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Traumatic Brain Injury

What is traumatic brain injury?

Traumatic brain injury (TBI) happens when a sudden, external, physical assault damages the brain. It is one of the most common causes of disability and death in adults. TBI is a broad term that describes a vast array of injuries that happen to the brain. The damage can be confined to one area of the brain or in more than one area of the brain. The severity of a brain injury can range from a mild concussion to a severe injury that results in coma or even death.

What are the different types of TBI?

Brain injury may happen in one of two ways:


  • Penetrating brain injury. Penetrating, or open head injuries happen when there is a break in the skull, such as when a bullet pierces the brain.

What is diffuse axonal injury (DAI)?

Diffuse axonal injury is the tearing of the brain's long connecting nerve fibers (axons) that happens when the brain is injured as it shifts and rotates inside the bony skull. DAI usually causes coma and injury to many different parts of the brain. The changes in the brain are often microscopic and may not be evident on computed tomography (CT scan) or magnetic resonance imaging (MRI) scans.

What is primary and secondary brain injury?

Primary brain injury refers to the sudden and profound injury to the brain that is considered to be more or less complete at the time of impact. This happens at the time of the car accident, gunshot wound, or fall.

Secondary brain injury refers to the changes that evolve over a period of  hours to days after the primary brain injury. It includes an entire series of steps or stages of cellular, chemical, tissue, or blood vessel changes in the brain that contribute to further destruction of brain tissue.

What causes a head injury?


What causes bruising and internal damage to the brain?

When there is a direct blow to the head, the bruising of the brain and the damage to the internal tissue and blood vessels is due to a mechanism called coup-contrecoup. A bruise directly related to trauma at the site of impact is called a coup lesion (pronounced COO). As the brain jolts backwards, it can hit the skull on the opposite side and cause a bruise called a contrecoup lesion. The jarring of the brain against the sides of the skull can cause tearing of the internal lining, tissues, and blood vessels leading to internal bleeding, bruising, or swelling of the brain.

What are the possible results of brain injury?

Some brain injuries are mild, with symptoms disappearing over time with proper attention. Others are more severe and may result in permanent disability. The long-term or permanent results of brain injury may need post-injury and possibly lifelong rehabilitation. Effects of brain injury may include:

Cognitive deficits

  • Coma

  • Confusion

  • Shortened attention span

  • Memory problems and amnesia

  • Problem solving deficits

  • Problems with judgment

  • Inability to understand abstract concepts

  • Loss of sense of time and space

  • Decreased awareness of self and others

  • Inability to accept more than one- or two-step commands at the same time

Motor deficits

  • Paralysis or weakness

  • Spasticity (tightening and shortening of the muscles)

  • Poor balance

  • Decreased endurance

  • Inability to plan motor movements

  • Delays in getting started

  • Tremors

  • Swallowing problems

  • Poor coordination

Perceptual or sensory deficits


  • Loss of sensation or heightened sensation of body parts

  • Left- or right-sided neglect

  • Trouble understanding where limbs are in relation to the body


Communication and language deficits

  • Trouble speaking and understanding speech (aphasia)

  • Trouble choosing the right words to say (aphasia)

  • Trouble reading (alexia) or writing (agraphia)

  • Trouble knowing how to do certain very common actions, like brushing one's teeth (apraxia)

  • Slow, hesitant speech and decreased vocabulary

  • Trouble forming sentences that make sense

  • Problems identifying objects and their function


Functional deficits


  • Problems with organization, shopping, or paying bills

  • Inability to drive a car or operate machinery

Social difficulties

  • Impaired social capacity resulting in difficult relationships

  • Trouble making and keeping friends

  • Trouble understanding and responding to the nuances of social interaction

Regulatory disturbances

  • Fatigue

  • Changes in sleep patterns and eating habits

  • Dizziness

  • Headache

  • Loss of bowel and bladder control

Personality or psychiatric changes

  • Apathy

  • Decreased motivation

  • Emotional lability

  • Irritability

  • Anxiety and depression



Traumatic epilepsy

Epilepsy can happen with a brain injury, but more commonly with severe or penetrating injuries. While most seizures happen immediately after the injury, or within the first year, it is also possible for epilepsy to surface years later. Epilepsy includes both major or generalized seizures and minor or partial seizures.

Can the brain heal after being injured?

Most studies suggest that once brain cells are destroyed or damaged, for the most part, they don't regenerate. However, recovery after brain injury can take place, as, in some cases, other areas of the brain make up for the injured tissue. In other cases, the brain learns to reroute information and function around the damaged areas. The exact amount of recovery is not predictable at the time of injury and may be unknown for months or even years. Each brain injury and rate of recovery is unique depending on the amount of inflammation and damage. Recovery from a severe brain injury often involves a prolonged or lifelong process of treatment and rehabilitation.

What is coma?

Coma is an altered state of consciousness that may be very deep (unconsciousness) so that no amount of stimulation will cause the patient to respond. It can also be a state of reduced consciousness, so that the patient may move about or respond to pain. Not all patients with brain injury are comatose. The depth of coma, and the time a patient spends in a coma varies greatly depending on the location and severity of the brain injury. Some patients emerge from a coma and have a good recovery. Other patients have significant disabilities.

The brain injury rehabilitation program


  • Nature and severity of the brain injury

  • Type and degree of any resulting impairments and disabilities

  • Overall health of the patient

  • Family support



Areas covered in brain injury rehabilitation programs may include:

Patient need




Physical care

Nutritional needs, medicines, and skin care

Mobility skills

Walking, transfers, and self-propelling a wheelchair

Communication skills

Speech, writing, and alternative methods of communication

Cognitive skills

Memory, concentration, judgment, problem solving, and organizational skills

Socialization skills

Interacting with others at home and within the community

Vocational training

Work-related skills

Pain management

Medicines and alternative methods of managing pain

Psychological testing and counseling

Identifying problems and solutions with thinking, behavioral, and emotional issues

Family support




The brain injury rehabilitation team


  • Neurologist/neurosurgeon

  • Physiatrist

  • Internists and specialists

  • Rehabilitation nurse

  • Social worker

  • Physical therapist

  • Occupational therapist

  • Speech/language pathologist

  • Psychologist/neuropsychologist/psychiatrist

  • Recreation therapist

  • Audiologist

  • Dietitian

  • Vocational counselor

  • Orthotist

  • Case manager

  • Respiratory therapist

  • Chaplain

Types of brain injury rehabilitation programs


  • Acute rehabilitation programs

  • Subacute rehabilitation programs

  • Long-term rehabilitation programs

  • Transitional living programs

  • Behavior management programs

  • Day-treatment programs

  • Independent living programs

Online Medical Reviewer: Jasmin, Luc, MD
Online Medical Reviewer: Sather, Rita, RN
Date Last Reviewed: 5/1/2018
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