Brainstem Herniation in Diffuse Axonal Injury

Clinical Presentation and Diagnosis

The presence of dorsolateral brainstem lesions is associated with poor outcomes, according to the American College of Radiology 1
DAI rarely occurs in isolation, and traumatic subarachnoid hemorrhage, skull fractures, intraparenchymal hemorrhage, and acute subdural hematoma frequently co-occur with DAI, as reported by The Lancet Neurology 3
Brain herniation is documented as a distinct common data element separate from DAI in both the CENTER-TBI and TRACK-TBI studies, as noted by The Lancet Neurology 3
When evaluating a patient with DAI, brainstem herniation should be suspected if there is evidence of cisternal compression on imaging, as indicated by The Lancet Neurology 3
The patient demonstrates signs of increased intracranial pressure requiring ICP monitoring, with a threshold of >20 mmHg, according to clinical guidelines 4

CT has significant limitations in detecting DAI, and non-contrast CT may miss microhemorrhages associated with axonal injury, as reported by Praxis Medical Insights 2
MRI with T2*-weighted GRE and susceptibility-weighted imaging is 3-6 times more sensitive for detecting hemorrhagic axonal injuries, according to Praxis Medical Insights 2
MRI is indicated when CT is normal but unexplained neurologic findings persist, as recommended by Praxis Medical Insights 2, 4