Causes and Diagnosis of Brain Death
The causes and diagnosis of brain death involve catastrophic brain injuries followed by detailed medical testing. Understanding the causes and diagnosis of brain death helps families, healthcare providers, and legal systems make informed decisions about end-of-life care and organ donation.
Causes of Brain Death:
- Traumatic brain injury
Severe blows to the head — often from road accidents, falls, or violent trauma — can cause the brain to swell beyond the skull’s ability to accommodate pressure, leading to irreversible damage.
- Stroke or brain haemorrhage
A major stroke or aneurysm can cut off blood supply to the brain. This results in widespread brain tissue death.
- Cardiac arrest
When the heart stops pumping blood, oxygen flow to the brain is halted. After just a few minutes, brain cells begin to die.
- Severe brain infections
Conditions such as encephalitis or meningitis can cause severe brain swelling. If not treated quickly, this swelling can lead to permanent brain damage or even brain death.
- Lack of oxygen
Drowning, suffocation, or respiratory failure can result in prolonged hypoxia — the brain can only survive a few minutes without oxygen.
Diagnosis of Brain Death:
Medical professionals follow a strict protocol:
- Doctors must confirm that the brain injury has a clear, irreversible cause.
- Doctors must rule out any reversible conditions, such as drug overdose or hypothermia, before confirming brain death.
- Doctors test for brainstem reflexes by shining a light in the eyes to check pupil response, moving the head to observe eye movement, touching the throat to trigger the gag reflex, and pausing the ventilator to see if the patient tries to breathe on their own. These steps confirm whether any brain activity remains
If brainstem function is absent and the condition persists, brain death is declared.
In South Africa, two qualified doctors—often including a neurologist or critical care specialist—must confirm brain death. In complex cases, they may use EEGs or cerebral blood flow tests for added certainty.
Confirming the causes and diagnosis of brain death is essential for clarity, dignity, and appropriate next steps for the patient and their family.
👉 [Next: Legal and Ethical Aspects of Brain Death]
