Epilepsy Surgery

Epilepsy is a disorder where you have recurrent seizures. You have seizures or fits due to abnormal electrical activity in your brain. 

During a fit, your behavior will be strange. You will act as if you are not aware of the surroundings. There may be unusual movements of your body. Sometimes, you may even lose consciousness.

Symptoms of epilepsy

Some of the common signs are

• A sudden period of confusion where you find it hard to understand what is going on
• A staring spell where you will stop doing whatever you were doing and stare at a space ahead. It is more common in children aged between 4-14.
• Uncontrollable movements of your arms and legs
• Loss of consciousness 
• A feeling of fear and anxiety

These signs may vary based on the type of seizure. However, you will show the same signs during the different spells.

Types of seizures

There are two main types. 

1. Focal seizures are related to abnormal activity in one part of the brain, causing sudden movement in one body part like the hand or foot without the loss of consciousness. 
2. Generalized ones involve all areas of the brain, causing tonic-clonic movement of the whole body with loss of consciousness.

There are two subtypes of focal seizures.

1. Simple Partial Seizures, which is limited to only one part of the body
2. Complex Partial seizures involve the whole body after starting from one part. You may lose consciousness during this.

There are six subtypes of generalized seizures. 

1. Absence seizures - It occurs mostly in children where they stare into space, which lasts for a few seconds. Multiple episodes may occur in a day. Blinking of the eye and smacking of the lips are other signs.
2. Tonic seizures - The muscles in your arms and legs will become stiff, and you may fall.
3. Drop seizures - You lose control of your muscle movements due to loss of tone, making you fall. It mainly occurs in children. 
4. Clonic seizures - You will show repeated muscle movements mainly in your neck, face, and arms.
5. Myoclonic seizures - If you have this type, you will have sudden jerks in your arms and legs
6. Tonic-clonic seizures - First, your body will become stiff. Then, you will have jerky movements that last for a few minutes, followed by a loss of tone. You will have bladder incontinence, clenching of teeth, and tongue bite. You will lose consciousness, which you will regain after 15 – 20 minutes.

Causes and Risk Factors of Epilepsy

About 50% of the cases have no reason. Other cases may have reasons such as 

• Genetics: It tends to run in families
• Head injury: Road traffic accidents or any other incidents where your head is injured 
• Brain damage: Conditions like a brain tumor or stroke in adults above 35 years 
• Infections: like meningitis, AIDS, and viral encephalitis

Complications of Epilepsy

It can cause some other issues as well such as 

• Falling - You may fall during a fit spell, which may cause damage to the skull and bones
• Accidents – you are prone to road traffic accidents, drowning, injuries while sports, etc. if you have a seizure while doing these activities.
• Pregnancy complications - Seizures during pregnancy can cause damage to both mother and baby. Medicines can cause developmental anomalies in the fetus.
• Developmental delay – Epilepsy in newborns and young children affects their overall growth.
• Mental issues - problems like depression and anxiety will be common.

Treatment of Epilepsy

There are many groups of antiepileptic medications for treating epilepsy. Your doctor will decide the right one as per your age, type of seizure, and your general condition.

You have refractory epilepsy if you still have fits even after three medicines are given together at maximum tolerable doses for three months. Now you are a candidate for surgery. 

Investigations required for surgery

You will have to go through some tests. These tests will help the doctor to decide which surgery is best for you.

• Video EEG – You will be in observation for 48 hours to record your seizure activity. The doctor can then find the area for your brain, which is starting the electrical activity.
• PET CT Scan
• MRI of the Brain with contrast

Types of epilepsy surgery

Almost all of the surgeries need an opening in the skull bone to expose the lesion in the brain. Hence the surgeon will do a craniotomy before the epilepsy surgery.  

Resection surgery

It is the most common type of epilepsy surgery. During this, your surgeon will remove the area of your brain that causes fits. Your surgeon will precisely locate this area, called the seizure focus, with the help of various tests. 

There will not be any damage to critical areas of the brain, such as those that control memory, vision, speech, movements, etc. 

There are many types of resection surgeries.

Lesionectomy- The surgeon will remove the area of the lesion. It is helpful in those in whom the lesion is small. The main benefit is that the surgeon removes only a tiny part of the brain. If the lesion is a small tumor or an aneurysm, removing it will provide long term relief.

Temporal lobe resection- You will have this surgery if your lesion is the temporal lobe of the brain. It is very safe, with a success rate of more than 75%. You will be free from fits and will need only small doses of antiepileptic medicines after this. In the rest 25%, there will be a big reduction in the frequency and severity.

Parietal and occipital lobe disconnection - These lobes are at the back of your brain. You will have this surgery if the lesion is in any of these two lobes. In this surgery, the surgeon will disconnect the affected lobe from the rest of the brain to control the seizure.

Multiple subpial transections- If your seizure focus is in a critical area of your brain, removing it through surgery is not possible. The aim then is to isolate the lesion and prevent the spread of impulses to other areas of the brain. Your surgeon will make fine cuts in the gray matter of the brain surrounding the lesion. The gray matter lies below the pia matter, a membrane that surrounds the brain. These cuts prevent the transmission of impulses from the lesion.

Hemispherectomy- It is most effective in children in whom the seizure focus is a large area in one side or hemisphere of the brain. During the surgery, the surgeon will remove one half of the brain that acts as the focus of fits. 

Corpus callosotomy-  In this, the surgeon will cut the connection between the two halves of the brain. You will have this if you have severe and uncontrolled fits that make you fall. 

Other surgical treatments for epilepsy.

Apart from resection surgeries, there are a few other procedures such as

DBS surgery- In this, the surgeon implants electrodes into areas that act as a focus. Then the surgeon will place a stimulator under the skin in your chest and connect it to the electrodes. Whenever the stimulator observes the possibility of a fit due to abnormal impulses, it sends a signal to the area to stop the impulses.

VNS surgery- The surgeon will place a small generator in the chest and connect it to the vagus nerve with the help of a ‘lead’. The generator will stimulate the nerve at set intervals to prevent seizures

Stereotactic radiosurgery-  Low intensity radiations precisely target the lesion. There will not be any damage to other areas of the brain.