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Acoustic neuroma (or Vestibular Schwannoma) is a benign tumor of the myelin forming cells called "Schwann cells" of the 8th cranial nerve, known as the acoustic nerve, (or more properly the vestibulocochlear nerve) just after it has left the brainstem, in the pontine angle; also at the point where the peripheral part of the nerve meets the brain part of the nerve called "Hensen's node". The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ...
// C00-D48 - Neoplasms (C00-C14) Malignant neoplasms, lip, oral cavity and pharynx (C00) Malignant neoplasm of lip (C01) Malignant neoplasm of base of tongue (C02) Malignant neoplasm of other and unspecified parts of tongue (C03) Malignant neoplasm of gum (C04) Malignant neoplasm of floor of mouth (C05) Malignant neoplasm of...
The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ...
The International Classification of Diseases for Oncology (ICD-O) is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. ...
The International Classification of Diseases for Oncology (ICD-O) is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. ...
The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ...
The Diseases Database is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ...
MedlinePlus (medlineplus. ...
eMedicine is an online clinical medical knowledge base that was founded in 1996. ...
Schwannomas, also referred to as Neurilomas, are slow-growing central nervous system tumours arising from the supporting cells of peripheral nerves, which include cranial and spinal nerve roots). ...
Benign can refer to any medical condition which, untreated or with symptomatic therapy, will not become life-threatening. ...
Tumor (American English) or tumour (British English) originally means swelling, and is sometimes still used with that meaning. ...
In neuroscience, myelin is an electrically insulating phospholipid layer that surrounds the axons of many neurons. ...
Schwann cells are a variety of neuroglia that wrap around axons in the peripheral nervous system, forming the myelin sheath. ...
Cranial nerves are nerves which start directly from the brainstem instead of the spinal cord. ...
The vestibulocochlear nerve is the eighth of twelve cranial nerves, and also known as the auditory nerve. ...
The vestibulocochlear nerve is the eighth of twelve cranial nerves and also known as the auditory nerve. ...
The brain stem is the stalk of the brain below the cerebral hemispheres. ...
Multiple names used for this type of tumor include acoustic neuroma, acoustic neuronoma and vestibular schwannoma because it attacks the 8th cranial nerve which branches in to the vestibular and acoustic; and under a microscope the tumor resembles schwann cells. Schwann cells are a variety of neuroglia that wrap around axons in the peripheral nervous system, forming the myelin sheath. ...
Assessment
Associated symptoms are unilateral sensorineural hearing loss/deafness and vertigo. Additionally more than 80% of patients having acoustic neuromas have reported tinnitus. Larger tumors can compress local structures such as the facial nerve, and lead to local symptoms such as hydrocephalus. The term symptom (from the Greek syn = con/plus and pipto = fall, together meaning co-exist) has two similar meanings in the context of physical and mental health: A symptom may loosely be said to be a physical condition which shows that one has a particular illness or disorder (see...
Sensorineural hearing loss is a type of hearing loss in which the root cause lies in the vestibulocochlear nerve (Cranial nerve VIII), the inner ear, or central processing centers of the brain. ...
This article is about hearing impairment in the patholocial sense. ...
Vertigo, sometimes called a headrush, is the sensation of spinning while the body is stationary. ...
Tinnitus, ringing ears or ear noise is a phenomenon of the nervous system connected to the ear, characterised by perception of a ringing or beating sound (often perceived as sinusoidal) with no external source. ...
The structure of a thing is how the parts of it relate to each other, how it is put together. This contrast with process, which is how the thing works; but process requires a viable structure. ...
The facial nerve is seventh of twelve paired cranial nerves. ...
If the tumor grows next to the brain stem and grows large enough, the brainstem may become compressed. Also associated with these nerves is the 7th cranial nerve; this nerve controls the muscles of the face, salivation, tearing, and taste. If a significantly large tumor develops it can involve the 5th cranial nerve controlling the sensation face and eyes. Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ...
The facial nerve is seventh of twelve paired cranial nerves. ...
