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Brain & Nervous System Health Center

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Brain Lesions: Causes, Symptoms, Treatments

When you scrape your elbow, it leaves an area of inflamed skin, or a lesion. But what are lesions in the brain? And what causes them? How serious are brain lesions and how are they treated? Here is information about this confusing and unsettling health concern.

What Are Brain Lesions?

A lesion is an area of tissue that has been damaged through injury or disease. So a brain lesion is an area of injury or disease within the brain. While the definition sounds simple, understanding brain lesions can be complicated. That's because there are many types of brain lesions. They can range from small to large, from few to many, from relatively harmless to life threatening.

What Causes Brain Lesions?

Brain lesions can be caused by injury, infection, exposure to certain chemicals, problems with the immune system, and more. Typically, their cause is unknown.

What Are the Symptoms of a Brain Lesion?

Symptoms of a brain lesion vary depending on the type, location, and size of the lesion. Symptoms common to several types of brain lesions include the following:

What Are the Different Types of Brain Lesions?

Although they share a common definition -- injury or damage to tissue within the brain -- brain lesions vary greatly. Here are some common brain lesions.

Abscesses: Brain abscesses are areas of infection, including pus and inflamed tissue. They are not common, but they are life threatening. Brain abscesses often occur after an infection, usually in a nearby area, such as an ear, sinus, or dental infection. They can also appear after injury or surgery to the skull.

Arteriovenous malformations (AVMs): An AVM is a type of brain lesion that occurs during early development. Arteries and veins in the brain grow in a tangle and become connected by tube-like structures called fistulae. The arteries are not as strong as normal arteries. The veins are often enlarge because of the constant flow of blood directly from the arteries through the fistulae to the veins. These fragile vessels may rupture, leaking blood into the brain. In addition, the brain tissue may not receive enough blood to function properly. Damage to the brain may cause seizures as the first symptoms of an AVM.

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