Sonography of the Optic Nerve Sheath Diameter for Detection of Raised Intracranial Pressure Compared to Computed Tomography

Abstract

Ocular sonography shows good diagnostic test accuracy for detecting raised ICP compared to CT: specifically, high sensitivity for ruling out raised ICP in a low-risk group and high specificity for ruling in raised ICP in a high-risk group. This noninvasive point-of-care method could lead to rapid interventions for raised ICP, assist centers without CT, and monitor patients during transport or as part of a protocol to reduce CT use.

Detecting optic nerve head swelling on ultrasound and optical coherence tomography in children and young people: an observational study

“…Contrary to a recent meta-analysis of US studies in the detection of IHT,6 and despite all US in our series being performed by a highly skilled ultrasonographer, we found that US failed to detect two of the three cases of intracranial pathology at initial presentation in children. There are several factors which contribute to this difference.…”

“…US can detect optic nerve sheath dilatation (ONSD) with a sensitivity of 95.6% (95% CI 87.7 to 98.5) and a specificity of 92.3% (95% CI 77.9 to 98.4)6 and is considered a reference standard for papilloedema. However, this test requires an experienced examiner and a high-resolution scanner and is not widely available.…”

Use of A-scan Ultrasound and Optical Coherence Tomography to Differentiate Papilledema From Pseudopapilledema

“…Two recent meta-analyses showed that in neuro-intensive units, B-scan-measured optic nerve sheath diameter can differentiate papilledema from normal controls with good sensitivity (90–96%) and specificity (85–92%). 39, 40 However, these studies reported different optic nerve sheath diameter thresholds, thus internal validation should be performed.…”

Use of Intracranial Pressure Monitoring Frequently Refutes Diagnosis of Idiopathic Intracranial Hypertension

“…Emerging technologies such as point-of-care ultrasound evaluation of the optic nerve sheath diameter may provide a less invasive means in the future, but these methods are currently unavailable to most health care providers. 7 In addition to aiding the diagnosis of IIH, intracranial monitoring can also assist with determining whether a shunt is functional. Most IIH patients are young and have anatomically small, normal ventricles, making tapping of ventriculoperitoneal shunts infeasible.…”