Raised ICP

Question 1

Symptoms of raised ICP

Answer 1

• Morning eadache
• N/V (worse in morning)
• Altered conscious state
• Worse valsalva (cough, straining)

Question 2

Why is a headache worse in the morning with raised ICP?

Answer 2

• Worse in morning: have been supine - less venous drainage, CO2 up during night

Question 3

Signs of raised ICP

Answer 3

• Lowered GCS
• Papilloedema*
• Diplopia - sixth nerve palsy (CNVI has the longest intracranial nerve course ∴ sensitive sign)
• 3rd nerve palsy*
  1. Eye down and out
  2. Ptosis (levator palpabrae affected)
  3. Unilateral dilated pupil
• Focal neurological signs
• Signs of transtentorial herniation
• Cushing’s triad

Question 4

What visual changes does papilloedema lead to?

Answer 4

• Peripheral visual loss
  
  • Transient blindness
  • Blurred edges of optic disc, vessel origin not well marked, hazy

Question 5

What does Cushing’s triad involve, and explain how it occurs.

Answer 5

• Includes:

1. ↑ SBP (+ widening pulse pressure) i.e. hypertension
2. ↓HR (bradycardia)
3. Irregular respiration (Cheynes-Stokes)

• Explanation:

1. ↑ICP → ↓ cerebral BF → ↑SNS activity → ↑MAP 
2. Baroreceptors detect higher MAP → ↑vagal activity → ↓HR
3. ↑ICP affects brainstem → respiratory centre homeostasis changed → irregular breathing