Acoustic Neuroma – The Things you should know about it
Acoustic neuroma or also called as vestibular schwannoma is a non cancerous primary intracranial tumor found on the vestibulocochlear nerve which connects the ear to the brain. The tumor found on it can grow slowly but as it grows larger it presses on the balance and hearing nerves. Nonetheless, it is usually asymptomatic or does not usually exhibit symptoms and remains dormant if it does not involve cranial nerves or other parts of the brain.
Acoustic Neuroma symptoms include the following:
- Hearing loss on one or both ears
- Altered gait
- Dizziness accompanied with nausea and vomiting
- Sudden feeling of strong pressure on one or both ears
- Ringing in the ears
The following symptoms may occur in rare cases:
- Loss of sensation in either side of the face and mouth
- Altered gag reflex
- Altered level of consciousness
- Vision problems
- Pain on one or both ears and either side of the face
- Headache especially when you wake up in the morning or rise up in bed, standing up or any activities that requires exerting effort and pressure
Acoustic Neuroma Causes
The cause of acoustic neuroma is often associated with von Recklinghausen neurofibromatosis which is a human genetic disorder and may be present in the following forms:
- Neurofibromastosis type I – occurs during dulthood, involves the 8th cranial nerve which is the vestibulocochlear nerve but may also involve other cranial nerves.
- Neurofibromastosis type II- occurs before the age of 21, usually bilateral.
Other scientist and researchers believe that acoustic neuroma may also result from an idiopathic cause, meaning the underlying factor regarding the development of the said disease is still unknown.
What is known is that when it grows larger it presses the other parts of the cranial nerve which may in turn cause for an obstruction of the CSF or the cerebrospinal fluid thus increasing intracranial pressure.
What to do when symptoms are experienced?
If two to three symptoms given above occur to you once or twice every week, going to your physician will be the number one recommendation so they can be able to examine your ears very well. The symptoms may mask as middle ear infection and maybe taken for granted most of the time but here are some test to check and diagnose the problem.
- Contrast- enhance computed tomography or CT scan
- MRI with gadolinium enhancement
- Vestibular test
- Hearing test or audiology
- Physical exam
The following signs may be present on rare cases:
- Facial drooping on one side
- Unsteady gait
- Different size of pupils, one side may be dilated
- Caloric stimulation or the test for vertigo
- Brainstem auditory evoked response where hearing and brain function will be tested
- Electronystagmography where balance and equilibrium will be tested
Acoustic Neuroma treatment
Treatment for acoustic neuroma may depend from person to person because it is based on the size and location of the tumor, your overall health and as well as your age.
- Conservative Treatment
This kind of treatment begins with an observation period and is done only for small tumors that grow slowly. Physicians suggest that frequent monitoring should be done for patients who are elderly especially those at the age of 60 above for the neuroma is proven to grow only after 4-5 years, it may also shrink spontaneously as the years pass. Regular MRI scans are done annually to monitor the tumor’s growth and annual checkups with the physician should also be made to evaluate the signs and symptoms so as to prevent further damage.
- Radiation Therapy
Radiation therapy aims to decrease the size of tumor or to stop or slow it down from growing. There are an array of approach for radiation therapy however there are only four main methods which is as follows:
- Gamma knife radiosurgery
This is a single session approach where 201 beams of radiation are focused on the tumor itself. It may cause the tumor to stop growing and shrink the tumor for short term only since it causes necrosis or cell death on it.
- Fractionatedstereotactic readiotheraphy with a linear accelerator
This approach is less accurate than the gamma knife since it uses a moving gantry to focus a wider beam of ionizing radiation on the tumor. The dose its also higher but the good thing is, it does not harm the normal tissues around the tumor.
- Proton therapy
A cyclotron which is a type of particle accelerator, is used to generate the beam of protons to act on the tumor and kill it; these protons that are utilized can be immediately stopped just before they find their way out of the tumor thus decreasing the risk of damage to normal tissues.
Removal of the neuroma through surgery is only done when:
- Tumors are growing at a fast pace
- Tumors are large in size
- Tumors that are detected near a nerve which may cause possible hearing problems and other complications
- Tumors that cause symptoms
There are three surgical approaches that are commonly used for patients with acoustic neuroma, these are the following:
- Translabyrinthine Approach
This approach can be performed to remove any size of tumor in people who cannot clearly hear in the affected ear. If this kind of surgery is utilized, it will annihilate the hearing on the affected ear however, it is proven to be the safest route for removing the tumor.
- Middle Fossa
This surgery is applied for tumors that have less than 2cm in dimension, it is preferred by most patients since it has a direct access to the lateral end of the auditory canal thus gives the chance to conserve the hearing ability in the affected ear.
- Suboccipital Retrosigmoid
Suboccipital Retrosigmoid may or may not preserve the hearing function in the affected ear since it passes through the posterior semicircular canal before reaching the lateral end of the internal auditory canal where the tumor cells are usually located. If this happens then hearing may be loss.
As soon as you are experiencing the symptoms, consult your physician so no further damage will occur because if it is left untreated, it may damage the nerves that is essential for healing and balance and as well as the ones in charge for the sensation and movement in the face. Some large tumors can also cause fluid buildup in the brain which may be life threatening.