Epilepsy surgery

Epilepsy surgery

By Dr. Ravindra Patil

Overview

Epilepsy is a brain disorder that causes seizures or unusual sensations and behaviour. Medicines can control seizures. But sometimes medicines do not work and brain surgery for seizures or brain surgery for epilepsy is done.

Epilepsy brain surgery is not the first line of treatment, because it is a super major surgery. But surgery for epilepsy is most effective when seizures always occur in a single location in the brain. So, every epileptic patient does not get relief from seizures after brain surgery.

Special tests can determine if a patient is eligible for epilepsy surgery.

In epilepsy brain surgery a part area of the brain where seizures occur is removed.

Table of Contents

Goal of Epilepsy Surgery

Is to limit seizures after brain surgery, limit their severity with or without the use of medications.

How Do Seizures Kill

Poorly controlled epilepsy can have complications like:

  • Physical injuries during a seizure – a head injury can cause permanent disability or death
  • Drowning, if the seizure occurs during a bath or swimming
  • Depression and anxiety
  • It delays growth in children
  • Sudden death, a rare complication of epilepsy
  • Memory and other thinking skills loss

Types of epilepsy surgery

The type of brain surgery for seizures depends on the location of the electrical disturbance in the brain and the age of the patient:

  • Resective surgery, the most common epilepsy surgery, is the removal of a small portion of the temporal lobes of the brain.
  • MRI guided Laser interstitial thermal therapy uses a laser to pinpoint and destroy a small portion of brain tissue.
  • Just as a pacemaker controls heart rhythms, an implantable device for the brain detects abnormal activity and corrects it – before a person with epilepsy experiences a seizure. This innovative device is called a neurostimulator or a seizure pacemaker. It is a proven treatment for adults who have disabling seizures not controlled by medication.
  • MRI guided Deep Brain Stimulation is a permanently implanted seizure pacemaker in patient’s chest, which stimulates deep inside the brain. It releases regularly timed electrical signals that disrupt abnormal seizure-inducing activity.
  • Corpus callosotomy is a surgery to completely or partially remove part of the brain that connects nerves on the right and left sides of the brain.
  • Hemispherectomy removes one side of the gray matter of the brain.
  • Functional hemispherectomy is used in children that removes the connection nerves without removing actual brain.

Risks of brain surgery for epilepsy

Different areas of the brain control different functions. Therefore, risks vary depending on the surgical site and the type of surgery. The surgical team will help patients or their relatives understand the specific risks of your procedure, as well as the strategies the team will use to reduce the risk of complications. Risks may include the following:

  • Memory and language problems
  • Visual impairment
  • Depression, mood changes
  • Headache
  • Stroke
  • Seizure after brain surgery

Before operation

Special tests will detect exactly which brain part is to be operated upon.

  • Baseline electroencephalogram (EEG).
  • Continuous EEG with video monitoring records seizures as they occur. Evaluating EEG with during a seizure helps pinpoint the area of your brain to be operated.
  • MRI imaging to identify damaged cells, tumours or other abnormalities that can cause seizures.
  • Invasive EEG monitoring.
  • Video Invasive EEG monitoring.
  • PET scan: measures brain function.
  • Single-photon emission computerized tomography (SPECT) measures blood flow in the brain during a seizure.

Evaluations to understand brain function

Depending on the surgical site, your team may recommend tests to determine the precise areas of the brain that control language, sensory functions, motor skills or other critical functions. This information helps surgeons preserve function to the greatest extent possible when removing or altering a site in your brain. They are:

  • Functional MRI identifies regions of brain activity when you’re doing a particular task, such as listening or reading. This helps the surgeon know the precise locations in your brain that control a particular function.
  • Wada test. With this test, an injected medication temporarily puts one side of brain to sleep at a time. You’re then administered a test for language and memory function. This test can help determine which side of your brain is dominant for your language usage.
  • Brain mapping. Small electrodes match tasks with measurements of brain’s electrical activity.

Neuropsychological tests

Additionally, testing is usually recommended to measure verbal and nonverbal learning skills and memory function. These tests may provide additional insight into the area of the brain affected by seizures, as well as a baseline for measuring function after surgery.

How is surgery done

Hair will be shaved over the section of your skull that before the operation. IV tubes will be placed in veins and pre-operative medicines will be given

General anaesthesia is given. In some cases, awake surgery is done, more details are given at the end. Awake surgery helps save parts brain which control language and movement. But the patient feels no pain.

The surgeon operated through a small window in the skull after surgery the window of bone is replaced and fastened to the remaining skull for healing. Pain is reduced with appropriate medicine. Antibiotics are given to prevent infection. Total hospital stay for epilepsy surgeries will be about three to seven days.

Returning to work or school may take one to three months. Normal activity must started gradually.

Results

The outcomes of epilepsy surgery vary depending on the type of surgery performed. The best expected outcome is seizure control without medication.

The most common and best-understood procedure — resection of tissue in the temporal lobe — results in seizure-free outcomes for about two-thirds of people. Studies suggest that if you do not have a seizure in the first year after temporal lobe surgery — with medication — the likelihood of being seizure-free at two years is 87% to 90%. If you have not had a seizure in two years, the likelihood of being seizure-free is 95% at five years and 82% at 10 years.

If a patient remains seizure-free for at least one year, medicines may be discontinued. If seizures occur, they are controlled by medicines.

Awake brain surgery

Awake brain surgery is a type of brain surgery for seizure performed on the brain while the patient is awake and alert. Awake brain surgery is used to treat some brain (neurological) conditions, including some brain tumours or epileptic seizures.

To summarise, surgery on the brain for epilepsy is useful for those people whose seizures originate from one part of the brain. It is a procedure for seizure which is useful when medicines don’t work.