What is an Acquired Brain Injury (ABI)?
An Acquired Brain Injury (ABI) refers to any damage that occurs to the brain after birth as opposed to congenital or hereditary brain conditions.
Common causes of an ABI:
Lack of blood flow or oxygen supply
Stroke: One of the most common causes, strokes occur when blood flow to the brain is stopped or disrupted. It can be in the form of a blocked artery (ischemic stroke) or burst blood vessel causing bleeding into surrounding tissues (haemorrhagic).
Hypoxia: This is when brain cells die due to reduced oxygen supply to the brain.
Cardiac Arrest: This can result in an interruption of blood flow to the brain.
Traumatic external forces
Traumatic Brain Injury (TBI): This refers to any trauma to the brain from an external force, such as a direct blow to the head, crush injury, or penetration injury. They commonly occur due to falls, motor vehicle accidents, sports injuries and assaults.
Infections and tumours
Meningitis or Encephalitis: Infections such as these cause inflammation of the brain or its surrounding tissues and as such may result in brain damage.
Tumours: Both cancerous (malignant) and noncancerous (benign) tumours in the brain can cause damage by killing brain cells and put pressure on healthy tissue within the enclosed space of the brain as they grow. Sometimes treatment may also damage healthy tissue.
Toxins and substance abuse
Exposure to Neurotoxins: Natural or manmade toxins such as heavy metals or carbon monoxide can cause damage to the brain when inhaled or ingested.
Substance abuse: Chronic alcohol or drug abuse can result in brain damage, either due to toxic effects or by triggering conditions that impair the brain’s oxygen supply.
Neurodegenerative conditions
Neurodegenerative conditions: Disorders such as Multiple Sclerosis, Parkinson’s Disease, Alzheimer’s Disease and Huntington’s Disease can lead to ABIs due to progressive brain damage over time. However, these conditions often have their own unique exercise implications and are treated differently.
Consequences of an ABI
The effects of an ABI vary considerably person to person and are primarily determined by which area/s of the brain are affected and the severity of the injury. Age at the time of injury, duration of time since the injury occurred and social support systems available (e.g. family support, community resources) also factor into the effects of an ABI.
Consequences can include:
Cognitive impairments include deficits in memory, attention and arousal (e.g. lethargy, fatigue, distractibility), language and communication organisation (e.g. ability to recall words, names or objects [dysnomia] and difficulty with high-level receptive and expressive language) and planning and organisation (e.g. goal setting, making and keeping appointments).
Physical impairments such as impaired strength, increased muscle tone (hypertonia), contracture, impaired coordination and balance (ataxia), paralysis, hearing issues, visual disturbances, cardiorespiratory fitness reduction, tremor and seizure disorders and chronic pain.
Behavioural impairments include lack of acceptable social restraint (disinhibition), impulsivity and self-focussed and less aware of the needs and feelings of other people around them (egocentricity).
Social consequences often arise from behavioural impairments and can be expressed by difficulty forming and maintain close personal relationships, disruption to family life, unemployment, social isolation and loss of access to social routines (e.g. work, education, family events, leisure activities, community engagement).
Mental health and emotional consequences that can present include depression, anxiety, suicidal tendencies, loss of role and self-identity, emotional instability, irritability.
How exercise helps and the role of exercise physiologists
Individuals with an ABI are among the most physically inactive members of society, with those experiencing severe brain impairments being less active than those with mild to moderate impairments. This lack of physical activity negatively impacts health, fitness, and function, further exacerbating the primary impairments caused by ABI. Strong scientific evidence supports the following:
Aerobic exercise enhances cardiorespiratory fitness in people with ABI, with the recommended quantity and intensity of exercise being similar to that of the general population.
Resistance training boosts muscular strength in individuals with ABI. While the exercise intensity and volume needed for improvement are comparable to the general population, it’s important to note that no studies have specifically examined the effects of strength training on individuals with ABI who have spastic hypertonia, an impairment that could potentially influence outcomes.
Regular functional exercises (such as sit-to-stand, walking, and climbing stairs) can improve the ability to perform daily tasks (for example, making sit-to-stand transitions easier, increasing walking speed, or extending walking duration).
Exercise can help reduce depressive symptoms while enhancing other aspects of mood and overall quality of life.
Additionally, exercise, especially in group settings, offers structured opportunities for social interaction and the development of social skills.
Accredited Exercise Physiologists (AEPs) can evaluate a person’s physical abilities and create a personalized exercise program to meet their specific needs. These programs will focus on enhancing balance, mobility, overall muscle strength, and cardiorespiratory fitness. All these factors are essential for improving the quality of life for individuals living with an ABI.
Renae Hay – Exercise Physiologist
References
Exercise is Medicine Australia. (2022). Acquired brain injury and exercise. Exercise is Medicine Australia. https://exerciseismedicine.org.au/wp-content/uploads/2022/03/EIM-FactSheet_ABI_Prof_2022.pdf
Exercise Right. (2024). Acquired brain injuries. Exercise Right. https://exerciseright.com.au/acquired-brain-injury/