What are the causes of spontaneous intracranial subarachnoid (Subarachnoid) hemorrhage or intracerebral (Intracerebral) hemorrhage?

From the Guidelines

Spontaneous intracranial hemorrhage is most commonly caused by hypertension, which damages small blood vessels in the brain over time, leading to rupture, as well as cerebral amyloid angiopathy, vascular malformations, brain tumors, and coagulopathies, as supported by the most recent guideline from the American Heart Association/American Stroke Association in 2022 1.

Causes of Spontaneous Intracranial Hemorrhage

The causes of spontaneous intracranial hemorrhage can be categorized into several key areas, including:

• Hypertension: The most common cause, leading to damage of small blood vessels in the brain over time, resulting in rupture 1.
• Cerebral amyloid angiopathy: Particularly significant in elderly patients, this condition involves the deposition of amyloid beta peptides in the blood vessels of the brain, leading to their weakening and increased risk of rupture 1.
• Vascular malformations: Including arteriovenous malformations, cavernous malformations, and aneurysms, these abnormalities can lead to hemorrhage due to the structural weaknesses they introduce into the cerebral vasculature 1.
• Brain tumors: Both primary and metastatic tumors can cause intracranial hemorrhage by eroding into blood vessels or by causing vascular malformations 1.
• Coagulopathies: Disorders that affect the blood's ability to clot, such as hemophilia or the use of anticoagulant medications, can increase the risk of hemorrhage 1.
• Medication-related causes: Especially anticoagulant use (warfarin, direct oral anticoagulants), antiplatelet therapy (aspirin, clopidogrel), and thrombolytics, which can increase the risk of bleeding 1.
• Substance abuse: Particular substances like cocaine and amphetamines can trigger hemorrhage through acute hypertension or vasculitis 1.
• Infections and inflammatory conditions: Though less common, certain infections (like fungal infections or herpes encephalitis) and inflammatory conditions of blood vessels (vasculitis) can cause hemorrhage 1.
• Genetic disorders: Conditions such as Moyamoya disease, which affects the blood vessels in the brain, can also lead to intracranial hemorrhage 1.

Management and Recommendations

The management of spontaneous intracranial hemorrhage depends on identifying the underlying cause, controlling blood pressure, reversing anticoagulation if applicable, and sometimes surgical intervention for large hematomas or to address structural abnormalities, as recommended by the 2022 guideline from the American Heart Association/American Stroke Association 1. Key aspects of management include:

• Controlling blood pressure: Typically maintaining systolic BP below 140 mmHg in the acute phase to prevent further bleeding 1.
• Reversing anticoagulation: If the patient is on anticoagulant therapy, reversing its effects may be necessary to stop the bleeding 1.
• Surgical intervention: May be required for large hematomas, to relieve pressure, or to address underlying structural abnormalities like aneurysms or arteriovenous malformations 1.
• Diagnostic imaging: Utilizing CT, MRI, and angiography to identify the cause of the hemorrhage and to guide management decisions 1.

From the Research

Causes of Spontaneous Intracranial Hemorrhage

The causes of spontaneous intracranial hemorrhage can be divided into several categories, including:

• Hypertension: Uncontrolled hypertension is the most common cause of spontaneous intracerebral hemorrhage (ICH) 2, 3, 4
• Amyloid angiopathy: Cerebral amyloid angiopathy is another cause of lobar hemorrhages in older patients 2, 3
• Coagulopathy: Coagulopathy can increase the risk of intracranial hemorrhage 2, 4
• Vascular anomalies: Vascular anomalies, such as cerebral arteriovenous malformations (AVMs) and aneurysms, can increase the risk of intracranial hemorrhage 5, 6
• Tumors: Tumors can cause intracranial hemorrhage by disrupting the blood vessels in the brain 2
• Drugs: Certain drugs, such as anticoagulants and antiplatelet agents, can increase the risk of intracranial hemorrhage 2, 4
• Trauma: Trauma can cause intracranial hemorrhage, although this is not considered a spontaneous cause 5
• Hemorrhagic conversion of ischemic infarction: Ischemic infarction can convert to hemorrhage, causing intracranial hemorrhage 5
• Vasculitis: Vasculitis can cause intracranial hemorrhage by inflaming the blood vessels in the brain 5
• Venous sinus thrombosis: Venous sinus thrombosis can cause intracranial hemorrhage by blocking the flow of blood in the brain 5

Specific Causes of Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) can be caused by:

• Rupture of small perforating vessels off of larger cerebral arteries supplying deep brain structures, often due to chronic hypertension 3
• Cerebral amyloid angiopathy, which is more common in older patients 2, 3
• Coagulopathy, which can increase the risk of ICH 2, 4
• Vascular anomalies, such as AVMs and aneurysms 5, 6

Specific Causes of Subarachnoid Hemorrhage

Subarachnoid hemorrhage can be caused by:

• Rupture of an aneurysm in the subarachnoid space 5, 6
• Trauma, which can cause a tear in the blood vessels in the subarachnoid space 5
• Vascular anomalies, such as AVMs and aneurysms 5, 6
• Vasculitis, which can inflame the blood vessels in the subarachnoid space 5