neurosurgery

Question 1

what is the cushings response?

Answer 1

hypertension, bradycardia, ++ resp irregularity ( think of the medulla/ breathing center being crushed by all the extra ICP/fluid).

Question 2

what is the definition of cerebral perfusion pressure?

Answer 2

CPP= MAP- ICP ( mean arterial pressure - ICP) so think of it as the force pushing into the brain and the force that is stopping things from entering the brain

Question 3

what does it mean when we say the brain autoregulates?

Answer 3

cerebral brain flow is stable when the MAP is between 50-150 and the brain can regulate how much fluid is coming in. The injured brain cannot regulate , so is susceptibel to low or high BP.

Question 4

what are some ICP numbers you should know? why does cerebral blood pressure matter?

Answer 4

1) ICP of 10 is normal, abnormal is 20 or over, and deadly is about 40 mmHg. The brain’s perfusion/ blood flow matters because the brain has no 02 store and so all metabolism and energy depends on incoming glucose/ 02 from the bloos.

Question 5

define primary injury

Answer 5

injury at the moment, which is permanent with no therapy

Question 6

what is secondary brain injury?

Answer 6

the damage afterwards that is delayed and preventable. Can be due to hypoxoia, hypotension, infxn, seizure etc.

Question 7

GCS. I know you hate it but here we go.

Answer 7

Four eyes, so E is out of 4. then its EVM, so 4,5,6. For eyes, its from 1=none to 4= spontaneous. For verbal, you get 1 for none, and 5 for orientated. 3 is inappropriate words. Motor goes to 6 - obeys commands, 5 localizes, 4 withdraws 3, flexion.

Question 8

if someone has an uncal/ transtentorial herniation, what is the issue?

Answer 8

CN III is squished, get a blown pupil because you have obliterated the parasympathetic tone.

Question 9

if someone has a herniation and now half their body is numb/ they cant move it, whats the issue?

Answer 9

peduncle was involved - so the top of the brain, around where your motor homunculus is

Question 10

what happens in tonsilar herniation?

Answer 10

you crush your medulla and stop breathing

Question 11

how do you deal with head injury?

Answer 11

ABCs! A - consider intubation. B - check if )2 low or C02 is high. The latter helps to vasodilate the brain. C- in shock injury you have low BP and high HR, wheras cushings response is opposite. D ( diability) - mini neuro exam, E exposure.

Question 12

why do you get decreased breathing in cushings response?

Answer 12

decreased perfusion of the medulla

Question 13

what are the three types of hematomas

Answer 13

epidural - middle meningeal leads to circular lesion on CT. Subdural- shearing,