CSF Leaks

Cerebrospinal fluid (CSF) is a protective layer that supports and cushions your brain and spinal cord from sudden movements and injury. Three layers of membranes surround the spinal cord and cerebrospinal fluid. A CSF leak occurs when some of the fluid escapes due to a tear or hole in the dura mater (the outermost layer of membranes). If the leak is large, it may cause intracranial hypotension, leading to severe symptoms that make it hard to go about your routine. Some CSF leaks may heal with conservative methods like bed rest. However, usually, you may need surgery to repair the leak.

Cerebrospinal fluid (CSF) is a protective layer that supports and cushions your brain and spinal cord from sudden movements and injury. Three layers of membranes surround the spinal cord and cerebrospinal fluid. A CSF leak occurs when some of the fluid escapes due to a tear or hole in the dura mater (the outermost layer of membranes). If the leak is large, it may cause intracranial hypotension, leading to severe symptoms that make it hard to go about your routine. Some CSF leaks may heal with conservative methods like bed rest. However, usually, you may need surgery to repair the leak.

Types of CSF Leak

There are two types of CSF leak with varying symptoms, causes, and treatment approaches. 

1. Spinal CSF leaks: Occur due to tears in the soft tissues surrounding the spinal cord
2. Cranial CSF leaks: Develop in the head, and CSF escapes from the nose or ear

Causes of CSF Leak

About 90% of CSF leaks occur due to an injury. The other 10% of CSF leaks occur spontaneously, i.e., without any known cause. However, experts have linked them to some probable medical conditions. 

Injuries

Injuries that cause a spinal CSF leak include:-

Spinal tap (a lumbar puncture)

Epidural anaesthesia in the spine for pain relief during medical procedures

A head, neck, or spine surgery

Injury caused by a prior surgery on the spine 

Penetrating injuries like gunshot or stab wounds

Injuries that cause a cranial CSF leak include:-

A face or head injury

Injuries from previous ear, nose, or throat procedures

Congenital

Structural defects in the nose, sinuses, ear or other skull parts can cause cranial CSF leak

Inner ear malformations

Acquired

Acquired causes for a spinal CSF leak include:-

Bone spurs along the spine

Abnormalities in the dura mater around the spine’s nerve roots

CSF-venous fistulas (an abnormal connection between the dura mater and veins)

Acquired causes for a cranial CSF leak include:-

Intracranial hypertension (increased pressure in the brain)

Pseudotumor cerebri (false brain tumours due to high pressure in the brain)

Poorly functioning shunt

Other Minor Causes

Coughing

Sneezing

Lifting heavy objects

Straining for bowel movement

Exercising

Stretching

Falling

Causes of CSF Leak

About 90% of CSF leaks occur due to an injury. The other 10% of CSF leaks occur spontaneously, i.e., without any known cause. However, experts have linked them to some probable medical conditions. 

Injuries

1. Injuries that cause a spinal CSF leak include:-
2. Spinal tap (a lumbar puncture)
3. Epidural anaesthesia in the spine for pain relief during medical procedures
4. A head, neck, or spine surgery
5. Injury caused by a prior surgery on the spine 
6. Penetrating injuries like gunshot or stab wounds
7. Injuries that cause a cranial CSF leak include:-
8. A face or head injury
9. Injuries from previous ear, nose, or throat procedures

Congenital

1. Structural defects in the nose, sinuses, ear or other skull parts can cause cranial CSF leak
2. Inner ear malformations

Acquired

1. Acquired causes for a spinal CSF leak include:-
2. Bone spurs along the spine
3. Abnormalities in the dura mater around the spine’s nerve roots
4. CSF-venous fistulas (an abnormal connection between the dura mater and veins)

Acquired causes for a cranial CSF leak include

1. Intracranial hypertension (increased pressure in the brain)
2. Pseudotumor cerebri (false brain tumours due to high pressure in the brain)
3. Poorly functioning shunt

Other Minor Causes

1. Coughing
2. Sneezing
3. Lifting heavy objects
4. Straining for bowel movement
5. Exercising
6. Stretching
7. Falling

Symptoms of CSF Leak

The symptoms of spinal CSF leak include:-

1. Orthostatic headache (improves while lying down, worsens while standing up, coughing, or straining)
2. Pain in the neck or shoulder
3. Dizziness
4. Nausea or vomiting
5. Hearing changes
6. Tinnitus (ringing in the ear)
7. Phonophobia (sensitivity to sound)
8. Changes in vision
9. Photophobia (sensitivity to light)
10. Balance issues
11. Behavioural changes

The symptoms of cranial CSF leak include:-

1. Otorrhea (drainage of a clear fluid from the ears)
2. Rhinorrhea (drainage of a clear fluid from the nose)
3. Cutaneous sinus tract drainage (CSF leaks into your sinus tract, creating a pathway to drain through the skin)
4. Anosmia (loss of sense of smell)
5. Hearing loss
6. Metallic or salty taste in the mouth
7. Meningitis (inflammation of CSF and membranes surrounding the brain and spinal cord)

Symptoms of CSF Leak

The symptoms of spinal CSF leak include:-

1. Orthostatic headache (improves while lying down, worsens while standing up, coughing, or straining)
2. Pain in the neck or shoulder
3. Dizziness
4. Nausea or vomiting
5. Hearing changes
6. Tinnitus (ringing in the ear)
7. Phonophobia (sensitivity to sound)
8. Changes in vision
9. Photophobia (sensitivity to light)
10. Balance issues
11. Behavioural changes

