An acoustic neuroma (also sometimes termed a neurolemmoma or schwannoma) is a benign (non-cancerous) tissue growth that arises on the eighth cranial nerve leading from the Brain to the inner ear. The first symptom in 90% of those with a tumor is a reduction in hearing in one ear, often accompanied by ear noise or Tinnitus. Unsteadiness and balance problems may occur during the growth of the neuroma. Large tumours can press on the trigeminal nerve, causing facial numbness and tingling. The tumour is most commonly located at the base of the brain, where the auditory nerve leaves the Skull cavity and enters the bony structure of the inner ear.

Acoustic neuroma (or Vestibular Schwannoma) is a benign tumour of the acoustic nerve (more properly the Vestibulocochlear Nerve) just after it has left the brainstem, in the pontine angle. Acoustic Neuromais a non-cancerous tumour that may develop from an overproduction of Schwann cells that press on the hearing and balance nerves in the inner ear. Schwann cells are cells that normally wrap around and support nerve fibres. If the tumor becomes large, it can press on the Facial Nerve or brain structure.

Ears

There are two types of acoustic Neuromas: Unilateral acoustic neuromas affect only one Ear:

Account for 8 percent of all tumors inside the skull. May develop at any age, but most often occur between the age of 30 and 60 May be the result of gene damage caused by environmental factors.

Bilateral acoustic Neuromas affect both ears:

Are hereditary, caused by a genetic disorder called Neurofibromatosis. Develop in the teens or early adulthood.

These tumours are thought to arise when there is a defect in a certain tumour suppressor gene, which normally prevents tumours from occurring. The cause of the genetic defect is not known. However, acoustic neuroma is often linked with the genetic disorder neurofibromatosis type 2 (NF2). Acoustic neuromas are relatively uncommon in general, but they are one of the most common types of brain tumours. They affect approximately 1 out of 100,000 people per year.

The symptoms vary with the size and location of the tumour. Because the tumours grow so slowly, symptoms usually arise after the age of 30. Common symptoms include:

Tinnitus (ringing) in the affected ear Hearing loss in the affected ear Vertigo (an abnormal sensation of movement) Paralysis of facial nerve

Less common symptoms include: Headache

Upon awakening in the morning Which awakens patient from sleep Aggravated by lying down, reclining position Aggravated by standing up Aggravated by coughing, sneezing, straining, lifting (Valsalva maneuver)

With Nausea or vomiting Difficulty in understanding speech (out of proportion to total hearing loss) Dizziness Loss of balance Numbness in the face or one ear Pain in the face or one ear Transient vision abnormalities

Early diagnosis offers the best opportunity for successful treatment.

Head CT Audiology (a test for hearing) Caloric stimulation (a test for vertigo) Electronystagmography (a test of equilibrium and balance) Brainstem auditory evoked response (BAER, a test of hearing and brainstem function) MRI scan

Specific treatment will be determined by the physician(s) based on:

Patient's age, overall health and medical history Extent of the disease Expectations for the course of the disease Patient's tolerance for specific medications, procedures or therapies Patient's (or family's) opinion or preference

Treatment may include surgery to remove small acoustic Neuromas Surgery Goals of surgical treatment are removal of the tumour and prevention of facial paralysis. Preservation of hearing is more difficult. If a tumour is removed when it is very small, hearing may be preserved. Any hearing that is lost prior to surgery will not be regained. Large tumours usually result in total loss of hearing on the affected side. Large tumors may also compress nerves important for facial movement and sensation. These tumours can typically be safely removed, but the surgery often results in paralysis of some facial Muscles.

Stereotactic radiosurgery Radiosurgery is often performed in elderly or sick patients who are unable to tolerate brain surgery.

There are no guidelines for preventing the development of an acoustic neuroma because the cause is not usually known.

Acoustic neuromas are benign and noncancerous. They do not spread (metastasize) to other body systems, but they may continue to grow and compress vital structures within the skull.