Anoxic Brain Damage

(Anoxic Brain Injury; Hypoxic Brain Injury)

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 four minutes.

Progression of Anoxic Brain Damage
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Causes

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

  • Blood flow is blocked or slowed due to:
  • 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:

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
  • 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: 10/5/2020