Schwannoma Tumor

Schwannoma tumor occurs in the brain. It is a benign tumor affecting the nerve fibers. These brain tumors occur in the benign nerve sheath tumor that is made of Schwann cells. These cells produce the myelin sheath that provides insulation to the peripheral nerves. These are low risk benign tumors and we shall see the reasons in the following paragraphs.

What is it?
This type of tumor affect the nerve sheath of brains. These tumors arise from the supportive tissues of the nerves. These tumors are homogeneous in nature, that is, affect only the Schwann cells. The tumor tends to stay on the outside of the nerve. However, as the tumor grows it tends to push and displace the adjacent nerve fascicles present in the nerve. This tends to cause damage and lead to problems such as pain, weakness and numbness. They occur sporadically, and in only a few cases they tend to be a hereditary disorder.

Location
It occurs in specific regions of the brain. It is located in the following brain areas:

• Cranial Nerve V
• Cranial Nerve VII
• Cranial Nerve VIII
• Cranial Nerve VI and X (very rare)

Symptoms
The symptoms are related to the nerves it affects. Some of the commonly observed symptoms include hearing loss, tinnitus (ringing in ear), stiff neck, fluid accumulation in brain (secondary hyroencephalus), uncoordinated movement, ataxia affecting both arms, etc. In some cases, the tumor is asymptomatic and leads to pain, weakness, facial tingling, and numbness in the body. A few patients develop a mass in their neck or extremities. The nerves that are affected by the tumor may give rise to certain symptoms. These symptoms are as follows:

• Cranial Nerve V: Facial muscle paralysis, mostly on the same side. This leads to hearing loss and loss of corneal reflex. The corneal reflex is the immediate action of the eyelid to close when one touches the cornea.
• Cranial Nerve VI: When the cranial nerve VI is affected, it leads to double vision.
• Cranial Nerve VII: The symptoms in this case include Bell's palsy. This sudden paralysis of the face includes muscle weakness and distorted expression on the face.
• Cranial Nerve X: The cranial nerve X when affected leads to symptoms like weakness in the palate, tongue and nerve muscles. This weakness generally occurs on the same side of the location of the schwannoma brain tumor.

Diagnosis
The diagnosis generally includes a MRI scan with or without contrast. In some cases, a CT scan of the brain may also be taken. In some cases, a CT angiogram or an MR angiogram may be conducted.

Treatment
The tumor is generally asymptomatic in nature, especially, in case of geriatrics. The doctor may advice microsurgery to remove the lesions in case the patient experiences pain, weakness or numbness. In case the affected area is the brain or spine, radiosurgery may be carried out. In about 80 to 90% of the cases, surgery helps in reducing the weakness, numbness and pain experienced by the patients.

These tumors are very slow-growing tumors that affect the craniospinal nerve sheath. It can arise due to neurofibromatosis, a genetic disorder. Only in about 1% of the cases, these benign tumors turn into brain cancers like neurofibrosarcoma. For further information on schwannoma brain tumors and their treatment, speak to a health care provider for more details.