Traumatic brain injury

Traumatic Brain Injury

Traumatic brain injury (TBI) is a complex category of clinical conditions defined by a functionally significant alteration of brain function and/or structure resulting from the application of external physical force (including acceleration/deceleration and/or blast forces).
TBI occurs along a continuum of injury severity and can produce a broad range of neuropsychiatric disturbances of variable duration which are recognized during medical disability evaluation. The heterogeneity and complexity of both TBI and its sequelae present challenges in clinical care, research, public policy, and medicolegal proceedings.
Additionally, the effects of injury and the course of recovery vary, with:

  • injury severity (mild, moderate, orsevere)
  • comorbid or complicating neuropsychiatric conditions
  • psychosocial circumstances potentially influencing outcomes

What is Traumatic Brain Injury (TBI)?

Traumatic brain injury occurs when external physical forces (such as acceleration/deceleration or blast) cause a disruption in brain function and/or structure, resulting in the acute impairment of cognitive and/or elementary neurological functions. The term ‘traumatic brain injury’ should strictly refer to injuries induced by biomechanical forces. For brain injuries resulting from other causes such as anoxia, stroke, tumors, infection, or toxins, the term ‘acquired brain injury’ (ABI) is more appropriate. Competent clinical practitioners during medical disability evaluation should make this clear distinction.

TBI may be classified as either penetrating or nonpenetrating, based on whether or not the cranium has been breached.
Outcomes related to penetrating injuries are largely influenced by:

  • the nature and extent of neuroanatomy compromised by the penetrating object(s)
  • the additional risk for complication, particularly infection

Nonpenetrating injuries are more prevalent and we can classify them into three categories based on their severity: mild, moderate, and severe. It is important to note that these terms describe the impact of the injury on brain function. Taking even a mild brain injury seriously is crucial, as it requires immediate attention and an accurate diagnosis during a medical disability evaluation.

Causes of TBI

While performing a medical disability evaluation of a TBI suspect patient, it is crucial to include in the history- taking the cause of the injury so to get a glimpse of the possible destructive pattern of neurological structures.
Among the leading causes are:

  • falls
  • motor vehicle crashes and traffic-related accidents
  • being struck by or against an object
  • assaults

Many TBIs, especially in young people, happen while playing sports or doing recreational activities. Also a traumatic brain injury can ensue after an episode attack in patients with epilepsy, where they can fall or struck their head against rough and hard surfaces. Also some activities that lead to emergency department visits for TBI are bicycling, football, playground activities, basketball, and soccer.
While in the military, the leading causes of TBI arise from gunshots, fragments from an explosion, blasts, falls, motor vehicle crashes, and assaults.

Symptoms and course of illness after TBI

A broad array of neuropsychiatric symptoms may follow TBI of all severities.
Common physical symptoms include:

  • headache
  • fatigue
  • sleep disturbance
  • vertigo or dizziness
  • sensitivity to light and/or sound, and anosmia

Cognitive disturbances potentially range from level of arousal and attention through higher-order executive functions and social intelligence. Problems with complex attention, executive functioning, learning, memory, and speed of processing are common.
Additionally, emotional disturbances often include:

  • irritability
  • depression
  • anxiety
  • affective lability
  • decreased frustration tolerance

Behavioral disturbances or personality changes may involve:

  • aggression
  • disinhibition
  • impulsivity
  • apathy

Since infants and young children with brain injuries are usually unable to communicate symptoms such as headaches, sensory problems, and confusion, a medical disability evaluation of a child may involve observing a variety of symptoms, including the following:

  • Change in eating or nursing habits
  • Unusual or easy irritability
  • Persistent crying and inability to be consoled
  • Change in ability to pay attention
  • Change in sleep habits
  • Seizures
  • Sad or depressed mood
  • Drowsiness
  • Loss of interest in favorite toys or activities


If someone shows signs of moderate or severe TBI, they should seek medical attention as soon as possible. Since the initial brain damage caused by trauma is difficult to reverse, medical personnel prioritize stabilizing individuals with TBI and preventing further injury. Moreover, the primary concerns involve ensuring proper oxygen supply to the brain and the rest of the body, maintaining adequate blood flow, and controlling blood pressure. Medical disability evaluation combines the history of the injury, clinical examination, blood tests, and imaging tests to tailor the treatment. In addition, moderately to severely injured patients receive rehabilitation that involves individually tailored treatment programs in the areas of physical therapy, occupational therapy, speech/language therapy, physiatry (physical medicine), psychology/psychiatry, and social support.

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