Pathology of Trauma Flashcards
What are the five types of skull fracture?
Linear Depressed Comminuted 'Ring' 'Contre-coup'
Describe linear skull fractures
Commonly temporo-parietal from blow of fall onto top of the head and may continue onto the skull base - ‘hinge fractures’
Describe depressed skull fractures
Focal impact may push fragments inwards to damage the meninges, blood vessels and the brain
Risk of meningitis and post-traumatic epilepsy
Not typical of a fall onto a flat surface
What is a comminted fracture?
Fragmented skull - mosaic fracture
What is a ring fracture?
Fracture line encircling the foramen magnum caused by a fall from height, usually landing on the feet but sometimes on the head, leads to skull base and cervical spine being forced together
What is a contre-coup fracture?
Fracturing of the orbital plates caused by a fall onto the back of the head
Outline intracranial haemorrhage
Named by their position within the skull in relation to the meninges (extradural, subdural, subarachnoid)
Often caused by blunt force trauma, diagnosis challenging
Accumulation of blood within the rigid skull causes an increase in ICP which results in compression of the brain. The compression causes symptoms such as reduction in consciousness, and will ultimately cause death be compression of the brainstem due to herniation of the cerebellar tonsils into the Foramen Magnum
Describe extradural haemorrhage
Bleed between the dura and the skull, stripping the dura off the skull
Vast majority arise from arterial damage as a result of skull fracture - classically from the middle meningeal artery due to fracture of squamous temporal bone
Resulting haematoma causes raised ICP with developing symptoms
Lucid interval can occur but can deteriorate catastrophically later
Describe subdural haemorrhage
Bleed beneath the dura, usually from brdging veins that pass from bain surface to drain into the large venous channels within the dura - rotational or shearing force can sever these veins, causing substantial bleeding
Frequently occurs with skull fracture
Lucid interval may be seen
Chronic subdural haematoma may result, particularly in the elderly and can be mistaken for dementia
Describe subarachnoid haemorrhage
Bleeding beneath subarachnoid layer, natural disease is most common cause - rupture of cerebral artery ‘berry’ aneurysm
Frequently seen in association with cerebral contusion
Collapse is usually rapid and death can occur very quickly due to irritant effects of blood in the subarachnoid space
Describe cerebral oedema
Common and rapid result of brain injury, especially in children
Can develop in minutes and lead to a massive brain swelling with raised ICP and ‘coning’
What is a diffuse axonal injury?
Widespread axonal destruction, multiple minute haemorrhages throughout white matter
Not always caused by trauma, therefore traumatic DIA (tDIA) is used
Often result of traumatic injury with rapid deceleration e.g. vehicular collisions, falls from height
Diagnosis can only be made with microscopy of the brain tissue
Clinically patients are comatose when tDAI is fully developed
Which areas of the brain are particularly susceptible to diffuse axonal injury?
Corpus callosum Para-sagittal white matter Posterior internal capsule Rostral brainstem Cerebellar peduncles
