24/05/2024
Head Injury is a frequent cause of emergency department attendance, accounting for approximately 3.4% of all presentations with an incidence of around 450 cases per 100000 population per year In the UK around 500000 children with head injuries attend hospitals every year and
head injury admissions account for nearly 10%.
Head injury associated with Traumatic Brain Injury TBI occurs at an incidence of 20-40 cases per 100000 population per year. most common cause of death in young adults aged 15-24 years and more common in males than females.RTA are most common cause of TBI in the UK.
The cost of poor outcomes from TBI is measured not only in personal terms but also in socio-economic costs of neuro-rehabilitation, long-term nursing care supportive care and lost income generation.
🔬Pathophysiology:
Cerebral blood flow and autoregulation :
Normal CBF is approx 55ml 100g min, maintained by cerebral autoregulation Mean arterial pressure of b/w 50 and 150 mmHg.
Intracranial pressure and brain herniation:
The brain is confined by a rigid container, the skull, mass lesion displacement of CSF and venous blood out of the intracranial cavity.
🧪Primary vs. secondary brain injury
Primary injury occurs at the time of impact and includes injuries such as the Brainstem and hemispheric confusion, diffuse axonal injury and cortical lacerations.
The secondary injury occurs after the moment of impact and is often preventable, causes are hypoxia, hypotension, raised ICP, reduced cerebral perfusion pressure and pyrexia.