Anoxic Brain Damage

(Anoxic Brain Injury; Hypoxic Brain Injury)

How to Say It: An-OKS-ik

by Cynthia M. Johnson, MA

Definition

Anoxic brain damage (ABD) is harm to the brain due to a lack of oxygen. Brain cells without enough oxygen will start to die after about 4 minutes.

Progression of Anoxic Brain Damage

Causes

Oxygen is carried to the brain in the blood. ABD is when:

Blood flow is blocked or slowed due to:
- A clot or stroke
- Shock and heart problems, like a heart attack
Blood flow is normal, but the blood doesn’t have enough oxygen due to:
- Lung disease
- A lack of oxygen in the air, which may happen at high altitudes
- Being around certain poisons, such as carbon monoxide
- An event that is stopping breathing, such as drowning, choking, or suffocation

Risk Factors

Problems that may raise the risk of ABD are:

Sudden cardiac arrest or heart attack
Choking
Suffocation
Drowning
Electrical shock
Broken gas appliances that discharge carbon monoxide
Heart arrhythmia
Stroke
Drug use

Symptoms

Problems may be:

Headache
Problems with thinking and focus
Mood swings
Loss of consciousness
Seizures
Clumsiness
Coma
A decline in brain function days or weeks after the event (rare)

Diagnosis

You will be asked about your symptoms and health history. A physical exam will be done. You may need to see a doctor who treats brain problems.

These tests may be done to find out more about problems with brain function:

CT scan
MRI scan
Electroencephalogram (EEG)—a test that measures the electricity in the brain
Single-photon emission computed tomography (SPECT) scans—a type of CT scan that looks at parts of the brain
Evoked potential tests—tests used to check the senses

Treatment

Initial Treatment

Treatment will depend on the cause. Choices are:

Oxygen to raise the amount of oxygen in the blood
Medicine to help get enough blood with oxygen to the brain
Cooling the brain to limit problems

Rehabilitation

Recovery can take months or years. It depends on how long a person went without oxygen. Many people can get back most of the abilities they lost.

These therapies may be needed:

Physical therapy to retrain motor skills, such as walking
Occupational therapy to relearn daily skills, such as dressing and going to the bathroom
Speech therapy to work on language problems
Counseling for behavior and emotional issues

Prevention

ABD is often caused by accidents. These cannot always be prevented.

RESOURCES:

Brain Injury Association of America
http://www.biausa.org

National Institute of Neurological Disorders and Stroke
http://www.ninds.nih.gov

CANADIAN RESOURCES:

Ontario Brain Injury Association
http://obia.ca

Public Health Agency of Canada
http://www.phac-aspc.gc.ca

References:

Cerebral hypoxia information page. National Institute of Neurologic Disorders and Stroke website. Available at: https://www.ninds.nih.gov/Disorders/All-Disorders/Cerebral-Hypoxia-Information-Page. Accessed June 18, 2018.

Rubinos C, Ruland S. Neurologic complications in the intensive care unit. Curr Neurol Neurosci Rep. 2016;16(6):57.

Last reviewed September 2020 by EBSCO Medical Review Board Rimas Lukas, MD
Last Updated: 5/21/2021

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