Exploring the science, ethics, and controversies surrounding the reversal of neurological death
For most of human history, death was seemingly straightforward—the heart stopped beating, breathing ceased, and the body grew cold. But advances in medical technology have complicated our understanding of life's end. The concept of brain death/death by neurologic criteria (BD/DNC) represents one of medicine's most profound and controversial boundaries: the determination that a person has died because their entire brain, including the brainstem, has irreversibly ceased to function.
Brain death was first defined in 1968 by the Harvard Medical School committee, establishing criteria that have evolved but remain fundamentally similar today.
Brain death is different from a vegetative state or coma. In brain death, there is no brain activity and no chance of recovery, while other states may have some brain function.
| Term | Definition | Importance |
|---|---|---|
| Brain Death/Death by Neurologic Criteria (BD/DNC) | Permanent cessation of all functions of the entire brain, including the brainstem | Legal definition of death in most countries |
| Irreversibility | Incapable of being reversed or returned to normal function | Core concept in death determination |
| Near-Death Experience (NDE) | Profound psychological events with transcendental elements near death | Challenges our understanding of consciousness |
| Uniform Determination of Death Act (UDDA) | 1980 US law establishing standards for determining death | Foundation for legal death determination |
| Ancillary Tests | Diagnostic tests (EEG, angiography) used to confirm brain death | Provides objective evidence of cessation of brain function |
In 2016, a company called Bioquark announced plans for a groundbreaking and controversial study titled "Reversal of Death by Neurologic Criteria." The trial aimed to examine whether a combination of intrathecal bioactive peptides, stem cells, lasers, and median nerve stimulation could effectively reverse brain death6 .
The study design immediately raised ethical and scientific concerns within the medical community. Critics argued that the study had no scientific foundation and represented a "cruel, false hope" for grieving families6 .
| Intervention | Proposed Mechanism | Scientific Basis |
|---|---|---|
| Intrathecal bioactive peptides | potentially promote neuronal repair and regeneration | Limited evidence in spinal cord injury models |
| Stem cell therapy | potentially replace damaged neurons and support cells | Preliminary research in stroke and traumatic brain injury |
| Laser therapy | potentially stimulate cellular energy production and repair | Used in various rehabilitation settings with mixed results |
| Median nerve stimulation | potentially activate central nervous pathways | Shown to improve consciousness in some brain injured patients |
The medical community's skepticism about reversing brain death stems from the very definition of death by neurologic criteria. BD/DNC requires irreversible cessation of all functions of the entire brain, including the brainstem6 . By definition, if something is reversible, it isn't brain death.
Traditional cessation of circulatory and respiratory functions
Absence of circulation and breathing for >5 minutes
Irreversible cessation of all brain function3
Complicating our understanding of death are reports of near-death experiences (NDEs)—profound psychological events with transcendental elements that occur in life-threatening conditions1 . About 10-20% of people who survive life-threatening conditions report NDEs1 4 .
Studies have found large overlaps between NDE reports and experiences induced by drug consumption, epilepsy, brain stimulation, and ischemic stress1 .
Some features of NDEs have been reported without life-threatening conditions, challenging both psychological and neurobiological explanations9 .
Measures electrical activity in the brain to determine cortical silence in brain death determination
Visualizes blood flow in cerebral vessels to confirm absence of intracranial blood flow
Measures blood flow velocity in cerebral arteries to assess cerebral circulatory arrest
Measures electrical responses to nerve stimulation to evaluate functional integrity of neural pathways
Measures pressure inside the skull to assess severity of brain injury and swelling
Measures biological markers in blood or CSF to evaluate neuronal damage
| Research Tool | Function | Application in Brain Death Research |
|---|---|---|
| Electroencephalography (EEG) | Measures electrical activity in the brain | Determines cortical silence in brain death determination |
| CT Angiography | Visualizes blood flow in cerebral vessels | Confirms absence of intracranial blood flow |
| Transcranial Doppler | Measures blood flow velocity in cerebral arteries | Assesses cerebral circulatory arrest |
| Somatosensory Evoked Potentials | Measures electrical responses to nerve stimulation | Evaluates functional integrity of neural pathways |
| Intracranial Pressure Monitoring | Measures pressure inside the skull | Assesses severity of brain injury and swelling |
| Biomarker Assays | Measures biological markers in blood or CSF | Evaluates neuronal damage (e.g., NSE, S100B) |
The proposal to reverse brain death raises profound ethical questions about the definition of death, patient dignity, and the proper boundaries of medical research6 7 .
While the Bioquark trial was widely criticized, it raised important questions about the finality of brain death and highlighted ongoing evolution in our understanding of death2 6 .
The controversial attempt to reverse brain death represents both the promise and perils of pushing scientific boundaries. While scientific curiosity drives medical progress, research must remain grounded in ethical principles and scientific plausibility.
"In an odd way, it can be very fulfilling to bring a family a definitive diagnosis that says, 'You don't have to make any decisions. It's over.' To take that suffering off of them because their loved one meets the legal criteria of death, as morbid as it is, really prevents a tumultuous time."
"If one subject in health law and bioethics can be said to be at once well settled and persistently unresolved, it is how to determine that death has occurred."
The line between life and death may continue to evolve with scientific advances, but for now, brain death remains a medically and legally valid determination of death. Future research should focus not on reversing death, but on improving how we diagnose it, understand it, and support families through it—while maintaining public trust in medicine's ability to know when death has truly occurred.