anterior cerebral artery
Summary
The anterior cerebral artery (ACA) is one of the terminal branches of the internal carotid artery that supplies the medial aspects of the frontal and parietal lobes. ACA strokes typically present with contralateral lower extremity weakness greater than upper extremity, along with behavioral changes and urinary incontinence.
Detail
The anterior cerebral artery arises from the internal carotid artery and is divided into A1 (precommunicating) and A2 (postcommunicating) segments by the anterior communicating artery. The ACA supplies the medial frontal and parietal cortex, including the paracentral lobule (motor and sensory cortex for the lower extremity), supplementary motor area, and parts of the corpus callosum. Clinical presentation of ACA infarction includes contralateral leg weakness and sensory loss (greater than arm involvement due to the homunculus organization), behavioral changes (apathy, abulia), urinary incontinence, and sometimes alien hand syndrome. The ACA territory is less commonly affected by stroke compared to middle cerebral artery territory. Anatomical variants include azygos ACA (single unpaired vessel) and hypoplastic A1 segments, which can affect collateral flow during occlusion.
Sources
- Netter's Atlas of Human Anatomy
- Adams and Victor's Principles of Neurology
- First Aid for the USMLE Step 1
- Stroke: Pathophysiology, Diagnosis, and Management
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