Arachnoid Cysts
Arachnoid cysts are fluid-filled sacs that develop between the brain or spinal cord and the arachnoid membrane, one of the protective layers surrounding the central nervous system. Most arachnoid cysts are congenital (present at birth) and are known as primary arachnoid cysts. Secondary arachnoid cysts may develop later in life as a result of brain surgery, trauma, head injury, tumours, infection, or inflammation.
These cysts are filled with cerebrospinal fluid (CSF), the fluid that surrounds and protects the brain and spinal cord. In some cases, an arachnoid cyst may interfere with the normal circulation of cerebrospinal fluid and place pressure on surrounding structures.
Symptoms
Many arachnoid cysts cause no symptoms and may remain undetected for years. However, if a cyst becomes large enough to compress nearby areas of the brain or spinal cord, symptoms may develop, including:
- Headaches
- Nausea and vomiting
- Lethargy or fatigue
- Dizziness
- Seizures
- Hearing difficulties
- Neurological symptoms
- Problems with balance and walking
- Muscle spasms or weakness
- Bowel or bladder dysfunction
- Back pain
- Tingling, numbness, or reduced sensation in the arms and legs
Diagnosis and Treatment Options
To diagnose an arachnoid cyst, Dr Tollesson will review your medical history and symptoms and perform a physical and neurological examination. Diagnostic imaging studies, such as computed tomography (CT) and magnetic resonance imaging (MRI) scans, are commonly used to confirm the diagnosis and determine the size and location of the cyst. In some cases, additional imaging studies may be required.
Treatment depends on the size and location of the cyst, as well as the severity of symptoms. Most arachnoid cysts do not require treatment and can be monitored with periodic imaging to assess for growth or changes over time.
If the cyst is causing symptoms or affecting neurological function, surgical treatment may be recommended.
For cysts located within the brain, treatment often involves fenestration, a procedure in which a small opening is created in the cyst wall to allow fluid to drain and circulate normally. In some cases, a shunt may be required. This involves inserting a catheter to divert excess fluid to another part of the body, where it can be safely absorbed.
For arachnoid cysts affecting the spinal cord, treatment may involve surgical removal, fenestration, or shunt placement, depending on the location and characteristics of the cyst.
Recovery
Recovery varies depending on the size and location of the cyst, the type of treatment performed, and the patient’s overall health. Some patients may experience temporary neurological symptoms or confusion following surgery.
Post-operative care may include:
- Follow-up MRI scans
- Rehabilitation therapy
- Physiotherapy
- Occupational therapy
- Speech therapy, if required
- Psychological support
- Pain management as needed
In some cases, additional follow-up procedures or surgery may be required. Dr Tollesson will discuss your expected recovery and ongoing care requirements based on your individual circumstances.
