Ischemic brain attack is usually caused by which of the following?

Ischemic brain attack is usually caused by which of the following?

• A. Narrowing or blockage of arteries that supply the brain
• B. Dilation of arteries
• C. Blockage of veins
• D. Infection of brain tissue

Answer: (A)

Ischemic brain attack happens when the brain’s blood supply is reduced because the arteries feeding the brain become narrowed or blocked. This reduction is most often due to atherosclerotic plaque narrowing a cerebral artery or a clot (thrombus) or piece of clot (embolus) occluding a vessel, cutting off oxygen and nutrients to the affected area and causing focal neurologic deficits. Dilation of arteries would not produce ischemia; a blockage of veins can cause different problems (venous infarction) and isn’t the typical mechanism of an ischemic stroke. Infection of brain tissue leads to encephalitis or an abscess, not an ischemic event.

Ischemic brain attack happens when the brain’s blood supply is reduced because the arteries feeding the brain become narrowed or blocked. This reduction is most often due to atherosclerotic plaque narrowing a cerebral artery or a clot (thrombus) or piece of clot (embolus) occluding a vessel, cutting off oxygen and nutrients to the affected area and causing focal neurologic deficits. Dilation of arteries would not produce ischemia; a blockage of veins can cause different problems (venous infarction) and isn’t the typical mechanism of an ischemic stroke. Infection of brain tissue leads to encephalitis or an abscess, not an ischemic event.