Epilepsy surgery - a guide for patients

MRI: What is MRI, how does it work, and is it safe?

MRI (Magnetic Resonance Imaging) produces very detailed images of the brain, showing soft tissue and areas of possible damage, small tumours, developmental abnormalities, and abnormal blood vessels. It uses a strong magnetic field and radio frequency waves to produce images created by sophisticated hardware and computer software.

Unlike X-ray, diagnostic MRI is not known to have any harmful side-effects. As a precaution, however, we try to avoid the use of MRI during pregnancy, unless there is an urgent clinical reason to do the scan.

What does an MRI scan involve?

Before your scan, we go through an MRI safety checklist to see if there is any reason why it would not be safe to carry out your scan. If you have certain types of heart pacemaker, cerebral aneurysm clips, or other surgical implants, an MRI scan may not be possible. Please let the radiographer know if you have any implants.

Before the scan, you need to remove jewellery, watches, hair clips, hearing aids, bank cards, coins, or keys, as it would be dangerous if they were taken into the scan room. You will be asked to lie down on the scan table, which moves into the scanner. The scan is painless and you will be given earplugs as the scanner makes loud noises. The radiographer will speak to you via a two-way intercom.

The scan usually lasts for about 30 minutes and we ask you to keep as still as possible. After the scan, you can carry on your normal activities straight away. Each scan produces hundreds of images, which the neuroradiologist will study in order to produce a detailed report for your neurologist, usually within three to four weeks.

EEG

EEG (electroencephalography) consists of attaching electrodes to the scalp to record the brain’s electrical activity. EEGs usually take place as an outpatient, unless it forms part of a video-EEG telemetry admission. Sometimes, we make 24-hour recordings, using portable EEG equipment, which you can take away.

EEG and Video Telemetry

We carry out the combination of EEG and video telemetry recordings as an inpatient procedure on the Jules Thorne Telemetry ward at NHNN, or at the Sir William Gowers Centre at Chalfont. These are a continuous recording of your brain waves (EEG) using small discs attached to your scalp with glue. At the same time, we make a video recording. This usually continues for several days. The purpose is to record at least one of your typical seizures so that we can see what happens during a seizure and how your brain waves change at the time.

Whilst on the ward, you stay in an individual bay with a bed, comfy chair and TV with Freeview. Apart from using the washroom and toilet, we will ask you to stay in your bay for as much time as possible. You cannot leave the ward to smoke, but we can provide nicotine replacement therapy. You may bring books, games, a laptop, mobile phone etc with you. There is free wifi. We encourage visits from family or friends.

Can I wash while I have the test?

You cannot wash your hair or have a shower until the study has finished, but you can have a wash. Nursing staff are available to help with washing and dressing, if required.

What if I do not have a seizure?

If you do not have a seizure, your consultant may suggest that you return for another one to two weeks of recordings.

Medication whilst you are on the ward

Please bring your usual medication. While on the ward, we may consider reducing your anti-seizure medication, to increase the chances of recording a seizure. The decision to do this depends on a number of factors, including seizure frequency and severity. If medication is reduced, we will put a small plastic tube (cannula) in a vein so that, if necessary, we can give you medication urgently to stop a seizure, as some people may have longer or more severe seizures. Medication will return to the usual dose 24 hours before discharge. If it is reduced, we recommend that someone accompanies you home after your stay.

You will have a neuropsychological assessment to help us understand how your brain works, and the effects your epilepsy may be having. This usually lasts two to three hours and includes reading, drawing and memory tests. Please bring your reading glasses with you. There are no pass or fail marks.

We need to find out the patterns of your abilities – what you find easy, and what you find more difficult. People often wonder whether epilepsy surgery will affect their memory. Some people find that it improves after the operation; most experience no change. If your memory was poor before the operation, it is likely to stay that way. Memory problems get worse after surgery for around one in three people. Your age, type of operation and your pre-existing memory skills all influence the effects that surgery will have on your memory.

We will discuss with you the likely effect of surgery on your memory and other cognitive abilities and we will suggest some strategies that may help you if you experience any additional memory problems following surgery. We will usually reassess your memory three and 12 months after surgery, and will try to coordinate these appointments with your other follow-up appointments at the hospital.

Emotion, behaviour & epilepsy surgery

Emotional difficulties and depression are closely linked to epilepsy and so we will arrange for you to see our neuropsychiatrist. People with certain emotional difficulties may not respond well to surgery and it is important to assess you for these problems. Secondly, some people may develop emotional difficulties after surgery. Effective help can be given if this is necessary.

Which emotional problems are common after epilepsy surgery?

