Introduction
Brain cysts are delimited cavities in brain tissue, which can be either empty or filled with fluid. Sometimes they are additionally divided into several small chambers. Brain cysts are generally benign and, as long as they do not cause any symptoms, do not always need to be treated. In this case they are often a coincidental finding. However, if the patient has symptoms of failure, headache or other symptoms caused by the brain cysts, they must be treated.
Causes
There can be many different causes for the development of brain cysts. In general, cysts can form following previous damage to brain tissue. For example, if the blood supply to the brain is too poor at one point, for example due to calcification in the vessels, this leads to a stroke.
The affected brain tissue is severely damaged because it was temporarily undersupplied and may even die. This leads to liquefaction of the affected tissue. This can then develop into a cyst.
Clots in the efferent brain vessels can also lead to brain tissue damage due to blood congestion, which can also manifest itself through reactive cyst formation. Brain cysts have also been found to be more common in people who have suffered from high blood pressure for a long time. Patients with high blood pressure are particularly at risk for bleeding into brain tissue (intracerebral bleeding), as the vessels are eventually no longer able to withstand the high pressure and rupture. Following such bleeding, if they survive, brain cysts can also develop.
Arachnoid cysts
Finally there are the arachnoid cysts. They are named because these cysts are located in the arachnoidea, the so-called spider web skin. This is the middle layer of the meninges that surround the brain from the outside.
Usually arachnoid cysts are congenital and are usually discovered by chance during an MRI or CT examination. They are benign and usually fluid-filled (usually with cerebrospinal fluid, i.e. normal brain fluid). If they do not cause the patient any discomfort, they do not necessarily need to be treated. However, if the arachnoid cysts compress important areas of the brain due to their location and impede their function, treatment is necessary.
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