Acoustic neuroma
Acoustic neuroma is a noncancerous (benign) tumor that extends on a section of the eighth cranial nerve, (which runs from your brain to your inner ear) and controls equilibrium and hearing. Also known as vestibular schwannoma, acoustic neuroma is one of the most common types of brain tumors. Though, these tumors are unusual, occurring in about one person in 100,000.
Signs and symptoms
The signs and symptoms of acoustic neuroma are produced from the tumor pressing on the hearing segment of the eighth nerve. Most acoustic neuromas increase slowly, over many years to become large enough to cause signs and symptoms. Most likely observed in people between ages 30 and 60, acoustic neuromas are uncommon in children, and a higher incidence of occurring in women. In unusual cases, an acoustic neuroma may develop large enough (up to 6 centimeters) to compress on the brainstem and be critical
For some people, the tumor remains so tiny ( less than 1.5 centimeters) it never causes problems. They may need no treatment other than regular monitoring by their doctor .In unusual cases, an acoustic neuroma may develop large enough (up to 6 centimeters) to compress on the brainstem and be critical. Also, large tumors can stop cerebrospinal fluid flow which can cause increased fluid pressure in skull (hydrocephalus). If they need treatment, the choices include radiosurgery and surgical removal.
Signs and symptoms include:
* Permanent Hearing loss, typically gradual — although in some cases sudden — and occurring on only one side or more prominent on one side
* Ringing (tinnitus) in the affected ear
* Dizziness (vertigo)
* Loss of equilibrium
* Facial numbness and tingling
* Headaches
* Mental Confusion
The cause of acoustic neuromas is unknown. But, the tumors, in unusual cases, are a sign of neurofibromatosis 2, a genetic disorder that involves the development of tumors on the vestibulocochlear nerve (bilaterally).
Diagnosis
Because signs and symptoms of acoustic neuroma are likely to develop slowly and because hearing loss, tinnitus and dizziness can be signs of other middle and inner ear problems, it may be complicated for the doctor to identify the tumor in its beginning stage. Acoustic neuromas often are found during testing for other conditions.
* Scans. Magnetic resonance imaging (MRI) or computerized tomography (CT) scans of the head can provide images that confirm the presence of an acoustic neuroma.
* Hearing test (audiometry). During this test performed by a hearing specialist (audiologist), the patient wears earphones and hears sounds directed to one ear at a time. The audiologist presents a range of sounds of different tones and asks them to specify each time they hear the sound. Each tone is repeated at soft levels to find out when they can barely hear. The audiologist also will present various words to determine their hearing ability.
* Electronystagmography (ENG). This test assesses balance (vestibular) function by identifying abnormal rhythmic eye movement (nystagmus) often present with inner ear conditions. The test measures involuntary eye movements while stressing balance in various ways.
* Brainstem auditory evoked response (BAER). This test tests hearing and neurological functions. Electrodes on the scalp and earlobes capture the brain's responses to clicking sounds heard through earphones and record the responses on a graph.
Treatment
There are three choices for managing an acoustic neuroma: observation to determine whether it's growing and how fast, radiation and surgical removal.
Monitoring
If it is a small acoustic neuroma that isn't growing or is growing slowly and causes few or no signs or symptoms, the doctor may decide to monitor it, especially if in an older adult or otherwise not a good candidate for treatment.
The doctor may suggest regular imaging and hearing tests to determine whether the tumor is growing and how quickly. If the scans show the tumor is growing or if the tumor causes progressive hearing loss or other difficulties, treatment may be necessary.
Radiation
Several forms of radiation are used to treat acoustic neuromas. One, a procedure called gamma-knife radiosurgery, enables doctors to deliver radiation accurately to a tumor without making an incision. The doctor attaches a lightweight head frame to the numbed scalp. Using imaging scans, the doctor localizes the tumor and then plots where to apply the radiation beams. This procedure often is performed under local anesthesia.
The purpose of radiosurgery is to stop the growth of a small tumor. It also may be used for residual tumors, portions of a tumor that traditional brain surgery can't remove without damaging brain tissue.
It may take weeks, months, or years before the effects of radiosurgery become evident. The doctor will monitor the progress with follow-up imaging studies.
Immediate side effects of gamma-knife procedures are minimal and may include nausea, neck stiffness, and pain where the frame was attached to the scalp. Long-term risks may include facial paralysis and hearing loss.
Surgical removal
The purpose of surgery is to remove the tumor and maintain the facial nerve to prevent facial paralysis and preserve hearing. Performed under general anesthesia, this type of surgery involves removing the tumor through an incision in the skull. Recovery may take six to 12 weeks.
Risks include infection, bleeding, and reaction to the anesthesia. As with radiosurgery, there is a risk of hearing loss and facial paralysis. The patient is not likely to regain hearing lost as a result of the acoustic neuroma.