For the band, see Saliva (band). ...
Taste is one of the most common and fundamental of the senses of animals. ...
The trigeminal nerve is the fifth (V) cranial nerve, and carries sensory information from most of the face, as well as motor supply to the muscles of mastication (the muscles enabling chewing), tensor tympani (in the middle ear) and other muscles in the floor of the mouth, such as the...
While most cases occur sporadically, acoustic neuroma may be attributable to neurofibromatosis (type 2) in about 5% to 10% of the cases. If the tumor is caused by Neurofibromatosis a slightly different type of tumor grows, then the tumor often involves the whole nerve rather than particular sections of the nerve as does the schwannoma which can make treatment more a greater challenge. Also the tumor is classically bilateral with this syndrome. Neurofibromatosis is a autosomal dominant genetic disorder. ...
Neurofibromatosis Type II is an inherited disease. ...
Treatment Indicated treatments for acoustic neuroma include surgical removal and radiotherapy. Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ...
Conservative treatment Because these neuromata grow so slowly, a physician may opt for conservative treatment beginning with an observation period. In such a case, the tumor is monitored by annual MRI to monitor growth. Records suggest that about 45% of acoustic neuromata do not grow detectably over the 3-5 years of observation. In rare cases, acoustical neuromata have been known to shrink spontaneously. Oftentimes, people with acoustic neruromata die of other causes before the neuroma becomes life-threatening. (This is especially true of elderly people possessing a small neuroma.) The mri are a fictional alien species in the Faded Sun Trilogy of C.J. Cherryh. ...
Death is the cessation of physical life in a living organism, or the state of the deceased. ...
Old age consists of ages nearing the average life span of human beings, and thus the end of the human life cycle. ...
Since the growth rate of an acoustic neuroma rarely accelerates, annual observation is essential. Annual, from the Latin annuum, or year means pertaining to a year or happening every year. ...
Acoustic neuromata may cause either gradual or—less commonly—sudden hearing loss and tinnitus. However, the surgical and radiotherapy treatments are even more dangerous to the hearing in the affected ear. This article is a physical description of hearing impairment. ...
Tinnitus, ringing ears or ear noise is a phenomenon of the nervous system connected to the ear, characterised by perception of a ringing or beating sound (often perceived as sinusoidal) with no external source. ...
Surgery The surgery is done by several approaches and is associated with high incidence of complications and quality of life issues - but it often removes the tumor without recurrence. The vestibular nerve is usually removed on the operated side, resulting in severe imbalance, vertigo and dizziness. However, vestibular function improves rapidly due to compensation by the other ear and other balance mechanisms. Steadiness may never be 100% of the pre-surgical level, but patients are usually walking in the first week after surgery. Surgery also has a risk to the facial nerve which is "monitored" during the surgery. Best results (normal or near normal facial function) are most likely with small acoustic neuromas. The larger the tumor, the higher the risks associated with removing it. Three surgical approaches are commonly used. The first is the translabyrinthine, which destroys hearing in the affected ear. Of the surgical approaches, it tends to be the fastest (less anesthesia time) and allows the most complete removal of the tumor (less chance of recurrence). The two other approaches (suboccipital and middle fossa) are hearing preservation approaches, which have a chance of preserving some or all of the hearing in the affected ear. However, all or most of the hearing in the operated ear is lost approximately 50% of the time. In addition, a number of medical reports indicate that surgically preserved hearing in the operated ear is often not stable, but may deteriorate significantly over a period of years. The hearing preservation approaches tend to require longer surgery, have a higher risk of recurrence and both require brain retraction, which carries a low risk of brain damage. Acoustic neuroma surgery is highly technically demanding, and patients are advised to seek out surgical teams with extensive experience. A typical modern surgical operation For other uses, see Surgery (disambiguation). ...
The vestibular system, or balance system, is the sensory system that provides the dominant input about our movement and orientation in space. ...
Vertigo, sometimes called a headrush, is the sensation of spinning while the body is stationary. ...
