Manometry combined with cervical puncture in idiopathic intracranial hypertension

To determine by cerebral venography and manometry in patients with idiopathic intracranial hypertension the cause of the previously demonstrated venous hypertension in the superior sagittal and proximal transverse sinuses.Cerebral venous sinus pressure was measured before and immediately after C1-2 puncture with removal of 20 to 25 mL of CSF.Lowering the intracranial pressure by lateral C1-2 puncture during manometry has shown that the venous hypertension resolves immediately.These studies indicate that the venous hypertension is due to compression of the transverse sinuses by raised intracranial pressure and not due to a primary obstructive process in the cerebral venous sinuses.