Primary intracranial hypotension: pathogenetic and neuroradiological considerations.

Primary or spontaneous intracranial hypotension (SIH) is a rare syndrome which causes postural headache associated with spinal fluid hypotension. We report three cases of SIH, characterised on magnetic resonance imaging (MRI) by pachymeningeal enhancement not only at cerebral level, but also in the cervical spinal cord, which subsequently resolved completely and spontaneously. We discuss the possible pathogenetic mechanisms of the dural alterations and underline the radiological aspects.