Gliomas and Glioblastoma: Symptoms, Diagnosis, and Treatment

Gliomas are the most common tumors that begin in the brain itself. They arise from glial cells — the supportive cells that surround and protect neurons — and they range from slow-growing tumors that can be monitored or cured with surgery to faster-growing tumors, like glioblastoma, that need prompt, coordinated treatment. Whatever the type, treatment has advanced meaningfully in recent years, and an experienced team can make a real difference in both outcome and quality of life.

What is a glioma?

A glioma is a tumor that starts in the brain’s glial cells (unlike brain metastases, which spread to the brain from cancer elsewhere in the body). The main types are:

• Astrocytomas, which arise from star-shaped cells called astrocytes. Glioblastoma is the most aggressive form.
• Oligodendrogliomas, which tend to grow more slowly and often respond particularly well to treatment.
• Ependymomas, rarer tumors arising from the cells lining the brain’s fluid spaces.

How are gliomas graded?

Doctors describe gliomas by grade, from 1 to 4, based on how the cells look under the microscope and — just as importantly today — on the tumor’s molecular features:

• Grade 1–2 (low-grade) gliomas grow slowly, sometimes over many years.
• Grade 3–4 (high-grade) gliomas grow faster and require more intensive treatment. Glioblastoma (grade 4) is the most common high-grade glioma in adults.

Modern diagnosis relies heavily on genetic markers with names like IDH, 1p/19q, and MGMT. In plain terms, these markers tell your team how a tumor is likely to behave and which treatments it is most likely to respond to — two tumors that look similar on a scan can behave very differently depending on their genetics. This is why complete molecular testing matters.

Common symptoms

Symptoms depend on the tumor’s size, location, and how quickly it is growing. They may include:

• New or changing headaches
• Seizures — often the first sign, especially with low-grade gliomas
• Weakness, numbness, or clumsiness on one side of the body
• Changes in speech, vision, memory, or thinking
• Personality or mood changes noticed by family

Some gliomas cause no symptoms at all and are discovered on a scan done for another reason.

How are gliomas diagnosed?

Diagnosis starts with an MRI of the brain, which shows the tumor’s location and characteristics. A definitive diagnosis comes from examining tumor tissue — obtained during surgical removal or, when removal isn’t the right first step, through a biopsy — followed by molecular testing.

Research is also moving toward reading a tumor’s biology directly from imaging. Dr. Arnaout’s research team has developed AI tools that can predict a glioma’s genetic mutations from a standard MRI — a step toward “virtual biopsy” that may one day give patients answers before any procedure.

Treatment options

Glioma treatment is individualized and typically involves a multidisciplinary team: neurosurgery, neuro-oncology, and radiation oncology working together. Depending on the tumor’s type, grade, and location, treatment may include:

• Surgery. For most gliomas, the first and most important step is maximal safe removal — taking out as much tumor as possible while protecting function. Techniques such as awake craniotomy with brain mapping, intraoperative navigation, and minimally invasive keyhole approaches allow surgeons to remove tumors near speech, movement, or vision areas more safely than ever.
• Radiation therapy, precisely targeted to treat remaining tumor cells while sparing healthy brain.
• Chemotherapy, most commonly temozolomide, an oral medication. Molecular markers (such as MGMT) help predict how well it will work.
• Tumor treating fields (TTFields), a wearable device therapy used for glioblastoma.
• Clinical trials. For many patients — especially with glioblastoma — trials offer access to promising new therapies, from targeted drugs to immunotherapy. Being treated at an academic center makes these options easier to reach.

Low-grade gliomas in some situations are followed closely with serial MRIs rather than treated immediately — another reason an experienced team’s judgment matters.

Living with a glioma

A glioma diagnosis — especially glioblastoma — is life-changing, and statistics you may find online often lag years behind current care and reflect averages, not individuals. Your tumor’s molecular profile, your health, the extent of surgical removal, and access to trials all shape what lies ahead. Alongside treatment, supportive care — seizure management, rehabilitation, and neuro-oncology follow-up — helps protect what matters most: your independence and quality of life.

When to see a specialist

If you or a loved one has been diagnosed with a glioma — or an MRI has found something suspicious — an evaluation with a neurosurgeon who treats brain tumors every week can clarify whether surgery, monitoring, or another approach is the best next step. Second opinions are common and welcomed; the treatment plan set at the beginning often shapes everything that follows.

Dr. Arnaout specializes in the surgical treatment of gliomas, including awake craniotomy and minimally invasive approaches, and cares for patients as part of a dedicated neuro-oncology team.

To discuss your diagnosis or get a second opinion, request an appointment.