Neuro

Question 2

GCS: Eyes

Answer 2

4: Eyes open spontaneously
3: Eye open to verbal command
2: Eye open to pain
1: No eye response

Question 3

GCS: Best verbal response:

Answer 3

5: Orientated
4: Confused
3: Inappropriate words
2: Incomprehensible sounds
1: No verbal response

Question 4

Best motor response

Answer 4

6: Obeys commands
5: Localises to pain
4: Withdraws from pain
3: Flexion to pain
2: Extension to pain
1: No motor response

Question 5

Indications for CT head within 1 hr:

Answer 5

-GCS <13 on initial assessment in emergency -department
-GCS <15 at 2 hrs after the injury on assessment in emergency department
-Suspected open or depressed skull fracture
-Any sign basal skull fracture (haemotympanum, ‘panda’ eyes, cerebrospinal fluid leakage from the ear or nose, Battle’s sign
-Post traumatic seizure
-Focal neurological deficit
-> 1 episode vomiting

Question 6

Indications for CT head within 8 hrs

Answer 6

In those who have had some LOC or amnesia:

-Age 65 or older
-Any history of bleeding or clotting disorders
-Dangerous mechnism (Fall >1m, 5 stairs, pedestrian or cyclist struck by vehicle, occupant ejected from vehicle)
->30mins amnesia of events immediately before injury
-anticoagulation

Question 7

What are different categories for CT head indications in nice guidelines?

Answer 7

CT within 1 hr
CT within 8 hrs

Question 8

What is cushing’s reflex?

Answer 8

-Mixed vagal and sympathetic stimulation that occurs in response to raised ICP
-Results in hypertension and bradycardia

Cushings triad:
-irregular decreased respirations (due to decreased brain stem function)
-systolic hypertension (widened pulse pressure)
-bradycardia

Question 9

How is cerebral perfusion pressure calculated?

Answer 9

Mean arterial pressure - intracranial pressure

Question 10

In what circumstances would it be appropriate to admit a pt with a head injury?

Answer 10

-When CT not available
-Abnormal CT
-Prolonged loss of or deteriorating consciousness/abnormal GCS
-Focal neurological deficit
-Headache
-Penetrating head injury/skull fracture
-Alcohol/drug intoxication
-CSF leak (rhinorrhea/otorrhea)

Question 11

What is definition of brainstem death?

Answer 11

Defined as irreversible cessation of brainstem function

Question 12

What preconditions need to be met for a diagnosis of brainstem death?

Answer 12

-Apnoeic coma requiring ventilation and a known cause of irreversible brain damage
-Pt not sedated

Question 13

Brainstem death test: Pupil responses (nerves involved and reaction)

Answer 13

-CN II, III
-No direct/indirect reaction to light

Question 14

Brainstem death test: Corneal reflex

Answer 14

-CN V,VII
-No reaction to direct stimulation with cotton wool

Question 15

Brainstem death test: Pain reflex

Answer 15

-CN V and VII
-Pain tested in facial distribution
-Brainstem death cannot be diagnosed if response to central pain

Question 16

Brainstem death test: Caloric test

Answer 16

-CN 3, 6, 8
-Cold water instilled into auditory canal, nystagmus towards stimulation is looked for
-Absent in brainstem death

Question 17

Brainstem death test: Gag reflex

Answer 17

-CN 9 and 10

Question 18

Brainstem death test: apnoea test

Answer 18

-Pre-oxygenate and then disconnect from ventilator
-Insufflate oxygen into trachea, observe for sign of respiration until PaCO2 is above 6.65 kPa

Question 19

What are creterion for performance of brainstem death tests?

Answer 19

-2 doctors on 2 separate occasions
-Each must be >5 years post full GMC registration
-Death is deemed to have occured after first set of tests, this is time on death cert.

Question 20

What tests of brainsteam death are there?

Answer 20

-Pupil responses
-Corneal reflex
-pain reflex
-Caloric test
-Gag reflex
-Apnoea test
-If there are no signs to these tests when performed by appropriate clinicians, brainstem death can be diagnosed

Question 21

What are symptoms of raised ICP?

Answer 21

-Headache
-Nausea and vomiting
-Reduced level of consciousness

Question 22

What is normal ICP?

Answer 22

0-10mmhg in adults in supine position

Question 23

Explain Monro-Kellie doctrine

Answer 23

-Cranial vault is fixed space consisting of 3 components: blood (10%), CSF (10%), Brain parenchyma (80%)
-Expansion of any one of these components results in compensatory decrease to maintain ICP
-When compensatory mechanism is exhausted, there is an exponential increase in ICP even with small increase in volume of increased content/mass

Question 24

What are effects of raised ICP

Answer 24

-Decreased cerebral perfusion pressure causing iscahemia
-Midline shift causing ventricular obstruction
-Brain herniation, coma, eventually death

Question 25

How can ICP be reduced?

Answer 25

Reduced blood
-Regulate ventilation to maintain PaCO2 4-4.5 kPa (infreased vasoconstriction)–> co2 is vasodilator
-Use of hypertonic saline
-Diuretics: mannitol 20% 0.25-0.5 g/kg
-Upward tilt of head of bed to 20 degrees

Reduced CSF
-Direct tapping CSF from ventricular catheter

Reduced parenchyma
-Surgical debulking
-Craniectomy

Other
-Steroids may reduce swelling around tumours, but not in trauma situation
-Barbiturate coma
-Sedation +/- use of paralysis (reduced mro2)

Question 26

How can ICP be monitored?

Answer 26

-Subarachnoid bolt
-Epidural bolt (less accurate, less infection risk)
-External ventricular drain (can use to therapeutically remove csf)