Acute Ischemic Stroke

Highway Traffic Jam Starves the City

Imagine a major highway (carotid or vertebral artery) is the only road carrying fresh water trucks (oxygen and glucose) into a dense city neighborhood (brain territory). A traffic accident—a jackknifed truck (blood clot)—blocks the highway completely. The neighborhood's water treatment plant (neurons) stops receiving deliveries within seconds. The center of the neighborhood closest to the plant (infarct core) has no backup wells and runs dry immediately—those houses burn down (neurons die). But the outer ring of the neighborhood (penumbra) survives for a while using emergency water routed through back roads (collateral vessels) from neighboring districts, though the water pressure is dangerously low. Those outer houses are dark and cold but not yet burned—they can still be saved if emergency water delivery (reperfusion) arrives within a few hours. If the blockage stays too long, even the back roads get clogged with backed-up water (cytotoxic swelling (edema)), and the whole outer ring burns down too. The fire department (thrombectomy) can physically remove the jackknifed truck, or a chemical team (tPA) can dissolve the wreckage—but only if they arrive soon enough.