Global hypoxic-ischemic brain injury
- Lesion
When the whole brain loses blood or oxygen, as in cardiac arrest, the most sensitive neurons die first and border zones between arteries infarct.
What it is
Global hypoxia or ischemia follows cardiac arrest, profound shock, severe hypotension, drowning, suffocation or carbon monoxide poisoning. The brain is affected unevenly: some neurons, such as CA1 pyramidal cells of the hippocampus and cerebellar Purkinje cells, are especially vulnerable, and the zones at the far ends of two arterial territories lose flow first. Severe, prolonged injury causes widespread necrosis and, if the whole brain dies while the body is ventilated, brain death.
Step by step
- Systemic perfusion or blood oxygen falls below what the brain needs.
- Neurons with the highest activity and glutamate input fail first.
- Glutamate overload and calcium entry trigger cell death in vulnerable populations.
- If hypotension is sudden, border zones between arteries infarct.
- If restoration of flow is late, injury spreads to whole cortical layers and deep grey matter.
- Survivors may have amnesia, ataxia, seizures, a persistent vegetative state or brain death.
Patterns of global hypoxic-ischemic injury
| Pattern | Where | Typical setting |
|---|---|---|
| Selective neuronal necrosis | Hippocampus CA1, Purkinje cells, cortical layers | Brief cardiac arrest |
| Laminar (pseudolaminar) necrosis | Middle cortical layers, often in the depths of sulci | Prolonged hypoxia or hypotension |
| Watershed infarct | Border between anterior and middle cerebral artery territories | Sudden severe hypotension |
| Pallidal necrosis | Globus pallidus | Carbon monoxide poisoning |
| Diffuse necrosis and brain death | Whole brain | Prolonged arrest with later ventilation |
Clinical notes
- Mild injury gives transient confusion; severe injury gives coma, myoclonus and poor outcome.
- Brain death is a clinical diagnosis with strict criteria; it is legally death in Colombia and most countries.
Test yourself
Think of the answer, then tap the question to see it.
Which hippocampal region is most vulnerable to global ischemia?
The CA1 sector (Sommer sector) of pyramidal neurons.
Where does a watershed infarct form after sudden severe hypotension?
At the border between arterial territories, classically a parasagittal strip between the anterior and middle cerebral arteries.
Which deep grey structure is characteristically damaged by carbon monoxide?
The globus pallidus.
Elsewhere in DurgiPedia
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Cerebral hypoxia: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.