Spontaneous intracranial hypotension: review and expert opinion.

Spontaneous intracranial hypotension (SIH) results from spinal cerebrospinal fluid (CSF) leaking. An underlying connective tissue disorder that predisposes to weakness of the dura is implicated in spontaneous spinal CSF leaks. During the last decades, a much larger number of spontaneous cases are identified and a far broader clinical SIH spectrum is recognized. Orthostatic headache is the main presentation symptom of SIH; some patients also have other manifestations, mainly cochlear-vestibular signs and symptoms. Differential diagnosis with other syndromes presenting with orthostatic headache is crucial. Brain CT, brain MR, spine MRI, and MRI myelography are the imaging modalities of first choice for SIH diagnosis. Invasive imaging techniques, such as myelography, CT myelography, and radioisotopic cisternography, are progressively being abandoned. No randomized clinical trials have assessed the treatment of SIH. In a minority of cases, SIH resolved spontaneously or with only conservative treatment. If orthostatic headache persists after conservative treatment, a lumbar epidural blood patch (EBP) without previous leak identification (so-called "blind" EBP) is a widely used initial intervention and may be repeated several times. If EBPs fail, after the CSF leak sites identification using invasive imaging techniques, other therapeutic approaches include: a targeted epidural patch, surgical reduction of dural sac volume, or direct surgical closure. The prognosis is generally good after intervention, but serious complications may occur. More research is needed to better understand SIH pathophysiology to refine imaging modalities and treatment approaches and to evaluate clinical outcomes.