Experimental evaluation of the Spiegelberg intracranial pressure and intracranial compliance monitor - Technical note

The goal of this study was to compare the Spiegelberg intraventricular intr acranial pressure (ICP)/intracranial compliance monitoring device, which fe atures an air-pouch balloon catheter, with existing gold-standard methods o f measuring ICP and intracranial compliance. A Spiegelberg intraventricular catheter, a standard intraventricular cathet er, and a Codman intrapnrenchymal ICP microsensor were placed in five sheep , which previously had been given anesthetic and paralytic agents, to allow comparative measurement of ICP at incremental levels (range 5-50 rmn Hg). Intracranial pressure measured using the Spiegelberg intraventricular air-p ouch balloon catheter displayed a linear correlation with ICP measured usin g the standard intraventricular fluid-filled catheter (r(2) = 0.9846, p < 0 .001; average bias -0.74 mm Ng), as well as with ICP measured using the Cod man intraparenchymal strain-gauge sensor (r(2) = 0.9778, p < 0.001; average bias 0.01 mm Hg). Automated measurements of intraventricular compliance ob tained using the Spiegelberg compliance device were compared with complianc e measurements that were made using the gold-standard manual cerebrospinal fluid bolus injection technique at ICPs ranging from 5 to 50 mm Hg, and a l inear correlation was demonstrated between the two methods (r(2) = 0.7752, p < 0.001;average bias -0.019 ml/mm Hg). The Spiegelberg air-pouch ICP/compliance monitor provides ICP and complianc e data that are very similar to those obtained using both gold-standard met hods and an intraparenchymal ICP monitor over a range of pathophysiological ICPs. The automated closed Spiegelberg system offers practical advantages for the measurement of intraventricular compliance. Assessment of the clini cal utility and robustness of the Spiegelberg system, together with the dev elopment of an intraparenchymal device, would enhance the clinical utility of automated compliance measurement and expand the range of its application s.