Head Injury and Space Occupying Lesions

Question 1

what is the head trauma death rate?

Answer 1

10 per 100,000

Question 2

what kind of injury can head trauma be?

Answer 2

missile (open wound)

non-missile

Question 3

Which form of head trauma leaves the dura intact?

Answer 3

non-missle

Question 4

What are the features of missile damage?

Answer 4

focal damage
lacerations
haemorrhage in region of brain damage
high/low velocity

Question 5

What are the features of non-missile damage?

Answer 5

sudden acceleration/deceleration of the head
brain moves in cranial cavity
general causes are RTAs and Assualt falls
primary injury -> evolves to secondary injury

Question 6

When is injury in non-missile maximal?

Answer 6

at time of injury

• shear injury to axons and/or
• laceration or contusions of brain tissue

Question 7

Where are surface contusions and lacerations found?

Answer 7

found on lateral surface of the hemispheres and undersurface of temporal and frontal lobes

Question 8

What kind of injury can surface contusions and lacerations be and which is more serious??

Answer 8

coup or contracoup (diametrically opposite) contracoup more serious

Question 9

Where may the surface contusions extend?

Answer 9

into the subcortical white matter

Question 10

What causes contracoup injuries?

Answer 10

the brain moving back and forth in the skull

Question 11

What are cerebral contusions?

Answer 11

traumatic/mechanical disruptions of small capillary vessels which are a mix of whole blood and native tissue (plasma, RBCs)
have a mottled/speckled density

Question 12

What are the commonalities of intracranial haematomas?

Answer 12

10% extradural

56% intradural

Question 13

What is an extradural haematoma?

Answer 13

blood is between the dura and skull and as it expands removes dura from the skull

Question 14

What are the forms of intradural haematomas and their commonalities?

Answer 14

• 13% subdural - dura and arachnoid
• 3% subarachnoid - trauma from unusual circumstances
• 15% discrete intracerebral/intracerebellar hematomas
• 25% burst lobe - intracranial/intracerebral haematoma in continuity with a related subdural heamatoma - very serious

Question 15

What increases the likelihood of serious brain injury and why?

Answer 15

age - as you get older the brain starts to atrophy and thus increases space between brain and skull

Question 16

What is traumatic extradural hematoma?

Answer 16

usually a complication of a fracture in the temporoparietal region that involved the middle meningeal artery - can cause mid-line shift and herniation
minimal associated brain damage

Question 17

What can traumatic extradural hematoma cause?

Answer 17

midline shift and herniation - life threatening

Question 18

Where is traumatic extradural hematoma present?

Answer 18

in 10% of fatal cases

Question 19

What is a subdural hematoma?

Answer 19

haemorrhage in between dura and arachnoid

Question 20

What is subdural hematoma caused by?

Answer 20

tearing of the venous vessels that transverse the subdural space

Question 21

What are the types of subdural hematoma?

Answer 21

acute
chronic
gross

Question 22

How is an acute subdural hematoma classified?

Answer 22

sever head injury with rapid accumulation of blood

acute neurological deterioration

Question 23

How is chronic subdural hematoma classified?

Answer 23

only in v.young and v.old
minimal trauma
slow accumulations of blood - enlarges over weeks

Question 24

How is gross subdural hematoma classified?

Answer 24

acute layer of gelatinous blood

chronic - organised layer of dark, liquified clot surrounded by membranes -> compress the brain

Question 25

When does raised intracranial pressure occur?

Answer 25

when the volume of brain, CSF and blood exceed the normal of 1600ml

Question 26

Why is the skull a disadvantage at times?

Answer 26

with increased intracranial pressure it does not allow for expansion of brain parenchyma or CSF volume without a raise in pressure

Question 27

What are signs of raised intracranial pressure?

Answer 27

- papilloedema - pressure on the optic nerve - nausea and vomiting due to pressure in vomiting centre in pons and medulla - headache due to distortion of the dura - neck stiffness due to pressure on dura around cerebellum and brain stem

Question 28

Where does brain herniation occur?

Answer 28

through the routes of weakest resistance as a result of raised intracranial pressure

Question 29

What are the potential routes of herniation?

