Cerebrospinal fluid (CSF) rhinorrhea is the medical term for a rare condition in which the fluid that normally cushions the brain and spinal cord, cerebrospinal fluid, runs from the nose. For this to happen an abnormal path between the subarachnoid space of the brain and the nasal sinus cavities is inadvertently created. This abnormal space can be caused by:

A nasal sinus surgery complication

Some birth defects

An increase in intracranial pressure (ICP) (also called spontaneous CSF rhinorrhea)

Trauma to the head ﻿ ﻿ and face that causes a naso-orbito-ethmoid fracture and damage to the cribriform plate (a part of the frontal lobe that forms the "roof" of the sinus)

The exact incidence of CSF rhinorrhea is unknown but some studies have suggested that the rate of CSF rhinorrhea complications from sinus surgery is rare, only 0.5%. Thankfully, since the implementation of seat belt laws, the incidence of CSF rhinorrhea caused by trauma has also declined.

Symptoms

Rhinorrhea (runny nose) that is clear and watery may be the first sign of cerebrospinal fluid rhinorrhea.﻿﻿ Other signs and symptoms may include:

Headache

Salty or metallic taste in the mouth ﻿ ﻿

﻿ Drainage increases while leaning forward with head down

Lack of smell (anosmia) ﻿ ﻿

﻿ Nasal congestion

It is important to realize that these symptoms also occur in many other, more common, conditions and should be evaluated by an otolaryngologist (ear, nose, throat specialist or ENT) if they are not easily explained or do not clear up on their own in a week or so. However, if you have the symptoms listed above, you should not delay an evaluation since CSF rhinorrhea can lead to serious complications.

Diagnosis

If you are having the symptoms listed above, you should seek an evaluation by an otolaryngologist. If you had surgery, you should go to the surgeon that performed your procedure. However, if you have not had nasal sinus surgery, you should obtain any CT scans or other radiographic images of your sinuses that you may have had in the past and take them to an ENT specialist for evaluation.

During this appointment, you may be asked to perform a Smell Identification Test to determine if there is olfactory (smell) dysfunction. This test may be done before any treatment in order to determine the baseline function.

Depending on your situation, your doctor may also choose to perform an endoscopy.﻿﻿ This involves using a tiny fiberoptic scope to visualize any abnormalities to the superior nasal cavity and cribriform plate. Other testing that may be ordered by your doctor includes:

CT scan ﻿ ﻿

﻿ MRI

Β-2 transferrin assay (laboratory test on nasal drainage) to confirm that the substance is in fact CSF

Radioactive pledget scanning is an imaging test that can be rather time-consuming and involves inserting medical cotton in your nose and ears followed by a lumbar puncture

Intrathecal fluorescein can be used to both identify CSF leaks and to surgically repair them

Treatment

If you have cerebrospinal fluid rhinorrhea, it is important for you to receive appropriate treatment to prevent meningitis﻿﻿ (a sometimes very serious infection) or pneumocephalus (air in the cranial cavity).

Very small leaks may only require bed rest and medication to resolve. However, in most cases to cure cerebrospinal fluid rhinorrhea, surgery will be necessary.

The type of surgery required will depend on the cause of your condition (surgery or trauma).﻿﻿ The surgical success rate is good, however, complications may occur with any surgical procedure, especially those involving general anesthesia.

You should discuss the risk versus benefits of having the surgery with your doctor and follow any instructions they give you regarding fasting the day before and day of your surgery and any instructions on how you should take care of yourself after the procedure.

A Word From Verywell

While cerebrospinal fluid rhinorrhea is a rare condition, the complications (e.g. meningitis) can be serious and should not be taken lightly.