Undergoing an awake craniotomy

Reference Number: HEY475-2021
Departments: Neurology and Neurosurgery
Last Updated: 5 April 2021

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Introduction

This leaflet explains the procedure of an awake craniotomy and why it has been recommended that you have this form of surgery. It is not meant to replace the discussion between you and the healthcare team, but may act as a starting point for discussion. If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.

What is an awake craniotomy?

A craniotomy is an operation that involves temporarily removing part of the skull so that the surgeon can operate on the brain itself. It is the most common type of operation used to treat a brain tumour. The surgeon aims to remove as much of the tumour as possible. It may be mentioned to you as resection or debulking of tumour.

An awake craniotomy is an operation that is performed in the same way, but the patient is awake during the procedure. This is recommended when the tumour is near areas of the brain that are important for controlling speech, language or movement. If you are awake during the surgery the team can assess exactly what function each part of your brain controls using a technique called cortical mapping (see section below).

Why do I need an awake craniotomy?

You will have had an MRI scan which shows where the tumour is within the brain. The areas of the brain which control speech, language and movement are in the same general area for most people. Movement, for example, is controlled by specific areas in both hemispheres (sides) of the brain. Similarly, speech and language functions are found in specific areas; in right handed people this is usually in the left hemisphere of the brain, although it varies more in left handed people.

If your tumour is within or near to any of these areas, we may recommend that you have an awake craniotomy. This is to reduce the risk of permanent damage to your movement, speech or language abilities. It also helps in removal of as much as possible of the tumour safely (maximal safe resection).

What is cortical mapping?

This involves stimulating the surface of the brain with a tiny electrical current while you are asked to do certain tasks. You will not be able to feel the electrical current, but may notice changes in your body such as different sensations or being unable to do certain things. A physiotherapist and/or neuropsychologist will be with you during the operation and will ask you to do some tasks while the surgeon stimulates the brain. You might be asked to move certain parts of your body, or to name some pictures or read words from a screen.

At times during the operation you might find that you cannot complete the task you are asked to do. For example, it may be difficult for you to move a part of your body, or difficult to get your words out. You may also feel tingling or numbness in parts of your body. This does not mean that anything has gone wrong and is nothing to worry about. It means that the part of the brain the surgeon is stimulating is involved in that activity and lets the surgeon know where they can or cannot operate. It does not necessarily mean that the surgeon will be unable to remove parts of the tumour. The surgeon will stimulate the area around the tumour so that they can locate where speech/language/movement is within the brain.

There is also the possibility that you may experience a seizure (sometimes called a “fit”) during the surgery when a particular part of the brain is stimulated. There are many types of seizure; you may find that you feel an unusual sensation or experience twitching in part of your body. If this happens the surgeon will apply some cold sterile water to the surface of the brain (you will not feel this) to stop the seizure. Again, this does not mean that anything has gone wrong.

What happens before the surgery?

Depending on the timescale before your operation date you may have a pre-assessment clinic visit arranged to see a nurse for pre-operative work up like blood tests, ECG, Covid test, etc.

Before the operation you will have an anaesthetic review on the ward by the anaesthetist. This will give you the chance to ask any questions you may have about pain relief during the operation.

You will also be seen by a physiotherapist who will assess the strength in your limbs and discuss with you their role within the operation theatre.

You are allowed to drink fluids, which includes water, dilute juice, tea or coffee (with or without a small amount of milk) up until two hours before your surgery. Solid food is allowed up until six hours before the surgery.

What happens during the operation?

On the morning of surgery you will be taken down to the operating theatre. The anaesthetist will insert a drip into your arm that will give you some mild sedation drugs to help you feel relaxed and comfortable. A catheter may be inserted into your bladder to monitor fluid output and to stop you needing the toilet during the surgery. You will be asked to lie down on the operating table and we will make you as comfortable as possible. You will be able to talk to the team and ask questions at any time.

You are able to bring in your choice of music (e.g. CDs) to listen to during the procedure if you feel this will help you to relax during the operation. Alternatively, you could bring a tablet or iPad in this regard.

The surgeon will inject some local anaesthetic (pain relief) under the skin of your scalp – this will sting for a few seconds and then go numb. Once the area is numbed fully the surgeon will fix a clamp to hold your head firmly in place. The clamp is attached by three pins which go through the surface of the skin onto the outer surface of the skull. This clamp is then attached to a frame at the end of the operating table and you will not be able to move your head. You will temporarily feel some pressure when the clamp is fixed, but it should not be painful.

