Cerebrovascular Accidents | Nervous System

Table of Contents

Overview – Cerebrovascular Accidents

Cerebrovascular accidents (CVAs) encompass a spectrum of cerebrovascular conditions that impair blood flow to the brain. These include transient ischaemic attacks (TIAs), evolving or completed strokes, and haemorrhagic bleeds, each with distinct clinical profiles but overlapping risk factors and investigations. Final-year students must confidently distinguish these presentations and know when urgent interventions like thrombolysis or anticoagulation are indicated.

Definition

Term	Definition
TIA (Transient Ischaemic Attack)	Temporary focal cerebral ischaemia without infarction; resolves within 24 hours.
CVA (Cerebrovascular Accident)	Brain ischaemia lasting >24 hours due to vascular causes. Can be ischaemic or haemorrhagic.
Stroke (Clinical Syndrome)	Rapid loss of brain function due to interruption in blood supply. Stroke is the clinical manifestation of a CVA.

Transient Ischaemic Attack (TIA)

Definition

Brief neurological dysfunction from temporary focal cerebral ischaemia without infarction
Symptoms resolve within 24 hours
Often described as a “mini-stroke”

Aetiology

Thromboembolism (usually transient)
- From carotid atheroma
- Cardioembolic: AF, valve disease, mural thrombus, prosthetic valves

Pathophysiology

Temporary blockage of a cerebral artery → ischaemia
Reperfusion occurs before infarction → reversible symptoms
Prolonged ischaemia leads to infarct → stroke

Morphology

No infarction
Only metabolic/functional changes (no structural damage)

Clinical Features

Location Affected	Symptoms
Cerebral hemisphere	Contralateral hemiplegia
Brainstem	Cranial nerve signs, quadriplegia, visual disturbances
Lacunar region (basal ganglia)	Pure motor/sensory deficits
Retinal artery embolism	Amaurosis fugax (transient monocular blindness)

Differential Diagnosis

Migraine aura
Hypoglycaemia
Focal epilepsy
Hyperventilation
Retinal bleed/detachment

Investigations

Examination: BP, carotid bruit, murmurs, fundoscopy, ECG (AF?)
Bloods: FBC, U&Es, ESR, glucose, lipids
Imaging:
- CT Brain (exclude haemorrhage)
- Carotid Doppler ± angiography

Management

Risk Factor Control:
- Statins (simvastatin, atorvastatin)
- Antiplatelet (aspirin)
- Smoking cessation
- Antihypertensives (e.g. perindopril, candesartan, atenolol)
Anticoagulation (if cardioembolic): Warfarin ± heparin cover
± Carotid Endarterectomy (if significant stenosis)

Ischaemic Strokes

Definition

Vascular event leading to persistent neurological deficit (>24 hours)
Includes evolving or completed ischaemic strokes

Clinical Types

Subtype	Description	Typical Cause
Evolving CVA	Neurological deficit progressively worsening over >24h	Thrombosis
Completed CVA	Stable, non-evolving deficit	Embolism

Aetiology

Cause	Examples
Thrombotic (50%)	Atherosclerosis rupture, hypercoagulable state (e.g. OCPs)
Embolic (30%)	AF, mural thrombus, carotid atheroembolism, paradoxical emboli

Pathophysiology

Vessel occlusion → focal ischaemia
Neuronal infarction → permanent deficits
Most commonly affects MCA, then ACA, then PCA

Morphology

Early: oedema, flattened gyri, narrow sulci
~1 week: liquefactive necrosis, cavitation
Thrombolysis may cause petechial haemorrhages

Clinical Features

Territory	Signs
MCA (most common)	Contralateral hemiplegia (face/arm > leg), sensory loss, homonymous hemianopia, expressive aphasia (if dominant hemisphere)
ACA	Contralateral leg weakness, abulia, flat affect, frontal lobe signs
PCA	Visual deficits, memory loss, alexia without agraphia (if left-sided)

Investigations

Clinical exam
ECG (AF?)
Bloods: FBC, coags, lipids
CT Brain (rule out haemorrhage)
MRI Brain (higher resolution)

ACA stroke — https://case.edu/med/neurology/NR/acerebralartery4.htm

PCA stroke — https://case.edu/med/neurology/NR/acerebralartery4.htm

Management

Supportive: Fluids, O₂, BSL monitoring
Acute Treatment:
- IV tPA (within 4.5 hrs)
- Thrombectomy (if large vessel occlusion)
Secondary Prevention:
- Aspirin or clopidogrel
- Anticoagulation (if cardioembolic)
- Rehabilitation: speech, physio, OT

Prognosis

Mortality ~40%
Long-term morbidity: hemiplegia, aphasia, dementia, seizures

Haemorrhagic Stroke

Definition

Bleeding into brain parenchyma or surrounding spaces, leading to raised ICP and ischaemia

Aetiology

Cause	Details
Hypertension	Chronic → vessel rupture → intracerebral haemorrhage
AV Malformations	Congenital → rupture → bleeding into brain tissue
Aneurysms	e.g. Berry aneurysm → SAH
Trauma	Extradural (arterial) or subdural (venous) haemorrhage

Source: https://radiopaedia.org/cases/arteriovenous-malformation-cerebral-3

Morphology

Slit haemorrhages: Microbleeds that scar
Lacunar infarcts: Pale, cavity-like lesions in brainstem

Clinical Features

Sudden headache, vomiting, meningism
Anisocoria, nystagmus, focal neurological deficits
Signs of raised ICP: hypertension, bradycardia, Cheyne-Stokes
ALOC, herniation (uncal, tonsillar, subfalcine)

Investigations

CT or MRI Brain: Confirms bleeding site and size
Transcranial Doppler (AVM assessment)

Management

Supportive: Airway, fluids
Medical:
- BP control (β-blockers, ACEi, CCBs)
- Mannitol (↓ICP), corticosteroids
- rFVIIa, FFP, Vitamin K (if coagulopathy)
Surgical: Evacuation if haematoma >3cm or signs of herniation

Prognosis

40% mortality
75% of survivors have lasting disability

Summary – Cerebrovascular Accidents

Cerebrovascular accidents include transient ischaemic attacks, evolving or completed ischaemic strokes, and haemorrhagic strokes. Each type has unique causes and management strategies, with ischaemic strokes dominating in prevalence. Early recognition, imaging to rule out haemorrhage, and rapid intervention can significantly impact outcomes. For a broader context, see our Nervous System Overview page.