Walking Dead famed actress Kelley Mack has passed away at the age of 33 on Saturday at her birthplace of Cincinnati. Her demise was confirmed by a social media post by her sister, who mentioned, "It is with indelible sadness that we are announcing the passing of our dear Kelley. Such a bright, fervent light has transitioned to the beyond, where we all eventually must go." View this post on Instagram A post shared by Kelley Mack (@itskelleymack)]]> As per Deadline, the actress was battling with glioma of the central nervous system. She had also posted her health update battling the same, and shared how her radiation therapy had been going. View this post on Instagram A post shared by Kelley Mack (@itskelleymack)]]>What Is Glioma?As per the Johns Hopkins Medicine, glioma is a common type of tumor originating in the brain. About 33% of all brain tumors are gliomas, which originate n the glial cells that surround and support neurons in the brains, including astrocytes, oligodendrocytes and ependymal cells.Also Read: Vanishing Twin Syndrome: Love Island's Olivia Bowen Opens Up About Her Pregnancy Journey and Emotional StruggleGliomas are called intra-axial brain tumors because they grow within the substance of the brain and often mix with normal brain tissue.Types Of GliomaAstrocytomas: Astrocytomas are tumors that form in glial cells, specifically from connective tissue cells called astrocytes. They are the most common type of primary intra-axial brain tumor, making up almost half of all primary brain tumors. These tumors are most often found in the cerebrum, the large outer part of the brain, but they can also occur in the cerebellum, located at the base of the brain.Astrocytomas can affect both children and adults. In children, low-grade astrocytomas, known as pilocytic astrocytomas, are typically found in the cerebellum. In adults, these tumors are more commonly located in the cerebrum. The most aggressive form of astrocytoma is glioblastoma multiforme, a high-grade tumor that is considered the most malignant of all brain tumors. Its symptoms are often similar to those seen with other types of gliomas.Brain stem gliomas: Brain stem gliomas, also known as diffuse infiltrating brainstem gliomas or DIPGs, are rare and usually found in the brain stem. Due to their location and the way they grow by blending into normal brain tissue, they are generally not removable by surgery. These tumors most often affect school-age children and are responsible for the highest number of childhood deaths from primary brain tumors.Ependymomas: Ependymomas develop from ependymal cells, which line the brain’s ventricles or the spinal cord. Although they are rare, making up just 2 to 3 percent of primary brain tumors, they account for 8 to 10 percent of brain tumors in children, especially those younger than 10. In children, these tumors are usually found near the cerebellum, where they may block the flow of cerebrospinal fluid and lead to increased pressure in the skull. Ependymomas can also spread to other areas of the brain or spinal cord through spinal fluid, a process known as drop metastasis.Mixed gliomas: Mixed gliomas, also called oligoastrocytomas, contain more than one type of glial cell. There is some debate over whether these tumors should be classified as a separate type, and genetic testing of tumor tissue is often used to clarify the diagnosis. These tumors usually occur in the cerebrum and are most common in adult men.Oligodendrogliomas : Oligodendrogliomas form from oligodendrocytes, the supportive cells in the brain, and are usually located in the cerebrum. They make up about 2 to 4 percent of primary brain tumors and are more common in men, especially those in young to middle adulthood. Seizures are a frequent symptom, affecting up to 80 percent of patients, along with headaches, weakness, or speech problems. Oligodendrogliomas tend to have a better prognosis than many other gliomas.Optic pathway gliomas: Optic pathway gliomas are low-grade tumors found in the optic nerve or optic chiasm. These tumors often affect people with neurofibromatosis and can lead to vision loss and hormone-related problems, especially since they tend to grow at the base of the brain, near areas responsible for hormone control. When these tumors impact hormone function, they may be referred to as hypothalamic gliomas.What Are The Symptoms of Glioma?HeadachesSeizuresPersonality changesWeakness in the arms, face or legsNumbnessProblems with speechNausea and vomitingVision lossDizziness