Pathology of Head Injury Flashcards
What are the five basic injury types to the skin
Bruises - blunt force damages little blood vessels in adjacent skin
Abrasions/grazes - injuries to the superficial part of the skin
Lacerations - tears in the skin due to blunt force injuries (splits at weakest part)
Incisions - Cutting to the skin caused by sharp force energies
Thermal injuries
What is the different types of skull fractures
Ring fracture
Fissure fracture
Depressed fracture
Hairline fracture
What occurs in a ring fracture
Considerable energy is put into the skull from one point of impact the fracture spreads out and forms a ring and will often take in foramen magnum and if sufficient energy cause diastasis of the sutures
What occurs in a fissure fracture
Lesser energy is put into the skull from one point of impact (blunt force) but isn’t enough energy to go all the way around and complete a ring
What happens to cause either a ring or fissure fracture
Big force over a wide area is applied over the head
What occurs in a depressed fracture
is a break in a cranial bone with depression of the bone in toward the brain.
What happens to cause a depressed fracture
Localised blunt force applied to the head/skull
When would a hairline fracture require treatment in aid to prevent what?
If open, and causes infection via emissary veins leading to meningitis
What skull fracture has the least energy input
Hairline fracture
What is the three different intracranial haemorrhages
Extradural - blood accumulating between skull and dura
Sub dural - blood accumulating between dura and arachnoid
Subarachnoid - blood accumulation between arachnoid and pia
What is a common cause of extradural haemorrhage
Skull fraction damages the middle meningeal artery and leads to blood accumulation outside the dura matter and increases arterial pressure
What is the location of the middle meningeal artery
The middle meningeal artery runs through the foramen spinosum, underneath the temporal bone at the side of the head, and above the dura mater, a layer of protective brain tissue.
What is the signs of extradural haemorrhage
Unconsciousness
If don’t fall unconscious can later lead to death due to undiagnosed haemorrhage
What is the common cause of sub dural haemorrhage
Occurs as the brain moves in relation to dura of the skull,
The head hits a wall, and the brain momentums acceleration causes the
veins that submerse the dura space to move in different directions, which stretches and tear they leading to haemorrhage as they burst
Where is it common to see people lucid with chronic subdural heamatoma
elderly
alcoholic
How does a traumatic subarachnoid haemorrhage usual occur
Due to a traumatic injury e.g. being struck on the neck or a blow to the chin damaging the vertebral artery in the neck and causing a basal subarachnoid haemorrhage
How does a spontaneous subarachnoid haemorrhage occur
Ruptured cerebral aneurysm
Ateriovenous malformation - abnormal tangle of arteries and veins with no capillaries in between, the weakened vessels can rupture
What is the complications of subarachnoid haemorrhage
The blood vessel near aneurysm going into vasospasm (if cerebellar artery spasms can cause global hypoxic brain damage)
Stroke - area of brain that previously received oxygen from the affected artery is now deprived of oxygen in the blood
Increased pressure -Blood in the cerebrospinal fluid (CSF)
Pool/clot of Blood can irritate, damage, or destroy nearby brain cells
Hydrocephalus - Blood from a torn aneurysm can block CSF circulation
What is the symptoms of subarachnoid haemorrhage
Sudden onset
Thunder clap headache
Dizziness- leads to collapse
Photophobia
Nausea and vomiting
Stiff neck
blurred or double vision
loss of consciousness
seizures
What does subarachnoid haemorrhage focus on
stopping the bleeding, restoring normal blood flow, and preventing vasospasm.
How is subarachnoid haemorrhage managed
Surgical clipping to aneurysm/ ruptured vessel
Pain medication - alleviate headache
Anticonvulsants - prevents or treat seizures
How is the symptoms of subarachnoid haemorrhage managed
Pain medication will be given to alleviate headache
Anticonvulsant medication may be given to prevent or treat seizures
What are the surgical treatment for subarachnoid haemorrhage
Surgical clipping
Endovascular coiling
What occurs in surgical clipping
an opening in the skull (craniotomy) is made to locate the aneurysm. A small titanium clip is placed across the neck of the aneurysm to stop blood flow from entering.
What occurs in endovascular coiling
a catheter is inserted into an artery in the groin during an angiogram. The catheter is advanced through the blood stream to the aneurysm. Platinum coils or liquid glue (Onyx) are packed into the aneurysm to stop blood flow from entering.
What is the three types of intracerebral haemorhage
Cortical contusion
Intracerebral haemorrhage
Diffuse axonal injury
What causes cortical contusion
Brain momentum is different from the skulls momentum so in either acceleration or a quick deceleration the brain moves along skull base and strikes it causing bruising of the brain
or
Direct force can cause contusion on the surface of the brain
Where does a coup injury occur
where the direct blow occurs to the head there will be a contusion there as energy is transmitted through skin and scalp to the brain area affected
Where does a countercoup injury occur
Occurs at the frontal/temporal pole (on the side opposite the area that was hit)
When does a coup injury occur
When a moving object impacts the stationary head, coup injuries are typical
When does a contrecoup injury occur
while contrecoup injuries are produced when the moving head strikes a stationary object
What occurs in an intracerebral haemorrhage
A haemorrhage within the brain itself
What occurs in a blunt trauma if the petrous temporal bone is affected
Basal fracture - can affect cranial nerves and pituitary fossa
What is the two causes of intra-cerebral haemorrhages
Natural disease
Traumatic
What are examples of natural diseases causing intracerebral haemorrhage
Hypertensive
AV anomaly
Amyloid angiopathy (delicate susceptible vessels)
Vascular tumours
How does a traumatic intracerebral haemorrhage arise
Where you have vulnerable vessels - that respond unusually to energy that is transmitted during head injury and cause a massive zone of disruption bleeding into the brain
What occurs in a diffuse axonal injury
Occurs where you have big acceleration and deceleration injuries to the brain which causes a rotation
resulting in diffuse disruption to neurones
Where does a diffuse axonal injury occur
Deep within, white matter, basal ganglia
What is the fate of diffuse axonal injury
Death instantaneously
Declared brain dead
