Types of Stroke: The Mechanisms, Causes, and Signs of Onset for Ischemic Stroke (Infarction), Intracerebral Hemorrhage, and Subarachnoid Hemorrhage
Uncategorized
Stroke is largely categorized into three types: Cerebral Infarction (Ischemic Stroke), Intracerebral Hemorrhage, and Subarachnoid Hemorrhage. Each possesses distinct mechanisms and treatment approaches. While Cerebral Infarction (approx. 70–75%), where a vessel is blocked, is the most common in Japan, Intracerebral Hemorrhage (vessel rupture) and Subarachnoid Hemorrhage (aneurysm rupture) have high fatality rates and are characterized by greater urgency.
Types of Stroke
Type
Proportion (Japan)
Mechanism
Main Cause
Characteristic of Onset
Severity/Mortality Rate
Cerebral Infarction(Ischemic Stroke)
70–75%
A blood vessel in the brain is blocked, cutting off blood flow.
Atherosclerosis, atrial fibrillation, carotid stenosis, etc.
Often occurs while sleeping (noticed in the morning).
Moderate to Severe
Intracerebral Hemorrhage
15–20%
A small blood vessel inside the brain ruptures and bleeds.
High Blood Pressure (≥90%)
Sudden headache “like being hit by a bat” + paralysis during active hours.
Very Severe
Subarachnoid Hemorrhage(SAH)
5–10%
An aneurysm (a sac/bulge) on the brain’s surface ruptures.
Aneurysm (congenital or age-related).
Sudden “worst headache ever experienced”!
Ultra-Severe
Cerebral Infarction is Further Divided into 3 Subtypes (Important!)
Subtype
Proportion
Cause/Characteristic
Key Treatment Point
Cardioembolic Stroke
25–30%
A blood clot formed in the heart (especially due to atrial fibrillation) travels forcefully to the brain.
Sudden onset! Tends to result in a large infarct.
Atherothrombotic Stroke
30–40%
Atherosclerosis progresses in the large vessels of the neck/brain → a clot forms there and blocks the vessel.
Common in middle-aged and elderly individuals.
Lacunar Infarction
25–30%
Very small vessels deep within the brain become damaged and blocked due to high blood pressure.
Infarcts are small, but repeated occurrences lead to dementia.
Quick Comparison Table
Feature
Cerebral Infarction
Intracerebral Hemorrhage
Subarachnoid Hemorrhage
Headache at Onset
Infrequent
Severe (30–50%)
Ultra-Severe (≥90%)
Decreased Level of Consciousness
Mild to Moderate
Frequent
Very Frequent
Blood Pressure at Onset
Normal to Slightly High
Often Extremely High
High
Time Limit for Treatment
4.5–24 hours possible
Primarily limited to lowering BP
Surgery for re-bleeding prevention is the highest priority
Recurrence Prevention Drug
Antiplatelets or Anticoagulants
Antihypertensives (BP medication)
Surgery (Coiling or Clipping)
Convenient One-Sentence Summary
Cerebral Infarction → “A clogging disease” → Arm/leg paralysis noticed in the morning.
Intracerebral Hemorrhage → “A rupturing disease” → Severe headache + paralysis during activity.
