Chronic subdural haematoma (cSDH)

This leaflet intended for patients and their families to provide information and advice regarding the condition, its diagnosis and treatment options and pathways.

About chronic subdural haematomas

A chronic subdural haematoma, or 'cSDH', is a collection of old (‘chronic’) blood (‘haematoma’) that forms between the skull and membrane covering the brain, the dura. This originates from the damage to the veins supplying this membrane. This is called the ‘subdural space’.

The image above shows where a subdural haematoma can form. A membrane called the dura lines the inside of the skull. Because the skull is rigid, as the haematoma expands it cannot expand outwards and instead will push onto the brain, and possibly cause symptoms. The bigger a subdural is, the more likely it is to affect the brain. Subdurals can occur on one or both sides of the brain.

Symptoms

Most cSDH are small and do not cause any symptoms. However, some can slowly expand to compress and irritate the brain. This generally causes symptoms such as weakness of an arm or a leg, a facial droop on one side of the body or difficulty communicating. Occasionally, symptoms can occur suddenly, for example by causing a seizure or fit.

As well as these more specific symptoms, many patients exhibit other symptoms including:

• headache (generalised or localised to one side of the head or area) that may be mild or severe and progressively worse over time
• confusion
• drowsiness
• dizziness
• new unsteadiness on feet
• nausea and/or vomiting
• blackout (period of unconsciousness) and collapse

Different combinations of symptoms may present and change with time. Whilst ‘confusion’ is often a symptom that leads to a brain scan and the identification of a cSDH, on its own, it is rarely related. Symptoms such as arm or leg weakness, speech difficulties or headaches are a better indicator that the cSDH is causing a problem.

Diagnosis

A cSDH is diagnosed with a brain scan, such as computerised axial tomography (CT scan) or magnetic resonance imaging (MRI scan). Some blood tests will also need to be taken, especially if you are taking blood thinning medication. These tests along with a full history and examination, will determine whether the cSDH is causing symptoms that brought you to hospital.

Causes

We don’t fully understand why cSDH form.

Although this is a condition that most commonly affects older people, young people can also develop a cSDH.

A common idea is that an injury to the head has caused a bleed in the subdural space. The body has then failed to reabsorb this blood and instead sealed it off within a membrane, which slowly draws in fluid.

At the time of the injury, if occurred, there may be no signs or symptoms that there is bleeding, and you remain well. However, over time the clot can enlarge. This can be caused by the veins leaking, like a bruise, or as the haematoma liquefies it can increase in size.

It is unlikely this is a complete explanation as only two in three people can remember having any head injury prior to their cSDH and even amongst those who did, only one in three will have fresh blood (an acute subdural haematoma) in their subdural space on a brain scan at the time.

Certain groups of patients are more at risk for cSDH. These include:

• patients taking medication to thin their blood (eg warfarin, apixaban, edoxaban, aspirin or clopidogrel)
• older patients
• patients unsteady on their feet with increased likelihood of falling
• patients with liver disease making them more likely to bleed or bruise
• patients with haematological disease and/or clotting disorders
• patients who drink alcohol to excess

It is thought that these groups are more susceptible to developing a cSDH for various reasons. The brain gets smaller with age, meaning the subdural space is larger (as the skull remains the same size) and the blood vessels that cross the gap are stretched. These vessels are then more prone to tearing with even minor injuries, such as banging your head on a cupboard door. The above patient groups are at a higher risk of falls that could lead to a head injury, even minor, and are more likely to have blood that clots slowly. This process can occur over weeks to months.

Neurosurgical referral

Once the diagnosis has been made, your doctor will discuss your condition with the Neurosurgical team for advice and to make an ongoing treatment plan.

Patients may be admitted to their own hospital for observation, or it may be that the Neurosurgical team wish to assess you further, with a view to treatment or surgery. In this situation, if you have not come directly to the Neurosurgical Centre in Addenbrooke’s Hospital in Cambridge, a transfer to Addenbrooke’s Hospital will be organised.

