Table of ContentsView AllTable of ContentsSymptomsCausesComplicationsDiagnosisTreatmentOutlook
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Complications
Diagnosis
Treatment
Outlook
A runny nose can sometimes turn out to be a more serious condition known as a cerebrospinal fluid (CSF) leak. Also known asCSF rhinorrhea, this is a condition in which a fluid (calledcerebrospinal fluid) escapes through a tear in the membrane surrounding the brain and leaks into a nasal passage.
Although the two conditions can mimic each other, arunny noseusually affects both nostrils, while a CSF leak usually affects one. A CFS leak may also cause spinning sensations, double vision, and a loss of hearing or smell. Although both conditions may heal on their own, a CSF leak may sometimes require surgical repair.
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Symptoms of CSF Leak vs. Runny Nose
Depending on the cause, symptoms of a runny nose may include:
CSF rhinorrheais an entirely different situation in which a puncture of membranes surrounding the brain allows CSF to leak into a nasal passage, causing runny nose-like symptoms.
Depending on the underlying cause and severity, symptoms of a CSF leak may include:
Causes of a CSF Leak
A CSF leak is a relatively rare condition that affects one out of every 100,000 people at some people in their lives. Females are more affected than males, as are people who haveobesity.
CSF is a fluid that flows through and surrounds the brain and spinal cord made up of the same components ofplasma in blood(water, glucose, proteins, lipids, andelectrolytes) but with far less protein. Its role is to act as a watery cushion while providing nutrition and removing waste.
CSF is contained within a body of membranes called themeningesthat surround and protect the brain and spinal cord. Within the meninges are layers called thepia materandarachnoidthat are filled with CSF; overlying these is a tough outer layer called the dura mater.
A CSF leak occurs when these membranes are penetrated, allowing CSF to leak through the outermost dura mater. When this occurs around the brain (referred to as a cranial CSF leak), the fluids will naturally flow to the sinuses and out of a nostril.
CSF can also leak into theeustachiantubeandmiddle ear, but only if there is a defect like aruptured eardrumthat alters the internal ear pressure. The fluid can also flow from the eustachian tube down the back of the throat.
A puncture of the dura mater around the spinal cord (referred to as a spinal CSF leak) will not cause CSF rhinorrhea.
Causes of a CSF leak include:
Many CSF leaks require no treatment but those that are severe or persistent can place a person at increased risk of potentially serious complications such as:
Diagnosing a CSF Leak
If a CNS leak is suspected, the diagnosis will start with a physical exam and a review of your symptoms and medical history.
A battery of tests will likely be ordered, including:
Larger ones may require treatment to prevent bacterial meningitis or other serious complications. An ENT specialist, also known as anotolaryngologist, will recommend the best options based on your lab results.
The procedures commonly used to close a CSF leak include:
Outlook for a CSF Leak
If a CSF leak persists or recurs, it is often due tocerebral edema(brain swelling) orhydrocephalus(the buildup of CSF in the brain) common after any type of brain injury. Both of these can dislodge a blood clot and require medical intervention even if the leak is small.
Summary
A cerebrospinal (CSF) leak occurs when a hole develops in the meninges surrounding the brain and leaks out of the outermost layer of the meninges, called the dura mater. When this happens, CSF can leak out of a nostril, causing symptoms similar to a runny nose.
