Pathology of Head Injury Flashcards
What are the clinical aspects of head injury?
Primary insult- focal and/or diffuse brain trauma Secondary insults: -Hypotension -Hypoxia -Infection -Haematoma
How is head injury initially assessed and how does this translate to severity of head injury?
Glasgow Coma Scale
13-15= mild injury
9-12= moderate injury
3-8= severe injury
What are the complications of head injury?
Permanent physical disability Post traumatic epilepsy Intracranial infection Psychiatric illness Chronic subdural haemorrhage "Punch-drunk" dementia Fatal outcome
What are the different kinds of skull fractures?
Linear- commonly temporo-parietal from trauma
Depressed- focal impact which may push fragments inwards
Comminuted- fragmented skull
Ring fracture- fracture line encircling the foramen magnum
Contre-coup fractures- fracturing of the orbital plates caused by a fall onto the back of the head
What are the consequences of intracranial haemorrhage?
Accumulation of blood within the rigid skull causes an increase in intracranial pressure and results in compression of the brain, this causes symptoms including a reduction in conscious level
As ICP increases without intervention ultimately death will occur by compression of the brainstem due to herniation of the cereberllar tonsils into the foramen magnum
Describe the characteristics of an extradural haemorrhage
Bleeding occuring between the dura and the skull, accumulating blood strips the dura off the inner surface of the skull
Haematoma can cause increased ICP with developing neurological symptoms
Usually caused by bleeding of arteries in association to skull fractures (MMA due to temporal bone fracture)
Describe the characteristics of a subdural haemorrhage
Bleeding occurring between the dura and the arachnoid
Usually caused by bleeding from bridging veins
Any motion causing rotational forces can cause the veins to be stretched and torn
Describe the characteristics of a subarachnoid haemorrhage
Bleeding between the arachnoid membrane and the brain
Most commonly caused by natural disease- aneurysms
Collapse is usually rapid and death can occur very quickly due to irritant effects of blood in the subarachnoid space
What are the main kinds of intrinsic brain injury?
Cerebral oedema- common and rapid result of brain injury can develop in minutes and lead to massive brain swelling with raised intracranial pressure and coning
Cerebral contusion and laceration- direct mechanical damage to the brain substance
What is a diffuse traumatic axonal injury?
Serious rotational forces such as fall from height or vehicular collisions cause shearing of axons
What areas of the brain are most at risk fo a diffuse traumatic axonal injury?
Corpus callosum Para-sagittal white matter Posterior internal capsule Dorsolateral aspects of the rostral brainstem Cerbellar peduncles
