Low cerebrospinal fluid pressure syndromes.

Only 12 years ago the first report on pachymeningeal gadolinium enhancement in low-pressure headaches appeared in the literature. In this short interval the enormous impact of MRI on so-called "spontaneous intracranial hypotension" and "low-pressure head-aches" has become obvious. A much broader clinical and imaging spectrum of the disease is now recognized and a substantially larger number of patients is diagnosed. In the past decade there has been remarkable progress in understanding this disorder and its associated cerebrospinal fluid (CSF) dynamics. Some of the older concepts or presumptions have been challenged while novel observations continue to appear in the literature. We are still in the learning phase.