Cerebrospinal Fluid (CSF) Leak

What is a cerebrospinal fluid (CSF) leak?

A cerebrospinal fluid leak is when the fluid surrounding your brain and spinal cord leaks out from where it’s supposed to be. If the leak is large enough, it can cause severe symptoms that make it hard or even impossible to go about your life as usual.

What is cerebrospinal fluid?

Your brain and spinal cord have a surrounding protective layer of cerebrospinal fluid (CSF). CSF contains nutrients that your brain can use. The CSF layer also supports and cushions your brain and spinal cord from sudden movements.

The effect is similar to putting a grape inside a jar. If the jar is empty and you give it a good shake, you’ll bruise or damage the grape. That’s what would happen to your brain if you had no CSF. But if you fill the jar with water and then shake it, the water slows down how fast the grape moves and cushions it, preventing damage.

Who does it affect?

Spontaneous CSF leaks are more likely in people over 30 (the average age to have them is 42). People assigned female at birth are also much more likely to develop spontaneous CSF leaks.

How common is a CSF leak?

Having a CSF leak causes a drop in fluid pressure inside your head. That causes a condition known as intracranial hypotension (“intracranial” means “inside your skull” and “hypotension” means “lower than normal pressure”). Intracranial hypotension is a rare condition, and about 5 people out of every 100,000 have it.

However, it's very likely that CSF leaks happen more often than that number suggests. Experts don't know exactly how common CSF leaks are because they're difficult to diagnose. It's also common for healthcare providers to misdiagnose a CSF leak as another condition, like migraine, sinus infections or allergies.

How does this condition affect my body?

There's less fluid to surround, support and cushion your brain when you have a CSF leak. If the leak is small, it might not cause noticeable effects, or you might notice symptoms and mistake them for something else.

If the leak is large enough to cause intracranial hypotension, your brain will sink downward in your skull, putting too much pressure on its lower sections. That can disrupt how those parts of your brain work, causing symptoms ranging from minor and barely noticeable to severe and unbearable.

What are the symptoms of a CSF leak?

When CSF leaks are small enough that they don’t noticeably affect your brain, you may not notice any symptoms or might mistake the symptoms for something else. When a CSF leak is large enough that it causes intracranial hypotension, you’ll have symptoms related to pressure on the lower areas of your brain.

The most common symptom of intracranial hypotension from a CSF leak is a postural headache, which means a headache that changes depending on your posture. A postural headache with a CSF leak worsens when you sit up or stand and improves when you lie down.

Symptoms that depend on CSF leak location

Some possible symptoms of CSF leak depend on the location of the leak. Two likely places that CSF can leak into are your sinuses or your nose. In either case, you’ll have a runny nose (rhinorrhea) with thin, clear fluid. CSF coming out of your nose has two key differences from nasal mucus:

• If you wipe your nose with a handkerchief, drying nasal mucus will cause the cloth to stiffen, but CSF won’t.
• The runny nose may happen under certain circumstances, such as when you bend over to pick something up or tie your shoes.

Another place where leaking CSF can cause symptoms is your ears. Clear fluid coming out of your ears (otorrhea) is a symptom of a CSF leak. However, it's less likely to happen because for the fluid to leak out, you'd also have to have a hole or tear in your tympanic membrane (also known as your eardrum).

Other possible symptoms that happen with or because of a CSF leak

• Loss of sense of smell (anosmia). This usually happens with a CSF leak due to an injury to your face.
• Blurred or double vision (diplopia). This can happen when downward pressure on your brain causes problems with the ocular nerves, which connect to your eyes.
• Changes in hearing or hearing loss. This happens for similar reasons as double vision, with position changes putting strain or stress on the nerves connected to your ears.
• Pulsatile tinnitus. This is being able to hear your own pulse without using some kind of medical instrument or other means.
• Seizures. These are most likely to happen with large CSF leaks or those that cause severe intracranial hypotension.
• Neck pain and stiffness.
• Loss of appetite.
• Headaches, which can sometimes be severe or even unbearable.
• Dizziness or vertigo.
• Nausea and vomiting.
• Photophobia (light sensitivity).
• Balance and gait problems.

What causes a CSF leak?

Experts estimate that about 90% of CSF leaks happen because of injuries. The remaining 10% happen spontaneously or for unknown reasons.

