Project Type(s):
Clinical Research

Following severe cases of traumatic brain injury (TBI), the brain can swell, leading to elevations in intracranial pressure (ICP). Patients who develop high ICP following severe TBI are more likely to have poor neurologic recovery from their injury, and control of ICP likely contributes to improved outcomes. ICP detection and management is typically guided by invasive monitors placed through the skull and into the injured brain. These devices are highly accurate and reliable, but they are also expensive and expose the patient to rare but potentially serious risks. This is problematic because as few as one-third of patients are found to have elevated ICP, even when the best available evidence is used to guide their placement.

Using ultrasound to measure optic nerve sheath diameter (ONSD) could be an inexpensive, noninvasive and reliable means of monitoring ICP. Located behind the eye, the optic nerve sheath surrounds the nerve carrying visual signals to the brain. Increases in intracranial pressure are transmitted into this conduit, causing it to dilate. Ultrasound-measured ONSD has been shown to correlate with ICP in many neurologic conditions, including TBI, but it has not been systematically evaluated as a screening or a monitoring tool.

This study will routinely measure ONSD in patients undergoing invasive ICP monitoring for severe traumatic brain injury at Harborview Medical Center. The goal is to determine whether ONSD measurement with ultrasound can be combined with readily available clinical data to improve the prediction of elevated ICP, and to assess whether it can be used to monitor ICP during a patient’s hospital stay. If successful, ONSD measurement could have a significant impact on TBI care in both high and low resource settings.

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