Use of Intracranial Pressure Monitoring Frequently Refutes Diagnosis of Idiopathic Intracranial Hypertension

Background The diagnosis and management of patients with idiopathic intracranial hypertension (IIH) frequently relies on lumbar puncture to ascertain intracranial pressure (ICP). However, ICP values derived this way may be spurious owing to patient body habitus and behavior. We recently incorporated direct continuous ICP monitoring into the work-up for IIH. Methods Through billing records, we identified all patients during a 3-year period who had a diagnosis of IIH and who underwent ICP monitoring before shunt placement or revision. Patient demographics and clinical data were reviewed. Results Of 30 patients who underwent ICP monitoring with an intraparenchymal wire, 17 had undergone lumbar puncture within the previous 6 months. Results from lumbar punctures showed an elevated opening pressure in all 17 patients, whereas only 2 patients (12%) were found to have consistently elevated ICP with direct ICP monitoring. Of 15 patients being evaluated for shunting, 4 (27%) were found to have elevated ICP. Of the 15 patients with existing shunts, 2 patients (13%) were found to have malfunctioning shunts after pressure monitoring, and 3 patients (20%) had shunts that were found to be unnecessary and were removed. No patient experienced any complication from invasive monitoring. Conclusions Direct ICP monitoring is the gold standard for determining ICP and can be safely and effectively applied to the work-up and treatment of patients with IIH to reduce the occurrence of misdiagnosis and unnecessary surgery.