Acoustic Neuroma, also sometimes referred to as vestibular schwannoma, is a benign, non-cancerous tumor that grows on your vestibular nerve. The vestibular nerve connects the inner ear to the brain, carrying balance & hearing-related signals to the brain.
Acoustic Neuromas thus are directly responsible for any sudden hearing loss, the pressure inside the ear, dizziness, unsteadiness, &/or a ringing sound in the ears (also called tinnitus) among patients. Acoustic Neuroma usually starts from the Schwann cells covering the vestibular nerve. It can either grow slowly & or not grow at all during the entire duration of its existence in the body.
In rare cases, it may grow quite rapidly & become so large in size that it starts to press on the brain & cause issues with the vital functions of the organs. Acoustic Neuroma treatment generally consists of regular monitoring, radiation therapy, & surgical removal in some cases.
Acoustic Neuroma signs & symptoms are usually not very visible or obvious, at least initially. When symptoms appear, it’s usually due to the tumor’s effects on the hearing & balance of the patient. In some cases, the tumor can put pressure on adjacent nerves controlling facial muscles and sensation, also called facial and trigeminal nerves, nearby blood vessels, or brain structures, causing issues with their functioning.
As the tumor grows in size, it starts to cause some noticeable symptoms. These common signs & symptoms of acoustic neuroma include:
- Hearing loss, which is usually gradual & occurs in one of the ears or is more prominent in one of the ears. Although in some cases, hearing loss can be quite quick.
- Ringing or tinnitus in the affected ear or both ears,
- Disorientation, unsteadiness, or a loss of balance
- BPPV & other kinds of vertigo symptoms
- Facial numbness & in some rare cases, a loss of muscle movements & sensations
Acoustic neuromas are usually benign in nature & do not pose significant medical threats to a patient. However, in some rare cases, they may grow large enough to compress the brain stem, leading to severe symptoms & even death. Diagnosing the acoustic neuroma early on can help greatly with acoustic neuroma treatment, & may also help treat its side effects & symptoms such as BPPV & Vertigo.
Acoustic Neuroma Causes:
A malfunctioning gene on chromosome number 22 is usually the cause of Acoustic Neuroma. Under normal circumstances, this gene is responsible for producing a protein that regulates the growth of Schwann cells covering the vestibular nerve. When this gene malfunctions, it can lead to Acoustic Neuroma. Exactly what causes this gene to malfunction in the first place, is yet unknown to the medical community. Owing to this fact, there is no probable or immediate cause for an acoustic neuroma in most cases. A possible explanation could come in the form of the inheritance of chromosomes.
Risk factors for Acoustic Neuroma:
So far, the only medically confirmed risk factor for acoustic neuroma is having a parental gene affected with the rare genetic disorder, neurofibromatosis type 2. However, even with the above genetic abnormality, only 5% of acoustic neuroma cases are reported in the general population.
Acoustic Neuroma diagnosis:
Acoustic Neuroma is often difficult to diagnose in the initial stages as its symptoms can resemble those of multiple other conditions. The more telling signs & symptoms of acoustic neuroma often develop only in the later stages of the condition, making it even more difficult for doctors to accurately diagnose a patient. Your doctor will likely take your medical history along with a general overview of your symptoms, & conduct an ear examination.
Additionally, your doctor may also give you the following acoustic neuroma tests:
- Hearing test, also known as audiometry: This acoustic neuroma test is conducted by a hearing specialist, also known as an audiologist, & involves directing sounds to the ear, one at a time. The sounds vary in their range & tones, & your audiologist will ask you to report back every time you hear a certain sound. Each of the tones is repeated at weaker levels to determine your range of hearing.
- Imaging: Magnetic Resonance Imaging, or MRI, is often the physician’s choice of test to determine acoustic neuroma, & all other types of tumors as well.
MRI is used to diagnose tumors as small as 1-2 millimeters in diameter. However, a CT scan may miss tumors very small in size.
Acoustic Neuroma treatment strategies may vary based on your exact tumor size, location, frequency of symptoms, & medical history. Acoustic Neuroma treatment takes one of the three approaches; regular, watchful monitoring, surgery, & radiation therapy.
The monitoring aspect of Acoustic Neuroma comes in when your tumor is small, isn’t growing at all, or is growing gradually. This strategy is also used if your medical history makes other more aggressive treatment options unfit. In some cases, constant monitoring may lead to finding out that your acoustic neuroma has shrunk naturally. In which case, your doctor will continue to watch your condition & give you additional BPPV treatment & Vertigo treatment for any vestibular symptoms you develop.
In some cases, you will be needing surgery for your acoustic neuroma. The exact surgical procedure will depend on the exact location of your tumor, its size, & the severity of your symptoms.
The primary aims of the surgery will be to remove the tumor while preserving your hearing & facial muscles in the process.
However, surgery for acoustic neuroma treatment also involves certain complications. These include:
- Cerebrospinal fluid leaking through the wound
- Hearing loss
- Facial weakness
- Ringing in the ears, also known as tinnitus
- Issues with balance
- Headache that persists for a long time
- An infection of the cerebrospinal fluid also called meningitis
- Stroke or bleeding in the brain
Your radiation treatment may consist of a therapy called Stereotactic radiosurgery. Your doctor will recommend this treatment if your tumor is smaller in size( about 3 centimeters), if you’re old, & can’t tolerate surgery for some medical reason.
In this surgery, many tiny gamma rays deliver a predetermined dose of radiation to the exact specified location of the tumor without destroying any tissues around it. The primary goal of radiation therapy is to stop the growth of the tumor, preserve the facial nerve’s structure, & reinstate hearing. Radiotherapy may take weeks, months, or even years to show any effective results. Meanwhile, your doctor will continue to closely monitor your tumor’s growth & any additional symptoms.
In addition to all the other acoustic neuroma treatments, additional supportive therapy may be needed to help out the patient with additional symptoms. This includes palliative care, post-surgery care, & post-radiation therapy care to minimize the harms brought on by certain side-effects of these acoustic neuroma treatment procedures.