Intracranial hypotension: aggravation of headache at high altitude.

Spontaneous intracranial hypotension is an increasingly recognized disorder, often, although not always, characterized by the triad of low-opening cerebrospinal fluid pressure on lumbar puncture, postural headache, and diffuse parenchymal meningeal enhancement on magnetic resonance imaging of the head. We describe an unusual case of a patient with spontaneous intracranial hypotension presenting with postural headache and tinnitus, aggravated at high altitudes.