An image guidance system is used to find exactly where the tumour is in the brain. Your surgeon will hold a pointer over your head and look on a computer monitor screen, which will show inside your brain so the team know where the tumour is; this area will then be marked onto your scalp. Some of your hair may need to be shaved off, but only as much as is needed. Your scalp will be cleaned thoroughly with antiseptic solution, which may feel cold and a surgical drape is used to isolate the surgical site. A large plastic sheet will be hung up and attached to your forehead. This is done so that the procedure is done in a sterile environment. Local anaesthetic will then be injected under the scalp along the line where the cut will be made. Again, this may sting for a short time. Before making any cuts, the surgeon will check with you that you do not feel any pain.

The surgeon will make a cut through the scalp and clip the scalp back to expose the skull. A drill will then be used to cut out a piece of skull so the surgeon can see the brain. The drill can be a bit noisy for a short time, but you should not feel any pain. The brain does not directly sense pain so you will not feel the operation itself.

Once the brain is exposed, cortical mapping will be used to work out what the different parts of the brain do – see the above section for details. After the cortical mapping is complete the surgeon will remove the tumour. You will continue to complete the tasks while the tumour is being removed.

After the surgeon has removed as much of the tumour as possible, the piece of bone will be put back in and fixed into place and your scalp will be stitched up. The clamp will be taken off your head and it is likely you will have a bandage put around your head to keep the wound clean. You will be taken to the recovery room and then to the ward. Most people feel very tired after the operation.

Will I be awake throughout the entire operation?

There are 2 ways of doing this procedure. One way is being awake throughout the procedure. The other way is sleep awake sleep, where you would have a general anaesthetic to start with and when the surgeon has done the opening in the skull you would be woken up. You would be awake for the part where the tumour is removed and then put back to sleep for the part when the closure of the craniotomy is done.

Some patients are offered awake throughout and some are offered sleep awake sleep and that is normal.

In most cases you will be awake throughout the whole operation. You may be given mild sedation at times which will help you feel relaxed and may make you feel sleepy. It is fine to go to sleep during the first and last parts of the operation. The sedation will be stopped when we need you to be alert.

Sometimes, the surgeon or anaesthetist may make the decision to give you a general anaesthetic during the operation. This can happen for example if you develop breathing problems or have a seizure which is difficult to control. If this happens you will be asleep for the rest of the operation.

Will I have any pain?

Our aim is for you to have a pain free operation and if you feel pain at any time you should let us know at once.

The brain does not have any pain receptors so you will not feel the operation itself. You will be given an anaesthetic which is injected into the scalp to prevent you feeling any pain when the clamp is inserted. The injection itself can sting for a few seconds, but the area quickly becomes numb. You are also given an anaesthetic so that you do not feel the cut being made into the skin of your scalp. Throughout the procedure you will be able to talk to the team and let them know if you feel any pain so that they can give you something to help.

Will I be able to watch what is happening?

No. Clear plastic drapes will be attached to the front of your head and the surgeon will be working behind this drape. This is to keep the area sterile. There will always be someone on your side of the drapes with you and they will keep you informed of what is happening at all times.

Will I be able to move during the operation?

We aim to keep you as comfortable as possible during the operation and if you feel the need to move just let us know.

You will not be able to move your head as it is attached to the clamp to keep it securely in place. It is fine to cough or sneeze if you need to.

You may have a catheter put in before the operation so that you will not need to go to the toilet.

How will I feel after surgery?

Following surgery you will be transferred to the High Observation Bay of the ward or the High Dependency Unit. You will be monitored closely for the next 24 – 48 hours.

Most people find that they feel very tired after the surgery and need to sleep. In general however, recovery is quicker than from operations when you have been given a general anaesthetic (put to sleep). You can eat, drink and move around as soon as you feel ready.

If you experience any pain after the surgery please let the staff know. Pain relief medication will be given to ease pain.

Sometimes after surgery, people experience some problems in movement or in speech and language. This may be due to swelling and can improve over time. The risk of permanent side-effects cannot be completely removed, although having an awake procedure reduces this risk.

What are the risks of awake craniotomy?

Your surgeon will go through the risks of surgery with you. The risks depend on a number of things including the size, location and type of tumour, your current age, health and past medical history.

This surgery has been recommended for you because it is considered to be the safest option. Although there are risks with any surgery, there are also risks involved in not having surgery, as the tumour may continue to grow and may cause permanent damage to the brain.

What happens after discharge?

Your surgeon will see you a week or two after the operation to check on your recovery. The surgeon will discuss the results from the surgery with you. You will be told the diagnosis and given information about any further treatment you might need.

If you require any therapy to help your recovery, your therapist will arrange this with you as required while you are on the ward.

Contact details

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