A CSF leak is an escape of the fluid that surrounds the brain and spinal cord.
Causes, incidence, and risk factors
Any tear or hole in the membrane that surrounds the brain and spinal cord (dura) can allow the fluid that surrounds those organs to leak.
This fluid is called the cerebrospinal fluid (CSF). When it leaks out, the pressure around the brain and spinal cord drops.
Causes of leakage through the dura include:
- Certain head, brain, or spinal injuries
- Head injury
- Placement of tubes for epidural anaesthesia or pain medications
- Spinal tap (lumbar puncture)
Sometimes no causes can be found. This is called a spontaneous CSF leak.
Symptoms may include:
A headache that is worse when you sit up and improves when you lie down. It may be associated with:
- Light sensitivity
- Nausea
- Neck stiffness
- Drainage of CSF from the ear (rarely)
- Drainage of CSF from the nose (rarely)
Signs and tests
Diagnosis is usually based on your history of injury, surgery, or lumbar puncture.
Test may include:
- CT scan of the head with contrast dye
- MRI of the head
- Radioisotope test of the CSF to track the leakage
Treatment
Depending on the cause of the leak, many cases go away on their own after a few days. Complete bed rest for several days is usually recommended. Drinking increased fluids, especially drinks with caffeine, can help slow or stop the leak and may help with headache pain.
Headaches may be treated with pain relievers and fluids. If the headache lasts longer than a week after a lumbar puncture, a procedure may be done to block the hole that may be leaking fluid. This is called a blood patch, because a blood clot can be used to seal the leak. In most cases, this makes symptoms go away. Rarely, surgery is needed to repair a tear in the dura and stop the headache.
Symptoms of infection (fever, chills, change in mental status) that occur after surgery on the brain or spinal cord or a lumbar puncture are a medical emergency and need to be treated with antibiotics.
Expectations
The outlook is usually good depending on the cause. Most cases heal by themselves with no lasting symptoms.
Prevention
Measures such as wearing a helmet when riding a bicycle or motorcycle can help prevent head injuries that can lead to CSF leak.