Neuroimaging for neurovascular complications of traumatic brain injury

Traumatic brain injury typically causes extra-axial and/or intra-axial bleeding including subarachnoid hemorrhage, intraparenchymal hemorrhage, subdural hematomas and epidural hematomas. Less commonly, trauma can cause cerebrovascular complications, which involve either the arterial or the venous side. Because of the rarity of these pathological conditions, guidelines and recommendations for their management are still controversial.

The objective of this work is to describe the possible cerebrovascular complications of critically ill traumatic brain injured patients and to understand the most common underlying mechanisms and radiological features as well as their management. A variety of pathological entities will be addressed, such as post-traumatic aneurysms, carotid-cavernous fistula, arterial occlusion, arterial dissection (in potential association with brain ischemia), as well as arterial rupture/avulsion and post-traumatic venous thrombosis. Neurovascular complications of head trauma vary depending on the traumatic mechanism, on the site of impact and on the osseous structures involved. Early diagnosis is mostly based on Computed Tomography/Computed Tomography Angiography (CT/CTA) whose findings help guide patient management by detecting vascular lesions potentially leading to neurological deterioration. Magnetic resonance imaging may be useful in selected cases. Today Digital Subtraction Angiography (DSA) is mostly a diagnostic problem-solving tool when CTA findings are equivocal but advanced endovascular interventional techniques have improved the therapeutic possibilities in post-traumatic vascular complications.  CONCLUSIONS: Neurovascular complications are not common after head trauma but should not be overlooked because they might lead to severe and life-threatening consequences. Early diagnosis, and a multidisciplinary collaboration including neuroradiologists, neurosurgeons and neurointensivists is fundamental in order to prevent and minimize secondary brain damage in this population.