CORRELATION OF INTRACRANIAL-PRESSURE AND TRANSCRANIAL DOPPLER RESISTIVE INDEX AFTER HEAD TRAUMA

PURPOSE: To investigate the usefulness of transcranial Doppler ultraso nography in the evaluation of intracranial pressure changes after head injury. METHODS: Transcranial Doppler examinations and intracranial p ressure measurements using intraparenchymal monitors were performed in 12 cases of closed head injury. Twenty-four sets of data, including t he Glasgow Coma Scale, intracranial pressure, transcranial Doppler, an d carbon dioxide pressure were compared. The side-to-side difference i n the resistivity index was also assessed. RESULTS: There was a signif icant correlation between increased pressure values and resistivity in dex when comparing measurements from the same side. There was no corre lation between carbon dioxide pressure and any transcranial Doppler pa rameter or intracranial pressure measurement. No significant correlati on was found between the resistivity index and the Glasgow Coma Scale. End diastolic velocity was a stronger determinant of resistivity inde x than peak systolic velocity. CONCLUSION: The relationship of ipsilat eral measurements of intracranial pressure to resistivity index is val id. The resistivity index must be analyzed within the context of the p articular disease studied, especially with respect to the hemodynamic alterations. Initial findings suggest that intracranial pressure monit oring cannot be replaced by serial transcranial Doppler measurements i n the treatment of the patient with acute head injury.