|dc.description.abstracteng||Background: In some patients with hydrocephalus or idiopathic intracranial hypertension, symptoms continue after shunt operation. In these cases, elevated or lowered intracranial pressure (ICP) can be handled with adjustments of the shunt valves. The use of telemetric ICP measurements may help confirm clinical suspicion of cerebrospinal fluid underdrainage or overdrainage. We standardized measurements with a simple, repeatable maneuver for outpatient telemetric ICP recording and evaluated its test-retest reliability.
Methods: Data of patients who underwent ventriculoperitoneal or ventriculoatrial shunt placement and subsequent telemetric ICP sensor implantation were retrospectively reviewed. Telemetric ICP recordings in patients were conducted in the following manner: The standing-supine-sitting paradigm requires postural changes in 10-minute intervals over 30 minutes. First, the patient is requested to walk; second, to lay down; third, to sit down with a headrest elevation of 60°. ICP data (in mmHg) were reported as mean ± SD values. Test-retest validity was assessed using Pearson correlation analysis and Bland Altmann Plots.
Results: We evaluated 85 ICP datasets obtained repeatedly with a time difference of at least 24 hours. Overall test-retest reliability was excellent (Pearson correlation coefficient 0.99, P < 0.001), as were the scores for individual postures: standing (correlation 0.98, P < 0.001), supine (correlation 0.98, P < 0.001), and sitting (correlation 0.99, P < 0.001). A Blande Altman Plot showed no significant differences between the measurements. Further, we analyzed a possible influence of telemetric measurements on the decision-making for shunt valve adjustments, finding no significant data, probably mainly due to the retrospective design.
Conclusions: We confirmed high test-retest reliability of the standing-supine-sitting paradigm for telemetric ICP measurements in the outpatient setting. Prospective studies are needed to proof a positive influence on the decision-making.||de