Headache secondary to intracranial hypotension.

Intracranial hypotension is known to occur as a result of spinal cerebrospinal fluid (CSF) leaking, which may be iatrogenic, traumatic, or spontaneous. Headache is usually, but not always, orthostatic. Spontaneous cases are recognized more readily than in previous decades as a result of a greater awareness of clinical presentations and typical cranial magnetic resonance imaging findings. An underlying disorder of connective tissue that predisposes to weakness of the dura is implicated in spontaneous spinal CSF leaks. CT, MR, and digital subtraction myelography are the imaging modalities of choice to identify spinal CSF leakage. Spinal imaging protocols continue to evolve with improved diagnostic sensitivity. Epidural blood patching is the most common initial intervention for those seeking medical attention, and may be repeated several times. Surgery is reserved for cases that fail to respond or relapse after simpler measures. While the prognosis is generally good with intervention, serious complications do occur. More research is needed to better understand the genetics and pathophysiology of dural weakness as well as physiologic compensatory mechanisms, to continue to refine imaging modalities and treatment approaches, and to evaluate short- and long-term clinical outcomes.