Abstract
Background:: Optic nerve sheath diameter (ONSD) as measured by optic nerve sheath ultrasonography (ONSU) is used as a surrogate marker of intracranial pressure (ICP), especially in resource-limited settings. There is a growing interest in the use of ONSU in emergency and high-altitude setups. Notwithstanding multiple studies done on this subject, there is a paucity of data regarding standardization of techniques and comparison of ONSU with computed tomography (CT). Materials and Methods:: Thirty-five patients with a diagnosis of high-altitude cerebral edema were enrolled in the study. ONSD was measured in all patients using ONSU, along visual and coronal axis, and CT scan. We repeated ONSU in these patients on days 3, 7, 10, and 15 (day of discharge). Correlation between visual and coronal axis as well as CT scan was analyzed. Results:: The correlation of visual to coronal and coronal to visual was equally significant (both correlation coefficients being R2 = 0.983). Correlation of ONSD by visual axis to CT scan was better than coronal axis (correlation coefficient R2 = 0.986 vs. 0.96, respectively). Conclusion:: In our study, we found a strong correlation between the visual and coronal axes. Thus, either of the two axes can be used for monitoring ICP. However, it has been found that measurements along the coronal axis are challenging, especially in the emergency setup. ONSD measured along visual axis correlated better with CT scan as compared to the coronal axis.
Copyright
Association for Helping Neurosurgical Sick People. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-Non Derivative-Non Commercial License, permitting copying and reproduction so long as the original work is given appropriate credit.
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This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License, which permits unrestricted reproduction and distribution, for non-commercial purposes only; and use and reproduction, but not distribution, of adapted material for non-commercial purposes only, provided the original work is properly cited.
