Traumatic Brain/Head Injury (TBI)
Damage to living brain tissue caused by an external mechanical force. Common cause of death before age 50 yrs (10% of all deaths in USA). Mortality of 50% in severe cases.
Damage occurs to all tissues (neural, blood, meninges) – also get varying amounts of intra- and/or extra-cerebral ischaemia, haemorrhage and oedema. The haemorrhage and oedema act as space occupying lesions focal neurological deficits. Intracranial swelling herniation of brain tissue. Cranial fractures may lacerate arteries and meninges CSF leakage and/or entry of air and bacteria. Large amount of neurotransmitters are released, especially glutamate (excitatory) activation of ion channels calcium inlfux into cells --. increase in cellular metabolism and increased production of free radicals further damage.
50% are due to motor vehicle accidents; also commonly due to falls, assaults and failed suicide attempts.
No two cases of head injury are the same.
Concussion (loss of awareness and memory; unresponsiveness); contusions and laceration to cranium hemiplegia and focal neurological signs. If more severe rigidity of muscles, coma, hemiplegia, dilated and unreactive pupils, respiratory irregularity); if severe non-penetrating trauma coma, respiratory irregularity, unresponsive pupils, diffuse motor flaccidity
If subdural haematoma coma, wide pulse pressure, dilated and fixed pupils, spastic hemiplegia, hyperreflexia, rigidity (mortality and morbidity high following subdural haematoma)
10-40% develop epilepsy, up to several years later
Tend to have more cognitive and behavioural impairments than those with a stroke.
Initial – stabilise patient; clear airway; control acute bleeding; prevent further damage (eg spinal fracture)
Hospital – airway secured; IV lines; respiratory assistance; determine severity (eg Glasgow Coma Scale); CT or MRI (for determination of bleeding and to determine operable haematomas); neurosurgery for displace cranial fractures; protection against heat loss, fluid imbalances and airway obstruction; monitor for renal failure, convulsions; may need sedation
Rehabilitation – amnesia and post-concussion syndrome are common; physiotherapy and occupational therapy
Scales for measuring function and outcomes of those with TBI – eg Glasgow Outcome Study, Disability Rating Scale, Functional Independence Measure, Western Neuro Sensory Stimulation Scale
Concussion and the lower limb and as a public health issue (Podiatry Arena)