Cerebrospinal Fluid (CSF) Leak From the Nose

Introduction

A cerebrospinal fluid (CSF) leak occurs when the fluid surrounding the brain escapes through a defect in the skull base and drains into the nasal cavity. CSF normally cushions and protects the brain and spinal cord. When a leak develops, it may increase the risk of serious infections such as meningitis.

CSF leaks are relatively uncommon but require medical evaluation and treatment.

Causes

Several conditions can lead to a CSF leak:

Head Trauma

Injuries involving the skull base may create openings through which cerebrospinal fluid can escape.

Previous Surgery

Certain surgeries involving the sinuses or skull base can occasionally result in a CSF leak.

Tumors

Tumors affecting the skull base may erode bone and create a pathway for CSF leakage.

Spontaneous Leaks

In some patients, CSF leaks occur without trauma. Elevated intracranial pressure may be a contributing factor.

Symptoms

The most common symptom is clear watery drainage from the nose, often from one side. Patients may notice:

• Clear fluid dripping from the nose

• Drainage that increases when bending forward

• A salty or metallic taste in the throat

• Recurrent meningitis in severe cases

Because symptoms may resemble a runny nose, diagnosis may sometimes be delayed.

Diagnosis

Evaluation may involve:

• Nasal endoscopy

• Laboratory testing of the nasal fluid

• CT scan or MRI of the skull base

These tests help identify the location of the leak and guide treatment.

Treatment

Many CSF leaks require surgical repair. Today, most repairs are performed using endoscopic techniques through the nose, avoiding large incisions.

Endoscopic repair has high success rates and allows surgeons to reconstruct the skull base defect using graft materials.

When to Seek Medical Attention

Persistent clear nasal drainage, especially following head trauma or sinus surgery, should be evaluated by an ENT specialist.

Sources

• Cummings Otolaryngology: Head and Neck Surgery

• Schlosser RJ. Endoscopic management of cerebrospinal fluid leaks. Otolaryngologic Clinics of North America.