Raise ICP, SOLs and trauma Flashcards Preview

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Flashcards in Raise ICP, SOLs and trauma Deck (77):
1

What is the normal volume of CSF?

120-150ml
500ml a day

2

What produces CSF?

Choroid plexus in the lateral and 4th ventricles of the brain

3

What absorbs CSF?

Arachnoid granulations

4

What do lymphocyres in the CSF suggest?

Infection; viral or fungal
Autoimmune infection
Inflammation

5

What do neutrophils in the CSF suggest?

Bacterial meningitis

6

What is the definition of hydrocephalus?

Accumulation of excessive CSF within the ventricular system of the brain

7

What can cause hydrocephalus?

Obstruction to flow: inflammation, pus, tumours
Decreased reabsorption; post SAH, meningitis
Overproduction; very rare cause due to choroid plexus tumour

8

What is non-communicating hydrocephalus?

Obstruction to flow of CSF occuring within the ventricular system

9

What is communicating hydrocephalus?

Obstruction to flow of CSF outside of the ventricular system e.g. in subarachnoid space or at the arachnoid granulations

10

What occurs if hydrocephalus occurs before the closure of the cranial sutures?

Cranial enlargement occurs

11

What occurs if hydrocephalus occurs after the closure of the cranial sutures?

Expansion of the ventricles with an increase in intracranial pressure

12

What is hydrocephalus ex vacuo?

Dilation of the ventricular system and an increase in compensatory CSF volume secondary to the loss of brain parenchyma for example in alzheimer's disease

13

What are the causes of increased ICP?

Hydrocephalus
SOL
Diffuse lesion in brain e.g. oedema
Increased venous volume
Physiological; hypoxia, hypercapnia, pain

14

What are the consequences of raised ICP?

Intracranial shifts and herniations
Midline shift
Distortion and pressure on CNs and vital neurological centres
Impaired blood flow
Reduced level of consciousness

15

How is cerebral perfusion pressure calculated?

MAP - ICP; therefore ICP is too high, it will reduce blood flow

16

What are the 4 types of shifts and herniations within the brain?

Subfalcine
Tentorial
Cerebellar
Transcalvarial

17

What is a subfalcine herniation?

Unilateral or asymmetrical expansion of the cerebral hemisphere which displace the cingulate gyrus underneath the falx cerebri

18

What does a subfalcine herniation result in?

Compression of the anterior cerebral artery resulting in weakness and/or sensory loss on the contralateral side

19

What is a tentorial herniation?

Medial aspect of the temporal lobe (uncus) herniates over the tentorium cerebellar

20

What will a tentorial herniation result in?

Compression of the ipsilateral CN3; resulting in a blown pupil with impairment of ocular movement on the side of the lesion

21

What is a tonsillar herniation?

Displacement of the tonsillar cerebellum through the foramen magnum

22

What will a tonsillar herniation result in?

Compression of the respiratory centers of the medulla oblongata

23

What is a transcalvarial herniation?

Brain herniating through any defect in the skull e.g. fracture

24

What are the clinical signs of an increased ICP?

Papilloedema
Headache
N+V
Neck stiffness

25

What are the different types of SOLs?

Tumours; primary brain tumours, mets
Abscess; single/multiple
Haematomas
Localised brain swelling; swelling and oedema around cerebral infarct

26

What are the Si/Sy of brain tumours?

Sy: focal, headache, vomiting, seizures, visual disturbances
Signs; focal deficit, papilloedema

27

What is the difference in location of brain tumours between children and adults?

Children; 70% below tentorium cerebelli
Adults; 70% above tentorium cerebelli

28

What common cancers will metastasize to the brain?

Breast, bronchus, kidney, thyroid, colon and melanomas

29

What is used to grade primary brain tumours?

Mitoses
Neovascularization
Necrosis
Atypia, cellularity

30

What are the common malignant primary intracranial tumours?

Astrocytoma
Oligodendroglioma
Ependymoma
Medulloblastoma
Haemangioblastoma
Lymphoma
Pineal

31

What are the common benign primary brain tumours?

Meningioma
Schwannoma
Craniopharyngioma
Pituitary adenoma

32

What is the commonest brain tumour in children?

Medulloblastoma
Astrocytoma; pilocytic

33

Describe a pilocytic grade 1 astrocytoma

Common in children
Benign behaving
Long hair like processes
Cystic area

34

Describe a grade 2; low grade astrocytoma

Nuclear atypia

35

Describe a grade 3 anaplastic astrocytoma

Greater nuclear atypia
Mitotic activity

36

Describe a grade 4 glioblastoma

Extreme nuclear atypia
Mitotic activity
Necrosis
Neovascularization

37

What can be seen histologically from a glioblastoma?

