CSF leak

Definition

A CSF leak is an escape of the fluid that surrounds the brain and spinal cord.

Alternative Names

Intracranial hypotension

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 surgeries
• Head injury
• Placement of tubes for epidural anesthesia or pain medications
• Spinal tap (lumbar puncture)

Sometimes, no cause can be found. This is called a spontaneous CSF leak.

Symptoms

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.

Tests 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.

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.

Support Groups

Expectations (prognosis)

The outlook is usually good depending on the cause. Most cases heal by themselves with no lasting symptoms.

Complications

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.

Calling your health care provider

Call your health care provider if:

• You have a headache that gets worse when you sit up, especially if you have recently had a head injury, surgery, or childbirth involving epidural anesthesia.
• You have a moderate head injury, and then develop a headache that is worse when you sit up, or you have a thin, clear fluid draining from your nose or ear.

Prevention

Measures such as wearing a helmet when riding a bicycle or motorcycle can help prevent head injuries that can lead to CSF leak.

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References

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.