Cerebrospinal fluid (CSF) is a colorless fluid that cushions the brain, protecting it from mechanical trauma and infections. Nasal CSF leaks are caused by small, sometimes microscopic breaks in the barrier between the brain and roof of the sinuses. The diagnosis can be difficult to make because nasal drainage is also caused by allergies, sinusitis, and other inflammatory conditions. Causes of CSF leak include head injuries and prior head or sinus surgery.
Some leaks occur spontaneously without any trauma in patients with elevated intracranial pressure, termed idiopathic intracranial hypertension (IIH). This is a relatively rare condition with an average incidence of 0.001% (1:100000). Female gender, age between 20 and 45, and obesity are risk factors.
The most common symptoms of CSF leak include steady drip of clear fluid from the nose (typically just one side) and headaches. The major risk of leaving a CSF leak unrepaired is a life threatening infection of the lining of the brain called meningitis, which requires hospitalization and intravenous antibiotics to treat. Some patients have already had a recent prior episode of meningitis at the time of evaluation, which increases the suspicion of CSF leak even when the specific location is uncertain.
A complete evaluation including a history, medical history, and examination are first performed. Most commonly, you will be asked to collect, if possible, a sample of the fluid in a sterile container to perform a laboratory test that confirms whether the fluid is CSF. A CT scan and/or MRI of the sinuses are typically recommended to help identify the exact location of the defect responsible for the leak and assist with planning of the repair.
The management of CSF leaks at UCI is a multidisciplinary approach between specialties. A neurosurgeon is consulted to help with the treatment around the time of surgery with insertion of a lumbar drain to decompress the CSF space. In the majority of cases, no external incision is involved and the CSF leak can be managed using a minimally invasive, purely endoscopic approach through the nostrils. Image guided advanced surgical techniques are utilized to assist with identification of the exact location of CSF leak. Once the leak is identified, it is repaired using the patient’s own tissue, which can frequently obtained from within the nose. Typically, patients require a 2-3 day hospital stay.