What is the treatment for diffuse axonal injury?

Treatment of Diffuse Axonal Injury

There is no specific treatment for the primary axonal damage in diffuse axonal injury; management focuses entirely on preventing secondary brain injury through aggressive physiological optimization and supportive care. 1, 2

Immediate Diagnostic Evaluation

• Non-contrast CT must be performed immediately as the mandatory first-line imaging in all patients with suspected moderate to severe traumatic brain injury 1, 2, 3
• CT has significant limitations for detecting DAI, as microhemorrhages associated with axonal injury are often invisible on conventional CT 2, 4
• MRI should be obtained when CT is normal but unexplained neurologic findings persist (class I recommendation) 5, 1, 2
• The optimal MRI sequences include T2*-weighted gradient-echo (GRE), susceptibility-weighted imaging (SWI—which is 3-6 times more sensitive than GRE), and diffusion-weighted imaging (DWI) 5, 1, 2, 3

Acute Physiological Management

Maintain systolic blood pressure >110 mmHg to ensure adequate cerebral perfusion 1, 3

• Use vasopressors such as phenylephrine and norepinephrine when needed to rapidly correct arterial hypotension 3

Control ventilation through tracheal intubation and mechanical ventilation with end-tidal CO2 monitoring 1, 3

• Prevent hypocapnia, which causes cerebral vasoconstriction and increases the risk of brain ischemia 1, 3

ICP monitoring is recommended for patients with severe traumatic brain injury, with intervention typically indicated when ICP >20 mmHg 1, 3

• External ventricular drainage should be used for persistent intracranial hypertension despite sedation and correction of secondary brain insults 3
• Decompressive craniectomy may be considered for refractory intracranial hypertension 3

Neurosurgical Considerations

Neurosurgical interventions are necessary for: 3

• Removal of significant acute subdural hematoma
• Removal of symptomatic extradural hematoma
• Drainage of acute hydrocephalus
• Closure of open displaced skull fracture

Gadolinium-based contrast agents are not necessary for conventional MRI in traumatic brain injury (class IIb recommendation) 2

Rehabilitation and Prevention of Complications

Early physical therapy and rehabilitation are essential to prevent joint contractures and muscle atrophy 1, 3

Specific interventions include: 1, 3

• Proper positioning and frequent repositioning to prevent pressure sores and contractures
• Range of motion exercises initiated as soon as the patient is stabilized
• Splinting to maintain proper joint alignment and prevent contracture formation

Monitoring and Follow-up

• Regular neurological assessments are necessary to detect clinical deterioration 1, 3
• Follow-up imaging is indicated with neurological deterioration rather than on a routine basis 1, 3
• Regular multidisciplinary case reviews are recommended for patients with severe DAI 1, 2, 3
• Early communication with regional neuroscience centers is essential for patients with perceived devastating brain injury 1

Prognostic Factors

The location and extent of DAI lesions correlate with clinical outcomes: 2, 3

• DAI Stage 3 (dorsolateral brain stem lesions) is associated with poor outcomes 2
• The presence of both a contusion and >4 foci of hemorrhagic axonal injury on MRI is an independent prognostic predictor 2, 3
• Grade III DAI (brainstem involvement) has the highest mortality 6, 7

Establish patient values and preferences early to guide end-of-life care planning if needed, with honest and realistic discussions of the most likely outcome occurring at admission 1

Critical Pitfalls to Avoid

• DAI is often underdiagnosed with conventional CT imaging—maintain high clinical suspicion even with normal CT when mechanism and clinical presentation suggest DAI 3, 4
• The number of microhemorrhages, while helpful for accurate diagnosis, does not directly correlate with injury severity or outcomes 2, 3
• Survivors require long-term hospitalization and rehabilitation, with outcomes dependent on initial GCS and DAI grade 6