Traumatic Brain Injury

Traumatic brain injury (TBI) results from an impact to the head. It affects normal brain function and may affect a person’s cognitive abilities, including learning and thinking skills.

Certain types of brain injury may increase the risk of developing Alzheimer's disease or another form of dementia later in life. 

Dementia occurring as a result of TBI is progressive over time and can affect life span and complicate the management of coexisting health conditions.

Connections between falls and TBI

Falls are the leading cause of traumatic brain injury for people of all ages. People aged 75 and older have the highest rates of TBI-related hospitalization and death due to falls. The direct effects of the injury can include unconsciousness; inability to recall the traumatic event; confusion; difficulty learning and remembering new information; trouble speaking coherently; unsteadiness; lack of coordination and problems with vision or hearing. Some of these changes could be long-lasting or permanent.

Learn more about fall prevention here.

What changes can I expect?

Dementia-related symptoms from head injuries include those that affect thinking and concentration, memory, communication, personality, interactions with others, mood and behaviour.
People experience different combinations of these symptoms depending on the part of the head-injured, the force of the blow, damage caused and the person’s personality before the injury. Some symptoms appear rapidly while others develop more slowly. In most cases, symptoms have at least started to appear in the first month after the injury. 

Symptoms of a brain injury include:

  • Unconsciousness
  • Inability to recall the cause of the injury or events that occurred immediately before (or up to 24 hours afterwards)
  • Confusion and disorientation
  • Difficulty learning new information
  • Headaches & dizziness
  • Nausea and vomiting
  • Blurred vision
  • Ringing in the ears
  • Trouble speaking coherently
  • Changes in emotions or sleep patterns

The severity of symptoms depends on whether the injury is mild, moderate or severe.

Types of traumatic brain injuries

Traumatic brain injuries can be classified as mild, moderate or severe, depending on whether the injury causes unconsciousness; the duration of that period of unconsciousness; and the severity of symptoms. Even a mild traumatic brain injury can have serious and long-lasting effects.

  • Mild traumatic brain injury
    • Also known as a concussion. May cause unconsciousness for 30 minutes or less or may not cause any loss of consciousness. Symptoms often appear at the time of injury or immediately afterward, but occasionally may not develop for days or weeks. Symptoms are usually temporary and resolve within hours, days or weeks, but they can last months or longer.
  • Moderate traumatic brain injury
    • Leads to loss of consciousness lasting more than 30 minutes. Symptoms are similar to those of mild traumatic brain injury but more serious and longer-lasting.
  • Severe traumatic brain injury 
    • Causes loss of consciousness for more than 24 hours. Symptoms are similar to those of moderate traumatic brain injury but are very serious and can last for an extended period of time, even becoming permanent.

What are the causes?

  • Falls
    • The most common cause of traumatic brain injury in older adults. Direct effects of the injury for senior citizens may result in long-term cognitive changes, reduced ability to function and changes in emotional health.
  • Motor vehicle accidents
    • You can reduce your risk by keeping your vehicle in good repair, following the rules of the road and buckling up.
  • Sports injuries 
    • Also a cause of traumatic brain injury. Protect your head by wearing a helmet and other protective equipment when biking, skating or playing contact sports.

How is traumatic brain injury diagnosed?

Diagnosis of traumatic brain injury is often based on history, assessment of the person’s loss of consciousness, a detailed neurological exam (including examination of the reflexes) and imaging studies.

Neuropsychological testing is the most sensitive means of identifying dementia in persons with a head injury. It’s carried out by a specialist trained in clinical psychology and uses clinical rating scales to identify subtle cognitive issues. This testing also establishes clear baselines for measuring changes over time.

Head injury warrants a brain scan to determine whether any brain structures show physical abnormalities:

  • CT scan is the standard test for a person with a head injury. A scan performed one to three months after injury may detect damage not visible immediately after the injury.
  • MRI is more sensitive than CT scans in demonstrating certain types of injury.
  • Single Photon Emission Computed Tomography (SPECT) scan is a relatively new imaging method that is still being studied in people with head injuries. It may be better than CT scans or MRIs in detecting functional problems in the brain for some types of dementia or other brain disorders. SPECT is available only at some large medical centres.
  • Electroencephalogram (EEG) measures the electrical activity of the brain. It may be used to diagnose seizures or abnormally slow rates of brain activity.

Research findings

Research done in the last 20-30 years has established a link between moderate and severe traumatic brain injury and a greater risk of developing Alzheimer's disease or other types of dementia later in life. There is no evidence to suggest that a single mild TBI would increase the risk of dementia.

One of the key studies found that older adults with a history of moderate traumatic brain injury had a two to three time’s greater risk of developing Alzheimer's disease than others with no history of brain injury. People with a history of severe TBI had a four to five time’s greater risk of developing Alzheimer’s disease.

Studies also suggest that repeated mild traumatic brain injuries, such as those from contact sports like boxing, football, hockey and soccer, may be associated with a greater risk of a type of dementia called chronic traumatic encephalopathy (CTE).

What kind of treatment is available?

Most traumatic brain injuries are mild and can be managed with a short hospital stay for observation or at-home monitoring followed by outpatient rehabilitation (if needed). However, the most serious brain injuries require specialized hospital care and months of inpatient rehabilitation.

Treatment of dementia in a person with a history of traumatic brain injuries depends on the type of dementia diagnosed.

The strategies for treating Alzheimer's disease or another type of dementia remain the same, regardless of the presence or absence of a history of brain injury.

The person who has developed dementia will benefit from any of the following:

  • Behaviour modification
  • Cognitive rehabilitation
  • Medication for specific symptoms
  • Family or network intervention
  • Social services

Goals of these interventions include helping the head-injured person adapt to their injury cognitively and emotionally; and helping them master skills and behaviours that will support them in reaching personal goals. 

These interventions also help family members learn ways they can help the person and themselves cope with the challenges that come from a head injury.
These interventions can be especially important in establishing realistic expectations for outcomes and pace of improvement.

Further Information