Acoustic Neuroma Information from: Eight Edition Profession Guide To Diseases by: Lippincott Williams and Wilkins and from: mayoclinic.org
Acoustic neuroma is a noncancerous (benign) tumor that extends on a section of the eighth cranial nerve, (which runs from your brain to your inner ear) and controls equilibrium and hearing. Also known as vestibular schwannoma, acoustic neuroma is one of the most common types of brain tumors. Though, these tumors are unusual, occurring in about one person in 100,000.
Signs and symptoms
The signs and symptoms of acoustic neuroma are produced from the tumor pressing on the hearing segment of the eighth nerve. Most acoustic neuromas increase slowly, over many years to become large enough to cause signs and symptoms. Most likely observed in people between ages 30 and 60, acoustic neuromas are uncommon in children, and a higher incidence of occurring in women. In unusual cases, an acoustic neuroma may develop large enough (up to 6 centimeters) to compress on the brainstem and be critical
For some people, the tumor remains so tiny ( less than 1.5 centimeters) it never causes problems. They may need no treatment other than regular monitoring by their doctor .In unusual cases, an acoustic neuroma may develop large enough (up to 6 centimeters) to compress on the brainstem and be critical. Also, large tumors can stop cerebrospinal fluid flow which can cause increased fluid pressure in skull (hydrocephalus). If they need treatment, the choices include radiosurgery and surgical removal.
Signs and symptoms include:
* Permanent Hearing loss, typically gradual — although in some cases sudden — and occurring on only one side or more prominent on one side
* Ringing (tinnitus) in the affected ear
* Dizziness (vertigo)
* Loss of equilibrium
* Facial numbness and tingling
* Headaches
* Mental Confusion
The cause of acoustic neuromas is unknown. But, the tumors, in unusual cases, are a sign of neurofibromatosis 2, a genetic disorder that involves the development of tumors on the vestibulocochlear nerve (bilaterally).
Diagnosis
Because signs and symptoms of acoustic neuroma are likely to develop slowly and because hearing loss, tinnitus and dizziness can be signs of other middle and inner ear problems, it may be complicated for the doctor to identify the tumor in its beginning stage. Acoustic neuromas often are found during testing for other conditions.
* Scans. Magnetic resonance imaging (MRI) or computerized tomography (CT) scans of the head can provide images that confirm the presence of an acoustic neuroma.
* Hearing test (audiometry). During this test performed by a hearing specialist (audiologist), the patient wears earphones and hears sounds directed to one ear at a time. The audiologist presents a range of sounds of different tones and asks them to specify each time they hear the sound. Each tone is repeated at soft levels to find out when they can barely hear. The audiologist also will present various words to determine their hearing ability.
* Electronystagmography (ENG). This test assesses balance (vestibular) function by identifying abnormal rhythmic eye movement (nystagmus) often present with inner ear conditions. The test measures involuntary eye movements while stressing balance in various ways.
* Brainstem auditory evoked response (BAER). This test tests hearing and neurological functions. Electrodes on the scalp and earlobes capture the brain's responses to clicking sounds heard through earphones and record the responses on a graph.
Treatment
There are three choices for managing an acoustic neuroma: observation to determine whether it's growing and how fast, radiation and surgical removal.
Monitoring
If it is a small acoustic neuroma that isn't growing or is growing slowly and causes few or no signs or symptoms, the doctor may decide to monitor it, especially if in an older adult or otherwise not a good candidate for treatment.
The doctor may suggest regular imaging and hearing tests to determine whether the tumor is growing and how quickly. If the scans show the tumor is growing or if the tumor causes progressive hearing loss or other difficulties, treatment may be necessary.
Radiation
Several forms of radiation are used to treat acoustic neuromas. One, a procedure called gamma-knife radiosurgery, enables doctors to deliver radiation accurately to a tumor without making an incision. The doctor attaches a lightweight head frame to the numbed scalp. Using imaging scans, the doctor localizes the tumor and then plots where to apply the radiation beams. This procedure often is performed under local anesthesia.
The purpose of radiosurgery is to stop the growth of a small tumor. It also may be used for residual tumors, portions of a tumor that traditional brain surgery can't remove without damaging brain tissue.
It may take weeks, months, or years before the effects of radiosurgery become evident. The doctor will monitor the progress with follow-up imaging studies.
Immediate side effects of gamma-knife procedures are minimal and may include nausea, neck stiffness, and pain where the frame was attached to the scalp. Long-term risks may include facial paralysis and hearing loss.
Surgical removal
The purpose of surgery is to remove the tumor and maintain the facial nerve to prevent facial paralysis and preserve hearing. Performed under general anesthesia, this type of surgery involves removing the tumor through an incision in the skull. Recovery may take six to 12 weeks.
Risks include infection, bleeding, and reaction to the anesthesia. As with radiosurgery, there is a risk of hearing loss and facial paralysis. The patient is not likely to regain hearing lost as a result of the acoustic neuroma.
Acoustic Neuroma Information from: Eight Edition Profession Guide To Diseases by: Lippincott Williams and Wilkins and from: mayoclinic.org
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