Glioblastoma multiforme (grade IV astrocytoma) Glioblastoma multiforme (GBM) accounts for 52% of all brain gliomas and is the most common type of brain tumor in adults. These tumors contain highly aggressive cells that rapidly invade surrounding tissues. They usually originate in the cerebral hemispheres, but can be found anywhere else in the central nervous system. Can gliomas spread? Metastasis of glioma outside the nervous system is very rare. Usually, gliomas recur locally and may extend to other areas of the brain, but rarely to the spinal cord. Who develops glioma? Gliomas are uncommon compared to other cancers or tumors. Gliomas can occur at any age. The preferred age for mesenchymal astrocytoma is 35-55 years, while the preferred age for glioblastoma multiforme is 45-65 years, and is more common in men. What are the causes of high-grade brain tumors? We know that primary gliomas occur as a result of abnormal or uncontrollable growth of brain cells, but the cause of this growth is not yet known. One risk factor that has been identified is exposure to radiation (mainly due to radiation treatment to the head for other types of cancer). Research on other risk factors (such as exposure to specific chemicals, genetic factors, or infections) is ongoing. So far, there is no evidence to link it to certain things you may have done in your daily life, such as using a cell phone or dying your hair. Also, the vast majority of people with primary glioma do not appear to have a family history of brain tumors at this time, so glioma is not usually hereditary. However, if there is a history of other cancers in your family, you should inform your physician. Possible symptoms: Gliomas usually invade or extend into normal brain tissue, and the pressure of their growth may cause symptoms such as nausea, seizures, vomiting, dizziness or weakness in the upper and lower extremities. These symptoms may be related to the occupancy of the tumor itself or to swelling (edema) in the area surrounding the tumor. The same person may have many different types of symptoms, or may be asymptomatic for a long time, or have only mild symptoms. The chart below lists the types of brain function that may be affected depending on the location of the tumor.