Polycystic Ovary Syndrome

An acoustic neuroma is usually benign, but it can still be fatal if left untreated. This is because the tumour will keep growing. Once it runs out of space inside the small canal that links the inner ear to the brain, it begins to grow into the skull cavity.

The tissue at the base of the brain, including a structure called the brain stem, may become squashed by the growing tumour. This can cause a build-up of fluid know as cerebral spinal fluid (CSF). The brain stem is responsible for regulating important bodily functions, including consciousness, heart rate, breathing, blood pressure and swallowing.

There are two types of acoustic neuromas:

• Sporadic, unilateral acoustic neuromas. These tumors only grow on one side of the body in 95% of patients. They occur from sporadic (sudden), nonhereditary mutations. These unilateral acoustic neuromas may develop at any age, but most commonly occur in people between the ages of 30 and 60.
• Genetic, bilateral acoustic neuromas. Acoustic neuromas on both sides of the body only occur in people who have the genetic disorder neurofibromatosis type 2, a mutation in chromosome 22 that affects the gene responsible for production of Schwann cells. These patients often have other schwannoma-like tumors throughout the body, and treatments for these tumors are often different from the treatment for unilateral tumors.

In most cases of acoustic neuromas, the underlying cellular cause can be attributed to the failure of a regulatory gene, often referred to as a “governor” gene, to effectively inhibit the proliferation of Schwann cells. Schwann cells play a crucial role in insulating nerve fibers. When this inhibition mechanism falters, these cells begin to overmultiply, ultimately giving rise to the formation of acoustic neuromas.

As for environmental factors, the only firmly established link to an increased risk of developing acoustic neuromas is exposure to radiation targeting the head. There is currently no compelling evidence to suggest any association between the use of cell phones and the onset of these tumors.

It’s worth noting that acoustic neuroma is typically not considered a hereditary condition. However, approximately five percent of cases are connected to a genetic disorder known as neurofibromatosis type 2 (NF2). In individuals with NF2, bilateral vestibular tumors are common, often accompanied by the presence of other tumors within the brain and/or spinal cord. The majority of acoustic neuromas, though, occur sporadically and are not tied to hereditary factors.

The most common symptom is hearing loss in one ear (unilateral). This symptom happens to about 90% of people who have an acoustic neuroma.

Other symptoms that may occur in the early stages include:

• Ringing in the ears (tinnitus).
• Loss of balance.
• Sensation that you or your environment is moving (vertigo).

As the tumor grows, you may have other symptoms, including:

• Blurry or double vision.
• Facial numbness, weakness, spasms, pain, or paralysis.
• Taste changes.
• Headaches.
• Nausea and vomiting.
• Swallowing difficulty.

Symptoms of acoustic neuromas can mimic symptoms of other ear problems. This similarity makes it challenging to diagnose an acoustic neuroma. Talk to your healthcare provider if you notice any hearing changes.

The earlier the tumour is detected and treated, the greater the chance of a full recovery. Acoustic neuroma can be diagnosed using a variety of tests, including:

• Computed tomography (CT) scan – this is a specialised x-ray that takes three-dimensional pictures of the inner ear. However, small tumours may be missed by this method.
• Magnetic resonance imaging (MRI) scan – pictures of the inner ear are taken, using radio waves in a strong magnetic field instead of x-rays. MRI scans can usually detect smaller acoustic neuromas than CT scans. A dye may be injected to further highlight the tissues under investigation.