CSF Leak

A cerebrospinal fluid (CSF) leak occurs when the fluid surrounding the brain leaks and comes in contact with the nose, sinuses, or ear. The fluid is typically contained around the brain and spinal cord by a thick covering called the dura. The dura can be damaged by certain surgeries, head injuries, and tumors. Leaks sometimes occur spontaneously.

Symptoms typically include a headache that worsens when you sit up and eases when you lie down, and clear drainage from the nose when leaning forward or straining (CSF rhinorrhea), or the ear (CSF otorrhea).

A timely diagnosis and repair is important because if left untreated, the condition can lead to meningitis, brain infection, stroke, and death. Endoscopic advances allow most leaks to be repaired through the nose with small scopes and instruments. CSF leaks from the ear typically require an external incision.

For more detailed, technical information about CSF leaks, please read our CSF patient information sheet.


A variety of tests may be used to diagnose a CSF leak and accurately pinpoint its location.

Tests include:

  • Magnetic resonance imaging (MRI) or computed tomography (CT) scans
  • Nasal endoscopy
  • Testing of nasal secretions


Endoscopic CSF leak repair
– precisely identifies the location of the leak. Small pieces 
of tissue from the nasal lining are then placed on the site. The success rate is 90 to 95 percent with
 the initial attempt and carries far less morbidity than an open approach.
Repair of CSF otorrhea (drainage from the ear)
– requires traditional surgical incisions. The surgical option depends on the 
location of the leak – the posterior fossa or the middle cranial fossa. A posterior 
fossa incision is frequently performed as an outpatient procedure. A middle cranial
 fossa craniotomy requires three to four days in the hospital.

Surgical Risks and Complications

As with any surgical procedure, there are certain risks associated with endoscopic sinus surgery.

Those risks include:

  • Bleeding, scarring, and/or infection
  • Change in smell or taste
  • Injury to the eye (loss of vision, temporary or prolonged double vision, and eye tearing)
  • Potential for infection spreading to brain resulting in meningitis


The typical postoperative stay is two to three days to confirm closure of the leak. The stay can be longer if a spinal drain is needed during surgery. If sutures are required, they will be removed 10 to 14 days after surgery. The repair site can take four to six weeks for complete healing. The patient will be restricted in activities such as straining, lifting heavy items, and nose blowing.