Headache attributed to spontaneous intracranial hypotension.

UNLABELLED: Recent evidence suggests that spontaneous intracranial hypotension (SIH) is not as rare as previously thought. Orthostatic headache is the prototypical manifestation of SIH, but various headache syndromes have also been reported such as migraine-like headache, tension-type headache and non-specific headaches among the others. The International Headache Society (IHS) has recently proposed diagnostic criteria for headache attributed to SIH. Seventy patients consecutively seen at our institution between 1993 and 2005 and diagnosed with SIH were included in the study. SIH diagnosis was confirmed in all patients by brain-enhanced MRI: 23 were males (33%), 47 females (77%) and mean age was 45 years (range 18-69). FOLLOW-UP: median value 35 months (range: 8 months-14 years). Time between symptom onset and diagnosis was 4 months (median) (range 15 days-45 months). The IHS (2004) criteria for "Headache attributed to SIH" were applied. Typical brain imaging findings confirmed the diagnosis of SIH in all patients: criteria B and C were fulfilled in all patients. Criterion A of the IHS classification was not fulfilled in 34 (49%) patients. Sixty-two (89%) patients did not fulfil criterion D of the IHS classification; 28 (40%) did not fulfil both criterion A and D. So far, only 2 (3%) fulfilled all IHS criteria for headache attributed to SIH. The IHS criteria for headache attributed to SIH could not classify the headache in most of our SIH patients. A revision of the IHS criteria for headache attributed to SIH is necessary.