[Benign intracranial hypo- and hypertension].

Chronic headaches due to intracranial hypo- or hypertension (IHS codes 7.2 and 7.1) may be difficult to diagnose. In this article, we review their principal clinical characteristics, etiologies and therapies. Intracranial hypotension may be caused by CSF linkage, e.g. after lumbar puncture. It may also be "idiopathic" in which case a CSF leak, usually at the spinal level, may be difficult to demonstrate. Postural headache is the clinical hallmark of intracranial hypotension. The diagnosis is confirmed by leptomeningeal enhancement on MRI scans. The headache of benign intracranial hypertension may be aggravated by the supine position and accompanied by transient visual obscurations and tinnitus. Papillary edema supports the diagnosis but may be absent in some cases. Increased opening pressure of the CSF will confirm the diagnosis. Etiologies such as cerebral venous thrombosis, have to be excluded by adequate imaging methods. In both hypo- and hypertension syndromes, various therapeutic strategies have been proposed.