Ultrasound-Measured Optic Nerve Sheath Diameter Predicts Cognitive Dysfunction After Resuscitation: A Retrospective...

Optic nerve sheath diameter (ONSD) measured by bedside ultrasonography has emerged as a promising non-invasive surrogate marker of intracranial pressure and may have prognostic value in post-resuscitation patients. This retrospective observational study evaluated the utility of ONSD in predicting cognitive dysfunction among neurological intensive care unit (ICU) patients following cardiac arrest. A total of 60 adult patients who achieved return of spontaneous circulation (ROSC) were initially identified, of whom 48 patients with complete follow-up data were included in the final analysis. Serial ONSD measurements were obtained at baseline (within 6 h post-ROSC), 24 h, and 72 h using standardized transorbital ultrasound techniques. Neurological status was assessed using the Glasgow Coma Scale (GCS), and cognitive outcomes were evaluated using the mini-mental state examination (MMSE) and the Montreal cognitive assessment (MoCA) after recovery of consciousness. Patients with favorable neurological outcomes demonstrated significantly lower baseline ONSD values and a progressive decline over time, which correlated with improvement in GCS scores. In contrast, persistently elevated ONSD values were associated with poor cognitive outcomes, minimal neurological recovery, and higher early mortality. Receiver operating characteristic analysis identified an ONSD cutoff value of 5.8 mm for predicting poor outcomes, with a sensitivity of 42.9% and specificity of 85.9%. These findings suggest that serial ONSD measurements are a rapid, reproducible, and non-invasive bedside tool that may aid early neurological prognostication following cardiac arrest. Integration of ONSD with clinical parameters may enhance risk stratification in critical care settings.