Papillodema Flashcards
What is a papiloedema?
swollen disc secondary to raised intracranial pressure
What must be ruled out when a patient presents with disc swelling and raised intracranial pressure?
space occupying lesion
How is a papilloedema diagnosed?
ophthalmoscopy colour vision visual fields visual acuity pupil exam
What is the pathophysiology behind papilloedema?
subarachnoid space is continuous around the optic nerve and into the brain, when intracranial pressure increases in the brain, this is then transferred around the optic nerve which causes interruption of axoplasmic flow and venous congestion leading to swollen discs
What is the Monro-Kellie hypothesis?
because the skull is a fixed space, an increase in one of the components (Brain 80%, blood 10% or CSF 10%) must result in a decrease in one of the other components
What can increase in volume in the brain lead to?
blood vessel compression causing global brain ischeamia and swelling with hernitation through the foramen magnum
What can cause papilloedema?
tumours malignant hypertension overproduction of CSF obstruction of CSF circulation inadequate CSF absorbtion idiopathic intracranial hypertension
What is idiopathic intracranial hypertension due to?
not fully understood
may be due to things that obstruct CSF circulation:
stenosis of the transvere cerebral sinuses
increased abdo pressure in obese patients
OR due to things that blocks CSF absorption:
vitamin A
microemboli in sagittal sinus