Duret hemorraghe caused by traumatic brain injury: what the radiologist should know.

Transcription

1 Duret hemorraghe caused by traumatic brain injury: what the radiologist should know. Poster No.: C-1270 Congress: ECR 2012 Type: Educational Exhibit Authors: P. Dewachter 1, T. Vanderhasselt 1, K. De Smet 1, J. de Mey 2 ; 1 2 Brussels/BE, Brussel/BE Keywords: DOI: Diagnostic procedure, CT, Neuroradiology brain, Hemorrhage /ecr2012/C-1270 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. Page 1 of 7

2 Learning objectives To review the pathogenesis of Duret hemorrhage. To illustrate the radiographic features of Duret hemorrhage. To emphasise the importance of imaging follow-up after traumatic brain injury. Background Traumatic brain injury can result in hemorrhage in midbrain and pons at the time of impact (primary) or in a later stage (secondary). Secondary brainstem hemorrhage is called Duret hemorrhage. Duret hemorrhage is caused by downward (transtentorial) cerebral herniation due to raised intracranial pressure from a rapidly expanding supratentorial mass lesion. Duret hemorrhage has a high incidence of death and persistent vegetative outcome. There are few case reports describing good outcome. Arterial damage or venous congestion caused by sudden downward movement of the brainstem against a fixed basilar artery leads to disruption of the perforating arteries. Animal models showing raised ICP induced by inflation of intracranial balloons support this theory. Stretching and disruption of paramedian pontine perforating arteries may directly lead to hemorrhaging. Venous congestion due to venous thrombosis and venous infarction can also evolve to hemorrhage. Surgical decompression may promote Duret hemorrhage as part of a reperfusion injury. The reported incidence is higher in neuropathological (30-60%) than in radiological (5-10%) studies. This discrepancy can be explained by the fact that 20% of the damage is microscopically and by the fact that bleeding often occurs after the initial computed tomography (CT). Differential diagnosis includes primary traumatic brainstem hemorraghes, hypertensive bleeds and ruptured arteriovenous malformations. Duret hemorrhage represents 5-13% of traumatic brainstem injuries. Imaging findings OR Procedure details Page 2 of 7

3 Often there is an absence of brainstem injury on the initial CT-scan. CT / MRI findings are: - initial mass lesion - secondary lesion i.e typical Duret localisation in midbrain and pons at and near the midline of the rostral pons and the ventral tegmentum of the midbrain. - increased density consistent with blood in pons or midbrain, - compression of prepontine cistern, - anteroposterior elongation of the midbrain - ischemic lesions due to herniation Images for this section: Page 3 of 7

4 Fig. 1: Midline hemorrhagic focus in the upper brainstem, consistent with a Duret hemorrhage in a noncontrast axial CT Page 4 of 7

5 Fig. 2: Noncontrast reformatted noncontrast coronal image. A left subacute subdural hematoma is present (dashed arrows) Duret hemorrhage is observed (white arrow) We appreciate a descending transtentorial herniation. Page 5 of 7

6 Fig. 3: Axial T2WI demonstrating blood in the right paramedian pons. Page 6 of 7

7 Conclusion In this educational exhibit, we've discussed the pathogenesis and imaging findings of Duret hemorrhage after traumatic brain injury. It is important for every radiologist to understand the bad prognosis associated with this often small pontine bleeding. Personal Information Patrick Dewachter, MD UZ Brussel - Department of Radiology Laarbeeklaan Jette, Brussels, Belgium pdewachter (at) gmail (dot) com References Parizel PM, Makkat S, Jorens PG, et al. Brainstem hemorrhage in descending transtentorial herniation (Duret hemorrhage). Intensive Care Med 2002;28:85-8. Marupaka SK, Sood B: Atypical Duret haemorrhages seen on computed tomography. Emerg Med Australas 20: , 2008 Kamijo Y, Soma K, Kishita R, Hamanaka S: Duret hemorrhage is not always suggestive of poor prognosis: a case of acute severe hyponatremia. Am J Emerg Med 23: , 2005 Stiver SI, Gean AD, Manley GT: Survival with good outcome after cerebral herniation and Duret hemorrhage caused by traumatic brain injury. Case report. J Neurosurg 110: , 2009 Page 7 of 7