A cerebrospinal fluid (CSF) leak occurs when the fluid that surrounds the brain and spinal cord leaks out from the dura, the membrane surrounding those structures.


CSF leaks are a result of a tear in the dura that may occur spontaneously (infrequent and rarely lead to serious complications) or because of:

  • Trauma to the head
  • Certain types of brain and spine surgery
  • Destructive skull base lesions
  • Developmental defects of various skull bones
  • Procedures such as lumbar puncture or epidural anesthesia

Medial Temporal encephalocele with a large defect draining into the lefft sphenoid sinus



Factors associated with an increased risk of developing a cerebrospinal fluid leak include:

  • Head trauma
  • Certain brain or spine surgeries
  • Skull base tumors
  • Developmental defects S
  • Some spinal procedures

When CSF leaks occur, the most significant risk is infection. Any opening may allow bacteria to enter. This can lead to meningitis, a potentially life threatening complication. Pneumocephalus, a build up of air or gas within the cranial cavity, is another complication.


Clear, salty fluid leaking from the nose or ear is the most common symptom. Other symptoms that may indicate an infection include:

  • Headaches that are worse when sitting up and relieved by lying down
  • Neck pain or stiffness
  • Nausea or vomiting
  • Double or blurry vision
  • Dizziness
  • Changes in hearing or a sense of fullness in the ear
  • Light sensitivity
  • Mental status changes


Detection of a cerebrospinal fluid leak is based on symptoms and the patient’s history. Further work up would include:

  • Laboratory analysis of collected CSF
  • Special high resolution Computed tomography (CT) scan
  • Magnetic resonance imaging (MRI)
  • Cisternography
  • Surgical exploration, sometimes the only way to diagnose a CSF leak


Conservative management, or bed rest, resolves some CSF leaks, and pain relievers can treat headaches.. However, if the leak does not seal off, additional treatment will be necessary:

  • Lumbar drain placement which may allow the tear to repair itself
  • Epidural blood patch
  • Surgical repair of the tear, often done endoscopically, or through the nose
  • Antibiotics if symptoms of infection occur


Protective headgear during sports to prevent head injuries reduces the risk of trauma-induced cerebrospinal fluid leaks. If you want to learn more about cerebrospinal fluid leaks and their treatment, call the Mount Sinai Department of Neurosurgery at 212-241-2377.

Image used with permission from Joshua B. Bederson, MD

Written by the Mount Sinai Department of Neurosurgery.

This information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. Call you health care provider immediately if you think you may have a medical emergency. Always seek the advice of your physician or other qualified health provider before starting any new treatment or with any questions you may have regarding a medical condition.