CSF Leaks

CSF (Cerebral Spinal Fluid) Leaks


One of the most common complications of surgery for trigeminal Neuralgia is a Cerebral Spinal Fluid (CSF) leak. It is estimated that about 2% of people who have an MVD will end up with a CSF leak. It can also occur after any one of the Rhizotomies but is rare.


Cerebral spinal fluid is a clear, colorless fluid that circulates throughout the central nervous system and protects the brain and spinal cord. The cerebral spinal fluid is located between the brain and skull and serves two main purposes:

  1. Protection and Shock Absorption: The cerebral spinal fluid protects the brain and spinal cord from pressure caused by falls, movement and hard blows.
  2. Nutrients: The cerebral spinal fluid delivers nutrients to various parts of the nervous system.

There is on average about 120 -150 ml of CSF.  Amazingly, the CSF gets completely recycled every 6 to 8 hours.

Cause of CSF Leaks

During the MVD, the surgeon opens the dura and removes some CSF to gain better access to the Trigeminal nerve. Once the decompression is complete, the dura is closed – ideally in such a manner as to make it water tight. In some instances there is a small gap and fluid can leak out.  his can happen at the time of surgery or later during the healing process. The CSF is under pressure and finds it way out usually via the nose, the ear or the incision.

 Signs and Symptoms

  • Headache – usually worse when sitting or standing
  • Clear fluid drainage from the nose, ear or incision


Surgically caused leaks often stop spontaneously. The leakage stops within 1 week in 70% of patients, within 3 months in 20-30%; leakage rarely recurs.

For most people, bed rest with the head raised and observation are all that is needed.

If the leak does not stop spontaneously, a drain can be inserted via a lumbar puncture to reduce the pressure, allowing the body to heal itself. 

Finally if this fails, surgery is indicated either to put a patch over the site where the leak occurs or, in very rare instances, the skull is opened and the dura repaired.

Question sent to Dr. Kaufmann regarding CSF Leaks:  In your experience is CSF Leaks an issue following any of the percutaneous procedures or is it only a possible complication after the MVD?

Dr. Kaufmann’s response:

CSF leak doesn't occur after the needle procedures. Following MVD, it occurs as often as 5% of the time in some published series. In my experience doing now 600 MVDs, we encounter a persisting CSF leak in only 1%.

The leaks can show as CSF draining from the incision. If this occurs, usually in the first day or two, we apply more sutures to the skin, after freezing the area. Leaks may also show as a salty water drip felt at the back of the nose, dripping then down the throat or out the nose when leaning forward. The CSF travels through any hole in the dura and then through the air sinuses of the mastoid bone and finally through the eustachian tube.

This usually stops on its own, or with sitting up for a couple of days or, rarely, after draining some CSF by a spinal tap. If all that fails to stop the leak, then re-operation to better seal the bone edge of the craniectomy is done. If the leak is left untreated, there is a risk infection will occur, as bacteria come up from the nose, along the same course the CSF goes down.



Francis from Calgary had an MVD done in 1999. A few days after she went home she noticed clear fluid draining from one nostril and draining down her throat. She also had a salty taste in her mouth and had no appetite. She was readmitted to hospital. She had an unsuccessful lumbar puncture the first day. The plan was to repeat that the next morning, but the leak stopped overnight so no further treatment was necessary.


Marilyn had her MVD done in Calgary in 2005. After about two weeks, she noticed clear fluid draining from one nostril. She was advised to stay in bed for a few days. When that failed to stop the leak, she was admitted to the hospital and had a drain inserted via a lumbar puncture. After about ten days, that was successful. The leak stopped and she returned home pain free and problem free.


Ray from Yorkton had his MVD done in Winnipeg May 6th. He woke up from the MVD TN pain free and for the next two weeks was busy weaning himself all the drugs he had been taking. Then he noticed some clear fluid draining down the back of his throat and our one nostril. On the advice of his doctors he stayed at home taking it easy. That didn’t seem to help.

He returned to Winnipeg and was in hospital again for five days, during which time he had a drain placed via a lumbar puncture. For the first day, they drained 30 ml of CSF per hour; then 20ml the next day; and 10 ml per hour on the third day.  The leak stopped. 

Ray is home again still with no TN pain which is great, but he still worries about the CSF leak. At the moment, there are  no signs of recurrence, but at the time this newsletter was prepared he was having some trouble with a headache.

We have our fingers crossed for you Ray!!