Week 3 - Prerequisite knowledge

Question 1

What is the role of the reticular activating system (RAS)?

Answer 1

Arousal

It works with the cortex for awareness, forming the basis of LOC assessment (GCS/AVPU).

Question 2

What does the DRSABCDE primary survey include?

Answer 2

• Neuro focused exam (LOC, pupils, motor, speech, vital signs, glucose)
• Time of onset for stroke

This survey is essential for a comprehensive neurological assessment.

Question 3

What are the components of the Glasgow Coma Scale (GCS)?

Answer 3

• Best eye response
• Best verbal response
• Best motor response

GCS is used as a rapid screen for consciousness level.

Question 4

What are the signs of Cushing’s triad with raised ICP?

Answer 4

• Hypertension
• Bradycardia
• Bradypnoea

These signs are late and ominous indicators of increased intracranial pressure.

Question 5

What do pupillary changes indicate in a neurological assessment?

Answer 5

• Size
• Symmetry
• Light reactivity

These changes can help map lesion level and severity.

Question 6

Differentiate between decorticate and decerebrate posturing.

Answer 6

Decorticate: Flexion; Decerebrate: Extension

These postures indicate different levels of brain injury.

Question 7

What are the Cheyne–Stokes cycles indicative of?

Answer 7

Advanced brain dysfunction/near death

This pattern involves hyperventilation followed by apnea.

Question 8

What are the 3 intracranial compartments according to the Monro–Kellie Doctrine?

Answer 8

• Brain tissue
• Blood
• CSF

One must be offset by another or ICP rises.

Question 9

What does decorticate posturing indicate?

Answer 9

Lesion above midbrain

Decorticate (flexor) posturing is less severe than decerebrate posturing.

Question 10

What does decerebrate posturing indicate?

Answer 10

Midbrain/brainstem involvement

Decerebrate (extensor) posturing is considered more severe.

Question 11

What is the classic finding of pupil changes suggesting herniation risk?

Answer 11

Unilateral fixed dilated pupil

This indicates CN III compression and requires urgent escalation; document size/reactivity trend.