Left anterior cerebral artery infarct is unlikely to cause which symptom?

• A. Difficulty Making Decisions
• B. Reduced Comprehension
• C. Reduced Executive Functions
• D. Difficulty Planning

Answer: (B)

The key idea is which brain areas are supplied by the left anterior cerebral artery (ACA) and what functions they support. The ACA irrigates the medial frontal lobes, including areas involved in executive control, planning, initiation, and motivation (the medial prefrontal cortex and supplementary motor areas). Damage here tends to produce problems with executive functions, decision-making, planning, and abulia, along with contralateral leg weakness or motor/apraxia related to medial frontal regions.

Language comprehension, on the other hand, is centered in language-dominant areas supplied mainly by the left MCA (and, for some language functions, the PCA). Because those regions are not primarily fed by the ACA, a left ACA infarct is unlikely to cause reduced language comprehension.

So, difficulty planning, and reduced executive functions, and difficulties with decisions are expected with left ACA stroke, while reduced comprehension is not typical.