What are the differences between lacunar and cortical strokes in terms of signs, symptoms, and management?

Major Stroke Syndromes by Vascular Territory

Middle Cerebral Artery (MCA) Stroke

MCA strokes present with contralateral hemiparesis (arm > leg pattern), sensory loss, homonymous hemianopsia, and either aphasia (dominant hemisphere) or neglect (non-dominant hemisphere). 1

Dominant Hemisphere (Usually Left) MCA Stroke

• Motor/Sensory: Right-sided weakness and paresthesia with characteristic arm > leg pattern, facial droop 1
• Language: Aphasia (Broca's, Wernicke's, or global depending on extent) 1
• Visual: Left homonymous hemianopsia, monocular blindness affecting left eye 1
• Cortical sensory loss: Impaired stereognosis, graphesthesia, two-point discrimination 1

Non-Dominant Hemisphere (Usually Right) MCA Stroke

• Motor/Sensory: Left-sided weakness and paresthesia with arm > leg pattern 1
• Spatial: Neglect syndrome, abnormal visual-spatial ability 1
• Visual: Right homonymous hemianopsia, monocular blindness affecting right eye 1

Early CT Findings in MCA Stroke

• Hyperdense MCA sign (visible in 82-94% within 6 hours) 1
• Loss of gray-white matter differentiation 1
• Attenuation of lentiform nucleus 1
• Loss of insular ribbon 1
• Sulcal effacement 1

Critical pitfall: Involvement of >1/3 MCA territory carries poor prognosis and 8-fold increased hemorrhagic transformation risk with rtPA, though physician accuracy in detecting this is only 70-80%. 1

Other Major Vascular Territories

Basilar Artery/Posterior Circulation

• Decreased level of consciousness or coma (especially with basilar occlusion) 2
• Nausea and vomiting common 2
• Brain stem compression can occur with cerebellar strokes causing edema 2

General Stroke Presentation

• Sudden or rapid onset of focal neurological symptoms 2
• Most patients remain alert unless major hemispheric infarction, basilar occlusion, or cerebellar stroke with compression 2
• Headaches occur in approximately 25% of cases 2

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Lacunar vs. Cortical Stroke: Key Differences

Lacunar Stroke Characteristics

Lacunar strokes are small (<1.5 cm) subcortical infarctions caused by occlusive arteriopathy of deep penetrating vessels, typically presenting with classic lacunar syndromes without cortical signs. 2

Clinical Features

• Classic lacunar syndromes: Pure motor hemiparesis, pure sensory stroke, ataxic hemiparesis, dysarthria-clumsy hand syndrome 2
• No cortical signs: Absence of aphasia, neglect, hemianopsia, or cortical sensory loss 2
• Location: Deep brain structures (basal ganglia, internal capsule, thalamus, pons) 2
• Size: ≤1.5 cm on neuroimaging 2

Etiology and Pathophysiology

• Small vessel disease (SVD): Occlusive arteriopathy of penetrating arteries, not typical atherosclerosis 2
• Risk factors: Strongly associated with hypertension and diabetes 2
• Mechanism: Approximately 25% of all ischemic strokes are due to penetrating artery disease 2

Retinal Vessel Differences (Surrogate for Cerebral Small Vessels)

• Wider retinal venules compared to cortical stroke patients 3
• Decreased arteriovenous ratios (0.76 vs 0.78 in cortical strokes, p=0.03) 3
• Increased central retinal vein equivalent (44.9 vs 42.8 pixels, p=0.01) 3

Cortical Stroke Characteristics

Cortical strokes are larger infarctions involving the cerebral cortex, typically presenting with cortical signs and caused by large-vessel atherosclerosis or cardioembolism. 2

Clinical Features

• Cortical signs present: Aphasia, neglect, hemianopsia, cortical sensory loss 2, 1
• Location: Cortical or large subcortical areas 2
• Size: Generally >1.5 cm 2

Etiology and Pathophysiology

• Large-artery atherosclerosis: 20% of ischemic strokes, involving ≥50% stenosis of major cerebral arteries 2
• Cardioembolism: 20% of ischemic strokes, from high-risk cardiac sources 2
• Mechanism: Artery-to-artery embolism, hemodynamic insufficiency, or cardiac embolus 2
• Carotid disease: Significantly more common (50% vs 3%, p<0.01) 4

Long-Term Outcomes: Lacunar vs. Cortical

Mortality

• Cortical strokes have higher mortality than lacunar strokes 5
• Lacunar stroke patients show highest survival rate (85%) compared to cardioembolic stroke (55%) 2
• Age, male sex, and white matter hyperintensities increase death risk in both subtypes 5

Cognitive Impairment

• Similar dementia rates: 9.4% in lacunar vs 12.4% in cortical stroke at 9 years 5
• Cognitive impairment is common after lacunar strokes (37% incidence) despite small size, likely due to associated cerebral small vessel disease 6
• Dementia prevalence after lacunar stroke is 20%, with no significant difference compared to cortical strokes (OR 0.72,95% CI 0.43-1.20) 6

Functional Recovery

• Affected limb recovery and balance are worse after lacunar stroke compared to cortical stroke 5
• Moderate/severe disability reported by 12% at 9 years 5
• Cognitive concerns reported by 49-55% of survivors 5

Recurrent Stroke

• One-third of all patients experience recurrent stroke regardless of subtype 5
• Risk increases with presence of vascular risk factors (OR 2.27,95% CI 1.287-4.032) 5

Management Differences

Diagnostic Workup

• Both subtypes require: Brain CT/MRI, ECG, glucose, electrolytes, renal function, CBC, PT/INR, aPTT 2
• Lacunar stroke: Must exclude large-artery stenosis and cardioembolic sources to confirm diagnosis 2
• Cortical stroke: Requires evaluation for carotid stenosis, cardiac sources, and aortic arch disease 2

Acute Treatment

• Thrombolytic therapy eligibility is similar for both subtypes when within time window 2
• Critical distinction: Normal early CT does not exclude acute ischemic stroke; CT shows abnormalities in <50% of patients in first hours 1
• Time of onset defined as when patient was last known symptom-free 2, 1

Secondary Prevention Focus

• Lacunar stroke: Aggressive blood pressure and diabetes control targeting small vessel disease 2
• Cortical stroke: Antiplatelet therapy, statin therapy, carotid intervention if indicated, anticoagulation for cardioembolic sources 2

Key Pitfall

Systemic small vessel disease is not exclusive to lacunar stroke patients—both lacunar and cortical stroke patients demonstrate manifestations of systemic small and large vessel disease. 4 Therefore, comprehensive vascular risk factor management is essential for both subtypes.