Overview

Symptoms

The symptoms of a subdural haematoma can develop soon after a severe head injury, or gradually over days or weeks after a more minor head injury.

Sometimes you may not remember hitting your head at all.

Symptoms of a subdural haematoma can include:

• a headache that keeps getting worse
• feeling and being sick
• confusion
• personality changes, such as being unusually aggressive or having rapid mood swings
• feeling drowsy and finding it difficult to keep your eyes open
• speech problems, such as slurred speech
• problems with your vision, such as double vision
• paralysis (loss of movement) on one side of the body
• problems walking and frequent falls
• fits (seizures)
• loss of consciousness

These symptoms can often be mistaken for other conditions, such as strokes, infections or dementia.

What to do

You should always seek emergency medical treatment after a severe head injury.

Go to your nearest accident and emergency (A&E) department, or dial 999 to request an ambulance.

If you develop the symptoms listed above any time after a minor head injury, or don't remember hitting your head, you should also go to your nearest A&E department or call 999 for an ambulance as soon as possible.

A subdural haematoma can be very serious and needs to be assessed as quickly as possible.

Who can get it

Subdural haematomas are usually caused by a head injury.

Head injuries that cause subdural haematomas are often severe, such as from a car crash, fall or violent assault.

Minor bumps to the head can also lead to a subdural haematoma in a few cases.

A subdural haematoma develops if there's bleeding into the space between the skull and the brain (the subdural space) caused by damage to the blood vessels of the brain or the brain itself.

As this blood starts to build up in the subdural space, it can place pressure on the brain (intracranial hypertension) and can cause brain damage.

Who's most at risk?

Anyone can develop a subdural haematoma after a severe head injury.

Chronic subdural haematomas form gradually a few weeks after a minor head injury.

These are more commonly seen in older people and those who take blood-thinning medication, drink excessively, or have another medical condition.

This is explained below.

Increasing age

Most chronic subdural haematomas affect people over 60, and the chances of developing one increase with age.  

This is thought to be because most people's brains shrink to some degree as they get older.

This places the brain's blood vessels under increased tension, like a stretched rubber band, and means they're more vulnerable to damage from minor injuries.

Alcohol misuse

Drinking too much alcohol over a long period of time can also gradually cause the brain to shrink and make the brain's blood vessels more vulnerable to damage.

Blood-thinning medication

Taking medication to reduce your risk of blood clots can increase your risk of developing a chronic subdural haematoma.

This is because it means your blood clots less easily and any bleeding caused by a head injury is likely to be more severe.

Both anticoagulant medicines, such as warfarin, and antiplatelet medicines, such as aspirin, may increase your risk.

Other conditions

An increased risk of chronic subdural haematoma has also been linked with:

• epilepsy – a condition that causes repeated fits (seizures)
• haemophilia – a condition that stops your blood clotting properly
• having a ventriculoperitoneal shunt – a thin tube implanted in the brain to drain away any excess fluid to treat hydrocephalus
• brain aneurysms – a bulge in one of the brain's blood vessels that can burst and cause bleeding on the brain
• cancerous (malignant) brain tumours

Diagnosis

Subdural haematomas are diagnosed based on a person's medical history, symptoms and the results of a brain scan.

Checking your medical history

The doctor assessing you in hospital might suspect you have a subdural haematoma if you recently injured your head and have some of the main symptoms of a subdural haematoma, such as confusion or a worsening headache.

It'll also be helpful to know if you take medication to prevent blood clots, such as warfarin or aspirin, as these can increase your chances of developing a subdural haematoma.

If necessary, a blood test can be carried out to assess your blood's ability to clot.

Sometimes your doctor will want to find out if you have previously been diagnosed with another condition that can have similar symptoms to a subdural haematoma, such as dementia, Parkinson's disease or a brain tumour.

Tests may be carried out to rule these conditions out.

Assessing your symptoms

You'll be examined to see if you have any physical signs of an injury to your head, such as cuts and bruises.

Tests to check how your pupils react to light will be used to check for signs of a brain injury.

The Glasgow Coma Scale (GCS) will also normally be used to check your level of consciousness and help determine the severity of any brain injury.

The GCS scores you on:

• your verbal responses – whether you can speak appropriately or make any sounds at all
• your motor response – whether you can move voluntarily or in response to stimulation
• whether you can open your eyes

If your GCS score suggests there may be a problem with your brain, a brain scan will be carried out.

Brain scans

Most people with a suspected subdural haematoma will have a type of brain scan called a CT scan to confirm the diagnosis.

A CT scan uses X-rays and a computer to create detailed images of the inside of your body.

It can show whether any blood has collected between your skull and brain.

In a few cases, an MRI scan may be used to check for a subdural haematoma instead.

This is a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.

Treatment

Surgery is recommended for most subdural haematomas. Very small subdural haematomas may be carefully monitored first to see if they heal without having an operation.

If surgery is recommended, it'll be carried out by a neurosurgeon (an expert in surgery of the brain and nervous system).

There are 2 widely used surgical techniques to treat subdural haematomas:

• craniotomy – a section of the skull is temporarily removed so the surgeon can access and remove the haematoma
• burr holes – a small hole is drilled into the skull and a tube is inserted through the hole to help drain the haematoma

These techniques are discussed in more detail below.

Craniotomy

A craniotomy is the main treatment for subdural haematomas that develop soon after a severe head injury (acute subdural haematomas).

During the procedure, the surgeon creates a temporary flap in the skull. The haematoma is gently removed using suction and irrigation, where it's washed away with fluid.

After the procedure, the section of skull is put back in place and secured using metal plates or screws.

This is usually performed under a general anaesthetic, which means you'll be asleep while it's carried out.

Burr holes

Burr hole surgery is the main treatment for subdural haematomas that develop a few days or weeks after a minor head injury (chronic subdural haematomas).

During the procedure, one or more small holes are drilled in the skull and a flexible rubber tube is inserted to drain the haematoma.

Sometimes the tube may be left in place for a few days afterwards to drain away any blood and reduce the chances of the haematoma coming back.

Burr hole surgery is often carried out under general anaesthetic, but is sometimes done under local anaesthetic.

This means you remain awake during the procedure, but the scalp is numbed so you don't feel any pain.

Risks of surgery

Like all operations, surgery for a subdural haematoma carries a risk of complications. Most of these complications are uncommon, but they can be serious.

Some of the main problems that can occur after subdural haematoma surgery include:

• further bleeding on the brain
• infection of the wound or skull flap
• a blood clot in a leg vein (deep vein thrombosis)
• fits (seizures)
• a stroke

There's also a chance that not all of the haematoma can be removed and that some of the symptoms you had before surgery continue. These may get better over time or they may be permanent.

In some cases, the haematoma can come back during the days or weeks after surgery. If this happens, further surgery may be needed to drain it again.

Recovering from surgery

If surgery goes well and you don't have any complications, you may be well enough to leave hospital after a few days.

If you do develop complications, it may be several weeks before you're able to go home.

If you have persistent problems after surgery, such as memory problems or weakness in your limbs, you may need further treatment to help you gradually return to your normal activities.

The length of time it takes to recover from a subdural haematoma will vary from person to person.

Some people will feel a lot better after a few weeks, while others may never make a full recovery.

Recovery