Overview of Traumatic Brain Injury

Introduction

Acquired brain injury or head injury are broad terms describing an array of injuries that occur to the scalp, skull, brain, and underlying tissue and blood vessels in the head. Acquired brain injury does not include damage to the brain resulting from neurodegenerative disorders like Multiple Sclerosis or Parkinson’s Disease. Acquired brain injuries are broadly classified into; Traumatic brain injury derived from an external source and non-traumatic brain injury derived from either an internal or external source.

Table 1. Causes of Acquired Brain Injury
Traumatic Brain Injury Non-Traumatic Brain Injury
Falls Stroke e.g. Haemorrhage, Clot
Assaults Infectious Disease e.g. Meningitis, Encephalitis
Motor Vehicle Accidents Seizure
Sport / Recreation Injury Electric Shock
Abusive Head Trauma e.g Shaken Baby Syndrome Tumours
Gunshot Wounds Toxic Exposure
Workplace Injury Metabolic Disorders
Child Abuse Neurotoxic Poisoning e.g. carbon monoxide, lead exposure
Domestic Violence Lack of Oxygen e.g. drowning, choking, hypoxic & anoxic injury
Military Actions eg. Blast Injury Drug Overdose

Traumatic Brain Injury

Traumatic Brain Injury is “an alteration in brain function, or other evidence of brain pathology, caused by an external force”. [1] It occurs when an external force impacts the brain, and often is caused by a blow, bump, jolt or penetrating wound to the head. However, not all blows or jolts to the head cause traumatic brain injury: some just cause bony damage to the skull, without subsequent injury to the brain. Mild traumatic brain injury are also more commonly referred to now as Concussion.

Whole-brain tractography in an aged-matched control and in a case of 26-year-old patient, 15 months post-traumatic brain injury. Tracts are represented in a scalar mode (0.4–0): regions with higher FA values are colored in red (0.4) and the ones with lower FA (0) in blue. A diffuse reduction of FA values is evident in the TBI patient (blue prevalence), and quantified on the right column. [2]

Traumatic brain injury does not always have to be demonstrated by motor impairment but hidden non-motor like symptoms related to cognition and behaviour are altered in all forms of traumatic brain injury. This phenomenon and the nature of the population living with traumatic brain injury not being outspoken either demanding in their rights enforcement as well as the lack of insight into real impact of traumatic brain injury on society earned the traumatic brain injury the “silent epidemic” name. [4]

The strict algorithm-based treatment approach to Emergency and Intensive Care Medicine successfully saving lives of people sustaining traumatic brain injury has not been introduced adequately to intermediate or community Neurorehabilitation. The lack of systematic approach to Neurorehabilitation, general underfunding or difficulty accessing the services demonstrate the lack of financial efficiency following ever growing cost of live saving procedures and acute care. This also prevents the people living with traumatic brain injury to capitalise on the most valuable time for rehabilitative treatment and impacts on early achievements. Resultant severely increased care costs, unemployability and loss of income by the traumatic brain injury survivors but also often by family members providing care are other factors contributing to the widely underestimated social cost of traumatic brain injury.

Causes

The two most common causes of traumatic brain injury are Falls and Road Traffic Accidents, which includes vehicle collisions, pedestrians being hit by a vehicle, vehicle-cyclist and car-motorcyclist collisions as well as bicycle and motorbike crashes which do not involve another vehicle. Until recently, road traffic accidents were the primary cause of traumatic brain injury, but an international study published in 2013 reported that "falls have now surpassed road traffic incidents as the leading cause of this injury". [5]

Traumatic brain injury in sport has become a burning problem with clearly emerging long-term consequences. Many professionals have become involved in developing the evidence about complexity of symptoms, impact of its repetitive nature on brain health and long-term prognosis of sport related concussion. The evidence of its assessment and treatment as well as role in brain degenerative diseases is emerging and enhancing safety of those participating in sports like rugby, football, boxing, horse riding and racing, American football or ice hockey.

