What is an optic nerve glioma?
An optic nerve glioma is a type of brain tumor. There are multiple kinds of brain tumors. Typically, each type of tumor is named after the kinds of cells it affects.
Most optic nerve gliomas are considered low-grade and don’t grow as quickly as other types of brain tumors. They are found in the optic chiasm, where the left and right optic nerves cross. They are also referred to as optic glioma or juvenile pilocytic astrocytoma.
Optic nerve glioma is a rare kind of cancer that’s typically slow growing and found in children. It is rarely found in individuals over the age of 20. It has also been associated with the genetic disorder neurofibromatosis type 1, or NF1.
What are the symptoms of an optic nerve glioma?
Symptoms of an optic nerve glioma are caused by the tumor pressing against the nerves. Common symptoms of this kind of tumor include:
- nausea and vomiting
- balance problems
- vision disturbances
Other symptoms can include:
- involuntary eye movements
- memory impairment
- daytime sleepiness
- loss of appetite
- growth delays
Hormone problems may also appear because the tumors can occur near the base of the brain where hormones are controlled.
How is an optic nerve glioma diagnosed?
A neurological exam will typically show partial or total loss of vision or changes in the optic nerves. Increased pressure in the brain may be present. Other tests used to help diagnose optic nerve glioma include brain computed tomography (CT) scans, magnetic resonance imaging (MRI) of the brain, and biopsies.
How is an optic nerve glioma treated?
Treatment for these cancers is best done by a multidisciplinary treatment team. Specialized therapy may be needed if there is memory loss. Members of the treatment team can include neurosurgeons and radiation oncologists. Surgery and radiation therapy are two possible ways of treating optic nerve glioma. Your doctor can determine which type of treatment is best for you.
Surgery is not always an option. Surgery may be performed if doctors believe they can use it to completely remove the tumor. Alternately, if the tumor is not completely removable, surgeons may remove parts of it to help relieve pressure in the skull.
Radiation therapy can be done before surgery to shrink the tumor before doctors it. Alternately, it may be done after surgery to kill any remaining cancer cells. Radiation therapy involves using a machine to aim high-energy rays at the site of the tumor. Radiation therapy is not always recommended because it may cause further damage to the eyes and brain.
Chemotherapy uses medications to kill cancer cells. This is particularly useful if the cancer has spread to other parts of the brain. Corticosteroids may be administered to reduce swelling in the skull.
Treatment can kill healthy brain tissue. The dead tissue can look like cancer, so it needs to be monitored closely to ensure there’s no recurrence. Follow-up visits with your healthcare provider are necessary to check for side effects and ensure the cancer has not returned.
Long-term side effects may occur after treatment for an optic nerve glioma. These tumors typically grow in children, so the effects of radiation or chemotherapy may not be apparent for some time. Cognitive difficulties, learning disabilities, and impairments in growth might occur because of the cancer treatment. Talk with your doctor about possible future side effects and what can be done to reduce the damage caused by treatment.
Having cancer as a child can be socially and emotionally stressful. You or your child may benefit from counseling or a support group. For your child, being around their peers can be a big source of support.