What is cerebrospinal fluid?
Cerebrospinal fluid is a clear liquid surrounding the brain and spinal cord. It acts as a cushion for the delicate brain and spinal tissues. A reduction in cerebrospinal fluid, as is in the case of a leak, requires immediate care by a trained professional.
What is a CSF leak?
A CSF leak occurs when CSF escapes through a tear in the outermost layer (Dura) of the meninges, which surrounds the brain. The dura could get damaged due to a head injury or a surgical procedure involving the sinuses, brain or spine. Spontaneous CSF leaks could also occur and are usually caused due to increased intracranial pressure (pressure in the head). Although, they could occur without any identifiable cause.
There are two types of CSF leaks:
- CSF Rhinorrhoea: CSF rhinorrhoea occurs when there is a breakdown in the barrier between the spinal fluid areas and the nose and sinuses. The usual symptoms include watery nasal discharge that often worsens while leaning forward or during strenuous activities. In rare cases, there may not be any drainage and the leak may be realised after repeated episodes of Meningitis.
- CSF Otorrhoea: CSF otorrhoea occurs when there is a breakdown in the barrier between the spinal fluid spaces and the middle ear. It usually presents with watery fluid dripping or flowing from the ear. It can be a result of trauma and is common after fractures of the skull base. Usually, traumatic CSF otorrhoea resolves itself in about a week or two, and if not, surgical intervention is required. CSF leaks into the middle ear or mastoid could also arise as a result of surgical complications. However, these are extremely rare as proper care is taken during surgical procedures to prevent such occurrences.
What are the symptoms of a CSF Leak?
Some of the symptoms of a CSF Leak include:
- Headaches
- Nasal drainage of CSF (CSF is hard to distinguish from normal nasal discharge without testing)
- Tinnitus (ringing in the ears)
- Visual disturbances
- Meningitis (bacterial or viral)
How is a CSF Leak diagnosed?
The following tests may be recommended if the doctor suspects a CSF leak:
- Nasal fluid analysis: A test to detect the Beta-2 Transferrin protein, which is almost exclusively found in CSF.
- CT Scan: Produces detailed images of bones and planes of the brain.
- MRI Scan: Produces detailed images of organs and structures of the body. Helps in determining the location and severity of a CSF leak.
Surgery for CSF Leaks
- CSF Rhinorrhoea: The surgery is performed endoscopically through the nostrils and does not require cutting through the skin. The surgeon will use endoscopes to find the location of the leak. They would then place small pieces of nasal tissue (grafts) to block the leak. In some cases, synthetic tissue, cartilage and/ or bone may be used to reinforce the leak area. With success rates over 90-95%, endoscopic surgery is the preferred technique.
- CSF Otorrhoea: The surgery entails making an incision behind the ear. Part of the mastoid is removed, allowing access to the source of the CSF leak around the ear. The leak is then blocked using a graft harvested from the patient or a biomaterial graft.
What are the Risks associated with CSF leak surgery?
The risks of CSF leak surgery include bleeding, infection, scarring, change in smell and taste or injury to the eye (temporary or prolonged double vision, eye tearing or loss of vision). Another rare risk is the surgical manipulation of the CSF leak site that creates a potential for infection to spread from the sinuses to the brain, resulting in meningitis. Other risks involve those surrounding the use of general anaesthesia. However, all these risks are minimised by careful planning and care by the surgeons before and during the surgery.
What is the post-operative care for CSF leak surgery?
Patients are kept in the hospital for a few days to closely monitor for leak recurrence. It is critical to lay down and keep the head elevated. In some cases, due to the use of a lumbar drain, a longer hospital stay may be required.
Strenuous activities and heaving lifting should be avoided for a few weeks. Even nose blowing is forbidden as it could dislodge the tissue blocking the leak.
Any headache, vision change, recurrent nasal drainage, fever, or neck stiffness, could be a serious sign and should be reported to the doctor.
The above mentioned is the generalised post-operative care, however, each case is individually treated and care is provided to ensure the long-term success of the surgery for the specific patient.