What Is a Spinal CSF Leak?
Cerebral spinal fluid (CSF) is a clear, colorless bodily fluid that acts as a natural shock absorber for the brain and spine and protects them from the jolts and knocks the body endures throughout the day. It is secreted by the brain and found within a protective sac made of “dura” that surrounds the brain and spinal cord and is called the Dural sac.
Spinal CSF leaks occur when the fluid escapes or leaks out of the dural sac. The loss of this fluid causes the brain to lose its buoyancy and sag inside the skull. This results in a low volume of CSF remaining around the brain and spinal cord, also referred to as intracranial hypotension.
CSF leaks are rare, but can occur in children and adults. They are commonly misdiagnosed as migraines, other headache disorders, or sinusitis.
What Causes Spinal CSF Leaks?
CSF leaks can occur for a number of reasons, including:
- Trauma (caused by an injury)
- An injury to the head or spine
- Bone spurs along the spine
- Heavy straining such as lifting heavy objects
- Significant fall or motor vehicle accident
- Strenuous exercise or sports, especially when new to the person
- Prolonged severe coughing
- Iatrogenic (caused intentionally or accidentally during a medical procedure):
- A lumbar puncture (spinal tap)
- An epidural in the spine for pain relief, such as during labor and delivery
- Surgery on the spine
- Spontaneously (no known cause)
Risk factors for spinal CSF leaks include:
- Connective tissue disorders such as Marfan syndrome or Ehlers-Danlos syndrome
- Abnormalities of the dura mater around the nerve roots in the spine
- Abnormal connections between dura mater and veins (CSF-venous fistulas)
What Are the Signs & Symptoms of Spinal CSF Leaks?
The most common symptom of a spinal CSF leak is a headache. These headaches usually are described as:
- An “upright headache,” which is head pain that worsens after minutes to hours while standing and improves while lying flat, or a headache that is less obviously positional but gets worse as the day goes on.
- Cause pain in the back of the head
- May start or worsen with exertion (such as coughing or straining)
- Rarely, start suddenly ("thunderclap" headache)
- Neck or shoulder pain
- Ringing in the ears (tinnitus)
- Changes in hearing
- Nausea or vomiting
- Changes in vision
- Changes in cognition or behavior
How Are Spinal CSF Leaks Diagnosed?
If your doctor suspects a CSF leak, he or she may recommend the following tests:
- MRI of the brain and spine: MRI scans can help confirm the presence of a leak by showing typical findings in the brain or spine and help determine the location and severity of a CSF leak.
- Myelography — CT/MR and/or nuclear medicine: These two tests, each performed in a similar way, require a spinal tap (also known as a lumbar puncture) to administer a fluid (contrast agent) into the CSF that allows your doctor to identify if a CSF leak is present and the location of the leak. Specialized myelographic techniques like digital subtraction myelography and dynamic CT myelography can also be performed.
How Are Spinal CSF Leaks Treated?
Initial treatment may be conservative if the symptoms are not severe. This might include bedrest, oral and IV fluids, and oral and IV caffeine. Some cases resolve without any further treatment.
If conservative treatments have been unsuccessful, an epidural blood patch is the most common first treatment for spinal CSF leaks. In this procedure, your own blood is injected into the epidural space in the spinal canal. The blood clot that forms creates a seal to stop the leak, allowing the body to heal the tear in the dura. If several attempts of epidural blood patches do not work, other materials, such as epidural fibrin glue, NBCA (a medical grade superglue) may be tried. If these methods are not successful, other surgical approaches to repair the leak include using stitches (sutures) or aneurysm clips.
A small percentage of patients will require surgical repair by a spinal neurosurgeon who would treat a spinal CSF leak with stitches (sutures) or aneurysm clips.
What Are the Long-Term Effects of Spinal CSF Leaks?
Overall, the prognosis is good for the majority of patients with appropriate diagnostics and treatments, although some patients continue to have persistent symptoms despite several procedures.