Raised ICP, Space Occupying Lesions & Trauma Flashcards

1
Q

what can cause a raised ICP?

A
increased CSF production (hydrocephalus)
focal lesion in brain (SOL)
diffuse lesion in brain (oedema)
increased venous volume 
physiological (hypoxia, hypercapnia, pain)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is responsible for re-absorption of CSF?

A

arachnoid granulations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what should normal CSF contain and not contain?

A

contain small amount of protein and lymphocytes and glucose

no neutrophils or RBCs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the difference between non-communicating and communicating hydrocephalus?

A

non communicating = obstruction to flow of CSF occurs within ventricular system

communicating = obstruction to flow of CSF outside of ventricular system eg in subarachnoid space or at arachnoid granulations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens if hydrocephalus occurs before cranial sutures close?

A

cranial enlargement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is hydrocephalus ex vacuo?

A

dilation of ventricular system - increase in CSF volume

due to loss of brain parenchyma (eg in alzheimer’s disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the effects of raised ICP?

A

intracranial shifts and herniation
pressure on cranial nerves
impaired blood flow (CPP = MAP - ICP)
reduced level of consciousness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

describe how the brain can shift and herniate in raised ICP and what each shift can compress?

A

subfalcine = moves under falx cerebri, can squish anterior cerebral artery

tentorial = squishes CNIII - blown out pupil

cerebellar = compresses brainstem

transcalvarial = moves through skull fracture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are main clinical signs of raised ICP?

A

papilloedema
headache
neck stiffness (due to dura compression)
N&V

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what SOLs can be responsible for raised ICP?

A

tumour
abscess
haematoma
local swelling (eg oedema around infarct)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where do tumours arise in children vs adults in relation to tentorium cerebelli?

A
children = tumours below TC
adults = tumours above TC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what types of cancer most commonly metastasise to brain?

A
breast
bronchus 
kidney 
thyroid 
colon
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where in the brain are metastases most likely to present?

A

often seen at boundaries between matter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what type of malignant primary tumour is most common in adults vs children?

A

adults = astrocytoma

children = medulloblastoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what type of benign brain tumour is most common in adults?

A

meningioma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what type of grade 1 astrocytomas do children normally develop?

A

pilocytic

17
Q

what signs can be seen on histology which point towards a higher grade tumour?

A

abnormal cells
mitotic features (proliferation)
anaplasia
neoangiogenesis

18
Q

how do medulloblastomas appear on histology and why is this significant clinically?

A

cells are primitive undifferentiated embryonic cells

respond well to radiotherapy

19
Q

where do medulloblastomas usually occur in brain?

A

occurs in midline of cerebellum

20
Q

describe the different in cause of a single abscess vs multiple abscesses?

A

single - usually adjacent to source eg mastoiditis infection, next to fracture site

multiple - haematogenous spread eg pneumonia, endocarditis

21
Q

how are abscesses diagnosed?

A

CT or MRI

aspiration for culture and treatment (weeks of antibiotics)

22
Q

how does bacterial meningitis cause raised ICP?

A

inflammation of meninges irritates the arachnoid granulations - prevents them from reabsorbing CSF

23
Q

describe what is meant by a penetrating (missile) injury?

A

focal damage
lacerations in region of damage
haemorrhage
cavitation depending on high / low velocity

24
Q

what is a blunt or non-missile injury?

A

sudden acceleration / deceleration of head
the smaller the contact time is, the larger the force
brain moves within cranial cavity and makes contact with the cranium and bony protrusions

25
Q

what can cause blunt / non-missile injury?

A

RTAs
falls
assaults
alcohol

26
Q

primary injury is usually irreversible - true or false?

A

true - damage to neurones means they cant regenerate

preventative measures (seatbelts, crashmats) can be used to increase contact time

27
Q

what are the croup and contra-croup injuries?

A

croup - occurs at point of impact

contra-croup - occurs opposite of impact, due to rebound, often worse than initial injury

28
Q

a linear fracture across the squamous part of the temporal bone would cause which artery to rupture?

A

middle meningeal artery - would cause extradural haematoma

29
Q

what is diffuse axonal injury?

A

occurs at moment of injury and affects central areas

sheering of axons - electrical signals cant transfer

causes reduced consciousness and coma and axons become axonal bulbs

30
Q

what injury often causes extradural haematoma and what are the consequences of this?

A

fracture in tempero-parietal (middle meningeal artery)

immediate brain damage often minimal

untreated = midline shift (compression and herniation)

31
Q

what causes a subdural haematoma and what are the complications of this?

A

disruption of bridging veins

swelling of cerebrum on side of haematoma

non-treated non fatal haematomas become liquefied and form a yellow neomembrane (chronic)