Epilepsy surgery for adults

Below are types where surgeons take part of the brain away. The term for this is resective surgery:

• Temporal lobe surgery – Removing brain tissue in the temporal lobes that causes seizures. The temporal lobes are responsible for understanding language, memory and hearing
• Extratemporal surgery – Removing tissue in other parts of the brain that causes seizures. This is any brain surgery that takes place outside the temporal lobes
• Lesionectomy – Removing tumours, abscesses or other damage that has been causing seizures

• Hemispherectomy or hemispherotomy – Removing or partly removing one half of the brain. Sometimes, surgeons disconnect the outer layer from the rest of the brain as well

Below are types where one part of the brain is disconnected from another part. This surgery is to make your seizures less severe:

• Corpus callosotomy – Partly or fully cutting the connections between the 2 sides (hemispheres) of the brain. This stops seizures spreading from one hemisphere to the other. It is aimed at stopping falls and injuries from myoclonic, tonic and atonic seizures.
• Multiple subpial transection – Cutting the nerve fibres in the brain’s outer layers. This stops the seizure activity spreading. People with certain syndromes may be able to have this surgery. The aim is to reduce or stop seizures.

This is known as Laser Interstitial Thermal Therapy (LITT). It is different from the surgeries above.

Surgeons place a light fibre in the brain under anaesthesia through a small hole in the skull.  A laser light goes through the fibre and destroys the area of brain that is causing the seizures.

It is carried out in an MRI scanner and the wound left afterwards is small. This means you can often go home the next day and go back to your normal activities within a week.

It is used for people with drug-resistant focal epilepsy. This means their seizures are not controlled after trying two or more medicines.

• Standard EEG – electrodes are attached to the head using glue or paste. The EEG machine records the electrical signals from the brain on a computer.
• Video EEG telemetry – you will have continuous EEG and video for around 5-7 days in hospital.
• Invasive EEG telemetry – you might need a more detailed video-EEG telemetry.  This would include placing electrodes in the brain. This is called invasive EEG telemetry and it is only very rarely used.

You can read more about these tests on our EEG page.

This stands for magnetic resonance imaging. An MRI scan uses a strong magnetic field and radio waves. It can show if there’s a structural cause for your epilepsy.

Functional MRI scan (fMRI) – This is like the MRI scan but, during the scan, a specialist will ask you to do something, such as:

• Tap your thumb against your fingers or do other more difficult finger movements
• Look at pictures
• Answer questions on a computer screen

These activities increase the flow of oxygen-rich blood to a particular part of the brain. The fMRI will be able to pick this up.

This stands for single-photon emission computed tomography.

It uses an injection of a radioactive chemical (tracer dye) shortly after a seizure begins. This measures blood flow in the brain at the time of the seizure. Blood flow usually increases in the areas where the seizure begins and spreads.

This stands for magnetoencephalography. These scanners are only available in very specialist centres. They measure small magnetic fields generated in the brain. The results often work with the information from EEGs. The scanner sits outside your head as a large helmet. It can record unusual activity that is sometimes not detected by EEG. It can also track where the activity is more precisely.

During these there will be some tests. These will be to see if you have any memory or learning problems. They involve several games and puzzles. The test results help the surgeon in planning the type of surgery you might need. The results show if the part of your brain to be operated on has functions that other parts of your brain can’t take over.

This is to try to make sure you will not have any problems after surgery. It is also to help predict what problems might happen. The specialist will discuss the results with you and what they mean.

As part of your assessment you will see a psychiatrist. They will have experience of assessing people for epilepsy surgery.

They will see what other problems the epilepsy is causing and try to find out how well you might cope with surgery. This is particularly important if you have a psychiatric condition as well as epilepsy.

It usually takes several months to complete the assessment process. But, depending on the tests required, it can take over a year.

You would usually have your surgery at a specialist surgery centre. This might not be your local hospital.

The chances of being seizure-free after surgery varies from person to person. Among other things, it depends on the type of surgery, and what your scans and other tests show.

Your doctors will be able to tell you more. They will also be able to tell you about any complications that could happen after your surgery.

If you have a seizure after surgery this does not always mean that the surgery has been unsuccessful. It could be due to the direct stress of the surgery on your brain.

Some people might be able to stop taking their epilepsy medicines after surgery. But they would usually carry on with medicines for at least the first year.

About half of people who have temporal lobe surgery can slowly come off them and be seizure free. If the surgery was extratemporal this number is around a quarter.

Your neurologist will be able to give you more specific advice.

It’s not possible to know exactly what the outcome will be. But you will only have surgery if doctors believe that the benefits are greater than the risks.

Your doctors will discuss the chances of a good outcome and all the risks with you. If you are unsure of any risk, do ask your doctor.

Some people who can’t have brain surgery may be offered other surgeries to help control seizures.

One example is  vagus nerve stimulation. Your epilepsy specialist will be able to tell you more about whether this is an option for you.

Deep Brain Stimulation (DBS) is a type of brain surgery that is no longer offered within the NHS for people with epilepsy. This is because there isn’t enough evidence to prove that the risks outweigh the benefits. Risks include bleeding on the brain, depression and memory problems. It is still used for some people with Parkinsons.