Vestibular Schwannoma

Definition

A vestibular schwannoma, also known as an acoustic neuroma, is a type of non-cancerous tumor that develops from the Schwann cells that surround the vestibulocochlear nerve (eighth cranial nerve). This nerve is responsible for transmitting sound and balance information from the inner ear to the brain.

5 Must Know Facts For Your Next Test

1. Vestibular schwannomas typically develop slowly, often over many years, and can cause hearing loss, tinnitus, and balance problems as the tumor grows and compresses the vestibulocochlear nerve.
2. These tumors are the most common type of cerebellopontine angle tumor, accounting for approximately 8% of all intracranial tumors.
3. Symptoms of a vestibular schwannoma may include unilateral hearing loss, tinnitus, vertigo, and facial numbness or weakness, depending on the location and size of the tumor.
4. Diagnosis of a vestibular schwannoma typically involves a combination of imaging tests, such as MRI or CT scans, and audiological evaluations.
5. Treatment options for vestibular schwannomas may include observation, stereotactic radiosurgery, or surgical removal, depending on the size, location, and symptoms of the tumor.

Review Questions

• Explain the role of the vestibulocochlear nerve in the context of a vestibular schwannoma.
  • The vestibulocochlear nerve, also known as the eighth cranial nerve, is responsible for transmitting auditory and vestibular information from the inner ear to the brain. In the case of a vestibular schwannoma, the tumor develops from the Schwann cells that surround this nerve. As the tumor grows, it can compress the vestibulocochlear nerve, leading to symptoms such as unilateral hearing loss, tinnitus, and balance problems. The compression of the nerve by the tumor is a key factor in the clinical presentation and diagnosis of a vestibular schwannoma.
• Describe the typical diagnostic approach for a suspected vestibular schwannoma.
  • The diagnosis of a vestibular schwannoma typically involves a combination of imaging tests and audiological evaluations. Imaging tests, such as MRI or CT scans, are used to visualize the tumor and its location within the cerebellopontine angle. These scans can help confirm the presence and size of the vestibular schwannoma. Additionally, audiological evaluations, including hearing tests and balance assessments, are conducted to assess the extent of nerve dysfunction caused by the tumor. The integration of these diagnostic findings, along with the patient's clinical history and symptoms, allows healthcare providers to make an accurate diagnosis of a vestibular schwannoma.
• Evaluate the potential treatment options for a patient diagnosed with a vestibular schwannoma, considering the factors that may influence the choice of treatment.
  • The treatment options for a patient with a vestibular schwannoma depend on various factors, including the size and location of the tumor, the patient's symptoms, and their overall health status. Observation, or a 'wait-and-see' approach, may be appropriate for small, asymptomatic tumors that are not growing rapidly. Stereotactic radiosurgery, a type of targeted radiation therapy, can be used to shrink or stabilize the tumor in some cases. Surgical removal of the tumor, known as resection, may be recommended for larger tumors or those causing significant symptoms. The choice of treatment ultimately depends on a careful evaluation of the risks and benefits for the individual patient, taking into account the potential impact on hearing, balance, and other neurological functions.

Related terms

Schwann Cells:

Specialized cells that produce the myelin sheath, which insulates and supports nerve fibers in the peripheral nervous system.

Vestibulocochlear Nerve:

The eighth cranial nerve, responsible for transmitting auditory and vestibular information from the inner ear to the brain.

Cranial Nerve Examination:

A physical examination that evaluates the function of the twelve cranial nerves, including the vestibulocochlear nerve.