Brain Tumor Causes, Symptoms, Screenings & Tests

Most brain tumors are caused by genetic mutations that result in uncontrolled cell growth. Though some of these mutations can be identified with the latest technologies, many cannot.

Houston Methodist’s team of neurologists are at the forefront of brain and pituitary tumor research. By combining our multidisciplinary diagnostic expertise with recent advances in medical science, we have designed an empathetic approach to healing based on the genetic origins and profile of each patient’s tumor.  

Risks Factors for Brain Tumors 

Primary brain tumors (such as glioblastomas and anaplastic astrocytomas) originate in the brain. Primary malignant brain tumors account for 2% of all cancers in adults in the U.S. There are no definite risk factors that cause primary brain tumors, but some factors may increase your risk: 

• Radiation exposure – This is the best-known environmental risk factor. It is caused by receiving large amounts of radiation from X-rays or previous cancer treatments.  
• Weakened immune system – Having a weakened immune system also increases risk. This can be present at birth, or due to an auto-immune disease or cancer. 
• Genetic disorders – Most brain tumors are not tied to family history. However, certain genetic conditions may increase risk. Neurofibromatosis type 1 is the most common syndrome linked to a brain tumor.

Secondary brain tumors are caused by cancers that spread to the brain from other areas of the body.

Our team of neuroscientists continues to research the causes and risk factors of brain tumors. Houston Methodist genetic counselors can provide an assessment of your risk for certain types of brain tumors and may offer genetic testing based on those evaluations. 

Leaders in Brain Symptoms

Signs of brain tumors are varied and can be non-specific. Houston Methodist neurologists understand the nuances of these symptoms — our team of experts provides swift diagnoses and personalized treatment plans for all types of brain, spine and pituitary cancers and tumors. 

As a brain tumor grows, it applies pressure to the brain. The size and location of a brain tumor influences the severity and types of symptoms you might experience, such as:

• Confusion or memory loss  
• Drowsiness  
• Headache  
• Impaired heart and lung function  
• Loss of balance or coordination, or difficulty walking  
• Loss of bladder control  
• Nausea and vomiting  
• Numbness and tingling in one part of the body  
• Paralysis of part of the face or body  
• Personality changes such as irritability and depression  
• Seizures  
• Speech and communication difficulties  
• Vision, hearing, smelling or breathing problems
• Weakness

Having these symptoms does not always mean you have a brain tumor. However, it is important to discuss all symptoms with your doctor because they could indicate other health issues.  

Leaders in Brain Tumor Diagnosis

Our neurologists are on the leading edge of advances in brain tumor diagnosis, offering new technologies to identify, diagnose and treat individual tumors based on genetic predisposition.

Our brain tumor experts recommend a team-based approach to brain tumor screening, testing and diagnosis. We use advanced physical, procedural and imaging techniques to diagnose brain tumors, including: 

• Neurological exams – Brain tumor experts will check your reflexes, control of facial movements, vision and level of awareness to gauge the impact of a suspected tumor on your brain function.
• Biopsy – A procedure to remove a small amount of tissue to determine whether it is a tumor and examine its genetic makeup.  
• CT scan – A combination of X-ray images that create a detailed, cross-sectional image of the brain. 
• MRI – Using a magnetic field and radio waves, we produce detailed images of the brain and body to determine whether or how far a brain tumor has spread.  

 
If a tumor is detected, our doctors use a variety of new technologies to complete an in-depth study of the tumor and the genetic profile of each patient. Your doctor will also schedule additional tests to learn more about the tumor.  

Brain Tumor Grades

Primary brain tumors originate in the brain. Secondary (metastatic) brain tumors form in other parts of the body and spread to the brain. Houston Methodist neurologists assign brain tumors a grade based on the tumor’s point of origin and severity:

Grade 1 – Slow growing that is unlikely to spread  

Grade 2 – Less likely to grow and spread but more likely to reoccur  

Grade 3 – More likely to grow quickly, but no dead cells  

Grade 4 – Likely to grow and spread aggressively, with areas of dead cells  

Your brain tumor grade, along with findings of your diagnostic screenings and tests, will inform your personalized brain tumor treatment plan.  

After an initial CT scan revealed a mass on his brain, James “Lance” Mobley went on to fight a two-year battle with glioblastoma. He was the first human in the world to test oscillating magnetic fields to shrink his tumor. Lance's glioblastoma shrunk by 30 percent in just six weeks.