Hemodynamics

Biology

Venous pressure

Genus

Surgery

Pseudotumor cerebri

Cardiology

Sinus (botany)

Intracranial pressure

Botany

Thrombosis

Papilledema

Radiology

SSS*

Venography

Superior sagittal sinus

Internal medicine

Sagittal plane

Medicine

Nuclear medicine

Sigmoid sinus

Journal of NeuroInterventional Surgery

Objective To determine the relationship between normal physiologic and pathologic venous sinus pressures in patients with idiopathic intracranial hypertension (IIH), which is poorly understood. Methods Retrospective analysis was performed to identify patients with medically refractory IIH who were evaluated by angiography and retrograde venography with venous manometry. Patients were further subdivided into groups based on anatomic factors. Results 104 patients met inclusion criteria for the study. In the absence of non-invasive venographic screening, 58% of patients in this series were found to have pressure gradients of ≥8 mm Hg; 93% were located near the transverse-sigmoid sinus junction. Opening pressure (OP) is strongly predictive of superior sagittal sinus (SSS) pressures (p&lt;0.001) and also of the presence of a pressure gradient ≥8 mm Hg (p&lt;0.001). Twenty-three percent of patients with an OP &lt;25 had a pressure gradient ≥8 mm Hg compared with 77% of patients with an OP ≥35. Analysis of patients with OP ≤20 suggests that SSS pressures in patients without IIH should be less than 16–18 mm Hg with total cranial gradients &lt;5 mm Hg. Across all patients, a pressure decrement of approximately 1 mm Hg occurs with progressively more caudal transition across anatomic points of measurement. Conclusions This study describes intracranial and extracranial venous pressure measurements and gradients in different subgroups of patients with IIH. OP is highly predictive of intracranial venous pressures and significant venous pressure gradients.

A descriptive study of venous sinus pressures and gradients in patients with idiopathic intracranial hypertension