Pathology of Brain Tumours

Question 1

what is contained in the cranium ?

Answer 1

brain 
meninges
dural folds 
blood 
CSF

Question 2

what is the pressure gradient ?

Answer 2

P1 - P2

for examples the arterial pressure and the venous pressure

Question 3

what does CPP stand for?

Answer 3

cerebral perfusion pressure

Question 4

what does the CPP reflect?

Answer 4

reflects the pressure gradient to get into the cranium

Question 5

how do you calculate the CPP?

Answer 5

CPP = MAP - ICP

Question 6

how do you calculate the cerebral blood flow ?

Answer 6

CBF = CPP/CVR

Question 7

what mechanism is there that makes sure CBF remains constant as the CPP changes ?

Answer 7

auto regulation

Question 8

what is cushings triad ?

Answer 8

• decrease in heart rate
• decrease in resp. rate
• increase of BP

Question 9

when does cushings reflex occur?

Answer 9

cushings reflex is a late reflex which occurs when CBF is low to ensure that CPP is maintained

Question 10

how does auto regulation maintain CBF?

Answer 10

maintained by changing the diameter of the vessels

Question 11

when CPP increases what happens to the radius of vessels and why?

Answer 11

CPP increases

the diameters decrease to increase resistance and hence decrease cerebral blood flow to optimum level

Question 12

when CPP decreases what happens to the radius of vessels and why?

Answer 12

CCP decreases

the diameters increase so the resistance is less and hence the blood flow will increase back to optimum

Question 13

what shape is the auto regulation graph of CPP and CBF ?

Answer 13

sigmoid graph

Question 14

under what CPP does the brain start to become ischaemic and loss function ?

Answer 14

<50mmHg

Question 15

at which CPP does brain oedema occur due to hypertension ?

Answer 15

> 150mmHg

Question 16

what are four causes of raised ICP?

Answer 16

inflammation
vascular
tumours
hydrocephalus

Question 17

state some vascular disorders which could cause raised ICP ?

Answer 17

intracranial haemorrhage
brain swelling due to trauma
hypotension due to cardiac arrest

Question 18

what are the three opening in the brain where herniation can occur?

Answer 18

subfalcine space
tentorial hiatus
foramen magnum

Question 19

what abouts in the skull does a subfalcine hernia occur?

Answer 19

inferior border of the falx cerebri just superior to the lateral ventricles

Question 20

what structure sits in the tentorial hiatus ?

Answer 20

the brain stem

Question 21

when the cerebellum passes through the foramen magnum what is this called?

Answer 21

cerebellar coning

Question 22

when there is raised ICP, what happens to the CBF and why?

Answer 22

CBF decreases as the pressure gradient outside and inside the skull is less

Question 23

when the cerebrum herniates inferiorly and medially through the tentorium what is this called?

Answer 23

uncle grooving

Question 24

what type of hernia is it when the brain pushes through the skull following a fracture ?

Answer 24

transcalvarial

Question 25

what three tests and investigations can be done to test for loss of function due to a tumour and hence raised ICP?

Answer 25

Glasgow Coma Scale Pupillary dilation Localising signs such as weakness in one arm

Question 26

what cranial nerve is affected when there is a fixed dilated pupil?

Answer 26

Nerve 3 - oculomotor

Question 27

are brain tumours more common type of tumour in adults or children?

Answer 27

brain tumours is the 2nd most common ground of tumour in children

Question 28

where abouts in the brain are the majority of brain tumours in adults ?

Answer 28

70% above the tentorium

Question 29

where abouts in the brain are the majority of brain tumours in children ?

Answer 29

70% below the tentorium

Question 30

are brain tumours in children more likely to be primary or secondary ?

Answer 30

nearly all are primary in children

Question 31

what percentage of brain tumours are primary in adults ?

Answer 31

65%

Question 32

where are the common places secondary brain tumours have spread from ?

Answer 32

``` breast lung kidney colon melanoma ```

Question 33

where are the 7 locations a brain tumour can occur?

Answer 33

``` glial cells primitive neurorectoderm arachnoidal cell nerve sheath cell pituitary gland lymphoid cell capillary vessels ```

Question 34

what is a pituitary gland tumour called ?

Answer 34

adenoma

Question 35

what are the clinical complications of pituitary gland tumour ?

Answer 35

loss of endocrine function | may extend up to the optic chiasma

Question 36

what is a tumour os the capillary vessels called?

Answer 36

haemangioblastoma

Question 37

what are the two types of nerve sheath cell tumours called?

Answer 37

schwannoma | neurofibroma

Question 38

are schwann cells found in the CNS or PNS ?

Answer 38

PNS

Question 39

what type of cell in the CNS produces myelin?

Answer 39

oligodendrocyte

Question 40

what is a tumour of arachnoidal cells called?

Answer 40

meningioma

Question 41

are medulloblastoma more common in children or adults ?

Answer 41

children

Question 42

from what cells does medulloblastoma originate from ?

Answer 42

primitive neurorectoderm

Question 43

what are the four types of glial cell tumours ?

Answer 43

glioblastoma astrocytoma oligodendroglioma ependymoma

Question 44

what is ischaemic penumbra ?

Answer 44

area of ischaemia around a tumour

Question 45

what is the clinical significance of ischaemic penumbra ?

Answer 45

the ischaemia around the tumour can be removed to improve function of the brain tissue

Question 46

what is the function of glial cells?

Answer 46

CNS supporting cells - providing myelin - providing a favourable environment for neurones

Question 47

do glioma spread around the body ?

Answer 47

no stays in the CNS

Question 48

are glioma encapsulated ?

Answer 48

no they have diffuse edges

Question 49

what is the prognosis of glioma ?

Answer 49

high grade glioma grow fast and respond poorly to surgery | - survival time = 36 weeks

Question 50

can people live their entire life with low grade glioma without any complications?

Answer 50

yes

Question 51

state a treatable complication of low grade glioma ?

Answer 51

epilepsy can be triggered

Question 52

in which fossa does medulloblastoma usually occur ?

Answer 52

posterior fossa especially in the brain stem

Question 53

what is the prognosis of medulloblastoma ?

Answer 53

poor prognosis due to deep location and difficult access for surgery

Question 54

are meningiomas benign or malignant ?

Answer 54

benign

Question 55

how can meningiomas invade the skull?

Answer 55

via emissionary veins

Question 56

what is the most common nerve sheath tumour ?

Answer 56

acoustic neuroma

Question 57

what cranial nerve is affected by an acoustic neuroma ?

Answer 57

CN 7

Question 58

what is a symptom of acoustic neuroma ?

Answer 58

unilateral deafness

Question 59

what are two clinical signs that a patient may have a pituitary adenoma ?

Answer 59

acromegaly | giantism

Question 60

what is the prognosis of CNS lymphoma ?

Answer 60

poor - often deep and central site - difficult to biopsy - difficult to treat due to BBB

Question 61

do CNS lymphomas spread out of the CNS ?

Answer 61

no

Question 62

is there any lymph tissue in the brain ?

Answer 62

no

Question 63

what cell makes up a CNS lymphoma ?

Answer 63

B cell lymphoma

Question 64

where do capillary haemangioblastomas often occur ?

Answer 64

cerebellar hemispheres

Question 65

what are the complications of capillary haemangioblastomas ?

Answer 65

may bleed space occupying difficult to get to

Question 66

are secondary tumours mostly malignant or benign?

Answer 66

malignant

Question 67

what are secondary tumours often surrounded by ?

Answer 67

they are encapsulated surrounded by oedema

Question 68

are primary and secondary tumour histology similar ?

Answer 68

yes