[The so-called spontaneous low CSF pressure pressure syndrome. Case results indicating a disturbance in CSF/blood volume regulation].

The new IHS classification describes under the paragraph 7.2.3 the headache attributed to spontaneous low CSF pressure. We report on four patients with such a headache and discuss the probable pathophysiology, including results published in the literature. It seems that not the low CSF pressure itself is the cause for the headache but the unphysiological, increased vasodilatation of intracranial and epidural veins. This dilatation of veins also shows up in the typical radiological findings with meningeal contrast enhancement and enlarged epidural veins. A trial with caffeine, theophylline, or indomethacin is recommended; otherwise, the most effective treatment option is an epidural blood patch, which is effective also in the absence of a documented CSF leak.