the bony labyrin ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Neurotology
Neurotology or neuro-otology is a subspecialty of otolaryngology—head and neck surgery, also known as ENT (ear, nose, and throat) medicine. Neuro-otology is closely related to otology, clinical neurology and neurosurgery. Otology may refer to ENT physicians who "... tudynormal and pathological anatomy and physiology of the ear (hearing and vestibular sensory systems and related structures and functions) ...", and who treat diseases of the ear with medicine or surgery. In some instances, otology and neurotology are considered together—as so closely related that a clear demarcation between the subspecialties might not exist. For example, the University of Maryland Medical Center uses the term, "otologist/neurotologist". Otologists and neurotologists have specialized in otolaryngology and then further specialized in pathological conditions of the ear and related structures. Many general otolaryngologists are trained in otology or middle ear surgery, performing surgery suc ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Neurosurgeon
Neurosurgery or neurological surgery, known in common parlance as brain surgery, is the medical specialty that focuses on the surgical treatment or rehabilitation of disorders which affect any portion of the nervous system including the brain, spinal cord, peripheral nervous system, and cerebrovascular system. Neurosurgery as a medical specialty also includes non-surgical management of some neurological conditions. Education and context In different countries, there are different requirements for an individual to legally practice neurosurgery, and there are varying methods through which they must be educated. In most countries, neurosurgeon training requires a minimum period of seven years after graduating from medical school. United Kingdom In the United Kingdom, students must gain entry into medical school. The MBBS qualification (Bachelor of Medicine, Bachelor of Surgery) takes four to six years depending on the student's route. The newly qualified physician must then comple ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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William F
William is a masculine given name of Germanic languages, Germanic origin. It became popular in England after the Norman Conquest, Norman conquest in 1066,All Things William"Meaning & Origin of the Name"/ref> and remained so throughout the Middle Ages and into the modern era. It is sometimes abbreviated "Wm." Shortened familiar versions in English include Will (given name), Will or Wil, Wills, Willy, Willie, Bill (given name), Bill, Billie (given name), Billie, and Billy (name), Billy. A common Irish people, Irish form is Liam. Scottish people, Scottish diminutives include Wull, Willie or Wullie (as in Oor Wullie). Female forms include Willa, Willemina, Wilma (given name), Wilma and Wilhelmina (given name), Wilhelmina. Etymology William is related to the German language, German given name ''Wilhelm''. Both ultimately descend from Proto-Germanic ''*Wiljahelmaz'', with a direct cognate also in the Old Norse name ''Vilhjalmr'' and a West Germanic borrowing into Medieval Latin ''Wil ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Middle Cranial Fossa
The middle cranial fossa is formed by the sphenoid bones, and the temporal bones. It lodges the temporal lobes, and the pituitary gland. It is deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior cranial fossa by the clivus and the petrous crest. It is bounded in front by the posterior margins of the lesser wings of the sphenoid bone, the anterior clinoid processes, and the ridge forming the anterior margin of the chiasmatic groove; behind, by the superior angles of the petrous portions of the temporal bones and the dorsum sellae; laterally by the temporal squamae, sphenoidal angles of the parietals, and greater wings of the sphenoid. It is traversed by the squamosal, sphenoparietal, sphenosquamosal, and sphenopetrosal sutures. Anatomy Features Middle part The middle part of the fossa presents, in front, the chiasmatic groove and tuberculum sellae; the chiasmatic groove ends o ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |