A CSF leak is an escape of the fluid that surrounds the brain and spinal cord.
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:
Sometimes, no cause can be found. This is called a spontaneous CSF leak.
Symptoms may include:
Diagnosis is usually based on your history of injury, surgery, or lumbar puncture.
Tests may include:
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.
Headache 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.
The outlook is usually good depending on the cause. Most cases heal by themselves with no lasting symptoms.
Complications may occur if the cause is surgery or trauma. Infections after surgery or trauma can lead to meningitis and serious complications, such as swelling of the brain.
Call your health care provider if:
Measures such as wearing a helmet when riding a bicycle or motorcycle can help prevent head injuries that can lead to CSF leak.
Biros MH, Heegaard WG. Head injury. In: Marx J, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 7th ed. Philadelphia, Pa: Mosby Elsevier; 2009:chap 38.
DeAngelis LM. Tumors of the central nervous system and intracranial hypertension and hypotension. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 199.