Intracranial Pressure

Question 1

Intrcranial pressure is determined by –3 (also the normal value)

Answer 1

Volume of blood-125 ml
Volume of csf-120ml
Brain tissue-80% of total intracranial cavity

Question 2

Normal icp

Increased icp

Answer 2

110-120 mmh2o

>200 mmh2o….15mmhg

Question 3

Cause increased icp

Answer 3

Increased brain volume—edema
Increased blood–vasodilation and increased co2
Increased csf–hydrocephalus
Added mass–tumor

Question 4

Effect of increased icp–3

Answer 4

Decreased cerebral flow
Loss of autoregulation (capacity to dilate and constrict depend on the situation)
Brain herniation

Question 5

Systemic effect of increased inp/compensatory for maintenance of cpp

Answer 5

Cardio-respiratory CUSHING TRIAD (late manifestation)

Question 6

Cushing triad

Answer 6

Systemic hypertension
Bradycardia
Respiratory irregularities

Question 7

3 cranial compartment

Pressure difference between this compartment lead to…

Answer 7

Falx cerberi-left and right hemisphere
Tentorial hiatus-supra and infratentorial
Foramen magnum-large opening in the occipital lobe in skull

Herniation ( pressure difference in the compartment try to equalize)

Question 8

What is cerebral perfusion rate

And its formula

Answer 8

Pressure determine the cricurlation of the blood to the brain

Cpp=map-icp

Question 9

What is mean arterial pressure
And formula

Normal
High risk/stroke patient

Answer 9

Average pressure that drives blood toward the systemic organ

Map= systolic + 2diastolic/3

60
100

Question 10

Types herniation
Supratentorial 4
Inratentorial 2

All hemispeher involved

Answer 10

Supratentorial
1. Transtentorial
Central transtentorial
Peripheral/uncal transtentorial
2. Cingulate/subfalcine/transfalcine
3.transcalvarian
4.tectal/posterior

Infratentorial
Tonsillar/downward cerebellar
Upward cerebellar/upward tonsillar

Global herniation

Question 11

Not clinically significant as other type of herniation

Very slow
Part of hippocampal goes to other side

Answer 11

Cingulate/subfalcine/transfalcine

Question 12

Herniation with medullary dysfunction–more bradycardia

Answer 12

Tonsillar /downward cerbellar

Question 13

Dilatation of the pupil
posturing

Pressure on descending tract
Press the midbrain and cerbral cortex
Compromise the ras(reticular activating system)

Answer 13

Transtentorial

Question 14

Dilation of pupil
Central
Peripheral

Answer 14

Bilateral-pinpoint pupil bec primary affected pupil

Unilateral—-secondary to cn3 on the same side

Question 15

Uncal and central

transtentorial

Answer 15

Central
-cheyne stroke

Uncal
-contralateral hemiplegia(compression midbrain and cerebral peduncle)

Question 16

Herniation with cheyne stroke -2

Answer 16

Central transtentorial

Tonsillar

Question 17

Tonsillare herniation-4

Answer 17

Cardiorespi impairment
Systemic htn
Cheynes stroke
Nuerogenic hyperventilation

Question 18

Kernohan notch

Answer 18

Uncal

Autopsy notch on contralateral braistem

Question 19

Brainstem reflex-3

Answer 19

Corneal reflex
Dolls eye reflex
Caloric test

If negative all..negative brainstem reflex..brain death

Question 20

Produce csf-3

Production rate

Total volume of csf

Absorbed by

Answer 20

Choriod plexus-major 80-90%
Brain cells
Ependyam cells

0.3-0.5ml/min or 20ml/min approx 500ml/day

140ml

Arachnoid granulation neat the sinus

Question 21

Csf flow

Answer 21

Lateral ventricle
------foramen of monroe
3rd ventricle
------aqueduct of slyvius
4th ventricle
------foramen of magendie and luschka
Ventricular system

Question 22

Location choroid plexus

Large collection of fluid

Answer 22

All ventricle

Cistern

Question 23

Factors affecting the csf production-5

Answer 23

Intrcranial pressure and cerbral perfusion
Temperature( 7% increased in secretion rate per degree rise in the body)
Hypoxia and hypoglycemia
Neurogenic control (adregenic -dcreased csf production; cholinergic -decreased sf prod)
Drugs-acetazolamid and furosemide
(Carbonic anhydrase inhibition decreased csf prod)