Definition and Overview
Cerebral infarction is a key type of ischemic stroke in which nerve cells are irreversibly damaged due to blockage of blood flow to brain tissue due to occlusion or stenosis of cerebral blood vessels. It accounts for approximately 80-85% of all strokes and is one of the major causes of death and disability at home and abroad.
When cerebral infarction occurs, an ischemic core and surrounding ischemic penumbra are formed depending on the area where blood flow is blocked. The core is quickly irreversibly damaged, but the ischemic penumbra can be saved through rapid reperfusion. This is the core rationale for acute care.
Cause/Pathophysiology
The TOAST classification is widely used to classify the causes of cerebral infarction.
Large artery atherosclerosis is a type in which plaque forms in major cerebral blood vessels such as the carotid artery and middle cerebral artery, resulting in stenosis and occlusion. Cardioembolism is a type of blood clot that forms in the heart and blocks cerebral blood vessels due to atrial fibrillation, heart failure, or endocarditis. Small vessel occlusion (lacunar infarct) is a small lacunar infarct that occurs due to lipohyalinosis of small blood vessels in the brain. Other causes include coagulation disorders, arterial dissection, and vasculitis, and cryptogenic causes also account for a significant proportion.
At the cellular level, after ischemia, a chain reaction of excitotoxicity, oxidative stress, inflammation, and apoptosis occurs, resulting in expanded neuronal damage.
symptoms
Symptoms of cerebral infarction vary depending on the occluded blood vessel and the damaged area. Representative symptoms are summarized as FAST (Face-Arm-Speech-Time).
The main symptoms include sudden unilateral paralysis or loss of sensation in the arms or legs, sudden language impairment (aphasia or dysarthria), sudden unilateral facial paralysis, sudden visual disturbance or double vision, sudden and severe headache (need to differentiate from hemorrhagic stroke), sudden walking difficulty, and dizziness.
Transient ischemic attack (TIA) is a condition in which the same symptoms as cerebral infarction are fully recovered within 24 hours, but it is a precursor symptom of cerebral infarction and requires immediate evaluation and treatment.
diagnosis
If acute cerebral infarction is suspected, immediate emergency evaluation is performed.
A non-contrast CT brain imaging test is performed immediately to rule out cerebral hemorrhage. MRI (DWI, diffusion weighted imaging) can sensitively identify acute cerebral infarction even within a few hours of onset.
For vascular imaging, CT angiography (CTA) or MR angiography (MRA) is used to quickly evaluate whether large vessel occlusion is present. Electrocardiogram, echocardiogram, and blood tests (coagulation function, blood sugar, CBC) are also necessary to determine the cause.
treatment
The key to acute treatment is rapid reperfusion.
In IV thrombolysis, alteplase (tPA) can be administered to patients who meet the indications within 4.5 hours after symptom onset. tenecteplase is being studied as an alternative drug.
Mechanical thrombectomy can be performed using image-based screening (penumbra mismatch) within 6 to 24 hours after the last normal confirmation in patients with large vessel occlusion (mainly middle cerebral artery and internal carotid artery). DAWN Test (2018), it was confirmed that thrombectomy in the 6-24 hour window significantly improved functional outcome.
For secondary prevention, depending on the cause, antiplatelet drugs (large-vessel or small-vessel cerebral infarction) or anticoagulants (cause of atrial fibrillation) are administered, and blood pressure, blood sugar, and lipid management, smoking cessation, and endarterectomy (CEA) or stent placement (CAS) in case of carotid artery stenosis are performed.
prognosis
The mortality rate at one month after cerebral infarction is approximately 10-20%, and approximately 30-40% of survivors remain with long-term functional disability. Prognosis varies greatly depending on the size and location of cerebral infarction, treatment start time, underlying disease, and the aggressiveness of rehabilitation treatment.
The recurrence rate of cerebral infarction is high at approximately 10-15% within the first year, and appropriate secondary prevention treatment significantly reduces recurrence. In patients with atrial fibrillation, anticoagulant treatment reduces recurrent cardioembolic cerebral infarction by approximately 60-70%.
Early intensive rehabilitation treatment improves functional recovery, and research on the optimal timing and intensity of rehabilitation continues.
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This information is provided for medical educational purposes and is not a substitute for individual medical care or treatment. If you have any symptoms, be sure to seek professional advice. Inquiries: Osang Neurosurgery 1599-5453 | osns.co.kr