Arachnoid cysts are fluid-filled sacs located between the arachnoid membrane and the brain or spinal cord. These cysts can be congenital (primary) or acquired (secondary). Symptoms may include headache, dizziness, and seizures.
What are Arachnoid Cysts?
Arachnoid cysts are sacs filled with cerebrospinal fluid located between the brain or spinal cord and the arachnoid membrane, which is one of the three membranes that cover the brain and spinal cord.
Primary arachnoid cysts are present at birth and result from developmental abnormalities that occur in the brain and spinal cord during the early weeks of gestation.
Secondary arachnoid cysts are less common than primary cysts and develop as a result of head trauma, meningitis, tumor growth, or as a complication of brain surgery. Most arachnoid cysts occur in a region of the skull called the middle cranial fossa, outside the temporal lobe of the brain. Arachnoid cysts that affect the spinal cord are rarer. The location and size of the cyst determine the symptoms and when these symptoms start to appear. Most individuals with arachnoid cysts experience symptoms before the age of 20, especially in the first year of life, while some may never exhibit any symptoms. The incidence of arachnoid cysts is four times higher in males than in females.
Typical symptoms of an arachnoid cyst in the brain include:
– Headaches
– Nausea and vomiting
– Seizures
– Hearing and vision impairments
– Dizziness
– Balance and walking difficulties.
Arachnoid cysts around the spinal cord compress nerve roots and lead to symptoms such as progressive back and leg pain, tingling, or numbness in the legs or arms. The diagnosis is typically made through Diffusion-Weighted MRI (Magnetic Resonance Imaging), which helps differentiate fluid-filled arachnoid cysts from other types of cysts, or through a spinal scan.
Is there any treatment available?
The treatment of arachnoid cysts is still debatable. The need for treatment largely depends on the location and size of the cyst. If the cyst is small and does not disturb the surrounding tissue or cause symptoms, some doctors may choose not to treat it. In the past, doctors used to place shunts to drain the cyst fluid, but now they tend to prefer surgical techniques utilizing microneurosurgical techniques and endoscopic tools to either remove the cyst’s membranes surgically or create a window into the cyst. This allows the cyst fluid to flow into the cerebrospinal fluid and be absorbed.
What is the prognosis of the disease?
Untreated arachnoid cysts can progressively expand or cause damage to the brain or spinal cord due to cyst hemorrhage, leading to permanent and severe neurological damage. Symptoms generally improve with treatment.
