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Diffuse Axonal Injury

By

Gordon Mao

, MD, Johns Hopkins University

Last full review/revision Jun 2021| Content last modified Jun 2021

Diffuse axonal injury is widespread injury to axons, a part of the nerve cells, in the brain that can occur from a head injury.

Nerve impulses leave nerve cells through a part of the nerve cell called the axon. In diffuse axonal injury, axons throughout the brain are damaged.

Typical Structure of a Nerve Cell

A nerve cell (neuron) consists of a large cell body and nerve fibers—one elongated extension (axon) for sending impulses and usually many branches (dendrites) for receiving impulses.

Typical Structure of a Nerve Cell

The usual causes of diffuse axonal injury include falls and motor vehicle crashes. Diffuse axonal injury can occur in the shaken baby syndrome, in which violent shaking or throwing of a baby causes brain injury. As a result of diffuse axonal injury, brain cells may die, causing brain swelling, increasing pressure within the skull (intracranial pressure). Increased pressure may compound the injury by decreasing the blood supply to the brain.

Diffuse axonal injury typically causes loss of consciousness that lasts for more than 6 hours. Sometimes the person has other symptoms of brain damage. Increased pressure within the skull may cause coma.

Computed tomography (CT) or magnetic resonance imaging (MRI) is usually done to detect diffuse axonal injury.

Treatment of diffuse axonal injury is similar to treatment of other head injuries. For example, doctors make sure that breathing and blood pressure are adequate and take steps to keep pressure within the skull from increasing too much.

Surgery is not helpful.

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