It is common for brain tumors to cause seizures. Brain tumors can alter electrical activity in the brain, which leads to seizures.

Seizures are one of the most common symptoms of brain tumors. Not everyone with a brain tumor will experience seizures, and there are also many other causes of seizures.

Surgery to remove the tumor and anti-epileptic medication may help to control seizures in people with brain tumors.

This article looks at brain tumor-related epilepsy, treatment options, and outlook.

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Epilepsy is a condition in which people have recurring seizures. Doctors diagnose epilepsy if people have had more than one seizure. Brain tumor-related epilepsy (BTRE) is a type of epilepsy that occurs due to a brain tumor.

Of those with brain tumors, between 30–100% of people will have epilepsy.

Whether a brain tumor causes epilepsy may depend on the type of tumor. Neuroglial tumors and gliomas are the most common type of tumors that cause seizures, although seizures can occur from any brain tumor.

Brain tumors may cause seizures because the abnormal cells around the tumor or the tumor itself can cause an imbalance in brain chemicals.

This can lead to abnormal electrical activity in the brain, which causes seizures.

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Learn more about brain tumors.

Doctors may use an electroencephalography (EEG) test to show electrical activity in the brain and to help them decide which treatments may be best.

Treatment and management of BTRE may include:

Anti-epileptic medication

Anti-epileptic medication may be part of a treatment plan for people with BTRE.

Treating BTRE with anti-epileptic medication requires caution as there is an increased risk of drug interactions.

Other brain tumor treatments could interact with anti-seizure medication, increasing the risk of side effects.

Anti-epileptic medication for BTRE treatment may include:

  • levetiracetam
  • phenytoin
  • pregabalin
  • valproic acid
  • lamotrigine
  • lacosamide
  • brivaracetam
  • perampanel

Levetiracetam is an anticonvulsant that doctors may commonly use to reduce the frequency of seizures in people with brain tumors.

Surgery

Surgery is the standard approach to treating seizures with a brain tumor. The aim of surgery is to remove as much of the tumor as possible in order to stop seizures from occurring.

If doctors are unsure where the abnormal activity causing the seizures originates from, a surgeon may first implant electrodes into the brain to monitor electrical activity.

This helps doctors identify the source of abnormal electrical activity. Once they have identified this, they can then carry out a second surgery to remove the tumor and area of the brain that is causing the seizures.

Radiotherapy

Radiotherapy focuses on controlling a brain tumor, improving function, and improving survival. It may help to treat seizures.

However, there is a lack of data on the effects of radiotherapy on seizures from brain tumors.

Chemotherapy

People may have chemotherapy alongside radiotherapy to help treat brain tumors and reduce seizures.

This is a common treatment option in people with glioma tumors. Chemotherapy drugs may include:

  • temozolomide
  • procarbazine, lomustine, and vincristine
  • lomustine monotherapy

Surgery is usually the first-line treatment for brain tumors with seizures and, in most people, results in improved overall survival.

Total removal of the tumor may be the most important factor in controlling seizures with brain tumors.

Both anti-epileptic medication and anti-tumor treatments may help to control seizures in people with BTRE.

This section answers some frequently asked questions about brain tumors and seizures.

How often do seizures occur with brain tumors?

As many as 2 in 3 people with a brain tumor may experience at least one seizure or epilepsy.

According to a 2017 article, in around 30-50% of people with a brain tumor, a seizure may be the first symptom that then leads to diagnosis of the tumor.

In around 10-30% of people with a brain tumor, seizures may occur over the course of the condition.

The risk of seizures occurring with a brain tumor depends on various factors, including:

  • type of brain tumor
  • location of brain tumor (for example, cortical brain tumors have a higher seizure risk)
  • how fast the brain tumor grows, with slow-growing tumors having a higher risk of seizures
  • the grade of brain tumor, with high-grade tumors having a lower rate of seizures than lower-grade tumors
  • number of lesions, with an increased number of lesions linking to a higher risk of seizures

What are the final stages of a brain tumor?

In the final stages of a brain tumor, the frequency and severity of symptoms may increase, and brain tumor treatment is no longer effective.

This stage may occur in the last 3 months of life.

The main symptoms in the final stages of a brain tumor may include:

  • seizures
  • drowsiness or excess sleepiness
  • changes in motor skills or movement
  • difficulty swallowing
  • cognitive impairment, such as memory problems or difficulty concentrating

People may continue to take anti-epileptic medication in the final stages of a brain tumor to help control seizures.

Will removing a brain tumor stop seizures?

Surgery, as early as possible, to remove a brain tumor is one of the main ways to stop seizures.

Total removal of the tumor may be the most important factor in stopping seizures.

Brain tumors can cause seizures due to the tumor, or abnormal cells around tumors, causing an imbalance in brain chemicals and leading to abnormal electrical activity that causes seizures.

Treatments for brain tumor-related epilepsy may include surgery to remove the tumor, anti-epileptic medication, chemotherapy, and radiotherapy.

Surgery to remove the tumor may result in the best outcome for seizure control.