Diagnostic and Prognostic Value of Sonographic Optic Nerve Sheath Diameter in Patients with Ischemic Stroke or Hypertensive Intracerebral Hemorrhage.

BACKGROUND

Elevated intracranial pressure (ICP) is a critical complication in nontraumatic brain injury, yet invasive monitoring carries significant risks, and noninvasive alternatives remain undervalidated. Optic nerve sheath diameter (ONSD) ultrasonography represents a promising bedside technique, but data in nontraumatic populations are limited. This study evaluated the diagnostic and prognostic value of ONSD in neurocritical patients with ischemic stroke or hypertensive intracerebral hemorrhage.

METHODS

This prospective observational cohort study enrolled 100 neurocritical intensive care unit (ICU) patients with acute nontraumatic brain injury [ischemic stroke or hypertensive intracerebral hemorrhage; Glasgow Coma Scale (GCS) < 9] who underwent admission computed tomography (CT) and bedside ONSD ultrasonography. Sixty age- and sex-matched healthy volunteers were enrolled exclusively to provide descriptive reference values for physiological ONSD and were not included in the primary diagnostic or prognostic analyses. CT-based radiologic ICP surrogates were the reference standard. Exploratory analyses evaluated inter-eye variability, adjusted models, and in-hospital survival.

RESULTS

ONSD increased stepwise across healthy controls, patients with negative CT, and patients with positive CT (4.62 ± 0.33, 5.52 ± 0.51, and 6.50 ± 0.51 mm, respectively). Among neurocritical patients, a cohort-derived cutoff of ≥ 6.00 mm yielded 86.7% sensitivity, 85.0% specificity, 89.7% positive predictive value, 81.0% negative predictive value, 86.0% accuracy, and 0.901 area under the curve (AUC). Above-threshold ONSD remained independently associated with CT-positive elevated ICP after adjustment for age, body mass index (BMI), GCS, and systolic blood pressure (SBP) in exploratory multivariable analysis. Exploratory survival analysis showed significantly higher in-hospital mortality in patients with ONSD above the cohort-derived threshold (log-rank p = 4.77 × 10-13).

CONCLUSIONS

Bedside ultrasonographic ONSD measurement appears clinically useful for early triage and longitudinal bedside surveillance in neurocritical patients with ischemic stroke or hypertensive intracerebral hemorrhage, particularly when invasive monitoring is unavailable or delayed.