Arachnoid Cysts

An arachnoid cyst is a sac of cerebrospinal fluid (CSF) that has built up and been “trapped” in the brain, usually on the arachnoid membrane, the middle layer of tissue that protects the brain and the spinal cord. CSF is a clear, watery fluid that surrounds the brain and spinal cord to protect and nourish it. The exact cause for arachnoid cysts is unknown. Some may develop in infancy, while others may result from a head injury.

Symptoms & Diagnosis

Arachnoid cysts often are asymptomatic (causing no symptoms) and may go undiagnosed for years. Asymptomatic cysts may be discovered by coincidence when a patient undergoes an imaging study such as an MRI or a CT scan because of headaches or a head injury. When symptoms do occur it is because the CSF builds up over time, causing the cyst to grow and putting pressure on the brain. This pressure can cause headaches, problems with normal nerve functioning, seizures, or even brain hemorrhage. If excessive CSF begins to accumulate in the ventricles (cavities) of the brain, it causes hydrocephalus. 

Treatment

Sometimes surgery is needed to create space to allow CSF to flow freely around the arachnoid cyst. At Atlanta Brain and Spine Care, we offer state-of-the art minimally invasive techniques such a ventriculoscopy, which uses tiny instruments to create new passages for CSF. In other situations, arachnoid cysts can be treated with a shunt, a tube that re-directs the CSF to another part of the body.