Some arachnoid cysts cause no symptoms at all. When an arachnoid cyst does cause symptoms, those symptoms depend on where the cyst is located. When it’s located around the brain, symptoms include:
Arachnoid cysts around the spinal cord compress the spinal cord or nerve roots and cause symptoms such as:
An arachnoid cyst that causes any of these symptoms needs to be evaluated for possible treatment, as it may continue to grow and cause neurological damage as it puts pressure on surrounding brain tissue. Since many of these symptoms can be caused by a range of other conditions, an accurate diagnosis is critical (see Diagnosing and Treating an Arachnoid Cyst). The good news is that the prognosis for those with arachnoid cysts is excellent, and the surgery to drain or remove a cyst is safe and effective (see Surgery for Arachnoid Cysts).
Reviewed by: Jeffrey Greenfield, MD, PhD
Last reviewed/last updated: March 2021