Brain Stroke: Understanding Causes and Age Factors

Brain stroke is commonly associated with older adults, but recent trends show a concerning shift towards younger populations. Cases of strokes in individuals in their teens and twenties are becoming more frequent, indicating that brain stroke can affect people of all ages. However, the highest incidence remains among those aged 50 and above.

What Causes Brain Stroke?

There are multiple causes of brain stroke (cerebral infarction), and they can be classified into five subtypes according to the TOAST classification. These subtypes provide a comprehensive understanding of the different factors that contribute to brain stroke.

1. Large Artery Atherosclerosis

Large vessel atherosclerosis is the most common cause of cerebral infarction. Chronic conditions such as long-term hypertension, diabetes, hyperlipidemia, and obesity contribute to changes and damage in the vascular endothelium. This damage can lead to narrowing of the blood vessels, plaque formation, and eventually, large artery atherosclerosis. Managing these underlying conditions is crucial in reducing the risk of stroke.

2. Small Artery Disease

While atherosclerosis is also a factor in small vessel disease, another common cause is hypertensive small artery hyaline degeneration. This condition affects the smaller blood vessels in the brain and is a significant contributor to strokes. Blood pressure management plays a key role in preventing this type of cerebral infarction.

3. Cardioembolic Stroke

Heart-related causes are another major contributor to brain stroke. Conditions such as atrial fibrillation, infective endocarditis, patent foramen ovale, and cardiac myxoma can all lead to embolic strokes. These conditions allow blood clots or other debris to travel from the heart to the brain, blocking blood flow and causing infarction.

4. Other Underlying Causes

This category includes a broad range of less common but equally important causes of cerebral infarction. These may include hereditary vascular diseases, congenital fibromuscular dysplasia, infectious vasculitis following tuberculosis, and immune-mediated infarctions. In addition, central nervous system vasculitis and connective tissue disorders can also lead to stroke. Other contributing factors include tumor-related mechanisms and hemodynamic changes such as malignant tumor infiltration, cancer-related thrombosis, severe hypoperfusion disorders, and coagulation abnormalities.

5. Undetermined Etiology

Some cases fall under the category of undetermined cause, often seen in iatrogenic strokes where the exact origin remains unidentified. These cases require thorough investigation and monitoring to prevent future events and understand the underlying mechanism.