TCD and ONSD for Noninvasive Assessment of Increased ICP in TBI

• Transcranial Doppler (TCD) (Diagnostic test): Transcranial Doppler ultrasound will be performed by a trained operator through the temporal acoustic window to assess the middle cerebral artery bilaterally. Measurements will be obtained at a depth of 45-60 mm, including peak systolic velocity, end diastolic velocity, and pulsatility index. A pulsatility index greater than 1.3 and end diastolic velocity less than 25 cm/s will be considered abnormal according to the study protocol.
• Optic Nerve Sheath Diameter (ONSD) Ultrasound (Diagnostic test): Optic nerve sheath diameter will be measured by a trained operator using a high-frequency 5-15 MHz linear ultrasound probe. Measurements will be obtained from both eyes, with three measurements performed for each eye and the average recorded. The diameter will be measured 3 mm behind the globe with the patient supine and in a neutral head position, with the head of the bed elevated between 20° and 30°.

Primary outcomes

• Diagnostic accuracy of TCD pulsatility index (PI) and optic nerve sheath diameter (ONSD) for detecting CT signs of increased intracranial pressure Description: [At baseline / initial assessment]: Diagnostic performance of TCD-PI and ONSD measurements will be assessed by comparing them with signs of increased intracranial pressure on the initial CT brain scan. Sensitivity, specificity, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC) will be calculated. The optimal cut-off values will be determined using the Youden index.

Secondary outcomes

• Correlation of TCD pulsatility index with severity of CT brain findings [At baseline / initial assessment]: The relationship between TCD parameters, particularly pulsatility index, and the severity of CT brain findings will be assessed using the Marshall CT classification.
• Correlation of optic nerve sheath diameter with severity of CT brain findings [At baseline / initial assessment]: The relationship between ONSD measurements and the severity of CT brain findings will be assessed using the Marshall CT classification.

Sex: All, ages: 18 Years to 60 Years

Inclusion Criteria:

* Inclusion Criteria:

Age 18-60 years. Male and female patients. Patients admitted to the intensive care unit with blunt traumatic brain injury associated with diffuse brain edema on the initial CT brain scan.

Patient or legally authorized representative provides informed consent.

Exclusion Criteria:

Age less than 18 or greater than 60 years. History of vascular disease affecting brain vessels. Pregnant females. Inability to obtain adequate TCD signal from trans-temporal acoustic bone windows due to fusion of skull sutures or temporal bone injury.

Significant cardiovascular disease that may affect the TCD signal, such as significant arrhythmia.

History of cardiac arrest before admission. Blood flow velocity greater than 120 cm/sec in patients with subarachnoid hemorrhage, to exclude vasospasm as a cause of decreased blood flow.

Ocular trauma or orbital surgery that would interfere with ONSD measurement. Chronic hydrocephalus. History of Graves' disease with exophthalmos. History of disease affecting the optic nerve, such as glaucoma. Refusal of consent by the patient or legally authorized representative.

• Results publication: Sitanaya SN, Kamayanti F, Nugroho HA, Prabowo B. Comparing ultrasonographic optic nerve sheath diameter to head computed tomography scan to predict intracranial pressure elevation. SAGE Open Med. 2022 Feb 17;10:20503121221077834. doi: 10.1177/20503121221077834. eCollection 2022. PMID 35198210
• Results publication: Lioi F, Ramm-Pettersen J, Fratini A, Riva C, Colella N, Missori P. Ultrasonographic Assessment of Optic Nerve Sheath Diameter as a Screening Tool for Intracranial Hypertension in Traumatic Brain Injury. World Neurosurg. 2024 Dec;192:e42-e48. doi: 10.1016/j.wneu.2024.08.111. Epub 2024 Aug 27. PMID 39209251
• Results publication: Bellner J, Romner B, Reinstrup P, Kristiansson KA, Ryding E, Brandt L. Transcranial Doppler sonography pulsatility index (PI) reflects intracranial pressure (ICP). Surg Neurol. 2004 Jul;62(1):45-51; discussion 51. doi: 10.1016/j.surneu.2003.12.007. PMID 15226070
• Results publication: Gomez A, Batson C, Froese L, Sainbhi AS, Zeiler FA. Utility of Transcranial Doppler in Moderate and Severe Traumatic Brain Injury: A Narrative Review of Cerebral Physiologic Metrics. J Neurotrauma. 2021 Aug 15;38(16):2206-2220. doi: 10.1089/neu.2020.7523. Epub 2021 Mar 1. PMID 33554739
• Results publication: Chang T, Yan X, Zhao C, Zhang Y, Wang B, Gao L. Noninvasive evaluation of intracranial pressure in patients with traumatic brain injury by transcranial Doppler ultrasound. Brain Behav. 2021 Dec;11(12):e2396. doi: 10.1002/brb3.2396. Epub 2021 Nov 1. PMID 34725957
• Results publication: Hakeem A, Anwer M, Khan AV, Kumar H, Karthikeyan V, Sridhar R, Kumar A, Kumar A, Kumar S. Optic Nerve Sheath Diameter Estimation to Detect Increased Intracranial Pressure in Traumatic Brain Injury patients at a Level I Trauma Center in Eastern India. Korean J Neurotrauma. 2025 Apr 24;21(2):93-101. doi: 10.13004/kjnt.2025.21.e15. eCollection 2025 Apr. PMID 40353282

• Khaled M Maghawry, Professor, Principal investigator, Ain Shams University, Faculty of Medicine