How does a neurologist decide when an Arachnoid cyst is problematic? My 5yr old son has just been diagnosed with a cyst and he displays symptoms but I am totally confused as to when a surgeon will decide treatment.

Hi Naoimh -
There are two types of arachnoid cysts. Primary arachnoid cysts are present at birth and result from developmental abnormalities in the brain and spinal cord that arise during the early weeks of gestation. Secondary arachnoid cysts are not as common as primary cysts and develop as a result of head injury, meningitis, or tumors, or as a complication of brain surgery.

There has been active debate about how to treat arachnoid cysts, according to the National Institute of Neurological Disorders and Strokes. The need for treatment depends mostly upon the location and size of the cyst. If the cyst is small, not disturbing surrounding tissue, and not causing symptoms, some doctors will refrain from treatment. In the past, doctors placed shunts in the cyst to drain its fluid. Now with microneurosurgical techniques and endoscopic tools that allow for minimally invasive surgery, more doctors are opting to surgically remove the membranes of the cyst or open the cyst so its fluid can drain into the cerebrospinal fluid and be absorbed.

We have heard repeatedly from women with arachnoid cysts that it's critical to work with a neurosurgeon who has experience in dealing with these cysts. You may want to join a support group to learn more about the options available for your son and what other parents and patients have experienced. http://arachnoidcystnetwork.com/acanetwork/home.php

Let us know if this helps, and good luck to you. Pat