Long-term consequences of traumatic brain injury: A review of social, cognitive, neurological, and psychiatric outcomes
It is recognized that survivors of traumatic brain injury have to cope with numerous life challenges. The growing concern for the number of veterans returning with a brain injury has prompted a tremendous influx of research. These new studies contribute to the understanding of brain injury in both civilian and military populations.
The Institute of Medicine recently created a Committee on Gulf War and Health for Brain Injury in Veterans and Long-Term Health Outcomes. The results of their research reviews were published in the December 2009 issue of the Journal of Head Trauma Rehabilitation.
While many of the results should come as no surprise to people dealing with traumatic brain injury (for instance that TBI is associated with unemployment, depression, or cognitive deficits), the Committee also outlined health trends that are not as well known. Here we present a short summary of the Committee's findings on the social, cognitive, neurological, and psychiatric long-term outcomes after traumatic brain injury.
Social functioning describes the ability to maintain social relationships, employment, independent living, and leisure activities. Moderate, severe, and penetrating brain injury is well associated with problems maintaining long-term employment and adverse social function outcomes.
Cognitive outcomes describe potential difficulties in thought processes such as attention, memory, initiation, planning, or problem solving. Severe brain injury and penetrating brain injury are well associated with cognitive impairments that correspond to the injured brain area. Moderate brain injury is somewhat associated with cognitive impairments.
Neurological outcome refers to disorders of the brain such as seizures, Alzheimer's type dementia, parkinsonism (a combination of symptoms similar to Parkinson's disease), endocrine disorders, or visual problems. Moderate and severe brain injuries are well associated with:
- Dementia of the Alzheimer's type
- Unprovoked seizures
- Endocrine dysfunction, especially hypopituitarism
- Growth hormone insufficiency, and
- Diabetes insipidus.
Mild brain injury is somewhat associated with dementia of the Alzheimer's type and parkinsonism (when there is loss of consciousness). Severe brain injury is somewhat associated with the development of ocular/visual motor deterioration.
Psychiatric outcomes describe mood disorders such as depression or anxiety, as well as behaviors such as aggression or drug and alcohol use. Mild, moderate, and severe brain injuries are well associated with mood disorders and aggressive behaviors. Additionally, brain injury of any severity is somewhat associated with drug and alcohol use.
While several past studies have focused on immediate or short-term effects of brain injury, these reviews focus on studies of outcomes several months after injury. The most critical point made by the Committee is that traumatic brain injury can lead to chronic health conditions and needs long-term management in order to avoid potential consequences.
Severity of brain injury seemed to show differences in how well associated it was with a long-term outcome (particularly in mild TBI, where there were few strong associations). However, there were inconsistencies in how individual studies diagnosed mild and moderate brain injury, leading to difficulties when reviewing several studies as a whole.
It is likely that the more severe the brain injury, the more severe the long-term outcomes will be. But further research needs to be conducted in the field of mild brain injury in order to clarify some of the diagnostic inconsistencies and the controversial conflicts in past study results.
Bazarian JJ, Cernak I, Noble-Haesslein L, et al. Long-term neurologic outcomes after traumatic brain injury. Journal of Head Trauma Rehabilitation. (December 2009).
Dikmen SS, Corrigan JD, Levin HS, et al. Cognitive outcome following traumatic brain injury. Journal of Head Trauma Rehabilitation. (December 2009).
Hesdorffer DC, Rauch SL, & Tamminga CA. Long-term psychiatric outcomes following traumatic brain injury: A review of the literature. Journal of Head Trauma Rehabilitation. (December 2009).
Temkin NR, Corrigan JD, Dikmen SS, & Machamer J. Social functioning after traumatic brain injury. Journal of Head Trauma Rehabilitation. (December 2009).