Near-death experience during cardiac arrest and consciousness beyond the brain: a narrative review

In this narrative review, we will critically assess whether the occurrence of near-death experience (NDE) associated with cardiac arrest (CA) may be explained by brain electrical activity or whether this empirical evidence supports an alternative theory, namely, that consciousness may persist and function beyond the brain. Empirical evidence suggests that NDEs associated with CA likely arise during the patient's unresponsiveness, rather than in the early CA phases or after cardiopulmonary resuscitation (CPR), when the brain may still be functional or later recover. There has been no evidence that cortical electrical activations recorded in dying patients and during CPR may be involved in NDEs, since no reports of subjective experience have been associated with such brain recordings. Alternatively, these findings may be interpreted as a result of muscular artifacts or circulatory disturbances in such contexts. CA leads to the interruption of oxygenated blood flow to the brain and loss of cortical electrical activity within 10-30 seconds. During CPR, brain electrical activity may remain absent or severely disturbed. Given that NDEs appear to occur at the very moment in CA when the brain is severely compromised, this can be assumed as evidence for the continuity of consciousness beyond the brain.