Subdural Haematoma - Symptoms & Causes

What is subdural haematoma?

A subdural haematoma is a collection of blood (or blood clot) that forms between the dura mater (the outer protective covering of the brain) and the arachnoid mater (the middle layer of the meninges).

This condition occurs when blood vessels, usually veins, are damaged and bleed into this space. The accumulation of blood can increase pressure on the brain, potentially leading to brain damage or death if not treated promptly. Subdural haematomas usually occur due to head injuries, but sometimes they develop without an apparent cause, particularly in the elderly.

Difference between a subdural haematoma and a subarachnoid haemorrhage

A subdural haematoma and a subarachnoid haemorrhage (SAH) are types of bleeding within the head.

• Subdural haematoma refers to bleeding between the dura mater and the arachnoid membrane.
• Subarachnoid haemorrhage refers to bleeding in the subarachnoid space, between the brain and the thin tissues covering it.

The causes are different, but both require urgent treatment.

Types of subdural haematoma

• Acute subdural haematoma. This type occurs quickly after a severe head injury and can cause symptoms within minutes to hours. It is often life-threatening and requires immediate medical attention.
• Subacute subdural haematoma. Symptoms of this type develop more slowly, typically within days to weeks after the injury.
• Chronic subdural haematoma. This type can develop over weeks or even months after a minor head injury. It is more common in older adults and those on blood-thinning medications.

What are the symptoms of a subdural haematoma?

The symptoms of a subdural haematoma can vary depending on the size and rate of bleeding. Common symptoms include:

• Persistent and severe headaches.
• Difficulty thinking clearly or memory problems.
• Increased sleepiness or difficulty staying awake.
• Nausea and vomiting often associated with increased intracranial pressure.
• Weakness or numbness, particularly on one side of the body.
• Slurred speech or difficulty finding words.
• Blurred vision or double vision.
• Seizures.
• Loss of consciousness.

What causes a subdural haematoma?

Several factors can lead to a subdural haematoma:

• Head injury. Traumatic blows to the head, such as from falls, car accidents, or sports injuries, are the most common cause.
• Ageing. Older adults are at higher risk due to brain atrophy, which stretches and weakens blood vessels.
• Anticoagulant medications. Blood thinners can increase the risk of bleeding.
• Alcohol abuse. Long-term alcohol use can lead to brain atrophy and increased risk of injury.
• Medical conditions. Conditions such as haemophilia or other clotting disorders can contribute to the risk.

What are the complications and related diseases for a subdural haematoma?

A subdural haematoma can lead to several serious complications:

• Increased intracranial pressure. Accumulation of blood can increase pressure within the skull, causing further brain damage.
• Permanent brain damage. Depending on the severity and location of the haematoma, long-term neurological impairments can occur.
• Recurrent bleeding. The risk of additional bleeding episodes, particularly in those on anticoagulant therapy.
• Seizures.
• Death. Severe cases can lead to coma and death if not treated promptly.

How do you prevent a subdural haematoma?

Preventing a subdural haematoma involves managing risk factors and taking precautions:

• Wearing helmets and protective headgear during high-risk activities.
• Implementing safety measures to prevent falls, especially in older adults.
• Regular monitoring and appropriate use of anticoagulant medications.
• Reducing alcohol intake to lower the risk of injury.