What term describes a sudden disruption of blood flow to the brain?

The term that describes a sudden disruption of blood flow to the brain is a stroke. A stroke occurs when there's an obstruction in blood supply (ischemic stroke) or when a blood vessel in the brain bursts (hemorrhagic stroke), leading to tissue damage and loss of brain function. The immediate consequences are often severe, as brain cells begin to die without the necessary oxygen and nutrients provided by blood.

While a seizure may involve a sudden change in brain activity and can affect consciousness and motor control, it does not inherently involve a disruption of blood flow. Similarly, hemorrhage refers to bleeding, which could be a result of a stroke but is not solely defined as a disruption of blood flow to the brain. A heart attack, on the other hand, pertains specifically to the heart and is caused by a blockage of blood flow to the heart muscle, not the brain. Thus, stroke is the correct and precise term for the condition described in the question.