Introduction
A cerebrospinal fluid (CSF) leak occurs when there is an abnormal communication between the intracranial space and the nose or sinuses, allowing spinal fluid to escape through the skull base.
Patients may present with clear watery nasal discharge known as CSF rhinorrhea. Because persistent leakage increases the risk of meningitis and other intracranial infections, prompt diagnosis and appropriate treatment are essential.
Today, most skull base leaks can be treated using minimally invasive endoscopic techniques with high success rates.
What Is a CSF Leak?
Cerebrospinal fluid surrounds the brain and spinal cord and helps protect the central nervous system.
A leak occurs when a defect forms in the skull base and dura, allowing CSF to pass into the nasal cavity or sinuses.
Without treatment, persistent leakage may lead to serious complications including infection or meningitis.
Common Causes of CSF Leak
CSF leaks may occur due to:
- Head trauma or skull base fractures, mostly commonly cribriform plate defect
- Previous sinus or skull base surgery
- Spontaneous leaks associated with elevated intracranial pressure
- Meningocele or encephalocele
- Tumors affecting the skull base
- Congenital skull base defects
Symptoms of a CSF Leak
Patients with CSF rhinorrhea may experience:
- Clear watery nasal drainage, often from one side
- Drainage that worsens when bending forward
- Salty or metallic taste in the throat
- Positional headaches
- Recurrent meningitis
- Leakage following trauma or surgery
Diagnostic Pathway
Accurate diagnosis and localization of the leak are essential for successful treatment.
Typical evaluation includes:
- Clinical history and physical examination
- Nasal endoscopy to identify active leakage
- Laboratory testing of nasal fluid (beta‑2 transferrin or beta‑trace protein)
- High‑resolution CT scan of the skull base
- MRI when encephalocele or meningocele is suspected
- CT or MR cisternography in complex cases
Endoscopic CSF Leak Repair
Endoscopic endonasal surgery is now the preferred treatment for most anterior skull base leaks.
This minimally invasive approach allows surgeons to access the skull base through the nasal cavity without external incisions.
The goals of surgery are to:
- Identify the leak site
- Prepare the skull base defect
- Reduce any herniated tissue
- Reconstruct the skull base using grafts or vascularized flaps
- Restore separation between the brain and nasal cavity
Recovery After Surgery
After repair, patients are advised to avoid activities that increase pressure inside the nose or head.
These include:
- Nose blowing
- Heavy lifting
- Straining
- Forceful sneezing with the mouth closed
Follow‑up examinations ensure that the repair remains intact and healing progresses normally.
