Dr. Benjamin Bleier performing sinus surgery

CSF Leaks and Skull Base Defects

Cerebral Spinal Fluid (CSF) is the fluid that bathes the brain and spinal cord. Usually it is contained in one area within the skull and down the spine, but sometimes a tiny hole can develop between the brain cavity and the sinuses and nasal cavity. This is considered a CSF leak.

If a CSF leak is suspected, you should see a physician as soon as possible. If symptoms of meningitis (high fever, light sensitivity, neck stiffness) are suspected, you should go to the emergency room.


The most common symptom of a CSF leak is a headache that’s accompanied by an intermittent or constant nasal drainage. This increases or occurs more frequently when bending over or straining, usually dripping out of one side of your nose, rather than both. The fluid may also drip down the back of your throat. This fluid is very clear, like tap water, and may taste salty or metallic. When a CSF leak occurs, the main concern is that leak allows a direct communication between the nasal cavity and the brain, which gives bacteria and viruses a direct path to the brain. 

Meningitis, a serious infection to the lining of the brain, can result from this. Symptoms of meningitis include severe headaches, fever, nausea, stiff neck, light sensitivity, and an altered mental state.


CSF leaks are diagnosed by physical and endoscopic exams, and by collection and analysis of the fluid. Sometimes CT or MRI scans are ordered.


If a CSF leak is identified, it must be surgically repaired. The surgery is commonly performed through the nasal cavity endoscopically, without any external incisions. Depending on the size and severity of the leak, neurosurgeons may be called upon to help in surgery. The surgery is done under general anesthesia, with at least one overnight stay. 

This surgery is similar in approach to endoscopic sinus surgery, but technically more difficult. The leak is patched with either synthetic material or material from within the nasal cavity. This is used to permanently close the leak. There is usually a six-week recovery period after the surgery during which patients must limit their physical activities to prevent recurrence of the leak.

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