Intracerebral Hemorrhage Risk Factors
Intracerebral hemorrhage (ICH) is a subtype of stroke characterized by bleeding directly into the brain parenchyma. It has high mortality and disability rates.
Major Risk Factors
Hypertension (HTN)
- Most significant modifiable risk factor.
- Leads to small vessel disease (lipohyalinosis, Charcot-Bouchard microaneurysms).
- Classically associated with deep ICH (basal ganglia, thalamus, pons).
Cerebral Amyloid Angiopathy (CAA)
- Age-related amyloid-β deposition in leptomeningeal and cortical vessels.
- Associated with lobar hemorrhages.
- Common in elderly; may cause recurrent bleeds.
Antithrombotic Therapy
- Anticoagulants (warfarin, DOACs): ↑ risk, especially with supratherapeutic INR.
- Antiplatelets: mildly increase risk, particularly in older patients or with CAA.
Alcohol Abuse
- Chronic: leads to coagulopathy, liver dysfunction, and hypertension.
- Acute: may provoke hypertensive surges.
Illicit Drug Use
- Cocaine, amphetamines: cause acute hypertension and vascular damage.
Smoking
- Promotes vascular injury and increases blood pressure.
Hypocholesterolemia
- Low LDL and total cholesterol associated with increased ICH risk, especially lobar.
Non-Modifiable and Demographic Factors
Age
- Risk increases with age.
- CAA-related ICH more common in elderly.
Sex
- Slightly more common in males.
Ethnicity
- Higher incidence in Asian, Black, and Hispanic populations.
Genetic Factors
- APOE ε2/ε4 alleles → linked to CAA-related ICH.
- COL4A1/COL4A2 mutations → familial ICH syndromes.
Environmental and Emerging Risk Factors
Air Pollution (PM2.5)
- Chronic exposure associated with increased ICH burden.
- Disproportionately affects low-SES and urban populations.
Other
- Cerebral vascular malformations (AVMs, cavernomas).
- Hemorrhagic transformation of ischemic stroke.
- Neoplasms (primary or metastatic).
- Coagulopathies (congenital or acquired).
- COVID-19–associated coagulopathy.
Note: Risk stratification may differ by hemorrhage location (deep vs lobar vs infratentorial).