E-ISSN: 1019-5157
ISSN: 2651-5024
Research
Determination of Optic Nerve Sheath Diameter Cut-off after CSF Drainage in Adults with Elevated ICP: A Prospective Study
Gulsah Ozkaya✉ ,
Ozlem Korkmaz Dilmen ,
Eren Fatma Akcil ,
Yusuf Tunali
DOI: 10.5137/1019-5149.JTN.49051-25.4
Article in Press
Corresponding Author:
Gulsah Ozkaya (gulsahorak1@gmail.com)
Abstract
Aim
Background: Previous studies have established optic nerve sheath diameter (ONSD) cut-off values of 5.66.3 mm for detecting elevated intracranial pressure (ICP) (2022 mmHg) during acute phases. However, studies on ONSD-ICP correlation post-cerebrospinal fluid (CSF) drainage are limited. This study evaluates the relationship between ONSD and ICP in patients with controlled acute ICP elevation via external ventricular drainage (EVD).
Material and Methods
In a prospective observational study, simultaneous measurements of right and left ONSD, ICP, and cerebral perfusion pressure (CPP) were recorded in 44 adult patients with EVD. After baseline measurements, 5 mL of CSF was drained, and measurements were repeated 2 minutes later.
Results
Results: CSF drainage led to significant reductions in both ICP and bilateral ONSD (p=0.001 for all), while CPP increased significantly (p=0.038). We identified an ONSD cut-off of 5.35 mm for detecting ICP ≥15 mmHg, which had 53% sensitivity and 86% specificity (Youden index 0.395). However, we could not determine a reliable cut-off for ICP ≥20 mmHg (p=0.076).
Conclusion
Conclusion: When ICP is controlled through an EVD, the linear ONSD-ICP relationship observed during acute pressure elevations may be disrupted, particularly at higher pressures (≥20 mmHg). Although we found a cut-off of 5.35 mm for ICP ≥15 mmHg, the low sensitivity significantly limits its clinical utility. The fact that no reliable cut-off could be established for ICP ≥20 mmHg suggests ONSD has limited value for monitoring pressure after CSF drainage.
Background: Previous studies have established optic nerve sheath diameter (ONSD) cut-off values of 5.66.3 mm for detecting elevated intracranial pressure (ICP) (2022 mmHg) during acute phases. However, studies on ONSD-ICP correlation post-cerebrospinal fluid (CSF) drainage are limited. This study evaluates the relationship between ONSD and ICP in patients with controlled acute ICP elevation via external ventricular drainage (EVD).
Material and Methods
In a prospective observational study, simultaneous measurements of right and left ONSD, ICP, and cerebral perfusion pressure (CPP) were recorded in 44 adult patients with EVD. After baseline measurements, 5 mL of CSF was drained, and measurements were repeated 2 minutes later.
Results
Results: CSF drainage led to significant reductions in both ICP and bilateral ONSD (p=0.001 for all), while CPP increased significantly (p=0.038). We identified an ONSD cut-off of 5.35 mm for detecting ICP ≥15 mmHg, which had 53% sensitivity and 86% specificity (Youden index 0.395). However, we could not determine a reliable cut-off for ICP ≥20 mmHg (p=0.076).
Conclusion
Conclusion: When ICP is controlled through an EVD, the linear ONSD-ICP relationship observed during acute pressure elevations may be disrupted, particularly at higher pressures (≥20 mmHg). Although we found a cut-off of 5.35 mm for ICP ≥15 mmHg, the low sensitivity significantly limits its clinical utility. The fact that no reliable cut-off could be established for ICP ≥20 mmHg suggests ONSD has limited value for monitoring pressure after CSF drainage.
Keywords
: cerebral perfusion pressure; intracranial pathology; intracranial pressure
elevated
normal; optic nerve sheath