Ischemic vs. Hemorrhagic Stroke: Pathophysiology, Presentation, and Acute Management Differences

Stroke is a clinical syndrome of acute focal neurologic deficit from cerebrovascular cause. The two main subtypes—ischemic (87%) and hemorrhagic (13%)—require diametrically opposed acute treatments.

Pathophysiology

Feature	Ischemic Stroke	Hemorrhagic Stroke
Mechanism	Arterial occlusion → ischemia/infarction	Vessel rupture → intracerebral hemorrhage (ICH) or subarachnoid hemorrhage (SAH)
Common Causes	Atherothrombosis, cardioembolism, small vessel disease, dissection	Hypertension (ICH), aneurysm/AVM rupture (SAH), amyloid angiopathy, anticoagulation
Pathology	Core (irreversible) + penumbra (salvageable)	Mass effect, toxic blood products, secondary ischemia

Clinical Differentiation

• Onset: Both sudden. ICH/SAH more likely thunderclap, severe headache, vomiting, depressed consciousness.
• Deficits: Overlap (hemiparesis, aphasia, neglect). SAH: meningismus, photophobia.
• Exam clues: ICH—hypertension, cerebellar signs if posterior fossa. SAH—cranial nerve palsies (III, VI).

Imaging: Non-Contrast CT Head (First Line)

• ICH/SAH: Hyperdense blood immediately visible.
• Ischemic: Early signs (hyperdense artery, loss of gray-white, insular ribbon) subtle; normal in first hours.
• CTA/CTP or MRI/DWI for ischemic core/penumbra; CTA for aneurysm/AVM.

Acute Management: CRITICAL DIVERGENCE

Intervention	Ischemic	Hemorrhagic (ICH)
Thrombolysis (tPA)	YES (≤4.5 hrs, eligible)	CONTRAINDICATED (worsens bleed)
Thrombectomy	YES (LVO ≤24 hrs)	NO
BP Target	<185/110 (for tPA); then <140/90	SBP <140 (INTENSIVE) or <180 (standard) per INTERACT2/ATACH-II
Anticoag/Antiplatelet	Aspirin 24–48h post-tPA	REVERSE anticoagulants (PCC, vitamin K, idarucizumab, andexanet)
Surgery	Decompressive hemicraniectomy (malignant MCA)	Evacuation (superficial >30 mL, GCS 9–12); EVD for hydrocephalus; aneurysm clipping/coiling (SAH)

Prognosis

• Ischemic: 3-mo functional independence ~40–50% (tPA + thrombectomy era).
• ICH: 30-day mortality 35–45%; survivors often severe disability.
• SAH: 30-day mortality 25–35%; delayed cerebral ischemia (vasospasm) Days 4–14.

“Time is brain” for both. NEVER give antithrombotics before CT excludes hemorrhage.