Subarachnoid haemorrhage

Symptoms

There are usually no warning signs, but a subarachnoid haemorrhage sometimes happens during physical effort or straining, such as coughing, going to the toilet, lifting something heavy or having sex.

The main symptoms of a subarachnoid haemorrhage include:

• a sudden severe headache unlike anything you’ve experienced before
• a stiff neck
• feeling and being sick
• sensitivity to light (photophobia)
• blurred or double vision
• stroke-like symptoms – such as slurred speech and weakness on one side of the body
• loss of consciousness or convulsions (uncontrollable shaking)

Causes

A subarachnoid haemorrhage is most often caused by a burst blood vessel in the brain (a ruptured brain aneurysm).

A brain aneurysm is a bulge in a blood vessel caused by a weakness in the blood vessel wall, usually at a point where the vessel branches off.

As blood passes through the weakened vessel, the pressure causes a small area to bulge outwards like a balloon.

Occasionally, this bulge can burst (rupture), causing bleeding around the brain. More than 8 out of every 10 subarachnoid haemorrhages happen in this way.

A brain aneurysm doesn't usually cause any symptoms unless it ruptures.

But some people with unruptured aneurysms experience symptoms such as:

• sight problems
• pain on one side of the face or around the eye
• persistent headaches

It's not known exactly why brain aneurysms develop in some people, although certain risk factors have been identified.

These include:

• smoking
• high blood pressure
• excessive alcohol consumption
• a family history of the condition
• severe head injury
• autosomal dominant polycystic kidney disease (ADPKD)

Most brain aneurysms won't rupture but a procedure to prevent subarachnoid haemorrhages is sometimes recommended if they're detected early.

Risk Factors

Subarachnoid haemorrhages can happen at any age, but are most common in people aged between 45 and 70. Slightly more women are affected than men.

Subarachnoid haemorrhages are also more common in black people compared to other ethnic groups. This could be because black people are more likely to have high blood pressure.

Diagnosis

You'll need to have some tests done in a hospital to confirm if you have a subarachnoid haemorrhage.

A CT scan is used to check for signs of a brain haemorrhage. This involves taking a series of X-rays, which a computer then makes into a detailed 3D image.

You may also have a test called a lumbar puncture. A needle is inserted into the lower part of the spine so that a sample of the fluid that surrounds the brain and spinal cord (cerebrospinal fluid) can be removed. It will then be analysed for signs of bleeding.

Planning treatment

If the results of a CT scan or lumbar puncture confirm you've had a subarachnoid haemorrhage, you'll be referred to a specialist neuroscience unit.

Further tests are usually needed to help plan treatment, which may include either:

• computed tomography angiography (CTA) – using a CT scan
• magnetic resonance angiography (MRA) – using an MRI scan

Both of these tests are carried out in the same way as a CT scan. But a special dye is injected into a vein (usually in your arm or hand) to highlight your blood vessels and tissues.

Occasionally, an angiogram may be needed. This involves inserting a thin tube called a catheter into one of your blood vessels (usually in the groin). 

Local anaesthetic is used where the catheter is inserted, so you won't feel any pain. 

Using a series of X-rays displayed on a monitor, the catheter is guided into the blood vessels in the neck that supply blood to the brain.

Once in place, the dye is injected through the catheter and into the arteries of the brain. The dye casts a shadow on an X-ray, so the outline of the blood vessels can be seen and the exact position of the aneurysm identified.

Treatment Options

You'll usually be transferred to a specialist neurosciences unit if a subarachnoid haemorrhage is suspected.

These units have a range of equipment and treatments to support many of the body's vital functions, such as breathing, blood pressure and circulation.

If your condition is severe, you may be transferred to an intensive care unit (ICU).

Medicine

Nimodipine

One of the main complications of a subarachnoid haemorrhage is secondary cerebral ischaemia.

This is where the supply of blood to the brain becomes dangerously reduced, disrupting the normal functions of the brain, causing brain damage.

You'll usually be given a medicine called nimodipine to reduce the chances of this happening.

This is normally taken for 3 weeks, until the risk of secondary cerebral ischaemia has passed.

Side effects of nimodipine are uncommon but can include:

• flushing
• feeling sick
• increased heart rate
• headaches
• a rash

Pain relief

Medicine can be effective in relieving the severe headache pain associated with a subarachnoid haemorrhage.

Commonly used pain-relieving medicines include morphine and a combination of codeine and paracetamol.

Other medicines

Other medicines that may be used to treat a subarachnoid haemorrhage include:

• anticonvulsants, such as phenytoin – which can help prevent seizures (fits)
• antiemetics, such as promethazine – which can help stop you feeling sick and vomiting

Surgery and procedures

If scans show that the subarachnoid haemorrhage was caused by a brain aneurysm, a procedure to repair the affected blood vessel and prevent the aneurysm from bursting again may be recommended.

This can be carried out using one of 2 main techniques. The type of procedure used will depend on your health and the aneurysm's position. Both are carried out under general anaesthetic, meaning you'll be asleep throughout the operation.

Coiling

A thin tube called a catheter is inserted into an artery in your leg or groin.

The tube is guided through the network of blood vessels into your head and into the aneurysm.

Tiny platinum coils are then passed through the tube and into the aneurysm. Once the aneurysm is full of coils, blood cannot enter it.

