Intracranial hypotension syndrome: neuroimaging in five spontaneous cases and etiopathogenetic correlations

Intracranial hypotension (IH) is essential or, more frequently, secondary. This syndrome is characterized by severe postural headache and low opening cerebrospinal fluid (CSF) pressure; although other symptoms may exist. In this study five patients are investigated. Neuroimaging showed: on computerized tomography scan (CT), poor visualization of the cerebral sulci with small ventricles; on magnetic resonance imaging (MRI), subdural fluid collections with enhancement on the convexity, along the tentorium and in the upper cervix after administration of contrast medium and downward displacement of the brain. Radionuclide cisternography was normal in the two patients who underwent this treatment as well as the meningeal biopsy in another patient. In all patients the opening CSF pressure was low or unmeasurable. The clinical syndrome spontaneously recovered contextually to normalization of neuroradiological findings. The possible pathogenesis (dural border cell layer tear) was discussed and the importance of diagnostic confirmation with MRI and measurement of CSF pressure when IH is thought to be present was underlined.