intracranial pressure and cerebral blood flow

Question 1

what is found in the intracranial cavity

Answer 1

nervous tissue, blood vessels, venous channels and CSF

Question 2

what is normal ICP

Answer 2

5-15cm of water

Question 3

what increases in ICP is pathological

Answer 3

20cm

Question 4

what is the monro-kellie hypothesis

Answer 4

intracranial volume is fixed due to non-compliant skull and contents are non compressible

Question 5

name some pathology of ICP

Answer 5

shift of brain across various compartments, focal or global ischemia
pump failure on cell membrane and lead to cell death

Question 6

what is normal cerebral blood flow

Answer 6

700ml/min or 50ml/100g/min

Question 7

what is mean arterial pressure

Answer 7

difference between systolic and diastolic

Question 8

what does CBF depend on

Answer 8

mean arterial pressure
intracranial pressure
vascular resistance
auto regulatory mechanisms in the brain

Question 9

what is auto regulation

Answer 9

capacity to maintain constant blood flow in spite of variations in blood pressure
brain also has capacity to increase blood flow to specific regions in brain when these are active such as temporal lobe during speech

Question 10

mechanisms of auto regulation

Answer 10

autonomic neurogenic theory
endothelial mechnaims
myogenic autoregulation
metabolic auto regulation

Question 11

importance of CBF, ICP and autoregulation

Answer 11

brain tissue uses glucose and ketones exclusively for metabolism

brain tissues have no stored energy source

impaired blood flow leads to mitochondrial energy production failure within seconds and cell death within minutes

Question 12

what is neuromonitoring

Answer 12

continuous monitoring of ICP with surgically implanted pressure transducer

optimising cerebral perfusion pressure prevents brain insult by reducing high ICP and preventing high or low CPP