Papilloedema
Papilloedema refers to optic disc swelling caused by raised intracranial pressure. It is a clinical sign rather than a diagnosis, and should be distinguished from other causes of optic disc swelling.
Updated UKMLA guide to papilloedema: causes, symptoms, diagnosis, assessment and management.
Causes
Causes of papilloedema (i.e. causes of ↑ ICP):
- Idiopathic intracranial hypertension – most common cause in <50 y/o (esp. obese women of childbearing age)
- Space-occupying lesions (e.g. tumour, abscess, haemorrhage)
- Infection (e.g. meningitis, encephalitis)
- Obstruction
- Venous sinus thrombosis
- Hydrocephalus
Papilloedema ≠ optic disc swelling
- Optic disc swelling = a broad fundoscopy finding where the optic nerve head appears swollen, from any cause
- Papilloedema = optic disc swelling directly caused by raised ICP
Other causes of optic disc swelling (non-papilloedema):
- Optic neuritis
- Anterior ischaemic optic neuropathy
- Giant cell arteritis
- CRVO
- Malignant hypertension
- Compressive optic neuropathy and ocular trauma
Clinical Features
Papilloedema is a clinical sign of raised ICP, rather than a diagnosis.
| Signs of optic disc swelling on fundoscopy | Bilateral findings (can appear asymmetrically, but rarely unilateral):
|
| Signs and symptoms of raised ICP |
|
Assessment and Management
Papilloedema requires urgent specialist assessment and management.
Clinical assessment:
- Comprehensive clinical history
- Medication review (e.g. steroids, retinoids, tetracyclines, COCPs)
- Ophthalmic and neurological examination
- Measure blood pressure to assess for malignant hypertension / hypertensive emergency
Investigations:
- Initial: urgent neuroimaging
- MRI brain and orbits + venography is preferred
- CT can be used in acute setting and/or MRI is not immediately available
- Lumbar puncture may be performed after neuroimaging confirms it is safe
- Allows measurement of opening pressure, which supports raised ICP (NB ICP can be elevated even without visible optic disc swelling)
- CSF analysis can provide diagnostic clues
Do not perform lumbar puncture before neuroimaging if raised ICP is suspected, due to the risk of brain herniation if there is a space-occupying lesion.
If raised ICP is due to a space-occupying lesion, removing CSF from the spinal canal during lumbar puncture can create a pressure gradient between the skull and spinal canal. This can pull brain tissue downwards and cause brain herniation, especially tonsillar herniation, which can compress the brainstem and become rapidly fatal.
Management depends on the underlying cause of raised ICP and should be guided by specialist assessment.