Raised ICP, Space Occupying Lesions & Trauma Flashcards Preview

Neurology > Raised ICP, Space Occupying Lesions & Trauma > Flashcards

Flashcards in Raised ICP, Space Occupying Lesions & Trauma Deck (31):
1

what can cause a raised ICP?

increased CSF production (hydrocephalus)
focal lesion in brain (SOL)
diffuse lesion in brain (oedema)
increased venous volume
physiological (hypoxia, hypercapnia, pain)

2

what is responsible for re-absorption of CSF?

arachnoid granulations

3

what should normal CSF contain and not contain?

contain small amount of protein and lymphocytes and glucose

no neutrophils or RBCs

4

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

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

5

what happens if hydrocephalus occurs before cranial sutures close?

cranial enlargement

6

what is hydrocephalus ex vacuo?

dilation of ventricular system - increase in CSF volume

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

7

what are the effects of raised ICP?

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

8

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

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

tentorial = squishes CNIII - blown out pupil

cerebellar = compresses brainstem

transcalvarial = moves through skull fracture

9

what are main clinical signs of raised ICP?

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

10

what SOLs can be responsible for raised ICP?

tumour
abscess
haematoma
local swelling (eg oedema around infarct)

11

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

children = tumours below TC
adults = tumours above TC

12

what types of cancer most commonly metastasise to brain?

breast
bronchus
kidney
thyroid
colon

13

where in the brain are metastases most likely to present?

often seen at boundaries between matter

14

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

adults = astrocytoma

children = medulloblastoma

15

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

meningioma

16

what type of grade 1 astrocytomas do children normally develop?

pilocytic

17

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

abnormal cells
mitotic features (proliferation)
anaplasia
neoangiogenesis

18

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

cells are primitive undifferentiated embryonic cells

respond well to radiotherapy

19

where do medulloblastomas usually occur in brain?

occurs in midline of cerebellum

20

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

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

multiple - haematogenous spread eg pneumonia, endocarditis

21

how are abscesses diagnosed?

CT or MRI

aspiration for culture and treatment (weeks of antibiotics)

22

how does bacterial meningitis cause raised ICP?

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

23

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

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

24

what is a blunt or non-missile injury?

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

what can cause blunt / non-missile injury?

RTAs
falls
assaults
alcohol

26

primary injury is usually irreversible - true or false?

true - damage to neurones means they cant regenerate

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

27

what are the croup and contra-croup injuries?

croup - occurs at point of impact

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

28

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

middle meningeal artery - would cause extradural haematoma

29

what is diffuse axonal injury?

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

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

fracture in tempero-parietal (middle meningeal artery)

immediate brain damage often minimal

untreated = midline shift (compression and herniation)

31

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

disruption of bridging veins

swelling of cerebrum on side of haematoma

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