Net optic nerve sheath diameter as a factor for predicting intracranial hypertension

Area of Science:

• Neurology
• Radiology
• Ophthalmology

Background:

• Intracranial pressure (ICP) assessment is vital for neurological emergencies.
• Invasive ICP monitoring is controversial, necessitating alternative methods.
• Cranial MRI offers a non-invasive approach to evaluate ICP-related parameters.

Purpose of the Study:

• To assess correlations between optic nerve parameters from cranial MRI and ICP.
• To evaluate the diagnostic value of these parameters in predicting intracranial hypertension.
• To explore the potential of non-invasive MRI-based measurements for ICP assessment.

Main Methods:

• Retrospective analysis of 112 patients with suspected intracranial infections.
• Measurement of optic nerve diameter (OND), optic nerve sheath diameter (ONSD), and eyeball transverse diameter (EBTD) via cranial MRI.
• Calculation of net optic nerve sheath diameter (nONSD) and ONSD:EBTD ratio; ICP measured via lumbar puncture.

Main Results:

• Patients with intracranial hypertension showed significantly higher ONSD, nONSD, and ONSD/EBTD compared to those with normal ICP.
• Significant linear correlations were observed between nONSD and ICP (r=0.61), ONSD and ICP (r=0.36), and ONSD/EBTD and ICP (r=0.36).
• nONSD demonstrated promising predictive accuracy for elevated ICP, with 88.7% specificity and 80% positive predictive value at a threshold of 2.52 mm.

Conclusions:

• Net optic nerve sheath diameter (nONSD) shows strong potential as a non-invasive predictor of elevated ICP.
• Further prospective studies are required to validate nONSD's generalizability and clinical utility.
• Cranial MRI-derived nONSD may offer a valuable tool in managing neurological emergencies related to ICP.