Cetacaine, a typical topical anesthetic Anesthesia (American English), also anaesthesia (British English), is the process of blocking the perception of pain and other sensations. ...
Radiation Therapy Radiation therapy is done in a variety of ways, but mainly by two methods: gamma knife radiosurgery or fractionated stereotactic radiotherapy. In the gamma knife approach, 201 beams of gamma radiation are focused on the tumor in a single session. The damage to the tumor at the convergence point often causes it to stop growing or even shrink. The damage may be to the tumor cells and/or to the tumor vasculature. This "controls" the tumor, preventing growth. It is not clear what percentage of tumors are controlled by this method for long periods. In earlier times when higher radiation doses were used, the failure rate was about 12% (which then required surgery). Some surgeons feel that these tumors are much more difficult to remove after radiation treatment, but not all surgeons agree. Radiation does not remove the tumor, and when irradiated tumors are surgically removed, it is often found that they have growing tumor cells in them. Two risks of radiation treatment are carcinogenic progression of the acoustic neuroma (conversion from benign to malignant) or induction of other tumors (such as glioblastoma) in the nearby irradiated brain tissue. The incidence of these events appears to be low, and it is often said to be one in one thousand or less. This calculation is done by dividing the number of obvious cases of tumorigenic progression or secondary tumor reported in the medical literature by the estimated number of gamma knife procedures done in the world to date. This is not a scientifically valid method of estimating the carcinogenic risk of medical radiation exposures, and involves a list of very questionable assumptions. Clinac 2100 C accelerator Radiation therapy (or radiotherapy) is the medical use of ionising radiation as part of cancer treatment to control malignant cells (not to be confused with radiology, the use of radiation in medical imaging and diagnosis). ...
Radiosurgery is a medical procedure which allows non-invasive brain surgery, i. ...
Radiosurgery is a medical procedure which allows non-invasive brain surgery, i. ...
This article is about electromagnetic radiation. ...
In pathology, a carcinogen is any substance or agent that promotes cancer. ...
Benign can refer to any medical condition which, untreated or with symptomatic therapy, will not become life-threatening. ...
In medicine, malignant is a clinical term that is used to describe a clinical course that progresses rapidly to death. ...
The term induction has more than one meaning in the English language. ...
A glioma is a type of primary central nervous system (CNS) tumor that arises from glial cells. ...
The proper and scientifically valid way to estimate such risks can be found at the web site of the Health Physics Society(http://www.hps.org/), were estimates of the risks of CT scans and other procedures can be found. These calculations have never been made for gamma knife radiosurgery. The attraction of radiosurgery is that no one dies from it (not immediately anyway), it is almost painless, and there is no vertigo or facial paralysis immediately after. Facial nerve damage is usually mild, slow (months) and transient. Patients often return to work the next day. Since the tumor is not removed or destroyed by the treatment, there is a possibility of regrowth, which might be rapid. Due to the possibility of regrowth and the possibility of tumorigenic progression or secondary tumors, it is essential that radiation treatments for acoustic neuromas be followed by yearly MRI for the rest of the patient's life. MRI at this time (2005) cost about $3,000. Long-term secondary effects (for instance cognitive effects) on a scale of 10-20 years are not yet established for gamma knife surgery. Paralysis is the complete loss of muscle function for one or more muscle groups. ...
2005 (MMV) was a common year starting on Saturday of the Gregorian calendar. ...
Cognitive The scientific study of how people obtain, retrieve, store and manipulate information. ...
Fractionated stereotactic therapy involves a beam of ionizing radiation focused on the tumor from a moving gantry. The beam is wider and less accurate than that of the gamma knife. The total dose is also much higher than that used in gamma knife radiosurgery, but the fractionation of the dose (done on many different days) spares normal tissue. This method has not been done on as many patients as gamma knife procedures and there have not been as many years of follow-up study. This means that the tumor control by this method is not yet established, and the incidence of secondary effects of the radiation are not yet known. ...
A Gantry is an overhead crane, usually stradling (a support foot on either side) the payload to be lifted. ...
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