Expert Diagnosis and Management of Cerebrospinal Fluid (CSF) Leaks

Common Symptoms of a Cerebrospinal Fluid (CSF) Leak

CSF leaks from the nose most often present as clear, one-sided, persistent nasal drainage that is often worsened with bending forward or straining of any type. Individuals may also report a salty or metallic taste in the back of their throat. CSF leaks into the ear most commonly present as middle ear fluid resulting in hearing loss. If a tube is placed into the ear, the drainage will persist because of the amount of brain fluid that is made each day. This issue is taken seriously because there is a direct pathway between the nose or ear and the brain. If left untreated, an individual can develop meningitis which is an infectious process that causes inflammation of the lining of the brain. If left untreated, meningitis can be fatal.

Anyone who has any of the symptoms listed above should be evaluated by an ear, nose and throat specialist, particularly if they have recently experienced any of the following:

• Head or facial trauma
• Surgery on or around the base of the skull
• Ear or nasal surgery

UH Skull Base Specialists Have the Expertise to Diagnose

An early and accurate diagnosis of a CSF leak is essential for an optimal treatment outcome and can help prevent infectious complications. The ENT experts at University Hospitals have the experience to recognize and diagnose CSF leaks so that the appropriate treatment plan can be developed. In addition to evaluating each patient’s symptoms and medical history, our doctors may use the following techniques and tests to confirm a diagnosis of CSF leak:

Beta 2 transferrin: A sample of the fluid is collected and tested to determine whether or not the fluid is CSF. This is a critical step to determine whether or not your nasal or ear drainage is something that can be treated medically or if it requires surgical intervention.

Imaging tests: If a CSF leak is strongly suspected or confirmed, imaging tests will be ordered. Often, a CT will be the first scan performed because it provides excellent, high resolution images of the bony anatomy of the skull base and can help locate the site of leakage. If there is a concern that a portion of the brain or lining of the brain is entering the sinuses an MRI would also be obtained to better visualize the soft tissue anatomy. If the location of leakage is still unclear after CT and/or MRI, there are additional imaging studies that can be done in which contrast is injected into the back. The contrast solution then enters the brain fluid space and can be seen exiting the nose or ear.

Surgical Repair of CSF Leaks through the Nose

If the source of the CSF leak is through the nose, the repair will be performed by a UH rhinologist - an ENT subspecialist with advanced fellowship training in the medical and surgical treatment of nasal and sinus disorders.

Usually done under general anesthesia, CSF leaks through the nose will be repaired using minimally invasive endoscopic techniques. An endoscope - a long, thin flexible tube with a tiny camera and light attached at the end - will be inserted through the nostril. Images obtained from the endoscope help the surgeon to identify the location of the bony defect causing the leak.

Once the location of the leak has been found, the surgeon will use cartilage and other tissue from inside the nose to repair the area. The entire procedure is done through the nostrils and does not require any external incisions. This results in less bleeding, reduced pain and faster recovery times for most patients.

Surgical Repair of CSF Leaks through the Ear

If the source of the CSF leak is through the ear, the repair will be performed by a UH otologist - an ENT subspecialist with advanced fellowship-training in the medical and surgical treatment of conditions related to the ear.

CSF leaks through the ear usually occur when the area of bone between the ear and the brain becomes weakened, allowing a small portion of the brain to push through and break the surrounding membrane (dura). This is called an encephalocele or brain herniation. When the dura is broken, CSF can leak out through the ear.

Weakening of the bone that can lead to encephalocele can be congenital (present at birth) or may develop slowly over time as a person ages. It can also be the result of chronic ear infections and/or prior ear surgery performed to treat ear infections or other conditions. Obesity and obstructive sleep apnea are also potential risk factors for CSF leaks due to encephalocele.

The majority of patients with CSF leaks from the ear can be treated surgically using a transmastoid (through the ear) approach vs. a middle fossa (neurosurgical) approach. During the procedure, the surgeon drills through the mastoid bone (the bone behind the ear) to gain access to the middle ear. Once the encephalocele has been visualized, the defect is repaired using cartilage from other parts of the ear and/or the bone dust (pate) collected when the mastoid bone is drilled.

Transmastoid repair is often a same-day surgery that does not require a hospital stay and allows for a faster recovery. It is a highly effective approach and is particularly desirable for older patients and those who might not be able to tolerate the more invasive neurological approach