Traumatic brain injury (TBI) is defined as a blow or jolt to the head, or a penetrating head injury that disrupts the function of the brain.

The severity of such an injury may result in a brief change in mental status or consciousness. In more severe cases a TBI can cause extended periods of unconsciousness or amnesia. TBI can result in short or long-term problems with a patient’s ability to function independently.

Types of injuries

The direct injury that happens to the brain, skull, and other tissues at the time of the trauma is called primary injury.

Secondary injury is what can happen to the brain over the next few days as a result of the primary injury. This includes things such as development of blood clots on or in the brain, swelling of the brain, and increased pressure inside the skull. If this happens, it can keep the brain from getting all the oxygen and other nutrients needed to heal and work properly.

One important goal of treatment is to prevent or reduce the effects of secondary injury.

The leading causes of TBI are falls, motor vehicle/traffic accidents, being struck by, or against an object, and physical assaults. For active duty military personnel in war zones, blasts are a major cause of TBI.

Alcohol use and non use of seatbelts are both major risk factors for TBI.

To assess the existence or severity of a traumatic brain injury, a doctor will conduct an exam by asking questions about the injury, as well as simple questions to establish whether or not a patient’s brain is working normally. An exam may include checking a patient’s strength, balance, coordination, reflexes, and sensation. Imaging tests such as a Computed Tomography (CT) scan or Magnetic Resonance Imaging (MRI) may ensure that the brain is not bruised or bleeding.

Most recently, neurosurgeons at Harborview Medical Center have pioneered the use of transcranial Dopplers, portable ultrasound technology, to quickly and accurately study vessels in the brain that have been damaged as a result of trauma. The technology allows treatment to be customized to each patient’s unique injuries and helps patients avoid anticoagulation, or blood thinning, or extra surgeries.

Monitoring injuries

The greatest risk for secondary injury is in the first few days after a Traumatic Brain Injury (TBI). Some people are at lower risk and can be monitored on an acute care unit for a few days.  This will include neurologic examinations, which check on how well the brain is working.

Checks will be done frequently to observe eye pupil size and reaction, monitoring the ability to wake up, follow simple commands, and answer questions.

Complications associated with traumatic brain injury can include: 

• Changes to thinking, including problems with memory, changes in personality, trouble with attention and concentration, and impulsivity. 
• Depression 
• Heterotopic Ossification, which causes abnormal bone growth in selected joints, most commonly in the hips, shoulders, knees and elbows. 
• Musculoskeletal system problems, including osteoporosis, and worsening spasticity and dystonias. 
• Headaches 
• Hearing Loss caused by external bleeding in the ear canal, middle ear damage, cochlear injury, and/or temporal lobe lesions. 
• Visual system changes that can be recognized early on by redness, or watering and can include blurriness and double vision. 
• Neuroendocrine Disorders which may occur in women some years following a traumatic brain injury. 
• Fatigue