Anaplastic
Proliferation; numerous mitotic figures
Necrosis with assoc nuclear palisading
Neoangiogenesis

38

Describe a medulloblastoma?

20% of paeds CNS neoplasms
Poorly differentiated/embryonal
Occurs in midline of cerebellum and can easily disrupt CSF flow resulting in hydrocephalus

39

How are medulloblastomas treated?

Radiotherapy

40

What can result in a single brain abscess?

Local extension from:
Mastoditis, chronic otitis media, paranasal sinusitis, nasal facial and dental infection
Direct implantation: skull fracture

41

What can result in multiple brain abscesses?

Haematogenous spread; bronchopneumonia, bacterial endocarditis, bronchiectasis, lung abscesses, congenital heart disease (left to right shunt)
PWID

42

Where will multiple brain abscesses occur?

Grey and white matter boundary

43

What will occur with brain abscesses?

Central necrosis
Oedema
Fibrous capsule
Hypoxia and ischaemia
Excitotoxic injury

44

What are the symptoms of a brain abscess?

Fever
Increased ICP

45

How are brain abscesses diagnosed?

CT or MRI

46

How are abscesses treated?

Aspiration for culture and treatement

47

What is bacterial meningitis?

Inflammation of the leptomeninges and SF within the subarachnoid space

48

What can be seen on an LP from bacterial meningitis?

Abundant polymorphs and neutrophils
Decreased glucose

49

What can arachnoiditis result in?

Lack of CSF absorption
Hydrocephalus
Increased ICP

50

What organism causes bacterial meningitis in neonates?

E.coli; gram negative rods

51

What organism causes bacterial meningitis in infants and children?

Haemophilus influenzae; gram negative cocco-bacilli

52

What organism causes bacterial meningitis in adolescents and young adults?

Neisseria meningitis; gram negative diplococci

53

What organism causes bacterial meningitis in older adults or children?

Streptococcus pneumoniae; gram positive cocci in chains

54

What organism causes bacterial meningitis in older adults and those immunocompromised?

Listeria monocytoggene; gram positive rod

55

How can head trauma be classified?

Missile or non-missile (penetrating or blunt)

56

What can result from head trauma?

Skull #
Parenchymal and vascular injuries

57

What will a penetrating head trauma result in?

Focal damage
Lacerations in region of brain damage
Haemorrhage

58

What does the severity of a blunt injury rely on?

Initial velocity and the contact time; the smaller the contact time, the larger the force

59

What are causes of blunt head injuries?

RTCs
Falls
Assaults
Alcohol related injuries

60

What will the primary (impact) injury do?

Injury to neurones
Irreversible
Preventative measures; wearing a helmet and seat belts for example

61

What are the secondary head injuries?

Haemorrhage
Oedema
Potentially treatable

62

What is the clinical hallmark of head injuries?

Immediate change in conscious level is dependent on the scale of neuronal damage

63

What are examples of primary head injuries?

Scalp lesions
Skull fractures
Surface contusions and lacerations
Diffuse axonal injury
Diffuse vascular injury
Petechial haemorrhages

64

What are the 3 types of skull fractures?

Linear
Compound
Depressed

65

What is a linear skull#?

Straight sharp fracture line, that may cross sutures

66

What is a compound skull#

Assoc with full thickness scalp lacerations

67

Are base of skull fractures open or closed?

ALWAYS consider compound because there is a high change that base of skull fractures will lacerate the paranasal sinuses giving bacteria a route for entrance to the cranium

68

What is a contra-coup injury?

Injury to the non-impact side diametrically opposite the point of impact
Occurs as a rebound

69

What is a diffuse axonal injury?

Occurs at the moment of injury due to shearing strains on the axonal bulbs
Affects central areas

70

What will a diffuse axonal injury lead to?

Reduced consciousness and coma
Lead to vegetative state

71

What are secondary head injuries?

Intracranial haemorrhage
Reduced brain flow
Hypoxic brain damage
Excitotoxicity
Oedema
Raised ICP
Infection

72

What oedema is assoc with trauma?

Vasogenic oedema

73

What are the percentages surrounding traumatic intracranial haematoma?

20% are extradural
80% are intradural

74

What does a traumatic extradural haematoma result from?

Fracture of pterion rupturing the middle meningeal artery

75

What causes an acute SAH?

Disruption of bridging veins that extend from the surface of the brain into the subdural space

76

What are chronic subdural haematomas assoc with?

Brain atrophy

77

What is a chronic subdural haematoma composed of?

Liquefied blood/ yellow tinged fluid separated from inner surface of dura mater and underlying brain by neomambrane