TCD and ONSD for Early Risk Stratification of Traumatic Brain Injury

Overview

This observational study aims to evaluate the combined use of transcranial Doppler (TCD) and optic nerve sheath diameter (ONSD) ultrasound for early risk stratification of adults with traumatic brain injury (TBI) presenting to the Emergency Department. The study will assess whether ONSD measurements and TCD-derived middle cerebral artery pulsatility index (MCA-PI), in addition to clinical and computed tomography findings, can help identify patients at increased risk of early neurological deterioration. Adult patients with acute TBI and a Glasgow Coma Scale (GCS) score of 13 or less will be enrolled. TCD and ONSD measurements will be performed at emergency department presentation, with repeat measurements at 24 hours when clinically feasible in patients who have not developed early neurological deterioration. The primary outcome is early neurological deterioration within 24 hours.

Traumatic brain injury (TBI) is a major cause of morbidity and mortality and may be complicated by secondary neurological deterioration after the initial injury. Early identification of patients at increased risk of deterioration may facilitate closer monitoring and timely escalation of neurological management. This prospective observational cohort study will be conducted in the Emergency Department of Assiut University Hospitals. Adult patients aged 18 years or older presenting with acute traumatic brain injury, a baseline Glasgow Coma Scale (GCS) score of 13 or less, and an initial computed tomography (CT) scan demonstrating a traumatic intracranial structural lesion will be considered for inclusion. Patients with an immediate neurosurgical indication, significant orbital trauma or ocular pathology interfering with reliable ONSD measurement, previous decompressive craniectomy, or an inadequate temporal acoustic window preventing reliable MCA-TCD assessment will be excluded. At baseline, demographic and clinical data, neurological examination findings, GCS, pupillary findings, and CT findings will be recorded. CT severity will be assessed using the Rotterdam CT score. Bilateral optic nerve sheath diameter (ONSD) measurements and transcranial Doppler (TCD) assessment of the middle cerebral arteries will be performed at baseline. MCA pulsatility index (PI) will be the prespecified primary TCD variable for the primary predictive analysis, while other TCD parameters will be recorded as secondary or exploratory variables. Patients will be followed for 24 hours for the primary outcome of early neurological deterioration (END), defined as a new or worsening neurological abnormality attributable to TBI, including a decrease in GCS of 2 or more points from baseline when clinically assessable, a new pupillary abnormality, or a new focal neurological deficit not present at baseline. A repeat ONSD and TCD assessment will be performed at 24 hours only in patients who have not developed END before the scheduled assessment and when clinically feasible and safe. If END occurs before 24 hours, the exact time and type of deterioration will be recorded and research ultrasound examinations will be discontinued for that patient. No event-triggered research ultrasound examination will be performed. Secondary outcomes will include radiological progression on repeat CT within 24 hours when clinically indicated as part of standard care, escalation of neurological management including emergency neurosurgical intervention, external ventricular drainage or other intracranial pressure-directed intervention, and in-hospital mortality. The study procedures will not delay or interfere with standard clinical management.