Diagnostic Accuracy of Bedside Optic Nerve Sheath Diameter Ultrasonography for Detecting Raised Intracranial Pressure Compared With Brain CT Findings in Children With Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of morbidity and mortality among children globally, with an estimated incidence ranging from 47 to 280 cases per 100,000 children (1). The burden of pediatric traumatic brain injury (pTBI) in low- and middle-income countries (LMICs) is characterized, because most pTBI occurs in LMICs (2). TBIs can have both short- and long-term effects including impairment of physical, cognitive, or emotional functions (3). Advances in acute trauma care have decreased mortality rates (4). Elevated intracranial pressure (ICP) following TBI or stroke has been recognized as an important second insult that is strongly correlated with increased mortality. Therefore, an increase in ICP can cause a decrease in brain perfusion and may result in brain ischemia (5). Early detection of raised intracranial pressure (RICP) is considered a better strategy to prevent secondary brain insult (6). The gold standard for ICP measurement is invasive techniques (i.e., ventriculostomy and intraparenchymal microtransducers), associated with risks, such as infection and haemorrhage (7). Several methods for noninvasive measuring of elevated ICP have been proposed: radiologic methods including computed tomography and ophthalmological techniques (8). Some brain computed tomography (CT) findings, such as brain parenchymal swelling, midline shifting, and compressed basal cisterns, are traditionally used for the indirect measurement of raised ICP (9). Among non-invasive methods, the measurement of optic nerve sheath diameter (ONSD) has gained particular interest (7). The optic nerve sheath is continuous with the meninges of the central nervous system and is encased with the subarachnoid membrane. Cerebrospinal fluid (CSF), located in the subarachnoid space, accumulates in the optic nerve sheath, thereby widening its diameter in the setting of increased ICP and limited intracranial compliance (10). Ultrasound assessments of ONSD could be a better option because of the low cost and rapid bedside operation without the need for radiation exposure, especially for cases that are unstable and require real-time monitoring of ICP in an intensive care unit (11). Despite existing research, there remains a gap in evaluating the diagnostic accuracy of the ONSD measured via ultrasound for the prediction of increased ICP in pediatric patients (12). This study aims to assess the diagnostic accuracy of bedside optic nerve sheath diameter ultrasonography for detecting raised intracranial pressure in pediatric traumatic brain injury using brain CT findings as the reference standard.