CASE 1: TBI Flashcards
(21 cards)
What is a TBI
An injury to the head from an external mechanical force that may damage the scalp, skull or brain (leading to temporary or permanent impairments)
What is the etiology of a TBI?
A result of an external force impacting the head that strikes or penetrates the skull.
Two forms:
- Coup injury
- Contrecoup injury
What is a coup injury?
Occurs at the site of impact when an external force strikes the head. The brain slams against the inside of the skull at the point of impact causing damage.
What is a contrecoup injury?
As the head moves in response to the impact, the brain rebounds and strikes the opposite side of the skull, causing additional injury on the side opposite to the initial blow.
What is a focal injury
- Localised brain damage (often with bleeding), usually from a direct blow/penetrating injury (coup)
*Closed = skull isn’t broken & penetrating/open = skull is broken by an object
Provide 3 examples of primary brain damage following TBI?
Subarachnoid Haemorrhage: bleeding into space around the brain
Intracerebral haemorrhage: bleeding within brain tissue (dangerous raises pressure in the brain)
Diffuse axonal injury = shearing of brain cells
Secondary response to TBI
- Inflammation = release of cytokines and other immune cells = breakdown of blood brain barrier = inflitration of cells that damage brain tissue
- Oedema (brain swelling) = increases ICP
- Cerebral metabolic dysfunction = the brains ability to use 02/glucose is impaired = worsens injury
- Vasospasm and hypoperfusion = constriction of cerebral blood vessels = < blood flow = ischaemia/tissue damage
- Excitotoxicity and oxidative stress = excess glutamate released and overstimulation of neurons leads to calcium influx which damages brain
- Excessive apoptosis = increase in programmed cell death
Main complication from Oedema
Increase in ICP can cause a cerebral herniation = displacement of brain tissue from its normal position
RISK OF DEATH from respiratory arrest (medullary compression)
Requires close monitoring of GCS
Define the types of amensia
What are the categories of post-traumatic amnesia
Retrograde = memory loss for events before the injury
Post-traumatic = confusion/inability to make new memories (assessed via GCS + Westmead PTA scale).
Categories:
- < 24 hrs = mild
- 1-7 days = mod
- 1-4 weeks = severe
- More than 4 weeks = v severe
Most common group to experience a TBI
Elderly (due to risk of falls) = 41% of TBI’s
Followed by MVA (27%) and intentional self-harm (9%)
Risk factors for TBI (SCARFET)
Soldiers/Army
Contact sports eg rugby
Addicts
Road users/Drivers
Farmers
Elderly
Toddlers
What gender/age group is most at risk?
Males (2:1 ratio)
15- 24 year age group
*Lower incidence from 35-75, this increases at 75+ = falls = greater risk of TBI
What factors are associated with worse prognosis?
- Age (older = worse)
- Clinical severity = intracranial worse than extracranial
- Secondary insults: complications can cause further brain damage eg low 02 or low BP
- Structural abnormality on CT eg bleeding/swelling = poorer recovery
- Biomarkers
- Setbacks ie deterioration due to infection/swelling/seizure = delayed recovery
Surgical management of TBI
- Evacuation of haematoma
- Decompressive craniectomy
- Insertion of EVD’s/ICP monitors
- Surgical consultation and monitoring
Medical management of TBI
Anaesthetic: Used to induce unconsciousness during procedures such as intubation or surgery, and helps reduce cerebral metabolic rate and intracranial pressure (ICP).
Analgesia: Manages pain (often with opioids like fentanyl), which helps limit sympathetic responses that can raise blood pressure and ICP.
Sedatives: Medications such as propofol or midazolam are used to reduce agitation, lower brain oxygen demand, and improve synchrony with mechanical ventilation.
Ventilatory management: Mechanical ventilation is used to maintain normal oxygen and carbon dioxide levels, preventing hypoxia or hypercapnia that can worsen brain injury.
Hypothermia: Mild therapeutic hypothermia may be used to reduce brain metabolism and limit swelling, but carries risks such as infection and bleeding.
Infection, DVT & seizure prophylaxis: Preventative measures like antibiotics, anticoagulants, and anti-epileptics help reduce the risk of pneumonia, blood clots, and seizures after TBI.
Ongoing Physiotherapy management of TBI
- Impairments eg strength or balance
- Preventing contracture with low load prolonged stretching (daily)
- Task specific training eg bounding
- Strategies to address TBI impairments eg visual/auditory cues/written instruction/etc
Acute Physiotherapy management of TBI
- Optimising respiratory function: early mobilisation and positioning. TT - support medical team for early decannulation (weaning parameters)
- Early sitting and standing (even if still in coma)
- Management of spasticity and prevention of contractures
Evidence for TBI
A: Cardiorespiratory fitness
B: task-specific training eg STS, VR/conventional balance training and fine motor tasks for coordination
Clinical presentation of TBI?
- Impaired motor planning
- Decreased strength or coordination
- Sensory changes
- Muscle tone/spasticity
- Balance and proprioception deficits
- Delayed reaction time
- Cognitive challenges affecting attention, memory and dual tasking
What are the chronic phase complications for TBI
- Epilepsy: May start months or years after the injury.
- Autonomic Impairments: problems with thermoregulation, sweating, low heart rate and respiratory frequency, deregulated blood pressure
- Motor Impairments: hemiplegia; abnormal reflexes, initial flaccid tone that progress to spasticity
- Cognitive and Behavioural Impairments
- Cranial Nerve Injury: Permanent of temporary according to location and severity of injury
- Heterotopic Ossification: bone formation in the soft tissue (prolonged coma)
- Diabetes insipidus: Rare. Central. Related to injury to the pituitary
- Hydrocefalus: Haemorraghe in the ventricles or subarachnoide space
Impairments
Primary:
- Motor (weakness, dexterity, spasticity)
- Sensory
- Language (aphasia - receptive/expressive)
- Cognitive/perceptual eg slowed information processing, inattention, memory loss, spatial (neglect)
- Behavioural
Secondary
- Reduced fitness
- Depression
- Pain
