CSF (Spinal Fluid) Leakage

What is a CSF leak?

A leak of cerebrospinal fluid (CSF) can occur from head trauma, after surgeries around the brain, sinuses, ear or skull, and from procedures such as a spinal tap or lumbar puncture. CSF leaks can occur spontaneously as well. Because this fluid that surrounds the brain and spinal cord is under pressure—the body is constantly making new CSF—it will leak until it is stopped by a medical procedure.

What are the symptoms of a CSF leak?

Many times, there are no symptoms. But the most common symptom is a watery drainage from the nose (most commonly on one side) or a salty taste from CSF leaking in the back of the throat. Some patients may develop meningitis (infection around the brain) from bacteria that can get from the nose into the brain or go from the nose into the ear, and from there into the brain. If the ear is the source of the CSF leak, the fluid moves behind the ear drum, down the Eustachian tube to the back of the nose (nasopharynx) and into the back of the throat. If the leak accumulates behind the ear drum and a tube is placed in the ear drum, it can lead to a persistent leakage of spinal fluid through the tube.

Why is a CSF leak a problem?

A CSF leak is a channel for bacteria to get to the brain or spinal cord and cause a life-threatening infection.

Who gets a CSF leak?

There are four main categories of patients who develop CSF leaks:

1. People who have had skull-base tumor surgeries (e.g., for an acoustic neuroma, a meningioma or other tumors) and develop a CSF leak the surgery area that drains into the ear.
2. People who have had nose or sinus surgery that caused a break in the bone of the skull base (floor of the brain), allowing a leak through the opening.
3. People who have had ear surgery in which the bone separating the ear/mastoid from the brain is opened and the dura (the covering of the brain) is injured.
4. People who develop spontaneous CSF leakage around the ear or the sinuses. It can be congenital in some patients (i.e., they have an abnormally open channel between the spinal fluid space and the ear). It also can occur in patients who are heavier than their ideal body weight.

How is a CSF leak in the ear or sinus diagnosed?

This is done by performing a scan, most commonly a CT or MRI. Sometimes, these studies have to be performed with contrast agent injected into the cerebral spinal fluid space. This allows the specialist to see where the contrast material leaks. This is more useful for the sinuses than for the ear, where leaks tend to be slower and may not show up in these studies. Another type of study involves the injection of a radionuclide into the cerebral spinal space and an absorbent material is placed at the back of the nose. After a few hours, the absorbent material is removed and tested.

Finally, if fluid can be collected, it is tested for beta-2-transferrin, a protein unique to CSF.

Repairing a CSF leak

Most sources of CSF leakage around the ear and sinuses can be repaired with minimally invasive approaches using microscopes or endoscopes. Sometimes, a craniotomy (opening of the skull) is performed in conjunction with a neurosurgeon. If the leak occurs immediately after surgery, the treatment of choice is to place a lumbar drain into the spinal fluid space in the lower back, which will slowly remove fluid. The drain is usually in place for three to five days. Reducing the spinal fluid pressure and pressure on the area of the surgery (using packing or a dressing) is often enough to stop a leakage right after surgery.

CSF leaks that persist long after surgery or are spontaneous require surgery to repair the source of the leak.

CSF leaks around the ear

Treatment for leaks around the ear depend on the location of the leak’s source and the patient's medical status.

1. 1. If the source is around the mastoid bone (the bone behind the ear), some of the bone behind the ear must be surgically removed then the leak is stopped with tissue, fat and a special glue (Tisseal). Patients generally require an overnight stay in the hospital for this procedure.

View a video of this procedure below. Please note that images in this surgical video may be too graphic for some viewers.

2. A craniotomy and the placement of tissue and glue are also required when the source of the CSF leak is the top of the space behind the ear drum (middle ear) or the petrous apex (towards the center of the head). Sometimes, a lumbar drain must be placed. The patient generally stays about three or four days in the hospital.
3. Rarely, if the patient is very ill and cannot undergo a procedure under general anesthesia, a 15-minute procedure under local anesthesia can be performed to block the Eustachian tube. This prevents bacteria from gaining access. This will prevent meningitis but can cause a problem if CSF fills the middle ear (space behind the ear drum), which can cause some hearing loss and the sensation of the ear being plugged.

Sinus CSF leaks

The best treatment for CSF leaks around the sinuses is with an endoscope. The area of the leak may need to be identified by injecting a dye (fluorescin) into the spinal fluid. A special filter is used to see the green color of the leak in the nose. A variety of flaps can be created to plug the leakage spot. Sometimes, a lumbar drain is placed to improve the chances of stopping the leak.

Why come to UC Irvine for a CSF leak?

Dr. Hamid Djalilian is one of a few U.S. surgeons with extensive experience treating spontaneous CSF leaks around the ear. He is in the process of publishing the results of nearly a decade of minimally invasive surgical treatments for this condition. Our skull base team also has extensive experience with leaks after surgeries to treat skull-base tumors, which requires tight closure of the spinal fluid spaces to prevent CSF leakage.

To make an appointment with Dr. Hamid Djalilian or Dr. Harrison Lin, our experts in the treatment of CSF leaks around the ear, or with Dr. Naveen Bhandarkar or Dr. Edward Kuan, our expert in the treatment of sinus CSF leaks, please call 714-456-7017 or click here to request an appointment online.