Mood swings, anxiety and depression can affect 20-30% of people. These symptoms usually go away in four to six weeks, although some people may need antidepressant medication and / or counselling. In 3-4% of patients, a more serious psychiatric disorder, psychosis, can occur after surgery. This can result in disturbing thoughts and abnormal beliefs. Although not common, it is important to be aware of this risk when making your decision about surgery. This illness may require a period of inpatient treatment and may cause distress.

What treatment is available?

Most psychiatric complications of surgery resolve by themselves, or respond well to drug treatment. Counselling, psychotherapy and behavioural therapy may also be helpful.

How and where would I be managed?

We will arrange an appointment for you with our neuropsychiatrist. They will liaise with your GP and other doctors at NHNN and refer you for therapy, either in your local area or at NHNN or at Chalfont.

Less common investigations may be needed to help to pinpoint the source of the epilepsy.

PET (Positron Emission Tomography) scan

PET takes place at nearby University College Hospital (UCH). It involves an injection into a vein of a very small amount of sugar with a radioactive label. This sugar is taken up by the brain and detected by the scanner. The scan takes about 2 hours and you can go home directly afterwards.

SPECT (Single Photon Emission Tomography) scan

SPECT also takes place at UCH. It involves an injection into a vein of a radioactive tracer, at the time of a seizure, during video-EEG telemetry, and again when you are not having a seizure. It identifies changes in the brain blood flow at the time of seizures, as this may indicate where in the brain the seizures are coming from.

Other MRI scans

Other MRI scans at NHNN or the William Gowers Centre, Chalfont may be needed to look for possible abnormalities of the brain, using the MRI scanner in new ways. A functional MRI (fMRI) identifies the parts of the brain that are involved in important functions such as speech, reading, memory, vision, limb sensation and control of limb movements. You will be shown pictures and words whilst the scan is being done and we will ask you to carry out tasks, such as thinking of words beginning with a particular letter, or moving a hand.

Intracranial EEG Telemetry

You will have an appointment with the neurosurgeon before deciding whether to go ahead with this. There are two different options: either electrodes covering the surface of your brain (grids), or multiple electrodes going into the brain (SEEG). Both occur under general anaesthetic. To reduce the risk of infection, we shave your hair and keep a bandage on your head at all times. These recordings usually last for 1-2 weeks.

We may perform brain stimulation whilst the electrodes are in place to identify areas of the brain that are needed for sensation, movement or speech, and to find out whether these important areas are close to the area responsible for your seizures.

When we have recorded enough seizures, we will remove the electrodes. However, if grids are used, it may be possible to perform the definitive operation for your epilepsy straight after removing the grids.

Angiography

This is carried out at NHNN as a day case and is needed prior to having intracranial EEG telemetry, to visualise the blood vessels supplying the brain.

When the results of all investigations are available, the team will discuss your situation at a multi-disciplinary team meeting (MDT), and will write to you with the outcome and our estimate of the chances of you becoming free of seizures, and the risks of surgery.

If surgery is appropriate, your consultant will arrange to meet you and will make appointments with the neurosurgeon, and the neuropsychologist to discuss the risks and benefits in detail and your future admission.

Counselling for surgery

This is an opportunity for you and your family to raise issues concerning you and it is often helpful to prepare a written list of questions in advance. The psychologist will also have your clinic letters and reports to hand. He/she will wish to discuss your social support and family circumstances.

Expectations of surgery vary widely. We will discuss how your life has been with your seizures and what difference you may reasonably expect from yourself and others. Some individuals may have been getting financial benefits prior to surgery. It is important to note that if your operation is successful and you become seizure-free, you may lose these benefits.

There is no single independent organisation that focuses on helping people back into the workplace or college after a long period of incapacity.

Some helpful organisations are:

• Local Employment Service offer training, job finding and advice
• National Union of Students offer advice on grants, courses and access to education
• Citizens Advice offer advice on benefits, housing, employment, and other issues

The psychologist will be happy to discuss your reasons for wanting surgery, such as independent living, reducing medication, driving, going to college and starting a family.

Remember that, at best, successful epilepsy surgery will relieve you of your seizures, but everything else is up to you.

Talking to someone who has had surgery previously

If you would like to talk to someone who has already had epilepsy surgery, please mention this to your consultant or psychologist. Please remember that everyone’s experiences are personal and everyone is different, and so what you hear may not apply to you. A group of individuals who have had epilepsy surgery, ‘Brain Buddy’, meets at Queen Square every four months and can provide support through shared experiences.

How long does all this take?

At present, the wait for video-EEG Telemetry is several months and the time between first referral and having surgery is usually a year. If intracranial EEG is necessary, the process may take up to two years. This means that there is plenty of time to consider each step and whether you wish to proceed further. We have an epilepsy surgery coordinator who can keep you up to date with progress, and the next steps.

What do I have to do before going into hospital?

