Surgical Treatment

About Epilepsy

Surgical Treatment

Epilepsy and Neurosurgery
A basic guide for prospective neurosurgical patients

This content has been abridged for the website — please download the Full PDF Booklet for all the available information, including:

Who can be considered?
Types of surgery
Investigations before surgery
Decision time
What happens when you go into hospital?
After the operation
Coming home
Chances of success
Two personal experiences — Carl and Ann's stories
Glossary

Introduction

This information is for anyone interested in finding out more about epilepsy surgery. Although written for you, the potential patient, its contents will be of interest to all including family, friends, and health workers. It offers a step-by-step guide to what you can expect, from being considered for surgery in the first place, to coping with life afterwards.

Surgery is carried out with the aim of reducing the number of, or getting rid of altogether, seizures which can’t be satisfactorily controlled, either completely or partially, by antiepileptic medication.

The road to surgery is one of stringent and thorough procedures, including investigations, which may include hospital stays. However, since the first surgery for epilepsy was carried out in the late 19th century, surgical techniques have been ever progressing, with new advances meaning fewer risks to patients, and improved outcomes.

Surgery carries risks – and any patient must be fully committed, know the risks, and the chances of success and failure – but the quality of treatment is very high, and you will have an entire multidisciplinary team working on your behalf.

Before you even begin to consider surgery, and the major operation it entails, the medical team will be looking closely at a number of factors which would make you a candidate.

Who can be considered?

The majority of people with epilepsy have their seizures well controlled by medication. If you find that despite trying medication, your seizures refuse to be controlled, surgery could be an option, or at least, you could fall into the group of people for whom surgery is an option.

To be considered for surgery, three criteria need to be satisfied.

Your epilepsy cannot be satisfactorily controlled by medication.
This means either your seizures haven’t stopped, despite taking medication, or the side effects of the medication are unacceptable.
The seizures come from one area within your brain and that source can be identified.
For example, epilepsy can be caused by scar tissue or a lesion in the brain - if so, you satisfy at least one of the conditions for surgery: an identifiable focus within the brain. However, where epilepsy has followed a more generalised problem, such as encephalitis or meningitis, it is less likely a focus can be identified.
That the area of the brain causing the epilepsy can be removed safely.
If a focus can be found, the surgeon will look at how easy it is to get to this part of the brain and remove it safely. They will check that areas in your brain responsible for speech, sight and movement aren’t too near the piece to be removed.

Then there are a number of other factors to be taken into consideration:

What sort of epilepsy do you have?
Epilepsy can be either partial, meaning seizures start in part of your brain, or generalised, meaning they affect your whole brain. If you have partial seizures originating in your temporal lobe, your epilepsy is more likely to respond to surgery because the place it comes from can be more easily located and removed. Indeed, the majority of surgery is carried out on the temporal lobe. Secondarily generalised seizures - which means the epilepsy starts in one part of the brain and spreads - is also treatable, again because there is a definite place from which the epilepsy starts.
How long have you had epilepsy?
Seizures can stop spontaneously, or be controlled by medication, so immediate surgery is not offered. If seizure control has not been achieved after two years, surgery can be considered. However, because success of the operation isn’t just measured in terms of seizure reduction, but in quality of life (the effect of your seizures on work, education, relationships and so on) - if surgery is delayed too long, the ‘damage’ in those aspects may have already occurred.

Generally, if seizure control has not been established after two years, surgery can be considered as the next step in treatment.

If you’ve had seizures for a long time, you may be less suitable for surgery because the risks increase with age. The preferred time for surgery is in the younger years, because usually, the earlier it is carried out, the better the outcome. Surgery may therefore be considered in children as doctors recognise the potential impact of epilepsy on schooling and social development. Conditions found in children may include developmental disorders, for which you’ll need specialist paediatric advice (and which we don’t aim to cover in this booklet).

Unless the team can be sure there is a good chance of success and safety, surgery will not be recommended. That’s why, before you even get to the operating table, you have to go through pre-surgical evaluation which involves a series of investigations to determine if you are suitable, and the chances of surgery working for you.

Types of surgery

Most commonly, the aim of epilepsy surgery is to remove the part of the brain from where the seizures originate.

Temporal lobe surgery

Operations carried out on the temporal lobe (and you may hear the term ‘temporal lobectomy’ to describe this). This is because scarring – known as ‘mesial temporal sclerosis’ or ‘hippocampal sclerosis’ – on the inside of the temporal lobe is a common cause of epilepsy that can be treated surgically. Indeed, many of the investigations before surgery are designed to detect the presence of such scarring.

Operations on the temporal lobe will reduce seizures in up to 80% of patients. In the long-term, seizure outcome can also be predicted quite reliably – and if you are seizure free a year after surgery, there is only around a 10% chance of your seizures returning over a five-year period.