Global conflicts like the Global War on Terror had expose the military population to new pathomechanisms, but also enhance the development of subacute care and life-saving and neurosurgical procedures. [6] With the speed of global information share being faster than ever, the civil services benefit from military good practice dissemination.

Incidence

Traumatic brain injury has been a public health problem for many years, and for years to come will still be a main source of death and severe disability. According to World Health Organisation by 2020 traumatic brain injury will surpass many diseases as the major cause of death and disability. We are currently observing increasing number of traumatic brain injury due to medical advances in emergency medicine and intensive care but also due to decreasing fatalities as a result of safety and preventative measures such as decreased speed limits, use of helmets or development in army amours. Traumatic brain injury continues to be a critical health and socio-economic problem worldwide across low and high-income countries due its life-long consequences and can affect people at any age. Socioeconomic change of low and middle-income countries drives an increase in traumatic brain injury due to urbanisation and mechanisation

One study found that TBI was "a major cause of death and disability on the United States, contributing to about 30% of all injury deaths". [7] A 2010 study looked at data from several nations, and reported that:"each year 235 000 Americans are hospitalised for non-fatal TBI, 1.1 million are treated in emergency departments, and 50 000 die. A report from Victoria, Australia of traumatic brain injury numbers from 2006-2014 found a decline in the incidence of motor vehicle-related severe traumatic brain injury, suggesting that road injury prevention measures have been effective, but targeted measures for reducing the incidence of major head injuries from falls should be explored as in the over 65 age bracket these are on the rise. [8] The Northern Finland birth cohort found that 3.8% of the population had experienced at least 1 hospitalisation due to traumatic brain injury by 35 years of age, while the Christchurch, New Zealand birth cohort found that by 25 years of age 31.6% of the population had experienced at least 1 traumatic brain injury, requiring medical attention including hospitalisation, emergency department, or physician office. An estimated 43.3% of Americans have residual disability 1 year after a traumatic brain injury, with the most recent estimate of prevalence of US Civilian residents living with disability following hospitalisation with traumatic brain injury is 3.2 million". [9]

We are witnessing a change in traumatic brain injury distribution for age groups with childhood and aging being the highest risk population; gender with males being the most at risk between 10 and 20 years old and females between 70 and 80 [4], as well as mechanism contributing to injury with falls increasingly contributing to traumatic brain injury and blast related injury being most popular mechanism of battlefield sustained traumatic brain injury.

The incidence amongst children creates new challenges in the field of traumatic brain injury often overlooked like behavioural change or educational difficulties. Vulnerability to criminalisation amongst adolescents and young people with traumatic brain injury has been becoming another problem. Accessible housing and complex care needs follow the traumatic brain injury increasing incidence amongst elderly (Time for Change).

The access to emergency services as well as neurosurgical services determines mortality and recovery outcomes after traumatic brain injury across the world regions. In lower-income countries the access is scarce and determines higher numbers of severe disability post traumatic brain injury.

Mechanism of Injury

Closed Head Injury

  • Often occurs as a result of RTA, or a blow to the head, or a fall where the head strikes the floor or another hard surface..
  • In closed head injury, the skull is not penetrated, but it is frequently fractured.
  • Generally there is both focal and diffuse axonal damage.

Open Head Injury

  • This is caused by a penetrating wound, eg. by a weapon or from a bullet.
  • In these cases the skull is penetrated.
  • The brain injury is usually largely focal axonal damage.

Deceleration Injury

  • This frequently occurs in RTA, when rapid deceleration occurs as the skull meets a stationary object, causing the brain to move inside the skull.
  • Mechanical brain injury occurs due to axonal shearing, contusion and brain oedema.

