What is the emergency department disposition for a patient with axonal shearing injury, also known as diffuse axonal injury (DAI)?

From the Guidelines

Patients with axonal shearing injury should be admitted to the intensive care unit for close neurological monitoring and management, with consideration of MRI as a second-line study to evaluate persistent neurologic deficits unexplained by head CT, as it is more sensitive for small white matter lesions in traumatic axonal injury or DAI 1. When managing axonal shearing injuries, it is crucial to prioritize interventions that reduce morbidity, mortality, and improve quality of life. Key considerations include:

• Immediate neurosurgical consultation
• Intracranial pressure monitoring
• Hyperosmolar therapy with mannitol (0.25-1 g/kg IV) or hypertonic saline (3% solution at 0.5-1 mL/kg/hr) to control elevated intracranial pressure
• Maintaining cerebral perfusion pressure above 60 mmHg
• Ensuring adequate oxygenation (PaO2 > 100 mmHg) and preventing hypotension (systolic BP > 90 mmHg)
• Seizure prophylaxis with levetiracetam (1000 mg IV loading dose, then 500 mg IV twice daily) is often indicated
• Temperature control targeting normothermia (36-37°C) is important
• Patients should be positioned with head elevation at 30 degrees to optimize venous drainage
• Serial neurological assessments using the Glasgow Coma Scale should be performed hourly The use of MRI with diffusion-weighted imaging can detect acute ischemic stroke with higher sensitivity than head CT 1, and may be beneficial in evaluating patients with unexplained poor GCS scores. However, the necessity of MRI in the acute phase is still a topic of controversy, with some studies suggesting that additional findings may not affect management in the acute phase 1.

From the Research

Emergency Department Disposition for Axonal Shearing Injury

• Axonal shearing injury, also known as diffuse axonal injury (DAI), is a type of traumatic brain injury (TBI) that can result in significant morbidity and mortality 2.
• The severity of DAI can be assessed using magnetic resonance imaging (MRI) grading, which can help predict the time to recovery of consciousness 2.
• Studies have shown that patients with mild DAI (grade I) tend to recover consciousness within approximately 1 week, while those with moderate DAI (grade II) recover within approximately 2 weeks, and those with severe DAI (grade III) may take up to 2 months to recover 2.

Levetiracetam Prophylaxis in TBI

• Levetiracetam is commonly used as a prophylactic antiseizure medication in patients with TBI, particularly those with severe TBI or abnormal neuroimaging findings 3, 4, 5, 6.
• However, the efficacy and optimal dosing of levetiracetam in TBI patients remain unclear, and its use is not universally recommended 3, 5.
• Some studies suggest that levetiracetam may be preferred over other antiseizure medications in certain patient populations, such as those with supratentorial neurosurgical diseases 3.

Disposition and Management

• The disposition and management of patients with axonal shearing injury or DAI depend on the severity of the injury and the presence of other comorbidities 2.
• Patients with severe TBI or DAI may require intensive care unit (ICU) admission and close monitoring for potential complications, such as seizures or increased intracranial pressure 3, 4, 5, 6.
• The use of levetiracetam or other antiseizure medications should be individualized based on the patient's specific needs and risk factors, and guided by evidence-based protocols and clinical judgment 3, 5.