A: Demonstration of a spinal CSF leak

     Or, if criterion A not met

B: Cranial MRI changes of intracranial hypotension and the presence of at least one of the following:

1.     Low opening pressure (£ 60 mm H₂O)

2.     Spinal meningeal diverticulum

3.     Improvement of symptoms after epidural blood patching

Or,  if criteria A and B not met

C: The presence of all of the following or a least two of the following if typical orthostatic headaches are present:

1.     Low opening pressure (£ 60 mm H2O)

2.     Spinal meningeal symptoms

3.     Improvement of symptoms after epidural blood patching