Although generally the most successful type of surgery, there can be complications, and there is a mortality rate (risk of dying) of around 0.5%. Risks of side effects vary, but are between 2% and 4%. These side effects may include visual problems, memory problems and paralysis (stroke).

Any psychological problems following surgery are usually temporary but can include a period of depression. This is because the surgery ‘interferes’ with the temporal lobe, which is one part of the brain important for emotions. In all likelihood, any side effects you experience following surgery are likely to be temporary.

Generally speaking, temporal lobe surgery is thought to safe and side effects only occur in a small minority of people.

Lesionectomy

Sometimes a benign tumour may present with epilepsy as its only symptom.

If slow growing, these tumours may not need treatment in their own right. However, their removal can cure the epilepsy in 70%-80% of cases. Other non-tumourous lesions exist which, again, may cause epilepsy, and may be treatable by removing the lesion. Individual cases vary and will be discussed in detail with each patient.

Frontal lobectomy: these operations, carried out on the frontal lobe of the brain, tend to be less successful (apart from those carried out to remove a tumour or cyst from this area – Lesionectomy). There is up to 40% chance of being completely seizure free after the operation, but the possibility of undergoing a frontal lobectomy needs substantial discussion with the medical team.

Hemispherectomy

This is the name of a surgical procedure which removes or disables an entire cerebral hemisphere (one of the two divisions of the brain). This is carried out only if a whole side of the brain is damaged, and is most commonly performed on children who have severe or progressive neurological disease. This operation tends to be a specialised paediatric procedure and is only rarely performed.

Vagus Nerve stimulation

Vagus Nerve stimulation could be an option if you are not suitable for these types of surgery, or have had surgery without positive results. By stimulating the vagus nerve, it is believed abnormal brain activity could be intercepted. The procedure involves fitting a small generator, usually to the upper chest.

Complete abolition of seizures is rare and not all believe the benefit of treatment is good enough to justify it. Improvement in seizure control of at least 50% has been reported in around half of the people and, overall, about a third of patients may benefit. Patients considered are usually those with extremely frequent seizures.

Investigations before surgery

The road to surgery is a long and thorough one. The following are the pre-surgical tests and procedures you can expect to come across on your journey and they, in themselves, can take several months to complete.

The investigations you have will depend on the type of operation you are being considered for and how easy it is to locate the origin of your epilepsy. Some, such as affirming diagnosis, are usually straightforward.

Others are more complicated and may involve a hospital stay, particularly if the origin of your epilepsy isn’t easy to find.

Confirming diagnosis and the type of epilepsy you have: your medical history will be recorded, and the symptoms of your epilepsy investigated, so it can be confirmed that the diagnosis is correct, and which type of epilepsy you have.
Looking for scar tissues/lesions on the brain: an MRI scan uses a powerful magnet to produce images of the brain. This is called ‘neuroimaging’ and the aim is to look for possible scar tissue/lesions, which could be removed. This involves your brain (and you too!) being placed in a rather noisy and, for some people, claustrophobic, machine. For this procedure - which is both painless and safe - you can usually go as an outpatient.
Neuropsychometry consists of a standard series of tests on intellect and memory: these tests might consist of a number of word, memory and drawing/constructing tests which give clues to how different parts of your brain function. These tests are carried out to assess general intellectual ability and memory so the risk of memory loss can be gauged, and to try and identify which side of the brain is responsible for language and memory.
EEG video monitoring is a widely used evaluation. Many of you will have had an EEG, where electrodes are placed on your scalp and connected to a machine which reads your brain electrical patterns. In pre-surgical investigations, you may have an EEG with a difference. At the same time as having the electrodes in place, you’ll be videoed. The recording provides confirmation that you do have epilepsy and information as to where in the brain your seizures are originating.

For this investigation, you will have to stay in hospital as an inpatient, probably for around a week.

The aim is to evaluate the electrical activity in your brain due to seizures, and you may be taken off medication, or have the dose reduced.

It may be you need more specific electrodes than those offered by EEG. If so, you may have ‘depth’ electrodes inserted into your brain. This is done under general anaesthetic. Because these electrodes are in or on the surface of the brain, they give a more precise location of the epileptic focus. Once they are in place, a continuous EEG/video recording will be made. Do not expect immediate results, as extensive computer analysis is required.
Testing the potential effects of surgery on your brain: the test which traditionally does this is called the Wada (sodium amytal) test. However, this test is rarely used today, especially in children. If used, the test, which gives an understanding of the effects that surgery may have on your speech, understanding and memory, puts one side of your brain to sleep. A fine tube will be inserted in an artery of your groin and threaded up the main blood vessel of your body into your brain. This will be done through the guidance of an x-ray and allows the doctors/surgeons to assess whether the remainder of the brain can cope if part of it is removed.
Psychiatric assessments may be carried out to see whether there are of risks of psychiatric problems occurring after surgery. These assessments also act as a point of comparison - if psychiatric complications arise afterwards, were these problems there before, or are they a result of the surgery? It’s generally considered that if you are found to have any psychiatric features such as personality disorder or severe depression before surgery, this may make you unsuitable, unless the episodes were confined to the period after seizures (post-ictal) and therefore belonged with your epilepsy.

