Traumatic Brain Injury (TBI) involves damage to one or more parts of the brain due to external mechanical force. The most common causes of TBI include falls, motor vehicle crashes, and violence.
TBI is a leading cause of disability across the globe, with approximately 10 million individuals being affected annually1.
Traumatic brain injury can involve temporary loss of normal function of brain cells, through to more severe cases in which there is permanent loss of large areas of functional brain tissue.
Mild TBI has the highest rate of occurrence in the general population (~75% of cases), followed by moderate (22%), and severe (3%) forms2.
Pathology and functional impact of Traumatic Brain Injury
The specific symptoms an individual with TBI experiences are dependent on many factors, including whether the brain injury is diffuse or localised, regions affected, and the time period considered.
Loss of consciousness is common following brain injury. In mild TBI, this loss of consciousness tends to be brief (seconds to minutes), while severe TBI can result in long-term unconsciousness.
Other commonly reported symptoms of TBI include cognitive impairment, headache, dizziness, ringing in the ears, personality change, development of new psychiatric disorders (e.g. depression), neurological deficits, and seizures3.
A meta-analysis suggests that cognitive deficits in mild TBI show recovery with time4. However, research using sensitive neuropsychological tests indicates that mild TBI leads to persisting deficits in up to 30% of cases, an issue often overlooked5.
In moderate or severe TBI, cognitive deficits are more marked, and usually, persist over time despite first-line treatments6.
Research and development in Traumatic Brain Injury
Immediately following TBI, medical management can include ensuring brain perfusion/oxygen supply, controlling blood pressure (and intracranial pressure), and surgery to correct underlying damage or remove collections of blood from around the brain (hematomas).
Imaging investigations are used to assess underlying damage, not just to the brain itself, but also to bone structures including the spine. In the medium to longer term, tailored treatment programmes typically involve occupational therapy, physiotherapy, speech and language therapy, and psychiatric input.
Cognitive problems are common in people with TBI, and persist despite existing first-line treatments5,6. There is an on-going search for new treatments capable of reversing cognitive dysfunction in TBI, in order to maximise recovery and quality of life for those affected.
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Diaz-Arrastia R., et al (2014). Pharmacotherapy of traumatic brain injury: state of the science and the road forward: report of the Department of Defense Neurotrauma Pharmacology Workgroup. J Neurotrauma.
Salmond C.H., et al (2005). Cognitive sequelae of head injury: involvement of basal forebrain and associated structures. Brain.
Newcombe V.F., et al (2011). Parcellating the neuroanatomical basis of impaired decision-making in traumatic brain injury. Brain.
Sterr A., et al (2006). Are mild head injuries as mild as we think? Neurobehavioral concomitants of chronic post-concussion syndrome. BMC Neurol
- Humphreys I, Wood RL, Phillips CJ, Macey S. The costs of traumatic brain injury: a literature review. Clinicoecon Outcomes Res. 2013 Jun 26;5:281-7.
- Meaney DF, Morrison B, Dale Bass C. The mechanics of traumatic brain injury: a review of what we know and what we need to know for reducing its societal burden. J Biomech Eng. 2014 Feb;136(2):021008.
- National Institute of Neurological Disorders and Stroke (NIH).
- Rohling ML, Binder LM, Demakis GJ, Larrabee GJ, Ploetz DM, Langhinrichsen-Rohling J. A meta-analysis of neuropsychological outcome after mild traumatic brain injury: re-analyses and reconsiderations of Binder et al. (1997), Frencham et al. (2005), and Pertab et al. (2009). Clin Neuropsychol. 2011 May;25(4):608-23.
- Sterr A, Herron KA, Hayward C, Montaldi D. Are mild head injuries as mild as we think? Neurobehavioral concomitants of chronic post-concussion syndrome. BMC Neurol. 2006 Feb 6;6:7.
- Ruttan L, Martin K, Liu A, Colella B, Green RE. Long-term cognitive outcome in moderate to severe traumatic brain injury: a meta-analysis examining timed and untimed tests at 1 and 4.5 or more years after injury. Arch Phys Med Rehabil. 2008 Dec;89(12 Suppl):S69-76..