This means the aneurysm is sealed off from the main artery, preventing it growing or rupturing again.

Clipping

A cut is made in your scalp (or sometimes just above your eyebrow) and a small flap of bone is removed so the surgeon can access your brain. This type of operation is known as a craniotomy.

When the aneurysm is located, a tiny metal clip is fitted around the base of the aneurysm to seal it shut. After the bone flap has been replaced, the scalp is stitched together.

Over time, the blood vessel lining will heal along where the clip is placed, permanently sealing the aneurysm and preventing it growing or rupturing again.

Coiling versus clipping

Whether clipping or coiling is used depends on things such as the size, location and shape of the aneurysm.

Coiling is often the preferred technique because it has a lower risk of short-term complications such as seizures than clipping, although the long-term benefits over clipping are uncertain.

People who have the coiling procedure usually leave hospital sooner than people who have the clipping procedure, and the overall recovery time can be shorter.

But when these types of surgery are carried out as an emergency procedure, your recovery time and hospital stay depend more on the rupture's severity than the type of surgery used.

Sometimes surgery may not be advisable because it's considered too risky. This is called conservative treatment or management.

Whichever treatment you have, you will need to be closely monitored for some time to avoid complications.

Complications

A subarachnoid haemorrhage can lead to further problems.

Rebleeding

A potentially serious early complication of a subarachnoid haemorrhage is the brain aneurysm bursting again after it's sealed itself. This is known as rebleeding.

The risk of rebleeding is highest in the few days after the first haemorrhage, and carries a high risk of permanent disability or death. Because of this, aneurysm repair is needed as soon as possible.

Vasospasm​

Vasospasm (also called delayed cerebral ischaemia) is when a blood vessel goes into a spasm, causing the vessel to narrow.

The supply of blood to the brain becomes dangerously low, disrupting the normal functions of the brain and causing brain damage. It's most common a few days after the first haemorrhage.

Common symptoms are increasing drowsiness, which can lead to a coma, with or without other stroke-like symptoms, such as weakness down one side of the body.

There are many treatments that can be used to prevent and treat vasospasm, including a medicine called nimodipine.

Hydrocephalus

Hydrocephalus is a build-up of fluid on the brain, which increases pressure and can cause brain damage.

This can cause a wide range of symptoms, including:

• headache
• being sick
• blurred vision
• difficulty walking

Hydrocephalus is common after subarachnoid haemorrhage, as the damage caused by a haemorrhage can disrupt the production and drainage of cerebrospinal fluid (CSF). This can lead to increased amounts of fluid around the brain.

CSF is a fluid that supports and surrounds the brain and spinal cord. A constant supply of new CSF is produced inside the brain, while the old fluid is drained away into blood vessels.

Hydrocephalus may be treated with a lumbar puncture or a temporary tube that's surgically implanted into the brain to drain away the excess fluid.

Long-term complications

There are a number of long-term complications that can affect people after a subarachnoid haemorrhage.

Epilepsy

Epilepsy is where the normal working of the brain is interrupted, causing a person to have repeated fits or seizures.

There are different types of seizure, and symptoms vary. You may lose consciousness, have muscle contractions (your arms and legs twitch and jerk) or your body may shake or become stiff.

Seizures usually last between a few seconds and several minutes before brain activity returns to normal.

When epilepsy follows a subarachnoid haemorrhage, the first seizure usually happens in the year after the haemorrhage. The risk of having a seizure goes down over time.

Epilepsy can be treated using anti-epileptic medicines, such as phenytoin or carbamazepine. A neurologist will help decide which treatment you need and how long you need to take it for.

Cognitive dysfunction

Cognitive dysfunction is when a person experiences difficulties with one or more brain functions, such as memory.

Cognitive dysfunction is a common complication of a subarachnoid haemorrhage, affecting most people to some degree.

Cognitive dysfunction can take a number of forms, such as:

• problems with memory – memories before the haemorrhage are normally not affected, but you may have problems remembering new information or facts
• problems with tasks that require some degree of planning – you may find that even simple tasks, such as making a cup of tea, are difficult and frustrating
• problems with concentration or attention

There are a number of self-care techniques you can use to compensate for any dysfunction.

For example, breaking tasks down into smaller steps and using memory aids (such as notes or a diary) can help.

An occupational therapist can also help make day-to-day activities easier, while a speech and language therapist can help with communication skills.

Your care team can tell you how to access these types of services.

Most cognitive functions improve with time, but problems with memory can be persistent.

Emotional problems

Emotional problems are another common, long-term complication of a subarachnoid haemorrhage.

These problems can take a number of forms, such as:

• depression – feeling very down, hopeless and not getting any real enjoyment out of life
• anxiety disorder – a constant sense of anxiety and dread that something terrible is going to happen
• post-traumatic stress disorder (PTSD) – where a person often relives a previous traumatic event (in this case the haemorrhage) through nightmares and flashbacks, and they may experience feelings of isolation, irritability and guilt

These mood disorders can be treated using a combination of:

• medicine, such as antidepressants
• talking therapies, such as cognitive behavioural therapy (CBT)

When To See A Doctor

A subarachnoid haemorrhage is a medical emergency. Dial and immediately and ask for an ambulance if you or someone in your care has these symptoms.