AIM STUDENT MEMORY SUPPORT
Final Year MBBS | KMU Curriculum | Neuroscience-III
Cerebrovascular Disorders: Ischemic Stroke, Hemorrhagic Stroke & SAH
High-yield memory reinforcement, clinical associations and examination-focused rapid revision.
1. High-Yield Flashcards
Tap each question to reveal its answer.
What is the fundamental difference between ischemic and hemorrhagic stroke?
Ischemic stroke results from cerebral arterial occlusion; hemorrhagic stroke results from vessel rupture and intracranial bleeding.
Why can cerebral arterial occlusion cause irreversible neuronal injury?
Reduced oxygen and glucose delivery causes ATP depletion, ion-pump failure, cytotoxic edema and eventually neuronal death.
What neurological findings suggest a dominant left MCA stroke?
Right face-arm weakness with aphasia, often with a right visual-field defect.
What is the ischemic penumbra?
Hypoperfused, functionally impaired but potentially salvageable brain tissue surrounding the irreversibly injured infarct core.
Which initial imaging investigation is preferred in suspected acute stroke?
Urgent non-contrast CT brain, primarily to identify or exclude intracranial hemorrhage.
What does acute intracerebral hemorrhage usually look like on non-contrast CT?
A hyperdense (bright) blood collection within brain tissue, sometimes with edema and mass effect.
What is the important early MRI pattern of acute ischemic infarction?
Restricted diffusion: high signal on diffusion-weighted imaging with a corresponding low ADC value.
What is the difference between NIHSS and GCS?
NIHSS quantifies stroke-related neurological deficits; GCS measures level of consciousness using eye, verbal and motor responses.
What is the main purpose of reperfusion therapy in ischemic stroke?
Restore blood flow to threatened brain tissue and reduce permanent neurological damage in eligible patients.
Why is thrombolysis contraindicated in intracerebral hemorrhage?
It promotes fibrin clot breakdown and can increase intracranial bleeding and hematoma expansion.
What is the classical presenting symptom of subarachnoid hemorrhage?
Thunderclap headache: a sudden, extremely severe headache reaching maximum intensity rapidly.
How is a ruptured intracranial aneurysm definitively secured?
Endovascular coiling or surgical clipping, depending on aneurysm anatomy and specialist assessment.
Why is nimodipine prescribed after aneurysmal subarachnoid hemorrhage?
It reduces delayed cerebral ischemia and improves neurological outcomes following aneurysmal SAH.
What serious complication should be suspected when GCS falls with increasing midline shift?
Raised intracranial pressure with worsening mass effect and threatened brain herniation.
What is the key difference in secondary prevention of non-cardioembolic versus AF-related cardioembolic stroke?
Non-cardioembolic ischemic stroke usually requires antiplatelet therapy; atrial fibrillation-related cardioembolic stroke usually requires oral anticoagulation when appropriate.
2. Mnemonics
Mnemonic 1 — Stroke Warning Signs
BE FAST
B — Balance difficulty
E — Eye/vision changes
F — Facial droop
A — Arm weakness
S — Speech difficulty
T — Time to seek emergency stroke assessment
Mnemonic 2 — Glasgow Coma Scale Components
EVM = 4–5–6
E — Eye opening, maximum 4
V — Verbal response, maximum 5
M — Motor response, maximum 6
Total: 3–15 points.
Mnemonic 3 — Major SAH Complications
R–H–D
R — Rebleeding from an unsecured aneurysm
H — Hydrocephalus due to impaired CSF circulation
D — Delayed cerebral ischemia, often associated with vasospasm
3. Memory Tables
Table 1 — Ischemic Stroke vs Intracerebral Hemorrhage vs SAH
| Feature | Ischemic | Intracerebral Hemorrhage | SAH |
|---|---|---|---|
| Mechanism | Arterial occlusion | Bleeding into brain tissue | Bleeding into subarachnoid space |
| Typical presentation | Sudden focal deficit | Focal deficit ± headache, vomiting | Thunderclap headache ± meningism |
| CT findings | May be normal early; later hypodensity | Hyperdense parenchymal blood | Blood in sulci or basal cisterns |
| Main treatment | Eligible reperfusion therapy | Bleeding control and monitoring | Secure aneurysm when present |
| Major complication | Infarction and cerebral edema | Hematoma expansion, herniation | Rebleeding, hydrocephalus, delayed ischemia |
Table 2 — NIHSS vs Glasgow Coma Scale
| Feature | NIHSS | GCS |
|---|---|---|
| Purpose | Stroke deficit severity | Consciousness level |
| Assessment | Motor, sensory, language, vision and other deficits | Eye, verbal and motor responses |
| Score | 0–42 | 3–15 |
| Deterioration | Score increases | Score decreases |
4. Rapid Revision Points — Last-Minute Revision
Must Remember:
- Acute focal neurological deficit requires immediate stroke assessment.
- Non-contrast CT brain is the key initial investigation to detect intracranial hemorrhage.
- Dominant MCA infarction commonly causes contralateral face-arm weakness with aphasia.
- Early ischemic stroke may be invisible on CT; diffusion MRI may detect it.
- Intravenous thrombolysis is restricted to eligible ischemic stroke patients.
- NIHSS increases with worsening neurological impairment; GCS decreases with reduced consciousness.
- Intracerebral hemorrhage requires controlled blood pressure management and monitoring for expansion.
- Thunderclap headache is a major warning sign of SAH.
- Aneurysmal SAH requires consideration of coiling or clipping and nimodipine therapy.
- Secondary stroke prevention combines mechanism-directed medication, vascular risk-factor control and rehabilitation.
5. Clinical Memory Hooks
Clinical Hook 1 — Stroke Localization
Sudden right face-arm weakness with expressive aphasia → dominant left MCA territory involvement.
Clinical Hook 2 — Early Brain Imaging
Persistent focal deficit with initially normal CT → early ischemic stroke remains possible → consider diffusion MRI when appropriate.
Clinical Hook 3 — Hemorrhagic Stroke
Hypertension + sudden hemiparesis + hyperdense basal ganglia lesion → deep intracerebral hemorrhage.
Clinical Hook 4 — Subarachnoid Hemorrhage
Thunderclap headache + neck stiffness + blood in basal cisterns → SAH → investigate for ruptured aneurysm.
Clinical Hook 5 — Secondary Prevention
Ischemic stroke associated with atrial fibrillation → cardiac thromboembolism risk → long-term oral anticoagulation when appropriate.
6. Starred High-Yield Exam Points
Highest-priority KMU examination concepts:
- ⭐ Acute ischemic stroke → urgent non-contrast CT to exclude hemorrhage before considering thrombolysis.
- ⭐ IV thrombolysis requires eligibility assessment, including treatment timing and blood pressure control.
- ⭐ Large-vessel ischemic stroke → consider mechanical thrombectomy in eligible patients.
- ⭐ Sudden thunderclap headache → suspect SAH even when initial imaging is nondiagnostic.
- ⭐ Aneurysmal SAH → coiling or clipping reduces rebleeding risk; nimodipine improves neurological outcomes.
- ⭐ Worsening GCS with cerebral mass effect → suspect raised intracranial pressure and threatened herniation.
- ⭐ Non-cardioembolic ischemic stroke generally requires antiplatelet prevention; AF-related cardioembolic stroke generally requires anticoagulation when appropriate.