Many injuries can cause CSF leaks. These include:

• Injuries to your face, head, neck or spine. A common example of this is injuries from car crashes. The most likely injuries involve your nose, sinuses, ears, temples or the base (bottom) of your skull. Twisting or severe whiplash can also cause tears that leak CSF fluid near your spinal cord.
• Penetrating injuries (like puncture or stab wounds, gunshot wounds).
• Injuries from brain surgery.
• Injuries from ear, nose and throat medical procedures.
• Injuries from medical procedures on or around your spine, such as epidural anesthesia and spinal taps (lumbar punctures).

Non-injury causes

In about 10% of cases, CSF leaks happen for unknown reasons. However, experts have connected this problem to a few other medical conditions. Whether or not they cause CSF leaks is not yet known, but they do happen often enough that researchers are now looking to see if there is a cause-effect relationship.

• Connective tissue disorders that could cause a weakness in the layers of tissue that should contain the CSF (examples include Marfan syndrome and Ehlers-Danlos syndrome).
• Intracranial hypertension (high pressure inside your skull), which can cause tears in the surrounding tissue, creating a leak.
• Pseudotumor cerebri (false brain tumors).
• Obesity (especially class II or class III obesity).
• Structural defects in how your nose, sinuses or other parts of your skull formed (either that you had when you were born or that developed or happened at some point in your life).

Is it contagious?

CSF leak is not contagious. You can’t give it to or get it from others.

How is it diagnosed?

A healthcare provider can diagnose a CSF leak using a physical examination, along with gathering information about your symptoms, and asking questions about your medical history and circumstances. It’s also very likely that they’ll use certain kinds of lab tests and diagnostic imaging scans to confirm or rule out a CSF leak.

The combination of tests and methods they use depends on the suspected location of the leak, and whether or not you have any injuries (past or present) that could play a role.

What tests will be done to diagnose this condition?

There are several possible tests for CSF leaks. Most of them are imaging tests, which offer healthcare providers a way to look inside your head and back to locate possible leaks or damage that could contribute to them.

If you have CSF leak symptoms specific to your nose or face (especially a runny nose), your provider will likely want to test that fluid. The most likely lab test to help is a beta-2 transferrin test. This test looks for tau, a protein found in CSF but not in nasal mucus. Another possible test is a glucose test, as CSF has about the same amount of glucose as your blood, while nasal mucus has little-to-no glucose.

The most likely imaging and diagnostic tests include:

• Computerized tomography (CT) scans.
• Magnetic resonance imaging (MRI) scans.
• Digital subtraction angiography.
• Myelography.
• Cisternography.
• Lumbar puncture (spinal tap).*

*This is usually not a first-line test for CSF leak.

How are CSF leaks treated, and is there a cure?

In many cases, healthcare providers recommend no direct treatments for CSF leaks. That's because time and rest are all it takes for many injury-related CSF leaks to heal on their own.

In cases where a CSF might not or definitely won’t heal on its own, there are many different treatments and methods that can help. In most cases, it's possible to repair or seal the leak, stopping it from worsening or causing symptoms.

Chronic conditions, especially connective-tissue disorders like Marfan syndrome or Ehlers-Danlos syndrome, aren't curable. When this condition isn’t treatable or repairable directly or is the result of another condition, healthcare providers will try to treat your symptoms.

What medications or treatments are used?

The treatments you receive depend most on what caused the CSF leak and its location. Medications, surgeries and other non-surgical procedures can often help. Your healthcare provider is the best person to tell you about the medications they recommend and why they feel those will help in your specific case.

Conservative treatment

Conservative treatment is a non-direct way of treating CSF leaks. This treatment calls for a person to lie down and rest for a period of time. They'll also need to stay hydrated, and medications to treat inflammation and pain are common. Caffeine and salt may also be part of the treatment guidelines in cases where a leak causes low CSF pressure. If conservative treatment doesn’t work after one to two weeks, your provider will likely recommend moving to direct treatments.

Surgery and related procedures

Surgery is a common method to repair CSF leaks. The surgery can either directly close a leak or help reconstruct a damaged area when the leak is from a significant injury. Some surgeries may go through your skull to access a leak, while others might try to repair a leak through your nose or mouth. The location, cause and severity of the leak are often key factors in deciding the type of surgical procedure.

