​Arachnoid Cyst​

Arachnoid cyst is a common brain cyst formed in the central nervous system and is filled with fluid which is mostly the cerebrospinal fluid (The fluid in which brain and spinal cord bathes, and performs many functions along with protecting the brain). The cyst is formed in between the brain and arachnoid membrane (one of the three membranes that cover the brain)..

Arachnoid cysts are of two types; the primary arachnoid cysts which are congenital anomalies, formed as a result of splitting of the arachnoid membrane. They occur in the early gestation periods and are more common in children. Secondary arachnoid cysts are formed due to some head injury, brain surgery or meningitis, and can occur at any age.​