# Ichemic Stroke --- **Ischemic stroke** is a type of [[stroke]] caused by a narrowing or blockage of arteries in the brain, which can lead to cell death and loss of function. There are no fuel stores in the brain, which means that it doesn't take long to cause irreversable harm to the delicate neural tissue. Usually there is a core area that is effected immediately, which is irrecoverable, and a wider area around that core called an **ischemic penumbra** which, while damaged, is salvageable. Stroke care is all about saving the penumbra. The extent of the damage that results depends on the: - blood vessel involved - some vessels supply large areas of the brain, others small ares - vessels in the more superficial parts of the brain are much easier to treat that the ones deeper down. - adequacy of [[collateralization]] to the area of the brain - the main job of the Circle of Willis is to provide collateral circulation - rate of occlusion development - if the occlusion develops gradually, the brain can make new [[collateralization|collateral vessels]] to circumvent the occlusion - types of ischemic stroke - large artery thrombolic - small penetrating artery thrombolic - cardiogenic embolic stroke - cryptogenic stroke - other **Transient ischemic attacks** or **TIAs** are temporary bouts of ischemia brought on by a temporary clot, which usually resolve on their own--usually within 24 hours, and often times even faster than that. ![[ischemic penumbra.png]] ## The Ischemic Cascade **The ischemic cascade** is the series of events that follow an ischemic stroke - reduced blood flow occurs - anaerobic metabolism kicks off - remember there are no fuel stores in teh brian - lactic acid rises, pH falls - pumps and receptors do no work as well in low pH environments - ATP production plummets - cells in ischemic core die - cells in pneumbra die without intervention ## Diagnostic Tests After about a day, the ischemia will show up on an [[imaging|MRI]] ## Treatement ### Medical [[thrombolytics|tPA]] is a "clotbuster" that can be used to break down the clot and restore blood flow. ### Surgical A **thrombectomy** or a **stent retriever** is a well established option for removing [[thrombus|thrombi]], especially if they cannot use [[thrombolytics|tPA]] but sometimes even in conjunction with it. It is a procedure done through the femoral artery for patients who meet very specific criteria: - they can't have had prior deficits - 18+ - [[NIH stroke scale]] of 6 or higher ## Nursing Considerations - edema: ^ intercranial pressure, brain herniation - immobility - PT/OT - pressure ulcers - Q2 turns - contractures - falls/injuries - especially for rightsided strokes w/judement impairment/impulsiveness - CAUTIS - infections in general, but in particular with catheters. If they do need it, do a straight cath instead. - Arrythmias - will probably be on tele ___