It is important to carefully plan your admission and convalescence, with help at home for the first few weeks. You should not expect to be able to resume work for at least eight to ten weeks. We would recommend going back firstly on a part-time basis. We might ask you to come to a pre-assessment clinic at NHNN in the weeks before your surgery to make sure that there are no concerns with your general health, which would make surgery or the anaesthetic more risky.

What happens just before the operation and consent?

We will admit you to hospital on the morning of surgery, or one or two days beforehand, if more tests are needed. The day or morning before surgery, you will normally have an MRI scan, to guide and make your operation safer. The neurosurgical staff will meet you and ask for your written consent for surgery.

Before the operation

The night before, or the morning of surgery, you will need to wash your hair. At the time of surgery, we will shave the hair where we will make the incision on your head, and will mark your skin with ink. Your hair will quickly re-grow afterwards. The anaesthetist will explain to you what the anaesthetic will involve.

You will not be allowed to eat or drink for about 6 hours before surgery but you will receive your anti-seizure medication as usual. Operations can vary in duration between four to eight hours, according to the type of surgery that you are having. Your family can ask the nursing staff when they think you are ready for visits or calls.

If a close relative prefers to be at NHNN at the time of surgery, they may tell the ward sister where they will be so that a member of the operating theatre staff can let them know how you are.

Awake surgery

Sometimes the area of the brain to be operated on is close to the parts of the brain which control important functions, such as movement, feeling, or language. In order to operate safely, the neurosurgeon may suggest carrying out the operation whilst you are awake. This may sound alarming, but it is now very routine.

You will not feel anything and the surgeon will be able to test you throughout the procedure to ensure that there is no damage to brain functions. If this is planned, the neurosurgeon will discuss it in detail with you at your presurgical appointment.

Laser thermal therapy

Laser thermal therapy (LiTT) is an emerging alternative to conventional neurosurgery for some, but not all, individuals considering epilepsy surgery. We anticipate that this will be available in 2023. Laser light is used to destroy the part of the brain that is thought to be causing the seizures, through a 2mm drill hole in the skull. The inpatient stay would usually be 24 hours.

How will I feel when I wake up?

After the operation, you will wake up in the Recovery Ward. We will give you regular painkillers and tablets to stop you feeling sick. You may spend the first 12 to 24 hours after surgery in the High Dependency Unit (HDU) or Overnight Recovery to enable us to keep a close eye on you. It is usual to wake up with a headache.

The staff and nurses are very experienced with surgical patients and the medical staff will visit you each day. At first, there may be some swelling, particularly around your eyes, and the operation site, which will settle over the course of the first week.

During the first few days, you are likely to feel very tired and sleepy, because of the anaesthetic. You may have good days and bad days - this is normal. Please keep visitors to a minimum. They must be free of coughs, colds, upset stomachs, or other infections. Young children should only visit after discussion with the nursing staff and must be accompanied by an adult.

Seizures may occur within the first week after surgery and this does not mean that the surgery has been a failure. We will check your medication and possibly adjust it. When we are happy that you are making an adequate recovery, you can return home. This is usually five to six days after the operation.

What about care of my wound?

We usually close the cut on your head with stitches or clips, which are removed seven to eight days after surgery. Your wound needs to remain dry until the stitches are removed. You can wash your hair after the stitches are removed. You should treat the wound with care during the first few weeks, avoiding vigorous shampooing or brushing.

Please avoid scratching your wound. If you experience any discharge of fluid from the wound, or if you are worried about it, please contact the surgical team through their secretary (020 3448 3393), or ask your GP to contact the surgical team.

What about my recovery and returning to exercise?

During the weeks following surgery, it is important to rest. You may tire very easily and this is not unusual. Building up physical and mental activity slowly over the weeks will help.

When can I have sex after surgery?

As soon as you wish, provided that you feel physically and mentally ready.

Recovery at home after surgery

The after-effects of an anaesthetic may take a long time to wear off. For each hour of anaesthetic, you may take a week to feel entirely normal. So, for a three- to four-hour anaesthetic, it may take three to four weeks before you feel your energy returning. Try to drink plenty of fluids, eat regular meals, and sleep when you wish to.

You should build up activity slowly and try to spend part of each day up and about. You may start going for short walks when you feel up to it. Try to gradually build up your walking activity each day. Your aim should be to be back to almost normal activity by six weeks following the operation.

When will I have my next appointment?

We will arrange an appointment with the surgeon and your neurologist usually eight to 12 weeks after surgery. An MRI and memory tests will be carried out three to four months after surgery. We will probably not alter your medication for at least a year after surgery. You will also have a further assessment with the neuropsychologists one year after surgery. We may recommend a further MRI and EEG at this time. If there are concerns about your mental health, we will arrange for you to see a psychiatrist.