This will involve transfer in an ambulance and may happen quickly. Your referring hospital will advise you as to the next steps once they have discussed your care with the neurosurgical team in Cambridge.

Transfer

If you are transferred to Addenbrooke’s, you will be admitted to one of the neurosurgical wards. These are currently Wards A3, A4, A5, C7. If you require extra monitoring for any reason, you might be admitted to the Neurosciences Critical Care Unit (NCCU). Transfers can be affected by the availability of neurosurgical beds.

On arrival at Addenbrooke’s, you will be welcomed to the ward by the nursing staff. You will be seen by one of the neurosurgical doctors as soon as possible, they will assess you and organise some investigations. Commonly this will involve blood tests, an electrocardiogram (ECG – ‘heart tracing’) if you have any kind of heart issue, and a chest x-ray (if you have any lung problems). You may also go for a repeat CT (brain scan) of your head.

The neurosurgical team will decide whether and when an operation should take place. They will explain which operation you are likely to benefit most from and go through the risks and benefits of this procedure. They will then ask you to sign a consent form.

If you are not well enough to be able to understand the information you are given, and to make a decision regarding this, the neurosurgical team will treat you with your best interests in mind. Where possible, this will involve discussion with your next of kin.

You will be scheduled for surgery according to the urgency of your specific case and relative to the other patients that the department are treating at the same time.

Your relatives and friends may see you on the ward according to the ward’s visiting times. This information can be obtained once you arrive. The surgical and nursing teams will update your nominated next of kin.

Anaesthesia

If surgery has been chosen, the neurosurgeons will discuss your case with the Anaesthetist, a doctor responsible for putting people to sleep for an operation. Together a decision will be made as to the safest way to provide surgery.

Most commonly, this will take place under general anaesthesia (asleep). Occasionally, it is better and safer that the operation is performed under local anaesthetic, often with some light sedation.

To help make this decision the anaesthetist will come to review you and explain what to expect before and after an anaesthetic.

Anaesthesia is generally a very safe procedure; however, the risks of suffering problems (such as heart attacks, chest infections or DVT) during or after surgery increase in patients who are older or have significant other health conditions. The anaesthetist will be able to explain this when they visit.

You must not eat for at least six hours before any general anaesthetic, but you can drink water up to two hours before. It may be that you may fast for more than this as sometimes it is necessary to postpone surgery for other more life-threatening emergencies. We understand that this is not pleasant and will be frustrating if it should occur, but we will do our best to keep you updated at all times.

Treatment options

The treatment of a subdural haematoma is either surgery or conservative management.

If the cSDH is small or an incidental finding and not causing significant problems we may opt for ‘conservative management’, which means avoiding any invasive intervention and monitoring the situation. If this approach is chosen, your vital observations and symptoms will be monitored to ensure your condition is stable. You may be given medications to treat any other medical problems that have been identified, or to reverse the action of any blood-thinning medications you may be taking. This can be done as an outpatient, with planned follow up appointments, and may require further CT scans. Should any symptoms occur or worsen between appointments, it is recommended to attend your local accident and emergency department for assessment.

If surgery is chosen, an operation will happen within a few days. This will mean being admitted to hospital. The timing of this operation will depend on the severity of symptoms and is balanced against the priority of others awaiting emergency operations.

There are two common surgical treatments.

1. Burr hole evacuation – This involves the surgeon drilling small holes into the skull to wash the blood/clot and associated fluid away. Often a soft plastic drain is inserted into the space between the layers to help prevent the clot from reforming. This drain will remain in place for 24 to 48 hours, this will then be removed on the ward by a doctor.
2. Craniotomy (also known as a ‘mini craniotomy’), where a small disc of bone from the skull is removed to allow the cSDH to be washed clear. The bone disc is then reinserted and secured in place with metal clips before closing the skin. This operation may require you to have a drain inserted as described above.

