A glioma is any tumor that originates in the brain's supportive tissue, according to the American Brain Tumor Association. Known as glia, this tissue holds the neurons in place and ensures their ongoing function. Three types of glia produce tumors: astrocytes, oligodendrocytes and ependymomas.
Symptoms of glioma depend on the type of tumor. In the case of mixed glioma, when all three glia types blend together in the tumor, the increased pressure within the brain causes the initial symptoms. These symptoms include nausea and headache but also commonly include alterations in personality and behavior as well as issues with vision, notes the American Brain Tumor Association.
As with many types of tumors, researchers have not yet determined the precise cause of glioma. With regard to treatment, it varies with the type of tumor. In the case of mixed glioma, treatment sometimes includes surgery and subsequent radiation therapy, especially in a situation where a person has a high-grade tumor. Chemotherapy is also commonly used for cases of high-grade tumors. With optic glioma, careful scrutiny is the initial treatment plan, although if the tumor only involves the optic nerve, removing the tumor is an option as well, reports the American Brain Tumor Association.