Study Of Clinical Value Of Noninvasive Intracranial Pressure Monitoring With TCD In Patients With Traumatic Brain Injury

Objective: The increase of intracranial pressure (ICP) is the mostcommon syndrome found in neurosurgery and neurology. The monitoringICP by Transcranial Doppler ultrasonography (TCD) is one of studies onnoninvasive ICP monitoring technology in recent years. Manyexperimental and clinical researches give the evidences of correlationbetween TCD monitoring results and ICR However, there are still manyproblems needed to be resolved. This study was designed to analyze theresults from ICP and TCD monitoring in patients with traumatic braininjury (TBI) in order to further evaluate the clinical significance ofnoninvasive ICP monitoring with TCD.Method: The microsensors of intracranial pressure monitor wereinserted into cerebral parenchyma adjacent to operative sites andconnected to intracranial pressure monitor apparatus for continuousbed-beside ICP monitoring in 32 patients with TBI. The monitoring andmeasurements with TCD were performed beside beds on the followingday of surgery to record the spectral atlas systolic peak velocity (Vs),end of diastolic velocity (Vd),mean velocity (Vm),pulsatility index (PI)and resistance index (RI) of the middle cerebral artery (MCA) of sufferingside. The values of ICP were recorded at the same time. The patients weredivided into Normal ICP Group (ICP＜15mmHg, n=9), Mild ICP IncreaseGroup (15mmHg≤ICP＜20mmHg, n=6), Moderate ICP Increase Group(20mmHg≤ICP＜40mmHg, n=10) and Severe ICP Increase Group(ICP＞40mmHg, n=7). The comparative analyses of results of TCD andICP monitoring were carried out.Results: 1. Spectral atlas: The spectral atlas of Mild ICP IncreaseGroup showed no visible differences from those of Normal ICP Group. Aphenomenon of deepened notch before reaching D peak was found insome cases of Moderate ICP Increase Group while occurrence of singlecusp peak and disappearance of S₂ peak with decreased diastolic velocitywere observed in Severe ICP Increase Group.2. Parameter of TCD: With the increase of ICP, Vs, Vd and Vm weredecreased accordingly with the most significant dropping in Vd while PIand RJ were elevated gradually. Statistical analyses showed that there wereno significant differences in Vs between each increased ICP group andNormal ICP Group (p＞0.05). All the parameters from Mild ICP IncreaseGroup had no statistical differences from those of Normal ICP Group(p＞0.05). Vd, Vm, PI and RI from either Moderate ICP Increase Groupor Severe ICP Increase Group demonstrated statistical changes compared to relative parameters of Normal ICP Group (p＜0.05 or＜0.01)Conclusion: This study suggests that TCD can be applied to monitornoninvasively ICP and indicate the significant increase of ICP in patientswith TBI, but fail to detect mild increase of ICP. Spectral atlas is superiorto parameters of TCD in judgment of increased ICP.