Spontaneous Intracranial Hypotension.

Abstract

Spontaneous intracranial hypotension results from CSF volume depletion, nearly always from spontaneous CSF leaks. Spontaneous intracranial hypotension is increasingly diagnosed in practice; the number of atypical, unconfirmed, and doubtful cases is also increasing, as are treatment failures. These confront neurologists and create many challenges. This review provides neurologists with a guide to diagnosis, evaluation, and treatment of spontaneous intracranial hypotension. The clinical spectrum of spontaneous intracranial hypotension is expanding. Spontaneous CSF leak is considered a disorder with a variety of clinical manifestations and imaging features, sometimes quite different from what may be seen after dural puncture. The anatomy of the spontaneous CSF leak is frequently complex, with contributions from disorders of the connective tissue matrix and associated preexisting areas of dural weakness and meningeal diverticula. To locate the site of the leak, CT myelography is still the study of choice. For rapid-flow leaks, dynamic CT myelography has been very helpful, while slow-flow leaks can remain a lingering challenge. The fundamental question of whether a CSF leak is present in uncertain cases can be best answered by radioisotope cisternography. In most cases, epidural blood patch is the main treatment; however, bilevel or multilevel epidural injections are gaining some momentum as treatment for selected cases. This article outlines various clinical aspects of spontaneous intracranial hypotension, including headache characteristics, CSF changes, and imaging findings and their underlying mechanisms, as well as treatments and disease complications.