Definition

Glioma is a type of tumor that develops in the brain and spinal cord. Gliomas originate in the glial cells, which support and protect nerve cells. They are among the most frequent types of primary brain tumors. Three different types of glial cells can give rise to tumors. Gliomas are categorized based on the specific type of glial cells involved and the genetic traits of the tumor.

Types of gliomas include:

• Astrocytoma
• Ependymoma
• Oligodendroglioma

Knowing the type of glioma helps predict the tumor's progression over time, the appropriate therapy options, and the prognosis for recovery.

Causes

Like most primary brain tumors, the exact cause of gliomas is unknown. However, research suggests that DNA changes may lead to brain and spinal cord tumors like gliomas. Genes contain DNA that instructs cells on how to grow and divide. Mutations or changes in the DNA within genes can cause cells to divide uncontrollably.

Risk factor

Several factors can increase the risk of brain tumors, including:

• Age: The risk of brain tumors increases with age. Gliomas are most commonly found in adults aged 45 to 65, though brain tumors can occur at any age. Certain types of gliomas, like ependymoma and pilocytic astrocytoma, are more common in children and young adults.
• Radiation exposure: People exposed to a type of radiation called ionizing radiation have an increased risk of brain tumors. Examples of ionizing radiation include radiation therapy for cancer and radiation exposure from atomic bombs. Everyday forms of radiation like electromagnetic radiation from electrical sources and radiofrequency radiation from microwave ovens do not increase the risk of gliomas. It is still unclear whether cell phone use increases the risk of brain cancer. Some studies suggest a possible link between cell phone use and a type of brain cancer called acoustic neuroma, but many other studies do not. More research is needed in this area. If you are concerned about the potential link between cell phones and cancer, experts recommend reducing exposure by using speakerphone or hands-free devices, which allow the phone to be kept away from your head.
• Family history of gliomas: Gliomas are rarely inherited in families. However, having a family history of gliomas can double your risk. Some genes are linked to gliomas, but further research is needed to confirm the association between these genetic variations and brain tumors.

Symptoms

Symptoms of gliomas can vary depending on the type, size, location, and growth rate of the tumor. Common symptoms of gliomas include:

• Headaches
• Nausea or vomiting
• Confusion or decreased brain function
• Memory loss
• Personality changes
• Restlessness or irritability
• Balance problems
• Bladder problems (inability to hold urine, incontinence)
• Vision problems such as blurred vision, double vision, or loss of peripheral vision
• Speech difficulties
• Seizures, especially if the person has a history of seizures

Diagnosis

If a doctor suspects you have a brain tumor, you will be referred to a specialist in brain and nervous system diseases (neurologist). The doctor may recommend several tests and procedures, such as:

• Neurological exam: During a neurological exam, the doctor will check your vision, hearing, balance, coordination, strength, and reflexes. Problems in one or more of these areas may indicate which part of your brain could be affected by a tumor.
• Imaging tests: MRI is often used to diagnose brain tumors. In some cases, a contrast dye may be injected into a vein in your arm during the MRI to help highlight abnormalities in brain tissue. Other tests that may be performed include CT scans and PET scans.
• Tests to find cancer in other parts of the body: To rule out the possibility that the brain tumor is a result of cancer spreading from another part of the body, the doctor may recommend tests and procedures to determine the origin of the cancer. Gliomas originate within the brain and are not a result of cancer spreading from other body parts.
• Biopsy (removing and examining abnormal tissue): Depending on the location of the glioma, a biopsy may be done with a needle before treatment or as part of surgery to remove the brain tumor. Stereotactic needle biopsy can be used for gliomas in hard-to-reach or very sensitive brain areas that could be damaged by more extensive surgery. During this procedure, a neurosurgeon makes a small hole in the skull. A thin needle is then inserted through the hole. Tissue is removed through the needle, usually guided by a CT scan or MRI. The biopsy sample is then analyzed under a microscope to determine whether it is benign or malignant. A biopsy is the only way to definitively diagnose a brain tumor. This information also helps the doctor determine the stage of the brain tumor. The doctor will also examine the appearance and growth rate of the biopsy sample, which helps in planning treatment.

Management

Treatment for gliomas depends on the type, size, stage, location of the tumor, as well as your age, overall health, and preferences. In addition to removing the tumor, treatment for gliomas may also require medications to reduce symptoms caused by the tumor.

Doctors may prescribe steroids to reduce swelling and pressure in the affected brain area. Anti-seizure medications can also be used to control seizures.

Treatments to remove the tumor include:

• Surgery: Surgery to remove as much of the tumor as possible is usually the first step in treating most types of gliomas. In some cases, the glioma is small and easily separated from surrounding healthy brain tissue or located near sensitive areas of the brain, making surgery risky. In such situations, the doctor will remove as much of the tumor as can be safely removed. Removing part of the tumor can help reduce symptoms. In some cases, a pathologist can analyze tissue samples taken during surgery and report the results while the operation is still in progress. This information helps the surgeon decide how much tissue to remove. Surgery for gliomas carries risks such as infection and bleeding. Other risks depend on the tumor's location. For example, surgery on a tumor near the optic nerves can pose a risk to vision.
• Radiation therapy: Radiation therapy is usually performed after surgery, especially for advanced-stage gliomas.
• Chemotherapy: Chemotherapy uses drugs to kill tumor cells. The drugs can be taken orally or injected into a vein.
• Targeted drug therapy: Targeted drug therapy focuses on specific abnormalities in cancer cells. By blocking these abnormalities, the drugs can cause cancer cells to die.

Complications

Gliomas can have life-threatening complications, including:

• Brain hemorrhage
• Brain displacement due to the tumor
• Hydrocephalus (accumulation of fluid in the brain)
• Increased brain pressure
• Seizures

Prevention

Most risk factors for gliomas, such as age and race, cannot be controlled. However, early detection and treatment of early-stage gliomas can slow or prevent progression to advanced-stage gliomas.

If you have a family history of brain tumors, you can undergo genetic testing. Discuss with your doctor the risks and benefits of genetic testing.

Additionally, reducing radiation exposure to the head and maintaining a healthy lifestyle are also good preventive measures.

When to see a doctor?

You should consult a doctor if you experience signs and symptoms of gliomas. Early diagnosis and treatment can improve your prognosis.

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