ICP monitoring in the rat: Comparison of monitoring in the ventricle, brain parenchyma, and cisterna magna

Various methods of continuous intracranial pressure (ICP) monitoring during experimental procedures in the rat have been described. However, no system atic comparison of ICP monitoring in the ventricle, brain parenchyma, and c isterna magna has been reported. Since accurate and reliable ICP measuremen ts are important in experimental models of traumatic brain injury, the pres ent study was conducted to compare simultaneous ICP measurements from ventr icular, cisterna magna, and intraparenchymal monitors during ICP changes, S ubdural hematoma was produced by infusion of 0.3 ml of autologous blood int o the subdural space over 6 min, The ventricular and the intraparenchymal f iberoptic catheter produced reliable and comparable pressure recordings, th at did not statistically differ (p = 0.4), throughout the one hour monitori ng time, In contrast, the cisterna magna catheter was less reliable and pro duced significantly lower readings throughout the monitoring time (p < 0.00 1). The intraparenchymal device produced greater cortical damage than the v entricular catheter, In conclusion, ventricular LCP monitoring is the prefe rred method under these circumstances, since it is accurate and induces lea st brain damage.