Optic pathway glioma
Overview
A type of tumor that arises in the optic nerve which sends messages from the eye to the brain. These tumors tend to occur mainly in children under the age of 10. The tumor may affect the hormone center of the brain and hence can affect such things as growth and weight.
Symptoms
* Head tilting in infants * Abnormal eye movement * Head bobbing in infants * Vision loss * Developmental delay
Causes
Although we know what happens to the cells that form an optic pathway glioma, we do not really understand why this affects some children and not others. We cannot find a cause in the majority of children. An optic pathway glioma is not caused by diet, lifestyle or upbringing differences, medicines given to parents or children or difficulties with pregnancy and birth. Some children with the genetic condition neurofibromatosis type 1 are at an increased risk of developing these tumours.
Diagnosis
Diagnostic procedures for an optic pathway glioma may include: * physical examination - the child may demonstrate decreased vision, a loss of peripheral vision and/or abnormal eye movements * computerized tomography scan (also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. CT scans are more detailed than general x-rays. For optic pathway glioma, a CT scan of the brain is usually done. * magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body. For optic pathway glioma, an MRI of the brain is usually done. * examination and visual testing - an ophthalmologist will exam the child and conduct comprehensive visual testing. This information will be used in conjunction with MRI findings to make an accurate diagnosis. Surgical biopsy and tumor removal are not routinely performed due to the risk of damaging the delicate optic pathway system.
Treatment
There are three main types of treatment for children with brain tumours: surgery, radiotherapy and chemotherapy. For more information about these treatment options and any risks or side effects associated with them, please see the information sheets about surgery, chemotherapy and radiotherapy.