Cerebral Infarction (Ischemic Stroke)

What happens in a cerebral infarction

Brain cells need a constant supply of oxygen and glucose. When an artery is blocked, the area it supplies starts to die within minutes. Around the dying core lies a zone of stunned but salvageable tissue, the penumbra. Restoring blood flow quickly can save it. That is why stroke teams say "time is brain".

On a CT or MRI scan, the damaged area is called an infarct. An "old" or "chronic" infarct is a scar from a previous stroke, sometimes one that caused no noticed symptoms (a silent stroke).

Types of cerebral infarction

Symptoms

Symptoms depend on which part of the brain is affected, and start suddenly:

• weakness or numbness of the face, arm or leg, usually on one side
• trouble speaking, finding words or understanding (aphasia), or slurred speech
• loss of vision in one eye, or the same half of vision in both eyes
• double vision
• sudden dizziness, unsteadiness or loss of coordination
• difficulty swallowing
• confusion or neglect of one side of the body
• severe headache is less common than in bleeding strokes

Left-brain infarcts often affect language and the right side of the body. Right-brain infarcts often affect the left side, spatial awareness and attention.

Risk factors

• high blood pressure, the most important
• atrial fibrillation
• diabetes
• high cholesterol and atherosclerosis
• smoking
• obesity and physical inactivity
• heavy alcohol use
• age, male sex, family history
• previous stroke or TIA
• carotid artery stenosis
• sleep apnea, migraine with aura, estrogen-containing pills in smokers, and clotting disorders

Diagnosis

1. Rapid assessment: stroke scale scoring, blood sugar check, time of onset.
2. CT scan of the brain: done immediately to exclude bleeding (brain hemorrhage). Early infarcts may not show on CT.
3. CT angiography: looks for a large artery blockage suitable for thrombectomy. CT perfusion may identify salvageable tissue.
4. MRI with diffusion imaging: detects infarcts within minutes to hours and identifies small ones.
5. Finding the cause: ECG and heart monitoring for atrial fibrillation, echocardiogram, carotid ultrasound, blood tests for cholesterol, diabetes and clotting.

Emergency treatment

• Thrombolysis: clot-dissolving medicine (alteplase or tenecteplase) given through a vein, ideally within 4.5 hours of symptom onset, for eligible patients. The sooner, the better.
• Mechanical thrombectomy: a catheter is threaded to the blocked artery to pull out the clot. It is used for large vessel blockages within 6 hours, and up to 24 hours when scans show salvageable brain.
• Stroke unit care: monitoring of blood pressure, blood sugar, temperature and swallowing, and early mobilization.
• Aspirin within 24 to 48 hours (after bleeding is excluded) for most patients not receiving thrombolysis.
• Surgery to relieve swelling for very large infarcts in selected patients.

Recovery and rehabilitation

The most rapid recovery occurs in the first 3 months, but improvement can continue for a year or more.

• Physical therapy for strength, balance and walking
• Occupational therapy for daily activities
• Speech and language therapy for communication and swallowing
• Support for mood: depression affects about a third of stroke survivors and is treatable

Outcomes vary widely, from full recovery after small infarcts to long-term disability after large ones.

Preventing another stroke

• Antiplatelet medicine: aspirin, clopidogrel or both for a short period, depending on stroke type.
• Anticoagulants for atrial fibrillation.
• Statins to lower LDL cholesterol.
• Blood pressure control, usually aiming below 130/80.
• Carotid surgery or stenting for significant narrowing of the carotid artery on the stroke side.
• Lifestyle: stop smoking, exercise regularly, limit alcohol and salt, manage weight and diabetes, and treat sleep apnea.

Frequently asked questions

What is a cerebral infarction?

A cerebral infarction is an area of dead brain tissue caused by blocked blood flow in an artery. It is the brain damage that occurs in an ischemic stroke and can be seen on CT or MRI scans.

Is a cerebral infarction the same as a stroke?

A cerebral infarction is the result of an ischemic stroke, which accounts for about 85% of strokes. The other main type of stroke is hemorrhagic, caused by bleeding into or around the brain rather than a blockage.

What does an old cerebral infarct on a scan mean?

It means a stroke occurred in the past, sometimes without noticeable symptoms. It shows you are at higher risk of future strokes, so your doctor will review blood pressure, cholesterol, diabetes, heart rhythm and lifestyle and may start preventive medicines.

What is a lacunar infarct?

A lacunar infarct is a small infarct, usually less than 15 mm, deep in the brain, caused by blockage of a tiny artery. It is linked to high blood pressure and diabetes. It may cause pure weakness or numbness, or no symptoms at all.

Can you recover from a cerebral infarction?

Many people recover well, especially after small strokes or prompt treatment. Recovery is fastest in the first 3 months and can continue for a year or longer with rehabilitation. Larger infarcts may leave lasting weakness, speech or memory problems.