What Is an Acute Ischemic Stroke?

An acute ischemic stroke is an interruption in the supply of blood to the brain that causes brain damage because the brain cells are not getting enough oxygen. This condition can have a number of causes. The patient needs immediate treatment to prevent further brain damage and address the cause of the stroke. Large urban hospitals sometimes have stroke centers that focus on provision of stroke care, while in rural areas, access to appropriate treatments can be more variable.

One common cause of an acute ischemic stroke is thrombosis or embolus, where a clot of material breaks free and blocks one of the blood vessels in the brain. This can occur because of a disease process in the brain itself or because material like blood clots and arterial plaques travels to the brain. It will block the vessel, preventing blood from reaching tissue past the point of the occlusion. Patients can also develop acute ischemic stroke in response to a very sudden drop in blood pressure, a drug overdose, or debris caused by inflammation and infection.

When a patient experiences acute ischemic stroke, neurological symptoms start to develop. These can vary, depending on the part of the brain affected. Some patients have slurred speech, difficulty walking, or confusion. Others may notice fading vision, disorientation, or altered level of consciousness. These indicate that a process known as the ischemic cascade is underway. As brain cells die because of lack of oxygen, they release chemicals that kill neighboring cells, setting off a chain reaction that will not stop until the patient gets treatment.

Treatment with tissue plasminogen activator, a compound naturally produced in the body, is one option for acute ischemic stroke to break up clots in the brain. The patient may also need a mechanical treatment where a small coil is inserted into one of the vessels in the brain to free a clot and restore circulation. Medications to increase blood pressure or reverse the effects of a blood overdose can also be helpful for some patients.

After an acute ischemic stroke, a patient may need physical therapy and other treatment to recover brain function. Some patients cannot fully recover because the damage is too extensive, while others may be able to regain cognitive skills. There are some steps patients can take to reduce the risks of stroke. These include maintaining blood pressure in a safe range, controlling cardiovascular disease to prevent emboli in the bloodstream, and avoiding drugs known to cause stroke, like cocaine.