CSF Leaks and Repair
What Is A CSF Leak?
CSF leak refers to leakage of the fluid from their normal bony enclosure into surrounding areas. This could mean the fluid that surrounds and cushions the brain leaking into your nose or ear.
What Is Cerebrospinal Fluid (CSF)?
Cerebrospinal fluid commonly referred to as CSF, is a naturally produced fluid in the body that surrounds the delicate structures of the brain and spinal cord. It can sometimes be referred to as spinal or brain fluid. It acts as a soft cushioning fluid that insulates the brain and spinal cord from their hard bony enclosures. The average adult has approximately 200 ml of CSF total circulating in their body at any given time, about the same amount as a can of soda. However, the body will constantly absorb and re-produce CSF at a rate of about 700 ml per day, about the same amount as a liter bottle of soda.
What Is CSF Rhinorrhea?
CSF rhinorrhea refers specifically to leakage of brain fluid into the nose.
What Causes Sinus CSF Leaks?
Many sinus CSF leaks occur spontaneously and the cause may never be determined. Other leaks are caused by trauma such as a blow to the head, a tumor inside the nose, or brain or sinus surgery. In addition, some patients have “High-Pressure Hydrocephalus” where the CSF does not drain properly and the build-up of pressure can cause a leak into the nose.
What Are The Symptoms Of CSF Rhinorrhea?
There may be no symptoms to a CSF leak and you may not even know that you have one. The symptoms may make it hard to diagnose CSF leaks as they overlap with allergies and the common cold. In 2007 a study at Cedars-Sinai found that no CSF leaks were diagnosed correctly in the Emergency Room with an average diagnosis delay of 8 months. The potential symptoms of a nasal CSF leak are as follows:
- Clear fluid leaking out of your nose (rhinorrhea) or down the back of your throat (post-nasal drip)
- A salty or metallic taste in your mouth
- Neck pain or stiffness
- Positional headaches better when lying down and worse on sitting up
- Nausea or vomiting
- Hearing change or ringing in the ears
- A sense of being off-balance
- Sensitivity to sound (phonophobia)
- Sensitivity to light (photophobia)
- Loss of smell (anosmia)
- Cognitive changes
What Are The Complications Of CSF Leaks?
Because the area of leakage connects a non-sterile to a sterile area there may be the introduction of bacteria into the brain. This can cause meningitis or a brain abscess which can be life-threatening. Air may enter a hole and may cause pressure to the delicate structures of the brain and spinal cord. Some patients live for years with CSF leaks without detection or problems but the risk of complications is always present.
What Is The Way To Diagnose A Nasal CSF Leak?
A thorough history, physical, and intranasal exam are crucial in the diagnosis of sinus CSF leaks. During surgery, a gush of clear fluid seen with the endoscope may indicate entry into the dura that surrounds the brain. A CAT scan will show the skull base bony architecture and an MRI will show the soft tissue structures of the brain and sinuses. If the fluid can be collected then it can be sent for beta-2-transferrin testing which is diagnostic for CSF fluid.
How Is A CSF Leak Medically Treated?
A spinal drain may lower the pressure inside the head and allow the site of the leak to heal. This would include bedrest for one week, keeping the head elevated, and stool softeners to keep from straining. Medications like acetazolamide will decrease the amount of CSF made inside the brain and can also lower intracranial pressure. Some doctors may use antibiotics although evidence that they improve outcomes is currently not available.
How Is A CSF Leak Surgically Treated?
If a CSF leak is detected during a sinus surgery then it can be repaired at the time of surgery. If a leak fails medical management then a procedure may be needed to repair the defect leading to the brain. Generally, for a small hole, mucosa can be harvested from inside of the nose from the septum, floor of the nose or one of the turbinates. This can be placed over the hole and held in place with sealants, fat grafts, and dissolvable or removable packing. For small holes, this is usually successful if there is no elevated pressure inside the head. For larger defects sometimes bone or cartilage with larger grafts are needed to close the hole.
How Is CSF Rhinorrhea Treated Surgically?
Surgery is often times reserved for those patients who have failed medical and conservative management. CSF leaks can be repaired endoscopically through minimally invasive approaches through the nose. Using state of the art technology, image guidance is utilized to identify the source of the leak. Through endoscopes placed in the nose, the leak location can be identified with certainty. Fat is then harvested from a patient’s abdomen or thigh and used as a plug to stop the drainage. The surgeon may then place tissue sealant in the area of the leak to further support the closure of the leak. Surgery may also be used in combination with some conservative techniques to further facilitate closure and resolution of the leak.
What Do I Do If I Think I Have A CSF Leak?
If you have some of the above symptoms and they are not resolving then you should seek a medical opinion. An Otolaryngologist, Neurologist, or Neurosurgeon are appropriate to begin a work-up. This can be a chronic condition but with the potential complications and possible loss of quality of life, you should explore it further.