In most cases a burr hole surgery is preferred, as it is a less invasive procedure and very effective when the cSDH is largely liquid. If the cSDH is newer, then the blood can be more solid, and a craniotomy may be performed as the clotted blood cannot come out through the small burr holes. Sometimes this decision is made during the operation, ie whilst initially the surgery may have been planned as a burr hole, during the operation it may be recognised that a craniotomy is needed.

Care

Operative care

If you proceed to having an operation, you will need a small area of your hair to be shaved when asleep. This is to allow the surgeon to see and reduce the risk of infection. The surgeon does this, using sterile hair clippers.

The skin may be closed with sutures (thread like closure) or by surgical clips (like staples). Both are removed easily, typically seven to 10 days after your procedure, depending on how the wound has healed. If a drain was inserted and subsequently removed this will also be closed by a stitch which can be removed at the same time, normally by your GP services unless indicated otherwise.

Post-operative care

Once your procedure has finished, you will be woken in theatre and then taken to a recovery area. When you have recovered from the anaesthetic and are comfortable you will be transferred back to the ward area for monitoring and observations.

These procedures tend to be relatively painless. Medicines can be given to reduce nausea and pain following your procedure for as long as you will need them.

Occasionally, the anaesthetist and the surgeon may consider that you would benefit from being looked after in a higher dependency or critical care (‘intensive care unit’) area post-operatively.

To aid with your recovery other healthcare professionals may see you while you are on the ward, depending upon your individual needs. These include physiotherapists, occupational therapists, speech and language therapists and potentially social workers.

If you have been transferred from another hospital, plans to transfer you back to that hospital will be made as soon as you are safe and it is possible, this is called repatriation. Transfers of this nature are dependent on the availability of beds at that hospital and ambulance crews to affect the transfer. It is not uncommon for there to be delays at this point.

Caring for your wound

Dressings should be removed three days after your surgery. If the wound is clean and dry there will be no need to replace the dressing.

Clips or sutures can be removed seven to 10 days following your operation, as long as the wound has healed.

We advise that you keep the surgical area clean and dry. You may be able to wet the area, however we advise to avoid hair washing/shampooing until the clips/sutures are removed and the wound fully healed.

Monitor for any signs of infection such as swelling, redness, opening of the wound, leaking from the wound and generally feeling unwell, such as having a temperature.

Please note this is general advice and if you have been given specific instructions prior to your discharge please follow that advice.

Follow-up and longer-term recovery

Your longer-term recovery may be quick or take a long time. This is individual and will depend on the nature of the condition and your general health.

Often, if you have been transferred from a different hospital, this will mean transfer back to your local hospital, as they are able to ensure you get the rehabilitation and care you require to get back home safely (eg any necessary aids, adaptations or assistance in your home should you need any).

On discharge from the hospital instructions will be given as to when any stiches need to be removed. This appointment should then be made with nurse at your GP surgery. If you normally take medication to thin the blood, instructions will also be given as to when this can or if it should be restarted.

If you are a driver: you must not drive after leaving the hospital. This is regardless of whether you have had surgery or not, and you must inform the DVLA. The advice would be that you should drive on clinical recovery which will be determined in your follow up clinic appointment. This clinic appointment should take place eight to 12 weeks following your discharge from hospital; this is, however, dependent on clinic space availability.

There should be no restrictions to flying once you recover, but you must inform your insurance company.

A follow-up appointment will be made to see a member of the neurosurgical team to check on your recovery.

Who to contact

If you need specific help, you can call the numbers below (call the number according to who was looking after you):

• Mr Guilfoyle, Mr Helmy, Mr Brown, Mr Trivedi : 01223 216189
• Professor Hutchinson, Mr Timofeev, Mr Kolias : 01223 216127
• Mr Price, Mr Mair, Mr Joannides, Mr Santarius, Mr Morris : 01223 256246
• Mr Mannion : 01223 256981
• Mr Jalloh, Mr Garnett, Ms Craven : 01223 274492

You can visit the chronic subdural website (opens in a new tab) for further information.