Ancillary testing: Japanese challenge for brain-death diagnosis after announcement of world consensus

Abstract

In 2020, the world-consensus of determination of brain death and death by neurologic criteria (BD/DNC) was established. In this consensus, ancillary testing such as cerebral blood flow imaging or electrophysiology testing are recommended when the clinical examination cannot be completed. In this consensus, electroencephalogram (EEG) is not recommended as the ancillary testing for BD/DNC diagnosis since EEG cannot estimate the lack of brainstem function. However, EEG is still mandatory in Japan. The cerebral blood flow tests, such as CT angiography or MR angiography are widely spread in Japan, although these image tests are not recommended as additional ancillary testing due to lack of evidence. The BD/DNC ancillary testing has quite wide variety throughout the world. We thus need to modify the balance between our fashion and international trend on this topic. In this manuscript, the recent international consensus on ancillary testing for BD/DNC diagnosis is summarized, then the knowledge gap and problems on this topic is described.