Department of Computational Medicine & Bioinformatics
Novel Noninvasive Methods of Intracranial Pressure and Cerebrovascular Autoregulation Assessment: Seeing the Brain through the Eyes during Postoperative Care in Cardiac Patients
Hakam Tiba, Krishna Rajajee
Decision Support Systems
Since 2000, more than 300,000 service members have been diagnosed with TBI, and over 34,000 have experienced moderate to severe injury. In 53% of acute combat deaths between 2001 and 2011, the brain was the primary site of injury. Despite the disproportionately high incidence of TBI injury and deaths among U.S. warfighters, there is not a reliable noninvasive ICP monitoring technique available for use in the field. Elevated ICP following TBI is a powerful predictor of subsequent neurological deterioration and overall outcome.There is an urgent need to develop noninvasive methods to estimate and prevent elevated intracranial pressure (ICP) to prevent secondary brain injury and ensure adequate cerebral perfusion pressure as a fundamental component of TBI care. However, invasive ICP monitoring is not without both controversy and complications, and is unavailable in Role 1 settings. Although there have been technological advancements, no single noninvasive ICP monitoring technique has yet proven sufficiently reliable to adopt into routine practice.
Among other image modalities used for TBI assessment, a number of recent studies reported that hand-held optic nerve ultrasound (ONUS) may help identify elevated ICP. In the largest study of ICP prediction using ONUS to date, we found that optic nerve sheath diameter can accurately predict ICP > 25 mmHg in a mixed population of patients in a neurosurgical ICU. Our preliminary work has demonstrated the feasibility of fully automated algorithms to measure optic nerve sheath diameter. In this project we will further develop these algorithms to predict ICP from measuring the optic nerve sheath diameter.