Driving and the DVLA regulations

The DVLA regulations state that you must be seizure-free for at least a year before you are eligible to hold a private car or motorcycle driver’s licence. If you are seizure free and your medication is stopped, there is a higher risk of seizures recurring and you and your consultant would need to give this careful consideration.

During the tapering of the last medication and the subsequent 6 months, you are advised not to drive, even if no seizures have occurred. If any seizures did occur when medication was being tapered, you would have to wait again until you have had no seizures for 6 months and had effective doses of medication restarted, before restoration of your driving licence. The DVLA also require you to have a visual field test to ensure that it is safe for you to drive. This can be arranged at NHNN, the Sir William Gowers Centre, or by most opticians.

How soon may I travel after surgery?

We advise against air travel in the first two to three weeks, unless a brain scan has shown there is no air inside your head. After the initial few weeks of convalescence, there is no reason why you should not travel by land, sea or air.

When will I know if surgery has been successful?

Before surgery, the medical team will have carefully discussed the aims of the operation with you. In many cases, this is to completely stop the seizures; in others, it is to reduce the number or severity of seizures. Whatever the aims of surgery, these will usually have been achieved within two years. It is important to realise, however, that not having seizures may lead to other problems and stresses in daily life and therefore contact with your neurologist, psychiatrist and / or psychologist may need to continue for some time after this period.

Long-term follow-up

We have carried out epilepsy surgery at NHNN since 1990 and it is important for us to know how you get on in the long term. If you are no longer being seen at the hospital, we would like to write to you, your GP, and local neurologist on a yearly basis for an update on how you are getting on.

Unfortunately, there is never any guarantee that surgery is going to be completely successful. If surgery is not successful, we may decide to reinvestigate you after a year, to see if there is a possibility of further surgery being helpful.

If you wish to know more details about the epilepsy surgery programme at NHNN, you may be interested in some of our papers. These are primarily for a medical scientific audience and so do contain quite a lot of complex medical terminology and language:

1. Cleary RA, Thompson PJ, Fox Z, Foong J. Predictors of psychiatric and seizure outcome following temporal lobe epilepsy surgery. Epilepsia. 2012. Oct;53(10):1705-12. PMID: 22881990
2. Cleary RA, Thompson PJ, Thom M, Foong J. Postictal psychosis in temporal lobe epilepsy: risk factors and postsurgical outcome? Epilepsy Res. 2013;106(1-2):264- 72. PMID: 23642574
3. De Tisi J, Bell GS, Peacock JL, McEvoy AW, Harkness WFJ, Sander JW, Duncan JS. The long-term outcome of adult epilepsy surgery, patterns of seizure remission and relapse: a cohort study. Lancet. 2011;378(9800):1388-95. PMID: 22000136 21
4. Duncan JS. Selecting patients for epilepsy surgery: Synthesis of data. Epilepsy Behav. 2011;20(2):230-2. PMID: 20709601
5. Duncan JS. Imaging in the surgical treatment of epilepsy. Nat Rev Neurol. 2010;6(10):537-50. PMID: 20842185
6. Gooneratne IK, Mannan S, de Tisi J, Gonzalez JC, McEvoy AW, Miserocchi A, Diehl B, Wehner T, Bell GS, Sander JW, Duncan JS. Somatic complications of epilepsy surgery over 25 years at a single center. Epilepsy Res. 2017;132:70-77. PubMed PMID: 28324680
7. Rugg-Gunn FR, McEvoy AW, Miserocchi A. Epilepsy Surgery. Pract Neurol 2020; 20:4–14 doi:10.1136/practneurol-2019-002192.
8. Thompson PJ, Baxendale SA, McEvoy AW, Duncan JS. Cognitive outcomes of temporal lobe epilepsy surgery in older patients. Seizure. 2015;29:41-5. PMID: 26076843
9. Vakharia VN, Duncan JS, Witt JA, Elger CE, Staba R, Engel J. Getting the best outcomes from epilepsy surgery. Ann Neurol 2018; 83(4):676-690. doi: 10.1002/ana.25205. Review. PMID: 29534299.

It would be helpful for you to note down the names and contact details of the specialists involved in your care so that it is easier to make contact should you need to.

Hospital no:
Neurologist:
Epilepsy nurse specialist advice line (office hrs only): 020 3448 8627
Epilepsy nurse specialist email: uclh.epilepsy@nhs.net
Epilepsy surgery coordinator: 020 3448 8616
Epilepsy fax no: 020 3448 8615
Neurosurgery (secretary): 020 3448 3393
On-call neurosurgery SpR: 0845 155 5000, Bleep 8100
Psychologist:
Psychiatrist:

Epilepsy Department
Box 29
National Hospital for Neurology and Neurosurgery
London, WC1N 3BG