Coup-Contracoup Injury

PP TBI.png

Coup Injury

This occurs beneath the point of impact - may be associated with a skull fracture at the site of impact

Contracoup Injury

This occurs when the impact is sufficient to cause the brain to move within the skull; the brain moves in the opposite direction, and hits the opposite side of the skull, causing bruising.

Coup-Contracoup Injury

This is a frequent occurrence - opposite poles of the brain suffer injury.

Classification

There are various classification determinants utilized to classify traumatic brain injury. The clinical presentation and prognosis depend on the individual nature of the injury with often coexisting types of traumatic brain injury. The classification is important for acute management, treatment and prognosis as well as neurorehabilitation requirements. Classifications may be based on Patho-anatomic ie. what damage has occurred where in the brain, Injury severity, typically using the Glasgow Coma Scale [GCS] as the measure, where a score of 8 or less is defined as Severe traumatic brain injury or by the Physical mechanism causing the injury, categorised as contact or "impact" loading when the head is struck or strikes an object, as oppsed to non-contact or "inertial" loading, which is when the brain moves within the skull.

Clinical Presentation

The presentation depends on the areas of the brain which have been damaged. Spasticity if one of the early signs of traumatic brain injury, which often develops within a week post injury. Symptoms include hypertonicity and spasm of the affected muscles and an increase in deep tendon reflexes; it's severity can range from mild stiffness of the muscles to severe, and often painful, muscle spasms.

Signs and Symptoms

Traumatic brain injury can have wide-ranging physical, cognitive, psychological and physiological effects occurring immediately or elapsed. The symptoms might differ depending on the severity of traumatic brain injury, but some are not specific to the type of injury.

Table 2. Symptoms of Mild Traumatic Brain Injury
Physical Symptoms Sensory Symptoms Cognitive Symptoms
With or without loss of consciousness. If loss of consciousness: a few seconds to a few minutes Blurred Vision State of being dazed, confused or disoriented
Headache Ringing in the Ears Memory or concentration deficits
Nausea or Vomiting Bad taste in the mouth or changes in the ability to smell Mood changes or mood swings
Fatigue or Drowsiness Sensitivity to light or sound Irritability
Problems with speech Feeling depressed or anxious
Difficulty sleeping or sleeping more than usually Fatiguability
Dizziness or loss of balance
Table 3. Symptoms of Moderate to Severe Traumatic Brain Injury
Physical Symptoms Sensory Symptoms Cognitive Symptoms
Loss of consciousness from several minutes to hours or days Blurred vision Coma and other disorders of consciousness
Persistent headache or headache that worsens Double vision Profound confusion
Repeated vomiting or nausea Ringing in the ears Irritability
Convulsions or seizures Bad taste in the mouth or changes in the ability to smell Agitation, combativeness or other unusual behaviour
Dilation of one or both pupils of the eyes Sensitivity to light or sound Sad or depressed mood
Clear fluid or blood draining from the nose or ears Fatiguability
Sudden swelling or bruises behind the ears or around eyes
Inability to awaken from sleep
Weakness or numbness
Loss of coordination or balance
Irregular breathing
Difficulty speaking

Diagnostic Procedures

Post acute traumatic brain injury, all patients are encouraged to undergo an urgent neurological examination in addition to a surgical examination. [10] Magnetic Resonance Imaging (MRI) and Computerised Tomography (CT) scanning are frequently used in order to image the brain. CT Scanning is indicated in the very early stages post injury. The EFNS guidelines confirmed that the use of CT Scans can be limited to patients with mild traumatic brain injury that present with certain clinical signs and symptoms. The CT Scan can show potential fractures and can detail haemorrhages and haematomas in the brain, as well as contusions and swelling. MRI is often used once the patient is medically stable to give a more detailed view of the brain tissue.

