Ultrasound of the Optic Nerve Does Not Appear to Be a Consistently Reliable or Generalizable Method to Monitor Changes in Intracranial Pressure.

Objective: Invasive intracranial pressure (ICP) monitoring is the gold standard, but is not always readily accessible or practical. Ultrasound of the optic nerve sheath diameter (ONSD) has been proposed for detecting both elevation and change in the ICP. Our study is a prospective observational trial that seeks to determine if ultrasound can be reliably used to identify changes in ICP with naturally occurring variations in patient care.