The neurologist and the patient enter into full discussion about the benefits and risks of undergoing epilepsy surgery.

The neurosurgeon studies the results of the MRI scan as part of the decision-making process.

Decision time

The epilepsy surgery team, which comprises the neurologist, neuropsychologist, neurosurgeon, amongst others, will have discussed your case, including what the outlook would be for you with or without surgical treatment. Are the risks that you would undergo in surgery be far greater than the benefit to be obtained? If the potential benefit is felt to outweigh the risks, then you could be offered surgery. You will need to discuss potential risks with your doctor as part of your decision-making process if you are accepted for surgery.

You may be told at this stage that surgery isn’t possible for you. The risks you would be under would be far greater than any possible benefits. This may be a very disappointing time. You may be offered surgery. Now it’s your decision, and it can’t be overemphasised that, once surgery is offered, the decision to go ahead is yours and yours alone. Talk it over with as many people as you like. Ask as many questions of the medical team as you like. Only you can make the decision.

If you decide to accept the offer of surgery, you may then be placed on a waiting list.

What happens when you go into hospital?

You’ve made your decision and got to the front of the queue. It’s important you plan your hospital stay and your recovery time afterwards carefully. You will need to allow for 6-8 weeks to be at home, and if you work you will need to arrange the time off. If you feel unwell in the week or so before the operation, let your neurosurgeon know. This may mean postponing your operation but you will not lose time on the waiting list as a result. It is understood that you may wish to make arrangements for your home circumstances, for example, childcare and so on. If you experience problems, let your neurosurgeon know, because, within reasonable limits, hospital admission dates are negotiable; bear in mind, however, that other patients with urgent or life-threatening conditions will have priority.

Usually you will be asked to go into hospital a couple of days before surgery. Before the operation, you won’t be able to eat or drink anything for a few hours. An anaesthetist – the person responsible for putting you to sleep during the operation – will provide you with information about what the anaesthetic involves and also discuss your general health and wellbeing.

You might have to have your head partly shaved, and this will be the surgeon’s preference for working. Remember, hair grows! If you had a healthy head of hair to start with, it can take as little as a month to have a covering again. After the operation, you will have a surgical cut in your head that the doctors have made to get to your brain via your skull. This may have a dressing or bandage on it when you wake. The cut is usually within the hairline, so when your hair grows, it should become hidden.

After the operation

After surgery, you will be monitored carefully. When you wake, your head may be bandaged. You might feel sick, or have a headache and you will have an intravenous tube attached to provide you with fluids. Staff can give you regular medication for pain. The headache, which is normal considering you have just had brain surgery, should disappear after a day or two but may last much longer. You might feel tired and sleepy and you might not want to have lots of visitors at this time.

There can be other side effects after the operation, including an aching jaw, strange sensations in your head (such as swishing), and swelling and bruising where the surgical cut is.

There’s no set time you’ll be in hospital. Staff will continually monitor you and when they are happy with your progress, you’ll be able to go home.

Coming home

Make sure you can relax when you return from hospital. You’ll have a post-operative check around 6-8 weeks after surgery after which, if you want to, you can gradually begin to introduce activities back into your life, such as sport. Extreme sports should be avoided. If, however, after 12-24 months, you are doing well, even extreme activities can be contemplated.

You might have a seizure in the first few weeks after your operation. This doesn’t mean surgery hasn’t been successful – generalised tonic-clonic seizures which happen at this time are generally not considered by doctors to be an indication of failure. They may instead reflect the fact that your brain has been through the trauma of being operated upon. You will probably be kept on medication for at least a year, and up to two years, and then gradually taken down from your dosage over a further year if you elect for this.

Chances of success

The period after surgery is likely to be difficult. Depression may occur in the first year, and the risk of this is higher if you don’t have a reduction in or control of seizures afterwards. This could be intensely disappointing when your hopes have been high, and it is possible it could happen. On the brighter side, be reminded of the high success rate of the procedure.

This might sound strange, but coping with the success of the operation can be difficult too. If epilepsy has been to blame for all of life’s problems, you may find that if it disappears, and the problems still remain, you can feel disillusioned. Expectations are high (my life would be ‘such and such’ if I didn’t have epilepsy) and the way people relate to you may also change (were your relationships influenced by your epilepsy and/or were people more patient, or more sympathetic, and now aren’t?).

The ‘outcome’ of surgery is measured not only in the reduction or elimination of seizures. They will also consider how well your brain functions afterwards in terms of memory and so on, and how your quality of life has improved because of the operation.

It’s important you get the support you need during this time, which may, if you are ready to embark on finding out about surgery, seem a long way in the distance. Whatever stage you’re at – good luck!