What is CSF leak?
CSF stands for cerebrospinal fluid, a clear fluid which surrounds the brain and flows around the spine in the dura mater, the outer membrane surrounding the spinal cord and brain.
CSF makes the brain buoyant, allowing it to float in the skull without any pressure, and acts as a ‘shock absorber’ for the brain and spinal cord.
A CSF leak is an under-diagnosed, yet often debilitating, condition where there is a small tear, hole or defect in the dura mater, allowing the CSF to leak out.
What causes CSF leaks?
There are many reasons why people can develop CSF leaks. Some include:
- Trauma and injuries to the head and spine
- Following a lumbar puncture or epidural injection
- Following nasal, spinal or cranial surgery
- Spontaneous leaks (more likely in patients with connective tissue and hypermobility disorders, such as Ehlers Danlos Syndrome)
- The overdraining of a shut, which may be in place for people with conditions like hydrocephalus or Idiopathic intracranial hypertension (IIH)
- A CSF venous fistula, where CSF from within the dura drains into a vein
What are the symptoms of a CSF leak?
When the CSF leaks out, the overall pressure inside the skull drops. This is known as Spontaneous Intracranial Hypotension (SIH).
When CSF is lost, its cushioning effect is reduced and the brain slumps or sags downwards. This can produce a wide range of symptoms, including:
- Severe pain and headaches
- A feeling of pressure
- Blurred vision
- Neck pain
- Shoulder pain
- Dizziness and/or feelings of disequilibrium
- Cognitive impairment (sometimes described as brain fog)
- In rare cases, coma and death
Symptoms are usually remarkably worse when standing or sitting upright, and lessen or disappear when lying flat.