Blood patch injections

The most likely treatment for CSF leaks that don’t involve surgery is a procedure known as a blood patch. During this procedure, a healthcare provider inserts a needle into the lumbar section of your lower back. Once it’s in position, they’ll slowly inject some of your own blood into the CSF surrounding your spinal cord and the injected blood “patches” the leak. In some cases, more than one blood patch is necessary, but most people who need more than one will still feel some improvement after the first.

Medications

Several medications can help with a CSF leak. Some lower the pressure inside your skull, while others treat severe symptoms like pain. Antibiotics are also possible because bacteria that reach your brain through your CSF can lead to dangerous infections like meningitis and encephalitis.

Complications or side effects of the treatment

The possible complications and side effects from treatment depend on the location and severity of your CSF leak, what caused it, and what treatments you received. Your healthcare provider can explain the possible complications and side effects in your case and what you can do to limit or avoid these.

How to take care of myself/manage symptoms?

A CSF leak isn't something you can diagnose or treat on your own. If you suspect you have this condition, you should talk to a healthcare provider as soon as possible. That's because this condition has symptoms that are possible with severe conditions that need immediate medical attention.

How soon after treatment will I feel better?

The time to recover and start feeling better depends on treatment. Many people will feel some relief just by lying down and resting. But other people might need days or even weeks to recover.

How can I reduce my risk or prevent this condition?

CSF leak happens unpredictably, so it’s not preventable. However, you can try to reduce the risk of it happening by protecting yourself from conditions or circumstances that might cause a leak. However, that only works with causes related to injuries.

The most important thing you can do to avoid an injury-related CSF leak is to wear safety equipment. Face, head, neck and back injuries can cause the kind of damage that makes a CSF leak possible. Whether you're on the job or on your own time, using safety gear and equipment can help you avoid this possibility.

What can I expect if I have this condition?

CSF leaks are sometimes tricky to diagnose, but the overall outlook for this condition is good. While the symptoms can be unpleasant, severe or disruptive, this condition is usually treatable. The overwhelming majority of people who have CSF leaks will either recover when the leak heals or with treatments or surgeries.

How long does a CSF leak last?

CSF leaks can last days, weeks or even months, depending on the size of the leak and why it happened. Treatment can also greatly shorten how long you feel the effects of a CSF leak. Your healthcare provider is the best person to tell you more about how long this condition will affect you and what you can do to help yourself.

What’s the outlook for this condition?

Overall, the outlook for CSF leaks is very good. About 98% of people with CSF leaks will recover from them, no matter the cause.

How do I take care of myself?

If you have a CSF leak, you should follow your healthcare provider's guidelines on how to care for yourself. They're the best source of information for what you can and should do. They can also tell you what problem signs or warning indications to watch for and avoid.

When should I see my healthcare provider or seek medical care?

You should talk to or see a healthcare provider if you think you have a CSF leak. While this condition doesn't usually cause severe or life-threatening complications, it shares symptoms with urgent and dangerous conditions.

If you know you have a CSF leak, your healthcare provider will schedule follow-up visits to monitor you as you recover. You should also see them if you notice symptoms getting worse or causing new disruptions in your daily life.

When should I go to ER?

If you have a CSF leak, you should go to the ER if you have a sudden, severe headache, muscle weakness or trouble standing up. You should also see them if you notice any tingling or numbness anywhere on your body, especially in your hands, feet, legs and arms. Those can be a sign of injury to your spinal cord, which can lead to permanent paralysis.

You should also get emergency medical attention if you have stroke-like symptoms. These include:

• Weakness, numbness or paralysis on one side of your body.
• Slurred or garbled speech.
• Droop on one side of your face or vision loss in one eye.
• Trouble swallowing.
• Confusion, irritability or agitation.
• Trouble focusing, thinking or remembering.
• Sudden severe headache, especially if it interferes with your usual activities.

A note from Cleveland Clinic

Cerebrospinal fluid leaks are an uncommon problem, but they can cause extremely unpleasant or severe symptoms. Advances in modern medicine and technology mean healthcare providers better detect and diagnose this problem quickly and easily. Providers can also do more to treat this problem than in years past, so the outlook for this condition tends to be very positive.