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A Review of Ancillary Tests in Evaluating Brain Death

Published online by Cambridge University Press:  02 December 2014

Manraj K.S. Heran ,
Navraj S. Heran  and
Sam D. Shemie
Manraj K.S. Heran*
Affiliation:
Division of Neuroradiology, Vancouver General Hospital Department of Radiology, Children’s and Women’s Health Center of British Colombia, University of British Columbia, Vancouver
Navraj S. Heran
Affiliation:
Division of Neurosurgery, Royal Columbian Hospital, New Westminster, British Columbia
Sam D. Shemie
Affiliation:
Division of Critical Care, Montreal Children’s Hospital, McGill University, Faculty of Arts, University of Ottawa, Ottawa, Ontario
*
Department of Radiology, Vancouver General Hospital, 899 W. 12th Avenue, Vancouver, British Columbia, V5Z 1M9,Canada.
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Abstract

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The neurological determination of death (NDD) is primarily considered to be clinical. However, situations may arise where confounding factors make this clinical assessment difficult or impossible. As a result, ancillary tests have been developed in order to aid in the confirmation of brain death. As assessment of neuronal electrical activity; electroencephalography (EEG) is no longer recommended in this determination, tools assessing cerebral perfusion, as reflected by the presence or absence of cerebral blood flow (CBF), are the mainstay of NDD. The preferred ancillary test currently is Hexamethylpropylene amine oxime-single photon emission computed tomography (HMPAO SPECT) radionuclide angiography. When this is not available, or is equivocal, 4-vessel cerebral angiography can be used to determine the presence or absence of intracranial blood flow. However, as cerebral angiography has its own limitations, other techniques are sought by physicians in the Intensive Care and Neuro-intensive Care settings to replace cerebral angiography. In this article, we briefly review the history of diagnosis of brain death, pathophysiologic issues in making this determination, and currently available CBF imaging techniques, discussing each in turn with respect to their utility in the diagnosis of brain death.

Résumé:

RÉSUMÉ:

La détermination neurologique de la mort (DNM) est considérée comme étant basée principalement sur la clinique. Cependant, il existe des situations où des facteurs confondants rendent cette évaluation clinique difficile, voir même impossible. Des tests d’appoint ont donc été mis au point afin de faciliter ce diagnostic. L’évaluation de l’activité électrique neuronale (ÉEG) n’est plus recommandée. Les outils permettant d’évaluer la perfusion cérébrale, soit la présence ou l’absence de flux sanguin cérébral (FSC), sont devenus les test de choix pour déterminer la DNM. L’épreuve d’appoint de choix actuellement est l’angiographie isotopique (SPECT HMPAO). Quand cet examen n’est pas disponible ou que ses résultats sont équivoques, une angiographie cérébrale des 4 vaisseaux peut être utilisée pour déterminer la présence ou l’absence de FSC. Cependant, l’angiographie cérébrale a ses propres limites et les médecins oeuvrant à l’unité de soins intensifs ou de soins intensifs neurologiques ont recours à d’autres techniques pour y suppléer. Nous analysons brièvement l’historique du diagnostic de mort cérébrale, les aspects physiopathologiques de la DNM et les techniques d’imagerie qui sont disponibles pour l’évaluation du FSC. Nous discutons de l’utilité de chacune de ces techniques pour établir un diagnostic de mort cérébrale.

Type
Review Article
Information
Canadian Journal of Neurological Sciences , Volume 35 , Issue 4 , September 2008 , pp. 409 - 419
Copyright
Copyright © The Canadian Journal of Neurological 2008

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