Orthostatic Headache Caused by Cerebrospinal Fluid Leakage with Normal Cerebrospinal Pressure

ABSTRACT

Cerebrospinal fluid(CSF) leakage is known to cause orthostatic headaches. It shows diffuse pachymeningeal gadolinium enhancement on magnetic resonance(MR) imaging, typically associated with nonmeasurable or very low CSF pressures. The authors report a patient with orthostatic headache and a documented CSF leakage with normal CSF pressure. A previously healthy 37-year-old woman complained of sudden severe occipitonuchal pain with a five-day history. Brain MR images showed a hernia of the cerebellar tonsil, absence of subdural fluid collection, and no enhancement of pachymeninges after gadolinium injection. Lumbar puncture in lateral decubitus revealed an opening pressure of 140mm H2O. Radioisotopic cisternography revealed accumulation of the tracer in the lumbar region, suggestive of CSF leakage. Complete relief of the headache was obtained after applying two epidural blood patches. In the presence of convincing clinical features and imaging abnormalities, a normal CSF pressure should not discourage the clinician from searching for a source of CSF leakage.