Intracranial Haemorrhage

Intracranial haemorrhage (ICH), also known as intracranial bleed, refers to bleeding within the skull. This condition includes several subtypes: intracerebral bleeds, subarachnoid bleeds, epidural bleeds, and subdural bleeds. Intracerebral bleeding affects approximately 2.5 per 10,000 people each year.

Signs and Symptoms

Intracranial haemorrhage is a serious medical emergency due to the potential for increased intracranial pressure (ICP), which can crush brain tissue or restrict its blood supply. Severe increases in ICP can lead to brain herniation, where parts of the brain are squeezed past structures in the skull.

Common symptoms include severe headache, nausea/vomiting, seizures, dizziness, facial drooping, numbness, weakness, tingling, paralysis, speech problems, and sensory deficits such as blindness or deafness. Memory and attention problems, balance issues, coordination problems, and a decreasing level of consciousness or complete loss of consciousness may also occur.

Coma and persistent vegetative state are potential outcomes. Brain stem haemorrhage can cause additional symptoms like shortness of breath, difficulty swallowing, abnormal heart rate, and cardiac arrest.

Causes

Trauma is the most common cause of intracranial haemorrhage, leading to various types of haemorrhages such as epidural, subdural, and subarachnoid haemorrhages. Non-traumatic causes include hypertension, cerebral amyloid angiopathy, haemorrhagic conversion of ischaemic infarction, cerebral aneurysms, dural arteriovenous fistulae, cerebral venous sinus thrombosis, cerebral vasculitis, and mycotic aneurysm. More than half of intracranial haemorrhages result from hypertension.

Diagnosis

CT scans are the initial imaging choice due to their speed, accessibility, and high sensitivity in detecting brain injuries or diseases. MRI offers higher sensitivity for specific types of haemorrhages but is less commonly used due to longer imaging time, higher cost, and safety concerns with metallic foreign bodies.

The presence of the swirl sign on a CT scan, indicating active bleeding, suggests a high risk of death within a month and poor functional outcome if the patient survives.

Types of Traumatic Intracranial Haemorrhage

Epidural Haemorrhage

Epidural haemorrhage (EDH) occurs between the dura mater and the skull, typically due to trauma. It does not cross suture lines and appears as a biconvex shape on CT scans. The middle meningeal artery is commonly involved.

Subdural Haemorrhage

Subdural haemorrhage (SDH) results from tearing of bridging veins between the dura and arachnoid mater. It can cross suture lines and appears as a crescent shape on CT scans. SDH can progress from acute to chronic forms and may cause brain herniation.

Subarachnoid Haemorrhage

Subarachnoid haemorrhage (SAH) involves bleeding into the space between the arachnoid membrane and the pia mater. It is often caused by trauma or ruptured cerebral aneurysms and appears as hyperintense signals on MRI.

Types of Non-Traumatic Intracranial Haemorrhage

Hypertensive Bleed

Hypertensive bleeds typically occur in the basal ganglia, cerebellum, or occipital lobes and are associated with a high mortality rate. Follow-up CT scans are recommended to monitor the bleed.

Cerebral Amyloid Angiopathy

Cerebral amyloid angiopathy (CAA) involves the deposition of amyloid beta peptide in cerebral arteries, leading to microhemorrhages or large cerebral bleeds. Diagnosis is confirmed through imaging and brain biopsy.

Haemorrhagic Conversion of Ischaemic Infarction

Haemorrhagic conversion occurs in 43% of ischaemic infarctions and can lead to various types of haemorrhages. Monitoring with CT scans is essential for detecting significant haemorrhages that may require surgical intervention.

Cerebral Aneurysm

Ruptured cerebral aneurysms can cause SAH, presenting with a thunderclap headache and other neurological symptoms. Diagnosis is confirmed through CT scans and lumbar puncture.

Cerebral Arteriovenous Malformation

Cerebral arteriovenous malformations (AVMs) are abnormal shunts between arteries and veins, leading to intraparenchymal haemorrhage or SAH. Diagnosis is made through various angiographic techniques.

Management

Management includes immediate assessment and treatment to prevent further bleeding and complications. For patients on blood thinners, platelet function assays and plateletpheresis may be necessary. Observational data suggest that restarting blood thinners after an ICH may be safe and reduce thromboembolic complications.

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Self-assessment MCQs (single best answer)

Which of the following is the most common cause of intracranial haemorrhage?

Which imaging technique is typically the first choice for diagnosing intracranial haemorrhage?

What is a common symptom of intracranial haemorrhage?

In which space does an epidural haemorrhage occur?

Which of the following symptoms is indicative of a brain stem haemorrhage?

What is the typical appearance of a subdural haemorrhage on a CT scan?

Which condition is characterised by the deposition of amyloid beta peptide in cerebral arteries?

What type of haemorrhage involves bleeding into the space between the arachnoid membrane and the pia mater?

Which of the following is a potential consequence of severe increases in intracranial pressure?

Which artery is commonly involved in an epidural haemorrhage?