Neurological injuries and trauma

Question 1

What are different type of volume components that are in the skull and what is the total volume?

Answer 1

Blood
Brain
CSF
(1400-1700 ml)

Question 2

What is the equation showing the relationship between CPP, MAP & ICP?

Answer 2

CPP = MAP - ICP

Question 3

What happens in the brain if there is small increase in volume e.g. heamatoma?

Answer 3

CSF displaced downwards into the spinal cord —> reduced cerebral venous blood —> stretch of falx cerebri & tentorium cerebelli —> brain maintains normal ICP

Question 4

Normal ICP can be maintained at what increased volume?

Answer 4

110 ml approx.

Question 5

At what ICP pressure do small increases in volume cause large increases in ICP?

Answer 5

25 mmHg

Question 6

What happens to the equation once ICP pressure increases beyond threshold?

Answer 6

• As ICP increases, CPP decreases when blood pressure remains at normal levels
• Body’s response in order to maintain CCP is to increase systemic blood pressure and dilate cerebral blood vessels, which accelerates cerebral hemorrhaging and further raises ICP and lowers CPP vicious cycle.

Question 7

What is the preterminal sign?

Answer 7

Cushings Triad

Question 8

What is Cushings triad?

Answer 8

Bradycardia
Hypertension
Irregular respiration

Question 9

Signs of increased ICP? (6)

Answer 9

Dilate pupil 
Fixed CN III palsy
Aphasia
Hydrocephalus 
Herniation (uncal or tonsillar)
Brainstem herniation (coning)