Ischemic Stroke: What It Is, Causes, and Signs

Ischemic stroke, or cerebral infarction, is a condition in which an area of the brain stops receiving blood along with oxygen and nutrients. Cells die within just a few minutes. Below: the mechanism, causes, and the signs by which it is recognized.

What ischemic stroke and cerebral infarction are

The mechanism is simple and harsh: blood carries oxygen to nerve cells, and as soon as the flow to a region stops, damage begins within the very first minutes. Cerebral infarction, also known as ischemic cerebral infarction, is a disruption of cerebral circulation with damage to tissue and loss of function in the region left without blood. The causes are reduced cerebral blood flow, thrombosis, or embolism against a background of vascular, cardiac, or blood diseases.

Hippocrates called this condition "apoplexy" — a stroke; in the 17th century the Swiss pathologist Johann Jakob Wepfer showed that the cause may lie in blockage of a brain vessel, and the vascular nature of strokes was finally recognized only in the first half of the 19th century.

This is the most common type: ischemic stroke accounts for 70–85 percent of all strokes. A transient ischemic attack is distinguished separately — a brief blockage of blood supply without persistent cell damage; the risk of a true stroke after it is higher.

Why blood flow is disrupted: causes and risk factors

At the root is a clot that blocks or occludes a brain vessel.

The main risk factor is elevated blood pressure. Next come diabetes, heart disease, including atrial fibrillation, smoking, a personal or family history of stroke and transient ischemic attack, and age. Alcohol and illicit drugs, lack of physical activity, high cholesterol, unhealthy diet, and obesity also contribute.

Signs and symptoms of ischemic stroke

Symptoms appear quickly — they are united by the word "suddenly."

• Sudden weakness or numbness of the face, arm, or leg, especially on one side of the body.
• Sudden confusion, difficulty speaking or understanding.
• Sudden vision disturbance in one or both eyes.
• Sudden difficulty walking, dizziness, loss of balance.
• Sudden severe headache without a clear cause.

To help remember, there is the F.A.S.T. test: facial asymmetry when smiling, arm weakness when raising it, slurred speech — and time to call.

Types of ischemic stroke

Atherothrombotic stroke (about 34 percent) occurs against a background of atherosclerosis of large- or medium-caliber cerebral arteries, develops in a stepwise manner, often begins during sleep, and is frequently preceded by transient ischemic attacks. Cardioembolic (22 percent) begins suddenly, while awake, with pronounced deficit already at onset. Hemodynamic (15 percent) is associated with a drop in blood pressure or cardiac output. Lacunar (20 percent) — damage to small perforating arteries against a background of elevated pressure, with lesions up to 1.5 cm. About 9 percent are strokes of the hemorheological microocclusion type.

The size of the lesion differs by type: in lacunar stroke lesions do not exceed 1.5 cm, while in cardioembolic stroke the lesion is medium or large.

How ischemic stroke is diagnosed

The doctor asks about symptoms and medical history, then performs an examination: assesses clarity of consciousness, coordination and balance, numbness and weakness in the face, arms, and legs, speech, and vision. The instrumental part is computed tomography or magnetic resonance imaging of the brain; electrocardiography and echocardiography help identify heart disease or a clot that led to the blockage.

Why you cannot wait when stroke is suspected

Brain cells begin to die within a few minutes, which can lead to persistent brain damage, long-term disability, or death, and the earlier treatment is started, the more effective it is. Treatment depends on the type and stage of stroke, so the doctor needs to know when symptoms appeared.

Call 103 or 112 immediately if a person suddenly has a drooping corner of the mouth when smiling, weakness of an arm or leg on one side, slurred speech, loss of vision, loss of balance, or a sudden severe headache without cause.

This material is for reference — it explains the mechanism and signs but does not replace a doctor's consultation; the decision in a specific situation remains with the doctor.

This content is for reference and does not replace a doctor's consultation. Medical disclaimer