Brain Trauma

Introduction

Acquired brain injury (ABI) as a "silent epidemic". The term "silent epidemic" is used to characterize several undermining aspects related to ABI. On the one hand, the consequences are sometimes not visible in the short term and, on the other hand, a misperception of the level of prevalence and unfamiliarity of society with the long-term consequences in general.

A brain trauma, regardless of the cause, is not an event or a final endpoint but rather a starting point of a complex dynamic disease process. Injury of the brain initiates a multitude of cascades affecting multiple organ systems, disease-causing and disease-accelerating.

What form this will take, how extensive or severe the consequences will be per individual, depends on type of injury, severity of injury, age, gender, education, nutrition, prior brain traumata, among others.

As a result, symptom patterns can vary from one individual to another, making it challenging to diagnose, understand and treat if one relies only on symptoms. Additionally, the absence of objective evidence of symptoms does not mean that there is no damage. After all, complaints depend on brain and cognitive reserve that also varies from one individual to another, as this depends for example on age, education and intelligence.

TBI/ABI

A traumatic brain injury, is not only the most common brain injury, but also one of the most heterogeneous.
Over 10 years ago, research indicates that brain damage resulting from an acquired brain injury (ABI) involves more complex, long-term and intertwined processes than researchers previously recognised.

A traumatic brain injury (TBI) can lead to neurological, physical, emotional and neuropsychological changes and deficits that depend on the severity of the injury. However, it should be emphasised that the severity classifications are being used do not in themselves predict the extent of injury or resulting dysfunction.

Although all types of TBI share common features, children's immature brains respond differently to trauma than adult brains.
For example, children are more likely to have post-traumatic brain swelling, hypoxic-ischemic injury and diffuse rather than focal injury.
Compared with adults, children have a greater head-to-body ratio with the head supported by a weakly muscled neck, great flexibility of the cranial bones, less myelination and a greater relative ratio of water content and cerebral blood volume.

Toxic Brain Injury

Acute toxicity occurs almost immediately (seconds/minutes/hours/days) after an exposure. An acute exposure is usually a single dose or a series of doses within a 24-hour period. 
Chronic toxicity represents cumulative damage and takes many months or years to become an identifiable clinical illness. With repeated exposure or long-term continuous exposure, the damage from this type of exposure slowly builds up (cumulative damage) until the damage exceeds the person-borne threshold at which a various chronic toxic effects may occur; delayed symptoms.

Inhalation of toxic substances can occur in the work environment, not only as a result of an unanticipated incident but also by being in a work environment where people are unaware or insufficiently aware of the dangers of the substances present in the air. But one can also be exposed to toxic substances in the residential environment if one is near industry, an airport, or your home was built on an old industrial site that has not been remediated.

Toxic damage to the nervous system results from: 

  • Direct damage and death of neurons and glial cells.
  • Disruption of electrical signal transmission.
  • Disruption of chemical neurotransmission.
Inflammatory Brain Injury

Among the various pathological events that can lead to neuroinflammation are viral or bacterial invasions. HSV-1 infection causes brain damage via inflammation, mainly in the temporal and temporofrontal regions. Other brain regions can also be damaged.

When HSV-1 infects plasma membrane water-transporting proteins, it will lead to delayed removal of cerebrospinal fluid and degradation products. This slower disposal can also lead to the damaging build-up of β-amyloid plaques, which in turn can cause neurodegenerative diseases. A disrupted glymphatic system will exacerbate inflammation by suppressing cytokine discharge. This increases the number of cytokines present which in turn worsens neuroinflammation. Together with the accumulation of metabolic wastes a vicious cycle is created that maintains neuroinflammation. Inflammation disturbs sleep that will also fuel inflammation. As a result, acute inflammation will evolve into chronic inflammation that is the primary cause of a wide spectrum of autoimmune diseases, such as neurosarcoidosis, multiple sclerosis.

Blast Induced Brain Injury

An explosion in an open space, causes a pressure wave consisting of a momentary increase in overpressure caused, followed by a negative pressure phase, before returning to ambient pressure.
In the event of an explosion, such as the terrorist attack in Brussels, London and Madrid, in an enclosed space (e.g. a bus, metro or building) the maximum pressure is greatly enhanced because the explosive forces are contained. The enclosed space increases the peak overpressure and the duration of the positive pressure phase. The resulting complex explosive pressure curve has multiple peaks attributable to reflected pressure waves and may have a short static hyper-pressure phase.

During this process, people near the explosion may be injured by five mechanisms:

  1. the overpressure wave (primary injury),
  2. debris (secondary injury),
  3. physical displacement of a person's body (tertiary injury),
  4. heat and toxic substances (quaternary injury), and
  5. environmental pollutants (quaternary injury). 

The extent of brain and body injuries caused by the blast wave depends mainly on five factors:

  1. the peak of the initial positive pressure wave,
  2. the duration of the overpressure,
  3. the medium of the explosion,
  4. the distance to the incident blast wave, and
  5. the degree of targeting due to an enclosed area or walls.
Post Traumatic Stress Disorder (PTSD)

People with a traumatic brain injury, regardless of severity, can face a huge variety of potentially stressful events.
These involve the need to adapt to a new situation, including prolonged hospitalisation, medical interventions, absence from school or work, possible injuries beyond brain injuries, pain, at least a temporary loss of independence, possible disability and sometimes dramatic changes in relationships and careers.


A brain injury can therefore be regarded as both a physical and an emotional stressor.
Furthermore, these adaptive processes are in addition to a nervous system that may have a reduced ability to assess or optimally respond to stressors both physiologically and psychologically.

The ability to adapt to this is determined by multiple factors.

  • Age at the onset of the brain-damaging condition, the pattern of cerebral dominance, cultural and historical background, life situation and psychological make-up also influence how a person responds to the physical injury and its social and psychological consequences.
  • Moreover, the life changes experienced by people with brain injury are dynamic and reflect the constantly changing interactions between behavioural disorders and remaining abilities, an individual's appreciation of their strengths and weaknesses, and the support or pressure from family, social and financial factors.

Author: Daniel Dumalin | Date: 28/08/2023 | Last update: 21/09/2023