Answer 29

subfalcine tentorial tonsilar transcalvarium

Question 30

Where does the subfalcine herniation occur?

Answer 30

cingulate gyrus

Question 31

What happens with the subfalcine herniation?

Answer 31

unilateral or assymetric expansion of the cerebral hemisphere displaces the cingulate gyrus under the falx cerebri

Question 32

What is associated with a subfalcine herniation?

Answer 32

compression of anterior cerebral artery weakness and/or sensory loss in leg ischemic injury to parts of primary and motor cortex

Question 33

Where is a tentorial herniation?

Answer 33

medial aspect of the temporal lobe - hippocampal uncus and parahippocampal gyrus

Question 34

What is associated with tentorial herniation?

Answer 34

ispsilateral 3rd cranial nerve affected pupillary dilation impairement of occular movements on side of lesion

Question 35

What is tonsilar herniation?

Answer 35

displacement of cerebellar tonsils through foramen magnum

Question 36

Why is tonsilar herniation life threatening?

Answer 36

causes brainstem compression - vital respiratory centres in medulla oblongata

Question 37

What is a trancalvarium herniation?

Answer 37

where the swollen brain will herniate through any defect in the dura or skill

Question 38

What is associated with a transcalvarium herniation?

Answer 38

reduction in conciousness dilation of the pupil on same side as mass lesion bradycardia chenye-stoke respiration

Question 39

What is cheyne stoke respiration?

Answer 39

abnormal pattern of breathing with deeper and faster breaths followed by a gradual decrease that includes apnea - build up of CO2 in apnea -> hyperventilation-> apnea -> CO2

Question 40

What is a herniation usually treated with an why?

Answer 40

osmotic diuretic to reduce swelling

Question 41

What can be space occupying lesions?

Answer 41

brain tumours - primary or secondary (lungs tend to metastisize) abscesses heamatomas localised brain swelling

Question 42

What are the potential effects of rotational forces?

Answer 42

rotation as you fall can cause diffuse axonal injury - initiates at moment of injury - can cause a coma - can lead to vegetative state - non-missile injury

Question 43

What occurs in rotational injuries?

Answer 43

widespread disruption to the axons due to shear and tensile strains - causing microglial cells throughout white matter weeks later

Question 44

Diffuse Axonal Injury (DAI) caused by?

Answer 44

``` raised intracranial pressure progression of inflammatory disease progression of dementia hypoxia trauma - most common ```

Question 45

What are the pathological features of axons from DAI at 2-4 hours?

Answer 45

focal axonal accumulation of APP

Question 46

What are the pathological features of axons from DAI at 12-24hours?

Answer 46

axonal varicosity (swelling at the site)

Question 47

What are the pathological features of axons from DAI at 24hours -2 months?

Answer 47

axonal swelling

Question 48

What are the pathological features of axons from DAI at 2wks to 5 months?

Answer 48

glial reaction

Question 49

What are the pathological features of axons from DAI at 2mnths to years?

Answer 49

degeneration and loss of myelinated fibres

Question 50

What occurs to Nav channels in DAI?

Answer 50

increased expression and redistribution to demyelinated segments expression of primitive 1.2 channel

Question 51

What does adjusted expression of Nav do?

Answer 51

partial restoration of conductance has increased energy requirement increased Na influx

Question 52

What happens to the calcium exhanger?

Answer 52

brings in calcium influx and activates calpains | causes cytoskeletal disruption and disrupted anterograde flow

Question 53

What is the issue with the calcium exchanger in head trauma?

Answer 53

not enough energy to remove Na -> need to cool area and use medically induced coma to slow electrical activity -> protect from excitotoxicity

Question 54

What is found in CTE?

Answer 54

Tau rather than Ab

Question 55

What is found in regards to tau in CTE?

Answer 55

tau proteins accumulate in CSF - correlates with severity associated with repeated trauma - key regions of brain NFTs associated with cerebral atrophy

Question 56

CTE

Answer 56

chronic traumatic encephalopathy

Question 57

encephalopathy

Answer 57

disease of the brain