​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.​

Symptoms of arachnoid cyst usually appear during childhood. Some of them are common to other neurological disorders’ symptoms and include headache, nausea and vomiting, drowsiness, seizures. But arachnoid cyst may develop some other serious problems in your child like:

  • Mass protrusion in the skull

  • Hydrocephalus due to obstruction of normal cerebrospinal fluid (CSF) circulation

  • Endocrine symptoms such as early onset of puberty

  • Head bobbing

  • Visual impairment

When your child shows any of the above symptoms, we recommend you to consult the paediatric neurologists at the Mind and Brain Service Line at The Aga Khan University Hospital.

Your time with your doctor maybe limited, so make sure to prepare for your visit beforehand. Here are some tips to help get you started.

Arachnoid cyst is identified through scanning of the skull and brain. For this purpose, Computed Tomography (CT) Scan and/or Magnetic Resonance Imaging (MRI) would be ordered by your paediatrician, which will give clear images of the brain structure. 

Depending on the size, location and type of cyst, your or your child's doctor might select any of the following treatments.

  • A craniotomy may be performed in which the skull is opened and wall of the cyst removed so there is normal flow of rebrospinal fluid within the structure of brain and spinal cord.

  • Fluid within the cyst is removed through different techniques like burr hole drainage and minimally-invasive endoscopic fenestration. However, these techniques have risks of re-developing the symptoms after some time.

  • Shunting of the cyst, to divert the contained cerebrospinal fluid to some other part of the body by inserting a tubular structure

Please click here for some guidelines on what to do before your surgery.

Please click here for some guidelines on what to do on the day of your surgery.

If arachnoid cyst is left untreated, it may cause certain neurological disorders to your child.

Please click here for some guidelines on what to do on after your surgery.

The Aga Khan University Hospital offers various support services to help with managing or recovering from the disease or condition. These include but are not limited to nutrition, physiotherapy, rehabilitation, specialized clinics and some patient support groups. Your doctor or nurse will advise you accordingly.

 The Aga Khan University Hospital offers financial assistance to those who are in need and fulfil the eligibility criteria. For further information, you can contact the Patient Welfare Department. You can find the contact number of the Patient Welfare Department in the ‘Important Numbers’ section on the website homepage.

 The financial counselling staff is available during office hours, at the main PBSD (Patient Business Services Department), to answer your financial queries on treatments’ costs and authorize admissions on partial deposit as per hospital policies allow. The financial counsellor in the emergency room is open 24/7. You can find the contact number of the Patient Business Services in the ‘Important Numbers’ section on the website homepage.

Your doctor and or nurse will give you specific instructions about the prescribed medication. Please ensure that you take or use the prescribed medicine as advised. It can be dangerous to your health if you self-prescribe. Please inform the doctor or nurse beforehand if you have experienced any adverse reactions to any medications in the past. If you experience any symptoms of drug poisoning, overdose or severe reaction please contact the Pharmacy Service at The Aga Khan University Hospital immediately. You can find the contact number of the Pharmacy Services in the ‘Important Numbers’ section on the website homepage




The information provided on our website is for educational purposes and not intended to be a substitute for medical advice, diagnosis or treatment. You should always seek the advice of your doctor or other healthcare professional provider.