Intracranial Pressure Pathology

Question 1

What is the formula for raised intracranialr pressure

Answer 1

Increase in volume / mass of intracranial contents within fixed capacity of skull

If superior to 30cubic cm

Question 2

IC compartment % of brain

Answer 2

85%

Question 3

IC compartment % of blood

Answer 3

10%

Question 4

IC compartment % of CSf

Answer 4

5%

Question 5

First substance affected by raised intracranial pressure which is displaced

Answer 5

CSF

Question 6

In raised intracranial pressure what event leads to increase in cranial cavity

Answer 6

Intravascular pressure increase because of compression

Question 7

Normal pressure in cranium

Answer 7

10-15 mmHg

Question 8

Upper limit of normal intracranial pressure

Answer 8

20 mmHg

Question 9

Moderate increase of intracranial pressure which is not too dangerous

Answer 9

20-40mmHg

Question 10

Severe increase of intracranial pressure which is very dangerous

Answer 10

More than 40 mmHg

Question 11

Causes of raised intracranial pressure

Answer 11

Any intracranial expanding lesions ( tumors , hematoma, abscess, granulomatous , swollen infarct )

Infections ( meningitis , encephalitis)

Hydrocephalus

Cerebral edema

Question 12

Hydrocephalus

Answer 12

Accumulation of excessive CSF within the ventricular system

Question 13

Reasons of accumulation of CSF

Answer 13

Blockage of fluids which is congenital or acquired

Decreased absorption by arachnoid villous fibrosis or destruction , or sinus thrombosis

Increased production of CSF by choroid plexus papilloma or hyperplasia

Question 14

Types of hydrocephalus

Answer 14

Communication or non communicating

Hydrocephalus ex vacuo

Question 15

What is Hydro ex vac

Question 16

When can Hydrocephalus occur in children

Answer 16

Before or after closure of sutures

Question 17

Causes of cerebral edema

Answer 17

Cytotoxicity ( intracellular )due to hypoxia leading to cell swelling because can’t eliminate sodium

Vasogenic ( extracellular) bbb disrupted , leakage of fluid from capillaries -> mainly in white matter

Interstitial ( hydrocephalic) increased brain fluid due to CSF blockage

Question 18

Cerebral edema appearance

Answer 18

Broad gyri, flattening of gyri

Question 19

What a spatial compensation in increased intracranial pressure

Answer 19

Expansion of a lesion can lead to compression which can reduce CSF volume and reduce blood flow in vasculature

Question 20

What are the alterations in the brain due to the raised intracranial pressure

Answer 20

focal or localized destruction of neurons due to direct pressure effects

General neuronal degeneration due to the diffuse compression of blood vessels leading to ischemia

Question 21

Causes of of displacement of brain tissue in IC effect

Answer 21

Herniation

Question 22

What effect can lead to cranial nerve palsies

Answer 22

Intravascular pressure

Question 23

What is cranial herniation

Answer 23

Displacement of brain tissue past rigid folds (falx and tentorium ) or through openings in the skull like forâmes magnum

Question 24

Types of cranial herniation

Answer 24

Internal

External

Question 25

What is internal herniation

Question 26

What is external herniation

Question 27

Types of herniation

Answer 27

Sulbfalcine
Transtentorial
Tonsillar

Question 28

Arteries at risk of compression in subfalcine herniation

Answer 28

Compression of anterior cerebral artery

Question 29

Transtentorial herniation conséquence

Answer 29

Oculomotor nerve compression -> ocular changes

Ischemia in area supplied by posterior cerebral artery

Compression of kernohans notch leading to Hemiparesis

Hemorrhage in brainstem - duret

Question 30

Tonsillar herniation consequence

Answer 30

Respiratory and cardiac centers compromised

Question 31

Raised Intracranial pressure systemic effects

Answer 31

arterial hypertension
Myocardial dysfunction
Respiratory dysfunction
Mucosal ulcérations