Raised Intracranial Pressure

Question 1

What is normal intracranial pressure?

Answer 1

7-15mmHg in adults lying supine

Question 2

What are causes of raised ICP?

Answer 2

Tumours
Hydrocephalus
Brain Injury 
Idiopathic
Infection e.g. meningitis

Question 3

What are the clinical features of raised ICP?

Answer 3

Headache
-worse on lying down/coughing/straining
N&V
Papilloedema
Irritability

Cushing’s triad

• bradycardia
• wide pulse pressure
• irregular breathing

Can get cheyne stokes respiration

Question 4

What investigations are needed?

Answer 4

Neuroimaging for underlying cause
Measurement of intracranial pressure
-catheter placed into ventricles to monitor pressure

Question 5

What is the management?

Answer 5

A-E assessment
Position head at 30-40 degrees upright
IV mannitol 0.2mg/kg 20% over 15 mins
Controlled hyperventilation
-low CO2 leads to vasoconstriction and rapidly lowers ICP
Steroids for oedema surrounding tumour
Removal of underlying lesion

Weight loss if idiopathic

Removal of CSF
-via catheter/ LP or shunt depending on cause

Question 6

What are risk factors for idiopathic intracranial HTN?

Answer 6

Female
Obesity
Pregnancy
Drugs
-COCP
-tetracyclines
-Vit A
-steroids
-Lithium