The symptoms of cranial CSF leak include:-

1. Otorrhea (drainage of a clear fluid from the ears)
2. Rhinorrhea (drainage of a clear fluid from the nose)
3. Cutaneous sinus tract drainage (CSF leaks into your sinus tract, creating a pathway to drain through the skin)
4. Anosmia (loss of sense of smell)
5. Hearing loss
6. Metallic or salty taste in the mouth
7. Meningitis (inflammation of CSF and membranes surrounding the brain and spinal cord)

Factors that increase the risk of CSF leak include:-

Uncontrollable Factors

1. Age (People above 30 years of age are at higher risk)
2. Gender (Women are more likely to have a CSF leak than men)
3. A previous injury on and around the spine and skull
4. Connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome
5. Obstructive sleep apnea
6. Tumour at the skull base
7. Head trauma
8. Abnormalities of the inner ear or skull base

Controllable Factors

Obesity

Factors that increase the risk of CSF leak include:-

Uncontrollable Factors

1. Age (People above 30 years of age are at higher risk)
2. Gender (Women are more likely to have a CSF leak than men)
3. A previous injury on and around the spine and skull
4. Connective tissue disorders such as Ehlers-Danlos syndrome and Marfan syndrome
5. Obstructive sleep apnea
6. Tumour at the skull base
7. Head trauma
8. Abnormalities of the inner ear or skull base

Controllable Factors

Obesity

Diagnosis of CSF Leak

To diagnose a spinal or cranial CSF leak, the doctor will start by evaluating your medical history and conducting a physical exam. For a spinal CSF leak, the doctor may check the flexibility of your joints. On the other hand, for a cranial CSF leak, he/she may evaluate your nose and ear and check for any nasal discharge. He/she may further perform an MRI with gadolinium to detect abnormalities in the brain or spine, causing a CSF leak. 

Other diagnostic tests for a spinal CSF leak include:-

Myelography: It is a gold standard diagnostic test for CSF leak. The test uses digital subtraction fluoroscopy, a contrast dye, and an MRI or CT scan to locate the CSF leak. It also helps the doctor determine the most suitable treatment approach. 

Cisternography: The test evaluates CSF flow around your brain and spine. The doctor injects a chemical into the space surrounding your spinal cord. He/she then takes the images of the area several times to track CSF flow. 

Spinal tap (lumbar puncture): The doctor places a needle in your spinal column to measure CSF pressure. 

Other diagnostic tests for cranial CSF leak include:-

CT Myelography: A gold standard diagnostic test that uses a contrast dye and a CT scan to locate the CSF leak in the skull base. The test helps the doctor to determine the treatment approach. 

Tympanometry: The doctor tests your middle ear fluid to check for a CSF leak. 

Treatment for CSF Leak

1. Conservative treatment
2. These are the non-direct ways of treating a CSF leak. It involves measures such as:-
3. Bed rest
4. Elevating the head of your bed
5. Caffeine and salt for low CSF pressure

Medications

The doctor may recommend medications to treat symptoms or causes of a CSF leak, such as lowering the pressure inside your brain and relieving severe pain. He/she may recommend antibiotics to prevent bacteria from reaching your brain and causing infections like meningitis. You can also take stool softeners to prevent straining for bowel movements. 

Surgery is a commonly used method for repairing CSF leaks. The doctor may recommend surgery when the CSF leak does not improve with conservative methods or when the CSF leak is too severe to heal on its own. The surgery for a CSF leak involves repairing a tear or hole with stitches or muscle graft to prevent further leaks. However, the specific approach depends on the location of the leak.

If the tear in the dura mater causes fluid leakage through the nose, the surgeon may perform an endoscopic repair. 

If the tear causes fluid leakage from the ears, the surgeon may perform an open surgery through an incision in the scalp. 

Non-Surgical Treatments

1. Other non-surgical treatments for spinal CSF leak include:-
2. Epidural blood patch: In this procedure, the doctor takes a sample of your own blood and injects it into the CSF surrounding the spinal cord. The blood cells form blood clots, creating a patch to cover the tear. 
3. Sealant: The doctor mixes a special sealant with your blood and injects it into the spinal canal to cover the tear and stop the CSF leak. 
4. Trans-venous embolisation: It is a minimally invasive procedure for treating CSF-venous fistulas. The doctor glues the fistula from inside the culprit vein. 

Please note that the selection of the treatment approach is based on the location, causes, and severity of the CSF leak. 

The doctor may recommend direct treatments if conservative treatments do not work after one to two weeks. 

While preparing for the doctor’s consultation, make sure to:-

Take a prior appointment

Make a list of your symptoms

Write down your key medical information

Enlist all your medications, including herbs and supplements

Note down the questions for the doctor

Take a friend or family member along

Here’s what you can expect from your doctor during the visit:-

 When did you start experiencing the symptoms?

Are your symptoms continuous or occasional?

How severe are the symptoms?

Does anything improve or worsen the symptoms?

Have you had any surgery recently?

Do you have other medical conditions?

Here’s what you can ask the doctor about your condition:-

What is the cause of my symptoms?

Which diagnostic tests do I need to undergo?

Is the CSF leak temporary or chronic?

What are the treatment options, and which do you recommend?

Do I need surgery?

What are the risks involved?

Can my condition be managed without surgery?

How can I manage my other medical conditions with CSF leak?

Will losing weight help?

Do I need to follow any restrictions?

Conclusion

CSF leaks are uncommon, but they can cause severe symptoms when they occur. However, technological advances have helped doctors promptly diagnose CSF leaks. While some CSF leaks can heal on their own through conservative treatments, others may require surgery. Early diagnosis of CSF leaks can lead to better treatment outcomes and prevent complications. So if you are experiencing the symptoms of a CSF leak, get in touch with your healthcare provider TODAY!