UCLA Campus    |   UCLA Health    |   School of Medicine Translate:
UCLA Health It Begins With U

UCLA Neurosurgery


Conditions Treated

Intracranial Hypotension

General Information

  • Intracranial hypotension is a condition in which there is negative pressure within the brain cavity.
  • There are several possible causes:
    • Cerebrospinal fluid (CSF) leak from the spinal canal:
      • A leak following a lumbar puncture (spinal tap).
      • A defect in the dura (the covering the spinal tube).
        • Spontaneous, sometimes following exertion such as swinging a golf club.
        • A congenital weakness.
        • Following spinal surgery.
        • Following spinal trauma.
      • Following a shunt procedure for hydrocephalus.
        • Lumboperitoneal shunt.
        • Ventriculoperitoneal shunt with a low pressure valve.
  • In some cases, spinal CSF leaks can lead to a descent of the cerebellar tonsils into the spinal canal, similar to a Chiari malformation.
  • Large spinal dural defects can lead to herniation of the spinal cord into the defect.


  • The classic symptom is severe headache when upright, which is relieved when lying flat.
  • Other symptoms can include nausea, vomiting, double vision and difficulty with concentration.


  • Diagnosis is usually suspected based on the postural dependency of the headache, although in many cases the diagnosis of intracranial hypotension is not considered for some time.
  • A contrast-enhanced brain magnetic response imaging (MRI) scan typically shows thickened and brightly enhancing meninges (pachymeningeal enhancement). Other findings include descent of the thalamus and cerebellar tonsils.
  • Continuous intracranial pressure monitoring is definitive for documenting abnormally negative intracranial pressures.
  • The identification of the site of CSF leak in the spinal canal can be very challenging. In some cases, the site cannot be identified. Methods include:


  • If the site of the spinal CSF leak can be identified, then options include:
    • Epidural blood patch, performed by an anesthesiologist pain management specialist.
    • Surgical repair of the defect.
  • Over-draining CSF shunts are managed by replacing the valve with one that drains less.
    • Lumboperitoneal shunts may have to be removed or ligated.


  • If the cause of the intracranial hypotension can be identified, the outcome following treatment is typically excellent.

UCLA Rated One of the Top Hospitals in the Nation