Brain death, clinical death, vegetative coma… What do these concepts mean?

It can precede the announcement of death by a few hours, but sometimes by much longer. The state of brain death has been the subject of much discussion in recent days. A young girl, collateral victim of a Kalashnikov shot in Marseille, was declared in this desperate state, before the announcement of her death on Tuesday September 12. The previous week, a 16-year-old teenager was declared brain dead after a collision with a police vehicle in Elancourt (Yvelines). The Versailles prosecutor’s office announced him dead, before correcting it the next day. He finally died after his transfer to Turkey on Tuesday.

From brain death to clinical death, including certain comas, these states are regularly mentioned in the media, without us always knowing what they really correspond to. The consequences can be on a legal, societal or intimate level. Franceinfo takes stock of these different notions.

The state of brain death, or encephalic death

In the state of brain death, or encephalic death, “the brain is physically dead”with some “total and irreversible brain damage”, explains to franceinfo Philippe Charlier, forensic doctor and director of the Anthropology, Archeology, Biology Laboratory (LAAB) at Paris-Saclay University. The diagnosis can be made after two flat electroencephalograms lasting thirty minutes, carried out at least three hours apart, or via CT angiography, a quicker method. “By injecting a contrast product, we see that there is no longer any vascularization in the brain. This causes cerebral edema, specifies the specialist. We can then pronounce the state of brain death, which overlaps with the expression of past coma.”

“There can be the illusion of life, because the heart is still beating.”

Philippe Boxho, forensic doctor, author of “Interview with a corpse”

at franceinfo

The heartbeat, a reflex system, does not depend on the brain, unlike breathing. “These people need to be ventilated, they need respiratory assistance”, he continues. This temporary oxygenation makes it possible to preserve the patient’s organs during possible organ harvesting. This state can last for “a few hours to sometimes months”, points out Philippe Charlier. But “after a certain time, death finally sets in”, notes the forensic doctor. Essential functions carried out by the brain, such as hormonal balance or blood pressure, are no longer carried out correctly – despite treatment – ​​and this causes a “multi-organ failure, which results in cardiac death”he adds.

“At the end of the day, it all comes down to one simple truth: the only organ that cannot be artificially maintained or replaced is the brain.”, observed Sam Shemie, pediatric intensive care specialist at the Montreal hospital, in May at the time of the presentation in Canada of a harmonized definition of death, based on the brain. She describes it as “the permanent cessation of brain functions, characterized by the absence of consciousness and brainstem reflexes, including the ability to breathe independently”.

Brain death can be caused by a stroke, accident-related head trauma, suicide or homicide by firearm, or severe asphyxia (strangulation or hanging).

Cardiac death, or real and constant

A person’s death can only be confirmed after their heart has stopped. It’s here “cardiac death” Or “real and constant”, summarizes Philippe Charlier. We also talk about “clinical death”when there is an absence of heartbeat, muscle movements, spontaneous breathing and brainstem reflexes. “It’s the complete end, we can declare death from a legal point of view”indicates the forensic doctor, alerting however on “states of apparent death”. They can be linked to “hypoglycemia, hypothermia, taking certain medications such as beta-blockers, or even intoxication”, but are reversible.

“Defining death and making the diagnosis of death is not that easy. With the advancement of neuroscience, it is possible that we will further redefine it, because the limits are pushed back.”

Philippe Charlier, forensic doctor

at franceinfo

If the person did not die a natural death, the transition from a state of brain death to a state of cardiac death modifies the qualifications and charges in an investigation. In the case of the 16-year-old teenager who died a few days after his accident with a police vehicle, the reason for the judicial investigation opened for “unintentional injuries by a driver” should thus evolve, once the death certificate has been transmitted to the French judicial authorities.

On this death certificate there is a box “is there a medico-legal obstacle to landfilling?” If it is checked, the civil status officer cannot give the burial permit. This is generally the case when it is necessary to determine the causes of death, as part of an investigation.

Deep, vegetative or post-anoxic comas

Before the coma, which corresponds to the state of brain death, certain people can be plunged into deep comas, which precede death more or less quickly. In the Yvan Colonna case, for example, the Corsican inmate was initially described in the media as brain dead after being strangled by a radicalized fellow inmate. The family’s lawyer, Patrice Spinosi, had corrected it, speaking of post-anoxic coma, a type of coma resulting from oxygen deprivation in the brain. “These comas are due to incomplete brain damage. During examinations, we observe some areas of vitality”, explains Philippe Charlier. Yvan Colonna nevertheless died twenty days later.

In so-called vegetative comas, the individual also suffers from severe brain damage, but it is located “a few steps before the coma is over”analyzes the forensic doctor. “Some brain functions can be preserved, allowing for example spontaneous breathing or muscular movement”, he illustrates. According to several experts, this is the state in which Vincent Lambert was, who died on July 11, 2019 at the Reims University Hospital, after the interruption of care and more than ten years of legal battle. Some of those close to him believed, on the contrary, that he was in a pauci-relational state, a state of consciousness higher than that of “unresponsive wakefulness” (called a vegetative state). On this scale of deep comas, the essential question, according to Philippe Charlier, is to know whether the individual “is capable of interacting or not with the external environment”.