Table 4. Classification of Traumatic Brain Injury and indication for immediate CT Scan [10]
Classification Characteristics Referral for CT?
Mild
  • Hospital Admission
  • GCS 13 - 15
  • Loss of Concsiousness (if present) <30min
No
Category 1
  • GCS 15
  • 0 - 1 Minor Risk Factor (CHIP Rule)
  • Head Injury, No Traumatic Brain Injury
No
Category 2
  • GCS 15
  • > 1 Major Risk Factors
  • > 2 Minor Risk Factors (CHIP Rule)
Yes
Category 3
  • GCS 13 - 14
Yes
Moderate
  • GCS 9 - 12
Yes
Severe
  • GCS < 8
Yes
Critical
  • GCS 3 - 4
  • Reduced / Absent Pupillary Reactions
  • Reduced / Absent Motor Reactions
Yes
Glascow Coma Scale (GCS), Canadian CT in Head Injury Patients Prediction Rule (CHIP Rule)

Medical Management

The aims of initial emergency and early medical management are to limit the development of secondary brain damage, while providing the best conditions for recovery from any reversible damage that has already occurred. Establishing and maintaining a clear airway with adequate oxygenation and replacement fluids to ensure good peripheral circulation with adequate blood volume.

Surgical Interventions

Emergency surgery is often required to decompress the injured brain and minimize damage:

  • surgery to remove haematoma and thus reduce pressure on brain tissue;
  • removal of part of the skull in order to relieve pressure;
  • surgical repair of severe skull fractures, and/or removal of skull fragments from brain tissue;
  • insertion of an ICP Monitoring Device. [11]

Medical Interventions

Medication may also be used to limit secondary damage to the brain

  • Coma-inducing medication may be given, as a brain in coma requires far less oxygen, so if there is reduced oxygen and nutrient supply due to blood vessels being compressed by increased pressure, being in coma is therapeutic;
  • Diuretics, given intravenously, can be used to reduce the amount of fluid in soft tissues and thus help reduce pressure on the brain;
  • Anti-epileptic medication is often provided in the early stages to avoid any additional brain damage, which may be caused if a seizure were to occur.[11]

Physiotherapy Management

Just as two people are not exactly alike, no two brain injuries are exactly alike. Therefore, the approach to Neurological Rehabilitation and Physiotherapy post Traumatic Brain Injury should observe neuroplasticity, motor learning and motor control principles as well as a patient-centred approach with individual involvement in goals setting and choice of treatment procedures.

  • Initial treatment during the acute phase focuses on promoting respiratory health and prevention of secondary adaptive changes to the musculoskeletal system.
  • Subacute physiotherapy management focuses on provision of an appropriate environment to assist functional recovery and on assisted practice of meaningful tasks , relevant to the ability of the individual, using a full range of treatment modalities.
  • Postacute physiotherapy management focus on reversing secondary adaptive changes and improving specific motor skills with a focus on functional goals for day to day activities, and is dependent on skilled sensorimotor assessment and a collaborative approach with other team members, the individual and family. This stage ca include inpatient, outpatient and community based settings and for some individuals may require lifelong access to services including planned reviews.[11]

Summary

With the complexity of the traumatic brain injury and its consequences there is no speciality capable to deal with them alone. In traumatic brain injury management the role of Multidisciplinary Team is invaluable with Physiotherapist / Physical Therapist role at its heart form acute to chronic stages.

The currently growing insight into devastating impact of traumatic brain injury on individual’s, families’ and society’s life initiates widespread change in research and evidence implementation resulting in prevention, services design, legislation and funding. We are seeing developments in neuroprotective and neurorestorative treatments and therapeutic approaches driving the neuroplastic change at cell and network levels. We are accessing more precise diagnostic enabling more effective treatment choices. We are capitalising on gains of more advanced medical and rehabilitation centres with knowledge and evidence being widely shared. We are living in truly exciting times when more than ever can be done for traumatic brain injury survivors.

Resources

BrainLine An American multimedia website providing information and resources about treating and living with TBI; it includes a series of webcasts, written online resources and an electronic newsletter. It has a version in Spanish too.

