Arachnoid Cyst Information

Arachnoid Cyst and Arachnoid Brain Cyst

Arachnoid cyst are cerbrospinal fluid-filled sacs. These sacs are located between the three membranes covering the brain and the spinal cord (the other two are the dura mater and pia mater). The cyst forms during brain and skull development when the two fatty layers of the arachnoid membrane split and forms a cavity.

These cysts are a congenital disorder which may be the result of a functional genetic abnormality or a structural chromosomal abnormality. An archnoid cyst may be categorized based on their location and tissue type. Also, arachnoid brain cyst may slowly increase in the size over time depending on the patient. As the cyst increases in size, the patient’s brain may become compressed, leadung to the development of arachnoid cyst symptoms.


Most people do not experience any arachnoid cyst symptoms and may lead normal lives. However, there are a full range of problems including neurological, mobility, and behavioral. Some common neurological symptoms include seizures, nausea/vomiting, and chronic headaches and seek treatment from a neurologist who can monitor the patient’s condition with medication.

Some patients experience mobility problems. Walking becomes more difficult along with balance and leg numbness. The patient may require physical therapy to regain his/her balance and maintain a sense of independence.

Also, some patients experience behavioral symptoms such as confusion, aggression, and anxiety and seek treatment from a social worker or psychologist.


Treatments for arachnoid cyst vary from patient to patient and may be based on the size of the tumors, the symptoms, and any current medical conditions. A teenage patient would require a different medical approach compared to an older patient. For example, one common treatment is draining the arachnoid cyst by needle aspiration which is a simple technique. However, there is a high rate of recurrence with the symptoms returning and this may lead to frustration by the patient.

Moreover, a less common treatment involves shunting the cyst but this causes the patient to become shunt dependent which requires constant medical care.

A less invasive treatment benefits the patient by decreasing the risks of permanent complications, decreasing long-term pain, and reducing the overall costs for medications, therapy, and hospital costs.