TBI Flashcards
What is TBI?
Result of an external physical force to the brain causing transient or permanent neurological deficit
M:F TBI?
3-4:1
Age group most affected by TBI?
15-35
What are the main mechanisms of TBI?
- Focal pathology 2” contact (e.g. falls, assault)
- Diffuse pathology a/w acceleration / deceleration (e.g. traffic accident)
Brain also injured as a result of primary injury and secondary effects from the injury
What may focal brain injury cause?
- Lesion of scalp, skull and dura
- Surface contusions and lacerations to the brain
- Intracranial haematoma
What are skull fractures strongly associated with?
Development of intracranial haematoma
Where may contusions be located and what are they termed?
- Site of injury = coup
2. Opposite point of contact = contrecoup
Where are contusions more likely to be located?
Frontal and temporal lobes
Where may intracranial haematomas be located?
- Extradural: ovoid mass of blood between bone and dura
- Intradural: SAH, SDH, ICH
What are diffuse brain injuries?
Pathologies associated with acceleration / deceleration injuries.
What are diffuse brain injuries called?
Diffuse axonal injury (DAI)
What are the features of DAI?
- lesions of corpus callosum and other midline structures, parasagittal white matter, inter ventricular septum and walls of third ventricle
- Focal lesions in one or both dorsolateral sectors of the rostral brain stem
- Microscopic evidence of widespread damage to axons
What are the secondary mechanisms which may cause brain injury?
- Raised ICP
- Localised oedema around contusions
- Hypoxic damage
- Neurochemical / cellular changes
What are the types of consequences of head injury?
- Neurological impairment
- Medical complications
- Cognitive / behavioural complications
- Longer term lifestyle difficulties
What are the common neurological complications of TBI?
- Visual changes, esp diplopia CNVI palsy), altered accommodation and hemianopia
- Anosmia (40%)
- high level balance / coordination difficulties / vertigo / dizziness
- focal neuro deficits less common, related to focal trauma (e.g. assault with blunt instrument)
What are the likely medical complications of TBI?
- Spasticity
- Post traumatic epilepsy
- Heterotopic ossification
- Hydrocephalus (less common)
- Endo: SIADH and DI
- Psych e.g. depression
Type and management of spasticity post TBI?
May be generalised but usually causes focal problem.
- Rx: baclofen, botox if focal
- PT e.g. positioning, stretching
What is baclofen?
- CNS depressant and muscle relaxant
- GABA receptor agonist
- Beneficial effects in spasticity result from action at spinal and supra spinal sites
Prevalence post traumatic epilepsy?
8%
High risk injuries for development post traumatic epilepsy?
- Open head injuries
- Penetrating injuries
- Large intracerebral bleeds
- Pts who have early seizure (24h>7d)
Impact of seizures in first 24h on development of post traumatic epilepsy?
DO NOT IMPACT
What is heterotopic ossification?
Laying down of abnormal bone around joints
How does heterotopic ossification present?
Increased pain, heat, redness, swelling, decreased movement and often increased spasticity
How is heterotopic ossification confirmed?
Triple phase bone scan
How is heterotopic ossification managed?
- Indocid
- Surgery if functional impact once bone activity has ceased
Where does heterotopic ossification most commonly affect?
In order:
- hip
- elbow
- shoulder
- knee
When is hydrocephalus usually detected?
Rare complication; usually identified when pt function deteriorates or plateaus early in rehab
What is PTA associated with (in addition to impaired memory)?
- Poor orientation
- Poor attention
- Disrupted sleep wake cycle
- Fatigue
- Capacity for easy overstimulation
- Potential for significant agitation
How is PTA measured?
- Period during which there is no reliable day to day memory. -Measured from time of injury EVEN IF PT IN COMA
- measured using Westmead Scale (12pt) > orientation and memory
When is a pt considered out of PTA?
Must score 12/12 for 3 consecutive days to be considered out of PTA
Ideal management of PTA?
- Head injury service
- Single room
- Min stimulation
- Restricted visitors
- Reduce noise etc
- Usu no therapy except to avoid complications (e.g. PT to min spasticity)
What is indicated by PTA
Minor head injury (concussive type): quick and full recovery with appropriate management (except post concussion syndrome)
What is indicated by PTA 24h-1w?
Moderate injury: recovery over months; may have residual problems but good functional recovery
What is indicated by PTA 1-2weeks?
Moderate injury: good functional recovery over months
What is indicated by PTA 2-4w?
Moderate-severe injury: prolonged recovery process over 1-2y. Permanent deficits likely.
What is indicated by PTA >4w?
Severe injury - permanent deficits certain. Likely significant disability.
What is PTA a marker of?
Cognitive deficits; NOT physical or language based disorders
what are the most likely cognitive / behavioural problems post TBI?
- Memory impairment esp new learning
- Frontal executive problems (problem solving, planning and organisation, idea generation, rigidity of thinking, judgement, impulsivity). Increased frustration, lack of insight, disinhibition.
- Reduced attention (time, detail)
- Fatigue
- Reduced speed of information processing
What are the main aims of TBI rehab?
- Monitor duration and reduce behavioural effects of PTA
- Prevent complications / medical conditions
- Assess cognitive and functional status on emergence from PTA
- Remediate disability / activity limitation
- Provide education for patients and carers
- Follow up
What are the longer term participation restrictions of TBI?
- Inability to return to work, $ stress
- Difficulties maintaining and forming personal relationships
- Minimal participation in recreation activities
- Increased strain on family supports
- Difficulties with independent living
What is post concussion syndrome?
Subgroup of patients who develop persistent symptoms following minor head injury. Sx=
- HA
- Dizziness
- Complaints of memory disorder esp STM
- Fatigue
- > 3m post event
Initial PTA Mx issues?
- appropriate PTA Mx (environment)
- Assess basic physical functioning
- Monitor behaviour, educate carers
- Manage SIADH / other medical
Mx issues on emerging from PTA?
- Formally assess cognitive state (1-3w post PTA)
- Assess competency
- Educate client and carers re potential outcome given duration
- Education re drugs and alcohol
- Education re driving (not for 3months, may need OT assessment)
- Assess functional implications of injury
- Assess ability to live independently
- Refer to appropriate services
Issues to review in OP follow up TBI? ~6w post discharge
- When to act on vocational rehab referral
- Medically clear for driving assessment
- Continue to encourage EtOH abstinence
- Regular review on scheduled program (1,2,3,5,7,10y)
