Vascular etiology of intracranial hypertension.

We would like to thank the author of the Letter to the Editor for taking the time to comment on our study. Indeed Degnan et al. recommended the MR venography for detecting cerebral venous sinus thrombosis, but in cases of pseudotumor cerebri. They wrote: “some cases of IIH (idiopathic intracranial hypertension) have identifiable etiology, such as dural venous stenosis, which has been implicated in 14%e90% of patients with IIH” [1]. Farb at al. had the objective “to determine the prevalence and nature of sinovenous obstruction in idiopathic intracranial hypertension (IIH) using MR venography” and they concluded “using MR venography, the authors can identify IIH patients with sensitivity and specificity of 93%” [2]. Idiopathic intracranial hypertension has no known etiology or has various nonspecific associated factors, therefore situations with a known etiology cannot be included in an idiopathic disease. Vascular intracranial hypertension has the following etiology: any cerebral vascular illness that causes intracranial hypertension. There are clear differences between these illnesses. Vascular ICH involves vasogenic brain edema, the critical intracranial pressure (ICP) values are lower in vascular ICH until the decompensation of ICH, the increase in ICP is faster in vascular ICH and the treatment is symptomatic, as well as etiologic and pathogenic in vascular ICH. The brain edema appears to be balanced by the intraventricular pressure in idiopathic ICH, the ICP values are higher in idiopathic ICH, there is a very slow ICP increase and a longer period until the complete clinical syndrome has developed and the treatment is only symptomatic. About the interpretation of the results, the period from the first clinical signs until the complete clinical syndrome was only 2e3 weeks for three patients with transverse sinus stenosis included in vascular intracranial hypertension. The pressure of the CSF for these three patients before treatment was: 19 cm H2O, 18e20 cm H2O, and 25 cm H2O. Also,