The fallacy of the lacune hypothesis

Area of Science:

• Neurology
• Cerebrovascular Disease

Background:

• Lacunes are defined pathologically or radiologically as small cerebral infarcts that become cystic.
• They result from the occlusion of small arteries, leading to cavitary lesions.
• The clinical definition and understanding of lacunes remain confused.

Purpose of the Study:

• To review the definition, pathogenesis, natural history, and prognosis of lacunes.
• To describe the first experimental model for lacunes.
• To clarify the clinical understanding and investigation of lacunar syndromes.

Main Methods:

• Review of existing literature on lacunes.
• Description of an experimental model using photochemical damage to rat carotid arteries to induce microemboli.
• Analysis of pathological and radiological definitions and clinical presentations.

Main Results:

• Lacunes are small cerebral infarcts caused by small artery occlusion.
• An experimental model successfully produced lesions resembling human lacunes in rats.
• The "lacune hypothesis" is challenged, suggesting lacunar syndromes are simply small strokes.

Conclusions:

• Lacunes, or small strokes, have a guarded long-term prognosis despite low immediate mortality.
• The experimental model provides a new tool for studying lacunes.
• Lacunar syndromes should be investigated as small strokes, not attributed solely to hypertension and small vessel disease.