(A&E) (Clinical Imaging)

Overview

• As the brain and ventricles are enclosed by a rigid skull, they have a limited ability to accommodate additional volume
• Additional volume will therefore lead to a rise in intracranial pressure
• Aetiology → idiopathic intracranial hypertension, CNS infection (meningitis), space-occupying lesions (haemorrhage, aneurysm, tumours), increased CSF (hydrocephalus), cerebral oedema, increased BP (malignant hypertension)
• Normal ICP is ≤15 mmHg in adults in the supine position

Idiopathic Intracranial Hypertension ⇒ classically young, overweight females. Causes headache, blurred vision, papilloedema on fundoscopy, sixth nerve palsy. Tx with weight loss and acetazolamide (carbonic anhydrase inhibitor).

Making Diagnosis

Clinical Features:

• Cushing Triad (reflects brainstem compression) → irregular breathing, widening pulse pressure and bradycardia
• Bilateral Headache → worse in mornings and when lying down due to effect of gravity (also worse when coughing/straining)
• Vomiting
• Reduced levels of consciousness
• Bilateral Visual Loss → increased ICP may cause compression of optic nerve
• Papilloedema → swelling of optic disc (leads to blurring of optic disc margin on fundoscopy)