Model Systems Knowledge Translation Centre (MSKTS)  The Model Systems Knowledge Translation Centre works closely with researchers in the 16 Traumatic Brain Injury Model Systems to develop resources for people living with traumatic brain injuries and their supporters. These evidence-based materials are available in a variety of formats such as printable PDF documents, videos, and slideshows.

Headway A UK charity for TBI which has a comprehensive website, with information on the different aspects of TBI and its rehabilitation. It has a number of useful written resources for patients on the website, including ones on Brain Injury and Epilepsy, Loss of Taste and Smell after Brain Injury and Balance Problems and Dizziness after Brain Injury

References

  1. Menon DK, Schwab K, Wright DW, Maas AI; Demographics and Clinical Assessment Working Group of the International and Interagency Initiative toward Common Data Elements for Research on Traumatic Brain Injury and Psychological Health. Position statement: definition of traumatic brain injury. Archives of Physical Medicine and Rehabilitation. 2010 Nov;91(11):1637-40. doi: 10.1016/j.apmr.2010.05.017.
  2. Cavaliere C, Aiello M, Di Perri C, Fernandez-Espejo D, Adrian M. Owen AM, Soddu A. Diffusion tensor imaging and white matter abnormalities in patients with disorders of consciousness. Frontiers in Human Neuroscience. 2015 Jan;8:1-7. doi.org/10.3389/fnhum.2014.01028
  3. Shepard Centre. Understanding Traumatic Brain Injury. Available from: https://youtu.be/9Wl4-nNOGJ0[last accessed 30/08/19]
  4. 4.0 4.1 Peeters W, van den Brande R, Polinder S, Brazinova A, Ewout W, Steyerberg EW, Lingsma HF, Maas AI. Epidemiology of traumatic brain injury in Europe. Acta Neurochirurgica. 2015;157:1683–1696. DOI 10.1007/s00701-015-2512-7
  5. Changing patterns in the epidemiology of traumatic brain injuryfckLRBob Roozenbeek, Andrew I. R. Maas & David K. Menon Nature Reviews Neurology 9, 231-236 (April 2013)
  6. Baker MS. Casualties of the Global War on Terror and their future impact on health care and society: a looming public health crisis. Military Medicine. 2014 Apr;179(4):348-55. doi: 10.7205/MILMED-D-13-00471.
  7. Traumatic brain injury in the United States: emergency department visits, hospitalizations, and deaths. Faul M, Xu L, Wald MM, Coronado VG. Atlanta (GA): Centers for Disease Control and Prevention, National Center for Injury Prevention and Control; 2010
  8. Medical journal of Australia. Trends in severe traumatic brain injury in Victoria, 2006–2014 (last accessed 15.5.2019)
  9. The Epidemiology of Traumatic Brain InjuryfckLRCorrigan, John D. PhD, ABPP; Selassie, Anbesaw W. DrPH; Orman, Jean A. (Langlois) ScD, MPH The Epidemiology of Traumatic Brain Injury March/April 2010 - Volume 25 - Issue 2
  10. 10.0 10.1 Vos PE, Alekseenko Y, Battistin L, Ehler E, Gerstenbrand F, Muresanu DF, Potapov A, Stepan CA, Traubner P, Vecsei L, Von Wild K. Mild traumatic brain injury. European Journal of Neurology. 2012 19 (2): 191-198. 
  11. 11.0 11.1 11.2 Stokes M, Stack E, editors. Physical Management for Neurological Conditions E-Book. Third Edition. Elsevier Health Sciences; 2011 Apr 19.
  12. Brain Line. Living with a Traumatic Brain Injury. Available from: https://youtu.be/dyqGys9Htbo[last accessed 30/08/19]
  13. TEDx Talks. Follow the patient | Ben Clench | TEDxBrighton. Available from: https://youtu.be/2f1ueKZ8Rxc[last accessed 30/08/19]