Low-pressure/spinal fluid leak headache.

Low cerebrospinal fluid (CSF) pressure results in neurologic deficits, of which the most common manifestation is headache. Typically, the headache is postural - and specifically, orthostatic - in presentation. There are three hypotheses to explain the occurrence of headache associated with low CSF fluid. The first is traction on pain-sensitive intracranial and meningeal structures; the second is CSF hypovolemia; and the third is spinal loss of CSF resulting in increased compliance at the caudal end of the CSF space. Spontaneous intracranial hypotension (SIH), once believed to be rare, is now more commonly recognized. It is typically associated with orthostatic headache (although initially it may not be) and one or more other symptoms such as alterations in hearing, nausea, vomiting, neck stiffness, diplopia, and visual field cuts. Magnetic resonance imaging (MRI) of the brain with gadolinium is the first study of choice, which typically reveals diffuse pachymeningeal enhancement and, frequently, cerebellar tonsillar descent and posterior fossa crowding. Epidural blood patch (EBP) is the treatment of choice. Surgery and epidural fibrin glue injection are options for those who fail conservative therapy and/or EBP.