Types of Stroke: ischemic vs hemorrhagic — crucial differences
One in five strokes is hemorrhagic. The distinction between the two types is not an academic subtlety: treatment, urgency, and prognosis are fundamentally different. What you absolutely need to know.
1. Ischemic Stroke: when a clot blocks blood flow
Mechanism
An ischemic stroke is caused by the blockage of a cerebral artery, depriving an area of the brain of oxygen and glucose. There are two subtypes depending on the origin of the clot. Thrombosis occurs when a clot forms directly on an atheromatous plaque in a cerebral artery — often the result of years of hypertension and atherosclerosis. Embolism occurs when a clot formed elsewhere in the body (most often in the heart during atrial fibrillation) migrates to the brain and causes the blockage.
Thrombolysis and thrombectomy
Within the 4h30 window, intravenous thrombolysis (rtPA — Alteplase) chemically dissolves the clot. For occlusions of large arteries, mechanical thrombectomy (removal of the clot via catheter under angiographic guidance) can be performed up to 24 hours in selected cases. These treatments can reduce residual disability by 30 to 50% — provided you arrive at the hospital on time.
Typical symptoms
An ischemic stroke often begins gradually over a few minutes. Symptoms depend on the affected artery: a stroke of the middle cerebral artery (the most common) causes contralateral hemiparesis (partial paralysis on the opposite side), hemisensory loss, and, if the dominant hemisphere is affected, aphasia. Headaches are absent or mild, unlike in hemorrhagic stroke.
2. Hemorrhagic Stroke: when a vessel ruptures
Mechanism
In a hemorrhagic stroke, a cerebral vessel ruptures and blood flows into the brain tissue (intraparenchymal hemorrhage) or into the subarachnoid space (meningeal hemorrhage). The bleeding is doubly harmful: it deprives the downstream tissue of oxygen AND compresses and mechanically destroys the surrounding tissue due to the mass effect of the accumulated blood. Chronic hypertension is responsible for 60% of hemorrhagic strokes — it progressively weakens the small perforating cerebral arteries until they rupture.
Management of hemorrhagic stroke
Unlike ischemic stroke, thrombolysis is absolutely contraindicated in hemorrhagic stroke — it would worsen the bleeding. Management aims to control intracranial pressure, stabilize blood pressure, and, depending on the location and volume of the bleeding, assess the surgical indication (hematoma evacuation). Anticoagulants and aspirin are also contraindicated.
Characteristic symptoms
A hemorrhagic stroke often manifests suddenly, "like a thunderclap": exceptionally intense headache ("the worst pain of my life"), nausea and vomiting, altered consciousness that can lead to coma, and neck stiffness in meningeal hemorrhages. These symptoms reflect the rapid increase in intracranial pressure.
3. Complete comparative table
| Criterion | Ischemic Stroke | Hemorrhagic Stroke |
|---|---|---|
| Frequency | 80 % | 20 % |
| Mechanism | Arterial obstruction by clot | Vascular rupture, cerebral bleeding |
| Onset | Gradual (minutes) | Sudden (seconds) |
| Headache | Rare or mild | Intense, "thunderclap" |
| Consciousness | Often preserved initially | Often altered |
| Main causes | Atherosclerosis, atrial fibrillation, thrombosis | Uncontrolled hypertension, aneurysm, AVM |
| Emergency treatment | Thrombolysis (rtPA) / Thrombectomy | Blood pressure control, surgery if indicated |
| Aspirin/Anticoagulants | Beneficial in secondary prevention | Contraindicated in acute phase |
| 30-day mortality | ~20–25 % | ~40–50 % |
| Functional recovery | Variable depending on location and delay | Sometimes better (compressed vs destroyed tissue) |
4. Cognitive sequelae and rehabilitation
Whether ischemic or hemorrhagic, a stroke often leaves cognitive sequelae in 40 to 50% of cases: memory, attention, language (aphasia), planning, or spatial neglect disorders. These disorders are at the heart of post-stroke rehabilitation and directly impact autonomy and quality of life.
🧠 Cognitive support post-stroke with DYNSEO
• Training "Cognitive Disorders after a Stroke" — memory, attention, and daily life
• DYNSEO Memory Test — assess the cognitive impact of a stroke
• Training "Return Home after a Stroke"
• 62 cognitive stimulation tools — progressive rehabilitation
FAQ
What is the difference between ischemic and hemorrhagic stroke?
Ischemic (80%) is caused by a clot blocking an artery; hemorrhagic (20%) by the rupture of a vessel. Emergency treatments are opposite — thrombolysis beneficial in ischemic is contraindicated in hemorrhagic.
Which is more serious?
Hemorrhagic is more serious in the short term (mortality 40-50% vs 20-25% at 30 days). But survivors sometimes recover better functionally, as compressed tissue can regain its function once the blood is absorbed.
Can aspirin be given in case of stroke?
No, before hospitalization. Without a scan, it is impossible to differentiate the two types. Aspirin is beneficial in ischemic but can worsen hemorrhagic. Never give aspirin before medical evaluation.
How long to treat an ischemic stroke?
4h30 window for intravenous thrombolysis. Thrombectomy can be effective up to 24h in some cases. Every hour of delay represents the loss equivalent to 3.6 years of brain aging.
What are the causes of a hemorrhagic stroke?
Uncontrolled hypertension (60%), aneurysm (10-15%), arteriovenous malformations, coagulation disorders. In elderly people, cerebral amyloid angiopathy is an increasing cause.
Conclusion: two emergencies, two logics
The distinction between ischemic and hemorrhagic stroke is fundamental — but it does not change the immediate response to adopt: call 15 without delay. Only a brain scan performed in the hospital can differentiate the two types and guide optimal treatment. Cognitive sequelae, present in both cases, require early and tailored rehabilitation to maximize functional recovery.