Cerebrospinal Fluid Leak (CSF)

What is a Cerebrospinal Fluid Leak?

Cerebrospinal fluid (CSF) is a clear, odorless, water like substance that surrounds the brain and spinal cord providing a variety of necessary functions. CSF that surrounds the brain is separated from the nasal cavity and non-sterile outside environment by only a few thin layers of tissue and bone.  When a disruption occurs between these layers leading to a communicating whole the resultant effect is a cerebrospinal fluid leak.

CSF leaks are uncommon, however if left untreated can lead to meningitis and other severe life threatening intracranial complications.  The term CSF rhinorrhea describes the leakage of intracranial CSF into the nose.  Patients often report persistent, clear, water-like nasal discharge worse when bending forward, and associated salty or metallic taste. Diagnosis requires a strong clinical suspicion by a trained specialist.  Confirmation of CSF can be accomplished by collecting the fluid and sending it for laboratory analysis.  Imaging studies are also obtained to identify and locate the site of defect or defects if multiple.

What causes a CSF leak?

The most common causes of CSF leak include head trauma, surgical complications, or occurs spontaneous.  When caused by trauma patients may respond to conservative treatment with bed rest, instructions for CSF leak precautions, and possible lumbar drain placement.  When conservative measures fail, or when caused spontaneously or by surgical complications treatment often requires surgical repair.

The majority of CSF leaks occurring at the skull base can be repaired using a transnasal endoscopic surgical approach without the need for any external incisions.  Although most repairs offer initial success rates of 90% or better, this is largely dependent on the type, nature, and extent of the skull base defect.  Occasionally a lumbar drain may be placed and medication given to reduced the volume and pressure of CSF within the intracranial space. In addition to your ear nose and throat physician consultation with a neurosurgeon and ophthalmologist may be obtained to rule out other causative disorders.