Spontaneous Intracranial Hypotension

Spontaneous intracranial hypotension is a condition characterized by a lower-than-normal volume of cerebrospinal fluid (CSF) because of leakage of CSF through the dural membrane at one or multiple sites. The loss of CSF results in displacement of cerebral structures, causing headache and other neurologic symptoms. 1 The term “spontaneous” in relation to the disorder is used to differentiate it from intracranial hypotension caused by CSF leaks of known cause, such as craniospinal trauma, spinal surgery, or most commonly, lumbar puncture or spinal anesthesia. Although CSF pressure in this disorder, as measured by manometry during lumbar puncture, may be normal, 2 it is often lower than normal (with the normal value considered to be 6 to 25 cm of water, or 4.4 to 18.4 mm Hg), and the term “hypotension” continues…