Wouter I. Schievink
I saw my first patient with spontaneous intracranial hypotension in 1991 when I was a neurosurgery resident: A 22-year-old exotic dancer had been suffering with headaches for 6 weeks after a minor brawl, and she had seen a multitude of physicians. However, her head CT was normal, and no cause for the headaches was established until she saw Dr. Neath Folger at the Mayo Clinic in Jacksonville, Florida, who noted the orthostatic nature of her pain and expeditiously ordered a CT myelogram and a radionuclide cisternogram. These studies showed a CSF leak from a sizable thoracic arachnoid cyst, which was treated with an aneurysm clip, resulting in complete resolution of her symptoms. The patient was of a tall and lanky build, with some features of Marfan syndrome, and we surmised that a connective tissue disorder must be associated with her CSF leak. This occurred just prior to the first description of the typical MRI findings in spontaneous intracranial hypotension, and such a patient was considered to be exceptionally rare.
Nowadays, the diagnosis of spontaneous intracranial hypotension is made much more routinely, in large part because of MRI, but there remains much to be discovered about this disorder. One of the important and most basic questions is how to diagnose spontaneous intracranial hypotension. The paper “Diagnostic Criteria for Spontaneous Spinal CSF Leaks and Intracranial Hypotension,” published in AJNR, offers some guidance in answering this question. Mostly, the criteria of the second edition of the International Classification of Headache Disorders (ICHD-II) had been used, but those criteria were uncommonly restrictive and somewhat confusing. The objections to these criteria have been addressed in the soon to be published ICHD-III.