Spontaneous CSF leaks: low CSF volume syndromes.

Practically all cases of spontaneous intracranial hypotension results from spontaneous cerebral spinal fluid (CSF) leaks, often at the level of the spine and only rarely from the skull base. The triad of orthostatic headaches, diffuse pachymeningeal enhancement on head imaging and low CSF opening pressure is considered the hallmark of these leaks but substantial variability is noted in most aspects of this disorder including in features of the headaches, imaging and CSF findings, response to treatment and outcome.