Healthcare providers can diagnose a CSF based on your symptoms and a battery of tests, including imaging studies and an evaluation of nasal discharge. Most CSF leaks heal on their own, but those that are larger or persistent may need medical intervention to be sealed.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American College of Allergy, Asthma, and Immunology.Runny nose, stuffy nose, sneezing.Cedars-Sinai.Cerebrospinal fluid leak.Johns Hopkins Medicine.Cerebrospinal fluid (CSF) leak.University of California Irvine.Cerespinal fluid leak.Kwong KCNK, Mehta AR, Nedergaard M, Chandran S.Defining novel functions for cerebrospinal fluid in ALS pathophysiology.Acta Neuropathol Communication.2020:8(1):140. doi:10.1186/s40478-020-01018-0Tai YC, Tai YS, Ou CH, et al.Treatment, outcome, and relapse of spontaneous and nonspontaneous cerebrospinal fluid leak.Brain Sciences. 2022:12(3):340. doi:10.3390/brainsci12030340National Library of Medicine.Subdural hematoma.Pulickal GG, Sitoh YY, Ng WH.Tension pneumocephalus.Singapore Med J.2014 Mar;55(3):e46–e48. doi:10.11622/smedj.2014041Oh JW, Kim SH, Whang K.Traumatic cerebrospinal fluid leak: diagnosis and management.Korean J Neurotrauma. 2017 Oct 31;13(2):63–67. doi:10.13004/kjnt.2017.13.2.63
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American College of Allergy, Asthma, and Immunology.Runny nose, stuffy nose, sneezing.Cedars-Sinai.Cerebrospinal fluid leak.Johns Hopkins Medicine.Cerebrospinal fluid (CSF) leak.University of California Irvine.Cerespinal fluid leak.Kwong KCNK, Mehta AR, Nedergaard M, Chandran S.Defining novel functions for cerebrospinal fluid in ALS pathophysiology.Acta Neuropathol Communication.2020:8(1):140. doi:10.1186/s40478-020-01018-0Tai YC, Tai YS, Ou CH, et al.Treatment, outcome, and relapse of spontaneous and nonspontaneous cerebrospinal fluid leak.Brain Sciences. 2022:12(3):340. doi:10.3390/brainsci12030340National Library of Medicine.Subdural hematoma.Pulickal GG, Sitoh YY, Ng WH.Tension pneumocephalus.Singapore Med J.2014 Mar;55(3):e46–e48. doi:10.11622/smedj.2014041Oh JW, Kim SH, Whang K.Traumatic cerebrospinal fluid leak: diagnosis and management.Korean J Neurotrauma. 2017 Oct 31;13(2):63–67. doi:10.13004/kjnt.2017.13.2.63
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American College of Allergy, Asthma, and Immunology.Runny nose, stuffy nose, sneezing.Cedars-Sinai.Cerebrospinal fluid leak.Johns Hopkins Medicine.Cerebrospinal fluid (CSF) leak.University of California Irvine.Cerespinal fluid leak.Kwong KCNK, Mehta AR, Nedergaard M, Chandran S.Defining novel functions for cerebrospinal fluid in ALS pathophysiology.Acta Neuropathol Communication.2020:8(1):140. doi:10.1186/s40478-020-01018-0Tai YC, Tai YS, Ou CH, et al.Treatment, outcome, and relapse of spontaneous and nonspontaneous cerebrospinal fluid leak.Brain Sciences. 2022:12(3):340. doi:10.3390/brainsci12030340National Library of Medicine.Subdural hematoma.Pulickal GG, Sitoh YY, Ng WH.Tension pneumocephalus.Singapore Med J.2014 Mar;55(3):e46–e48. doi:10.11622/smedj.2014041Oh JW, Kim SH, Whang K.Traumatic cerebrospinal fluid leak: diagnosis and management.Korean J Neurotrauma. 2017 Oct 31;13(2):63–67. doi:10.13004/kjnt.2017.13.2.63
American College of Allergy, Asthma, and Immunology.Runny nose, stuffy nose, sneezing.
Cedars-Sinai.Cerebrospinal fluid leak.
Johns Hopkins Medicine.Cerebrospinal fluid (CSF) leak.
University of California Irvine.Cerespinal fluid leak.
Kwong KCNK, Mehta AR, Nedergaard M, Chandran S.Defining novel functions for cerebrospinal fluid in ALS pathophysiology.Acta Neuropathol Communication.2020:8(1):140. doi:10.1186/s40478-020-01018-0
Tai YC, Tai YS, Ou CH, et al.Treatment, outcome, and relapse of spontaneous and nonspontaneous cerebrospinal fluid leak.Brain Sciences. 2022:12(3):340. doi:10.3390/brainsci12030340
National Library of Medicine.Subdural hematoma.
Pulickal GG, Sitoh YY, Ng WH.Tension pneumocephalus.Singapore Med J.2014 Mar;55(3):e46–e48. doi:10.11622/smedj.2014041
Oh JW, Kim SH, Whang K.Traumatic cerebrospinal fluid leak: diagnosis and management.Korean J Neurotrauma. 2017 Oct 31;13(2):63–67. doi:10.13004/kjnt.2017.13.2.63
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